Coflexip SA & Anor v Stolt Comex Seaway MS Ltd & Ors [2000] EWCA Civ 242

EWCA-Civ

Coflexip SA & Anor v Stolt Comex Seaway MS Ltd & Ors

[2000] EWCA Civ 242 · 2000-07-31

- - - - - - - - - - - - - - - - - - - - - (Transcript of the Handed Down Judgment of Smith Bernal Reporting Limited, 190 Fleet Street London EC4A 2AG Tel No: 020 7421 4040, Fax No: 020 7831 8838 Official Shorthand Writers to the Court) - - - - - - - - - - - - - - - - - - - - - -

Antony Watson QC and Thomas Hinchliffe (instructed by Bird & Bird, London EC4A 1JP) for the Claimants/Appellants Richard Miller QC and Justin Turner (instructed by Clifford Chance, London EC1A 4JJ) for the Defendant/Respondent

ALDOUS LJ: 1. In his judgment of 22nd July 1999 Laddie J held European Patent (UK) No 0478 742 valid and infringed. The appellants, now called Stolt Offshore M.S. Limited, Stolt Offshore Limited and Stolt Offshore A/S, appeal with leave of the judge. I shall refer to them as Stolt. They also applied to re-amend their particulars of objections to rely upon a US patent as prior art and to introduce fresh evidence to establish that that US patent rendered the patent invalid. 2. Coflexip SA are the proprietors of the patent and their associated company Coflexip Stena Offshore Limited are exclusive licensees. I will refer to them as Coflexip. They supported the conclusion reached by the judge, and in the main, the reasoning of the judge. They resisted the introduction of the fresh evidence and the application to re-amend. They also contended in their Respondent's Notice that the injunction should have been in the usual form not that actually granted. 3. It follows that four issues arose on the appeal.(1) Was the patent infringed?

(2) Was the patent obvious?

(3) Should Stolt be allowed to introduce fresh evidence and re-amend their particulars of objections?

(4) Was the judge right to refuse to grant the injunction sought by Coflexip? I will deal with those issues in turn. 4. The patent claimed priority from 30th March 1990. It relates to an invention entitled "Device and process for unrolling of flexible tubular conduits essentially vertically". The background to the invention and to the issues raised in the proceedings were set out in detail by the judge in the introduction to his judgment and I can do no better than incorporate that part of his judgment into mine. "2. There are different types of submarine pipes. One consists of steel pipes. Sometimes they are coated in concrete or plastics materials. They are capable of being laid in very deep water. They are referred to in the art as rigid pipes. Another type which has become of increasing commercial significance in recent years is flexible pipe. These are normally made up of a number of layers of composites and reinforcing materials. Mr. Alain Coutarel, one of the inventors of the patent in suit and one of the Coflexip witnesses in this action, said that the types of flexible pipe which are commonly used in this art may have internal diameters of between 1.5 and 19 inches. They have very thick walls. Most members of the public would regard them as stiff or rigid. However, in the technical world of submarine pipes, they are considered to be flexible and exhibit characteristics which are specific to flexible pipes. As a practical matter those in the art have little difficulty in distinguishing one type of pipe from the other. There are difficulties associated with laying both types of pipes particularly in deep water. 3. The concepts which are central to this action can best be understood if two common examples are taken to illustrate the differences between rigid and flexible pipes. A copper pipe used in a domestic water system is rigid. If one end is clamped and the pipe is not too long, it will maintain an almost horizontal position without support at its free end. Its reluctance to bend can be referred to as its bending stiffness. If the end of the pipe is pulled down a bit it will flex. It is a bit "springy". When the force is removed, it will return to its original position. However, if more force is applied to the pipe, a point will arrive at which parts of its surface will begin to stretch. The pipe can be made to take up a permanently bent configuration. A plumber will do this by applying force to the copper pipe in a pipe bender. These characteristics were explained by Mr. Nash, the plaintiffs' expert, as follows:

"Rigid pipe has a finite bending stiffness. That is to say, if a sufficient load is applied to a length of rigid pipe it will deflect (i.e. bend). A rigid pipe can be bent elastically up to its elastic limit. This means that provided the pipe is not bent beyond its elastic limit (or yield stress), it will return to its original shape after the bending force has been removed. If a rigid pipe is bent beyond its elastic limit, this will result in the pipe being plastically deformed. This means that if the bending force is removed, the pipe will not return to its original profile, i.e. a permanent curvature will be induced into the pipe. A plastically deformed pipe can, within limits, be returned to its original profile. This is achieved by applying a sufficient bending force to the pipe in the opposite direction to that which originally caused the plastic deformation. In other words, if a straight section of pipe has been plastically bent one has to overstress (i.e. apply a stress greater than the yield stress) the pipe in the opposite direction in order to straighten it. This process, if carried out correctly, will not affect the pressure containing properties of the pipe, nor its resistance to hydrostatic forces. However, if a rigid pipe is plastically bent beyond a certain minimum radius of curvature, called its ultimate bending radius, the pipe will suffer permanent localised buckling or crimping. This will irreparably damage the integrity of the pipe."

Nash Witness Statement para. 13. These characteristics are exhibited by rigid steel submarine pipes. As long as they are not subjected to too much force they will be springy. If more force is applied they can be plastically deformed so as to take on a permanently bent shape. If they are bent beyond their ultimate bending radius, they buckle. 4. The behaviour of a flexible pipe is somewhat different. The bending stiffness of flexible pipe is several orders of magnitude less than that of rigid pipe. A common example of a flexible pipe is a garden hose. If it is held horizontally at one end it will tend to droop. It has a much smaller ultimate bending radius than a rigid pipe, so it will have to be bent much more acutely before it buckles. On the other hand a flexible pipe can not be plastically deformed. If bending force is removed from a flexible pipe which has not buckled it will tend to return to its original shape. It will not have acquired a permanent bent shape. However if a garden hose is fed over a hose reel and a weight is put on the free end, the latter will tend to pull the hose down onto the reel. The greater the weight, the more pronounced this effect will be. Because the walls of the hose are comparatively flexible this has the effect of squashing the hose onto the reel. The cavity in the centre of the hose will become oval and, at some point, it will close completely. When this happens the pipe is said to be crushed. Again these characteristics were explained by Mr. Nash:

"The bending stiffness of flexible pipe is several orders of magnitude less than that of rigid pipe. This is due to the lower bending stiffness of the materials which make up the flexible pipe and also because each layer is, to a degree, able to move relative to its neighbouring layer (in non-bonded flexible pipe). This means that flexible pipe can be bent to a much smaller radius of curvature than rigid pipe without exceeding its elastic limit. If one were to bend a flexible pipe beyond its elastic limit (also referred to as damaging bend radius or minimum bend radius), the pipe would be irreparably damaged so that it could not be straightened back to its original shape and its pressure containing properties would probably be impaired. However, flexible pipe can be bent to a very much smaller radius of curvature than rigid pipe without reaching its damaging bend radius. There is no plastic deformation with flexible pipe."

Nash Witness Statement para. 16. 5. Buckling and crushing can occur in both rigid and flexible pipes. However, because the walls of a rigid pipe are, by definition, comparatively rigid, they withstand crushing much better. So rigid pipes are less sensitive to crushing and more sensitive to buckling than their flexible equivalents. Also, as noted above, rigid pipes can be plastically deformed while flexible ones cannot. These concepts apply to rigid and flexible submarine pipes no matter what their size. Mr. Nash was therefore accurate when he said that rigid pipe and flexible pipe were and still are different in terms of their respective structure and bending characteristics. Those differences affect the way pipes are laid in water. It is convenient to consider the laying of rigid submarine pipes first. Laying rigid submarine pipes 6. When rigid submarine pipes were first laid in water from ships, the pipe was fed off the back of the ship in a more or less horizontal direction. The ship would be loaded with numerous lengths of straight pipe which were welded one by one on board to the end of the pipe being fed into the water. As more and more pipe was fed off the back of the ship, the weight of the unsupported pipe grew. This would pull down on the unsupported end of the pipe. This curvature of the pipe at the end near the laying vessel is called the overbend. To avoid permanent deformation here, the pipe was supported by a long curved guide, called a stinger. The stinger maintained a set minimum radius of curvature so that there was no plastic deformation of the pipe. With very rigid pipes (e.g. pipes of large diameter) being laid in very deep water, the stinger might have to be very long indeed, extending many tens of metres beyond the stern of the pipe-laying vessel. This could compromise the vessel's stability, particularly in rough weather. Furthermore in all cases steps had to be taken to ensure that the pipe did not contact the end of the stinger (or was carefully controlled on contact). The reason for this was that if the vessel suddenly backed up or moved forward too slowly relative to the pipe pay-out speed of the tensioners, there was a risk that the pipe would be bent around the end of the stinger, thereby risking damage to the pipe. 7. As the pipe is laid, a large quantity of it hangs in the water below the ship. The greater the depth of the water and the bigger the pipe, the greater the weight of this pipe. That weight will tend to pull the pipe towards the sea bed and off the ship. This has to be prevented by means of a mechanical "hand" which pulls on the end of the pipe as it leaves the ship and stops it going overboard. The mechanical hand is called a tensioner. If, for example, the size of pipe and depth of water mean that there is 200 tonnes of pipe hanging down below the ship, the tensioner would need to be able to exert at least 200 tonnes tension in an opposite direction to prevent the pipe being pulled overboard. In fact the tensioner may be made up of a number of smaller tensioners in sequence capable of exerting a total pull which exceeds that of the suspended weight of pipe. Pipe laying in this fashion can be illustrated as follows: Figure 1: 8. The pipe-laying ship has to be driven towards the right in this Figure. If it is not, the end of the pipe where it leaves the stinger will be pulled hard down by the weight of the pipe below it. It will therefore be pulled down and may hit the end of the stinger. This could cause high localised forces which tend to buckle the pipe. This horizontal thrust of the ship results in the pipe lifting off the stinger before it reaches the end of it. Because the horizontal thrust lifts the pipe off the stringer (in other words reduces its tendency to fall down vertically), this can be used to reduce the overall length of the stringer to some extent. However increased horizontal thrust means greater use of the vessel's engines and this in turn costs money. Figure 1 above also illustrates how the rigid pipe flexes. It describes an "S" shape in the water. As a result, this type of rigid pipelaying is called "S-lay". The deeper the water, the nearer the vertical the central section of the pipe will be as illustrated below. Figure 2: 9. Because in very deep water the pipe will tend to take up the shape shown in Figure 2, an alternative type of rigid pipe laying can be used in such situations. The angle at which the pipe is fed off the end of the ship is matched, as nearly as possible, to the natural angle which the pipe will take up in the water (its so-called catenary shape). The result is that the pipe is fed off the end of the ship at an angle to the surface of the sea. This is illustrated in Figure 3 below. Because the pipe takes up a generally "J" configuration, this form of pipe laying is called "J-Lay". Figure 3: In this illustration, the pipe is loaded onto the ship in short straight lengths. Individual lengths of pipe are lifted onto the ramp, held by clamps and welded onto the upstanding end of the pipe which leads down into the sea. 10. An alternative form of J-lay was used on a ship called the Apache which is a major piece of prior art relied on in this action. On this vessel rigid pipe is bent and spooled onto a very large reel. The bending subjects the rigid pipe to plastic deformation. The overall design of the rear half of the vessel is as follows: Figure 4: 11. The reel for carrying the pipe is part-shown on the right of this drawing. It can carry about 100 metric tonnes of pipe. The details of its operation will be considered later. However, at this stage it is worth noting that because the pipe is fed from a very large reel on which it had been plastically deformed, it reaches the aligner at the top of the ramp with a curve set in it. This has to be straightened out on the ramp. Furthermore, in this type of embodiment, and subject to a point of detail which will be considered below, there is no need for tensioners to hold back the pipe and to stop it falling off the end of the ship. Instead the reel on which the pipe is wound itself is powered so as to impart the necessary pull on the pipe. Were it otherwise, the weight of the pipe under the boat would simply strip the pipe off the reel and deposit it in a heap on the sea floor. Because in a J-lay arrangement, the angle of the ramp matches the angle of the top end of natural catenary of the pipe in the particular depth of water in which it is being laid, the angle of the ramp had to be adjustable to accommodate laying different sizes of pipe in different depths of water. Laying flexible submarine pipes 12. With flexible pipe the standard form of laying used in modest depths of water is to pass it more or less horizontally from a reel over a curved chute (called an "overboarding gutter") or wheel (called an "overboarding wheel" or "laying wheel") and down into the water. The catenary of such pipe from the point where it leaves the gutter or wheel to the sea bed is J-shaped. However because it is fed horizontally first, some in the industry call it a form of S-lay. Once again, to prevent the weight of pipe under the ship from stripping the rest of the pipe from the reel, some form of tensioning device is used upstream of the gutter or wheel. This can take the form of tensioners or the wheel on which the pipe is loaded can be powered. The "Recommended Practice for Flexible Pipe" API 17B published by the American Petroleum Institute in June, 1988 illustrates both of these methods and describes them as the most common Bundle H2, Tab 7 pages 89 and 90.. In 1990, powered reels were not suitable to lay flexible pipe in deep water where a tension capacity of more than typically 30 tonne was required. Accordingly, linear tensioners, such as caterpillar track tensioners, were used to provide the tension when greater tension capacity was required. The caterpillar tracks gripped the pipe so as to transfer the tension load from the pipe to the tensioner. An arrangement using tensioners is illustrated in Figure 5 below. The use of the laying wheel illustrated here is to stop the pipe being crushed by the effect of the weight of the line below the ship. According to the evidence before me, at least to some extent the increased crushing forces produced by laying heavier pipe in deeper water can be offset by increasing the radius of the gutter or wheel over which the flexible pipe is overboarded into the water. The increased radius means that the pipe is in contact with more wheel or gutter so that the crushing forces are distributed over a larger area. The crushing forces acting on any particular piece of pipe in the overboard section are thereby reduced. Figure 5: 13. As Mr. Nash said, because the stinger radius is so large and since the homogenous rigid pipe construction is inherently very robust, crushing of rigid pipe on the stinger is not under normal circumstances an influencing consideration. This is in marked contrast to flexible pipe where crushing is a considerable problem as the tension loads increase with greater weight and depth of pipe laying. Overboarding accessories 14. There is one respect in which buckling is a significant problem with flexible pipes. Such pipes are normally made in the factory in very great lengths. For example a flexible pipe with a 4 inch internal diameter may be made in individual lengths up to 10 km long and a 12 inch pipe may be made in individual lengths of up to 3 km long. These lengths have to be joined together. Each length of pipe has an end fitting at each end. To extend a flexible pipe, the end fitting on one length must be connected to the end fitting on another to make what is known as an intermediate connection. End fittings vary between 0.5 and 4 metres in length depending on the size of the pipe and its application. So an intermediate fitting may be from 1 to 8 metres in length. End fittings are made of steel and usually have a diameter twice the size of the diameter of the flexible pipe to which they are fitted. They are rigid. Other types of rigid accessories which are installed on to flexible pipe during production are bending stiffeners which are used on pipes called dynamic risers. Bending stiffeners are generally up to 7 metres long and are made of steel and polymer material. The diameter of a bending stiffener is normally 3-4 times the size of the diameter of the flexible pipe. There are other rigid accessories such as buoyancy modules and anodes. These are normally fitted to the pipeline during laying. Anodes are used as a means of protecting the end fittings against corrosion. They are made of a zinc or aluminium alloy. Their length is usually 1-2 times and their diameter 1.5-2 times the diameter of the flexible pipe. Usually several (5-10) anodes are located close together thus making a single large accessory. 15. These rigid accessories have to be overboarded. This means that they have to be lifted over the gutter or wheel and fed into the water. If such an accessory is fed round a wheel or gutter, the tension in the pipe will act on the pipe/accessory junction to give very high buckling forces over a very short distance. The problem is illustrated in Figure 6 below. Figure 6: 16. This propensity for local buckling has been a serious problem where the laying of flexible pipe is concerned. A significant number of possible solutions have been proposed and quite a few of them have been put into practice. Coflexip gave evidence relating to, and produced drawings of, some of these X Bundle Tab 1. . Mr. Coutarel explained that one way of overboarding the rigid accessories without damaging the pipe was to use a crane or the so-called A-frame which is sometimes located at the stern of the vessel. As the rigid accessory was unrolled from the reel, the laying operation was halted before the rigid accessory reached the overboarding gutter. The crane hook was attached to the rigid accessory. In this way the tension load from the weight of the suspended pipe was transferred from the reel to the crane which was then operated to lift the rigid accessory up and over the overboarding gutter. The crane then lowered the pipe and the rigid accessory attached to it below the level of the overboarding gutter. If the rigid accessory was an intermediate connection between two lengths of pipe, the tension was then taken up once again by the reel and the crane disconnected from the rigid accessory. The laying process then continued. In this case, during the operation of the crane, the powered reel no longer pulls the pipe. The load was taken by the crane. 17. An alternative device for overboarding rigid accessories was what was known as the "Chinese finger". The Chinese finger was a sleeve made up of interlaced steel cables of approximately 3-5 millimetres in diameter . It was fitted to the pipe a few metres downstream of the rigid accessory. As that part of the pipe to which the finger was attached came off the powered reel, the laying process was halted just before the finger reached the overboarding gutter. The finger was then attached by means of a cable to a winch on the vessel called the deck winch. The tension load was transferred from the reel to the deck winch. The unwinding of the pipe from the reel then continued, but with the tension load being taken by the deck winch via the finger. The part of the pipe held by the finger was passed around the gutter without difficulty since the finger was flexible. 18. The pipe was unrolled from the reel in this way until the end fitting passed below the level of the overboarding gutter. Because the tension was being taken by the deck winch and the finger, that part of the pipe immediately upstream of the Chinese finger to which the rigid accessory was attached was not under significant tension as it passed around the overboarding gutter. There was, therefore, less risk of damaging the pipe because the problem of bending the pipe at the same time as applying significant axial tension to it was avoided. As the rigid accessory was bent over the overboarding gutter the interface between the accessory and the pipe was not subjected to significant axial tension. Once it was below the level of the gutter, the rigid accessory was subjected to axial tension but not to bending stress. When the rigid accessory was below the level of the overboarding gutter, the winch cable was disconnected and laying continued in the normal way. The finger was usually left on the pipe as it was not an expensive item. 19. Mr. Coutarel's evidence was that the Chinese finger was more frequently used than the crane to overboard rigid accessories before the priority date of the Patent in Suit. In any event use of a crane or Chinese finger was standard practice in the industry at the priority date of the patent. They were used not only by Coflexip but others involved in laying flexible pipe at that time. There were also other solutions. For example one arrangement used and published before the priority date of the patent in suit operated as follows. Figure 7: (a) This shows the flexible pipe being fed from the tensioners at the right towards the laying wheel. The drawing illustrates a case in which some 300 tonnes of pipe are suspended off the end of the vessel. The rigid accessory is approaching the upper surface of the laying wheel. At this point a lift off device which is located between the tensioner and the laying wheel and is normally not in contact with the pipe, is lifted up so as to support the underside of the pipe and push it in an upward direction. This has the effect of lifting the right hand end of the accessory. This is illustrated in Figure 7(b) below. (b) The lift off device continues to rotate until it is in a position to allow the accessory to travel vertically past the laying wheel as shown in figure 7(c) below. (c) Finally the lift off device is pulled back to its original position. (d) It will be seen that although the pipe and the accessory are kept under tension at all times, the arrangement avoids there ever being an occasion on which there is any bending at the accessory/pipe junction. 20. A further method for overboarding involves moving the accessory round the laying wheel or overboarding gutter under very little tension. Two examples of this may be illustrated. The first was the subject of a Coflexip patent. Figure 8 21. A collar was fitted around one of the end fittings and wires (9) were attached to it in order to connect it to the winch used when a pipe has to be abandoned, e.g. because of bad weather, and recovered (hence the name "A&R" winch). The tension load was transferred from the tensioners to the A&R winch. The tensioners were then opened and the A&R winch wire was unreeled to allow the intermediate connector to pass through the tensioners. Unreeling continued until the collar reached a tilting frame (5). When the collar reached the tilting frame it automatically engaged with the frame. By continuing to unreel the A&R winch wire, the tilting frame was able to rotate and thereby lift the intermediate connector off the wheel. This meant that there was bending but no significant tension on the vessel side and tension but no bending on the sea side of the intermediate connector. This is illustrated in the following Figure. Figure 9 22. Once the tilting frame had completed its rotation, the collar automatically disengaged from the frame. The tension was transferred back to the tensioners and the A&R winch wire was disconnected. The tilting frame was brought back on board and normal laying was resumed. 23. Finally I should refer to another solution in relation to which Mr. Coutarel gave evidence and which was discussed during the course of the trial. This was an arrangement for overboarding accessories which used an hydraulic clamp. It is illustrated in Figures 10 to 13 below. Figure 10: The flexible pipe was supplied from a storage reel through three tensioners to the overboarding wheel. When the rigid accessory had passed through the three tensioners, the pipe was halted just before the rigid accessory reached the wheel. An hydraulic clamp was then fitted around the flexible pipe below the level of the wheel. Figure 11 The hydraulic clamp was then connected via slings to the A&R winch situated on the deck. The hydraulic clamp was closed and the laying tension was switched from the tensioners to the A&R winch. In this way, the section of pipe above the clamp, including the rigid accessory, was no longer under any significant tension. Paying out of the A&R winch then took place so as to allow the rigid accessory to pass over the wheel. As the rigid accessory passed over the wheel it was only subjected to bending, not axial tension. Figure 12 Once the rigid accessory was below the level of the wheel, the tension load was taken up again by the three tensioners. The hydraulic clamp was then opened and retrieved. The laying process then continued in the normal way. Figure 13 24. It should be noticed that this type of arrangement utilises tension applying devices in different orientations. The tensioners apply tension horizontally and the hydraulic clamp intermittently applies tension vertically. Summary of the relevant problems in laying flexible pipe. 25. From what has been said above, it can be seen that there were at least two problems facing those wishing to lay flexible pipe. I can do no better than adopt the description of them which was put forward by Mr. Coutarel and which I did not understand to be disputed. The first problem concerned the overboarding of accessories. There is a need to avoid bending the pipe at the interface between the pipe and the rigid accessory at the same time as a high axial tension is being applied to that point. If a high axial tension is applied to the pipe at the interface at the same time as it is subjected to bending stress, there is a severe risk that the pipe will become damaged. The second problem arises out of the radial contact loads induced by the axial tensile load (pipelay tension) when the flexible pipe is bent around the overboarding gutter or wheel. These contact loads are generally acceptable in shallow or medium water depth, but they are a limiting factor for laying flexible pipe in deep water as they tend to crush the pipe. The patent in suit addresses both of these problems and claims to have found a convenient solution to them." (Check layout and add in diagrams) The Patent 5. The patent was filed in French with the result that the document before the Court is an agreed translation. Such a document is never quite as good as the original, but the translation has proved sufficient. 6. The patent states at the outset that the invention relates to a method and a device for effecting the laying of flexible conduits, in particular with the tensioning means disposed in the vertical path of the tubular flexible conduit. 7. Mr Watson QC, counsel for Stolt, submitted that the essence of the invention described, when read fairly, was the passing of connectors, referred to as accessories, which joined the flexible conduits. I disagree. That submission disregards the opening paragraph and other passages of the specification. No doubt the method of passing connectors is an essential element of the process and apparatus described, but the invention relates generally to a process for laying flexible conduits. 8. On the first page the specification describes what was known, namely that the flexible conduit can be stored in a basket from which it is unwound. It then passes over a deflecting element, such as a wheel or a curved chute placed for example at the rear of the vessel. The specification states that as the depth increases, the size of the wheel needs to become increasingly larger and that creates difficulty. 9. On page 2 of the patent the problems caused by accessories are referred to:

"because these relatively rigid accessories, whose external transverse dimension is greater than the external diameter of the flexible conduits must pass over the deflecting element."

The specification then explains how the problem of accessories had in the past been solved using tipping gantries. However, it is said, with the devices of the known type, it is not possible to exceed a depth of water of the order of 500 metres when the internal diameter of the tubular flexible conduit to be laid reached approximately 30cm. 10. After referring to a patent application concerned with laying rigid conduits, this important passage occurs: "The object of the present invention is the laying of flexible conduits at depths that are substantially greater than those which are feasible by using the known means, as, for example, a depth of the order of 1000 to 2000 metres. The device in accordance with the present invention must be capable of withstanding considerable tractive forces which may reach and even exceed 250 tons in the case of a conduit with a diameter substantially equal to 30cm for a depth of 1000 metres. With the exception of sections having a rigid accessory, or having an increased rigidity relative to the flexure of the flexible conduits, and whose external bulk exceeds the external diameter of the flexible conduits, the lowering of a continuous length of a tubular flexible conduit is ensured by the main tensioning means which take up the mechanical tension exerted by the portion of the flexible conduit suspended on the tensioning means between the laying vessel and the bottom. In these conditions, the tension ahead of the tensioning means being exerted on the portion of the flexible conduit up the line and coming from the storage means is very low and preferably virtually negligible. It has been found that in these conditions, it becomes possible to subject a portion of the conduit situated in the portion ahead, between the storage means and the tensioning means, to relatively extensive bending, this being explained by the fact that in this case, there is no combination of the bending with an axial tractive load. The device in accordance with the invention thus makes it possible, without resorting to bulky and sophisticated equipment, to effect changes imposed on the flexible conduits between the point where it is extracted from the storage means and the point where it plunges into the water, the axis of the flexible conduits having, for example, to pass from a horizontal direction to a direction that is close to the vertical. It is thus possible to cause the flexible conduits to pass over a guide means, such as a curved chute or a wheel with a small diameter, including the passing of rigid and bulky accessories mounted on the conduit. The tensioning means used are of the linear winch type. It has been found that winches of this type make it possible to increase the load of the axial tension exerted by the flexible conduit and which has to be taken up by the tensioning means, which makes it possible to increase for a flexible conduit of a given structure, the depth of water in which it can be laid." 11. The specification then turns to explain, with the aid of figures, how rigid and bulky accessories can be passed using the invention. As the judge said: "29. The patent also describes how the parts of the pipe carrying accessories or end fittings are passed through the tensioners. Because accessories and end fittings have a diameter significantly larger than that of the pipe, the tensioners are opened up to allow them to pass through. While this is happening the open tensioners can apply no tension to the pipe. Consequently the accessory is attached to a winch which takes the strain while tensioners are open. Once the accessory has passed through, the tensioners are closed and the accessory can be disconnected from the winch. How this is done in relation to an end fitting is illustrated in the patent as follows: Figure 15

30. Drawing(a) shows the pipe (3) being supplied over the chute (4) to the top of the derrick (5). It passes down between, and is gripped by, the caterpillar tensioners (6, 11), passes through the open working table (7) and down through the moonpool (8). Above the derrick is a winch (19), which is also just visible at the top of the derrick in Figure 14 above, from which hangs a cable (20). What happens when an end fitting has to be lowered through the derrick and attached to the end fitting at the beginning of the next length of pipe is illustrated in drawings

(b) to (h). The cable is attached to the fitting and the winch takes up the strain. The caterpillar tensioners are then opened and the winch allows the end fitting to be lowered to the level of the working table which then shuts to prevent the end fitting from moving about laterally. The end fitting is clamped in this position and the cable (20) is released and wound back up by the winch. The end fitting at the beginning of the next roll of pipe is then passed down through the derrick. The two end fittings (21 a and 21 b ) are joined together. The caterpillar tensioners are closed and can resume taking the strain. The working table is opened and the vessel resumes laying. The same procedure, but without the need to join two end fittings, is used if the accessory is pre-fitted to the pipe." 12. The description in the patent concludes at page 10 lines 21 to 29 with this passage:

"Although the invention has been described with reference to tubular flexible conduits, it shall be duly understood that the laying of other flexible conduits does not depart from the scope of the present invention. The device and method in accordance with the present invention can be used in particular for the laying of cables, for example traction cables and above all, electric cables. Electric cables are understood to mean any cable comprising electrical conductors, as well as power cables and cables carrying information." 13. The patent has 9 claims. As the subsidiary claims are not alleged to have independent validity, it is sufficient to set out claims 1 and 3: "1. A process for laying from a floating support (1), a flexible conduit (3) comprising a rigid accessory (21, 21 a , 21 b ) mounted on the said flexible conduit (3) and having an outer dimension larger than the outer diameter of the latter, wherein one unrolls a flexible conduit (3) gripped at its outer surface by linear winch-type tensioning means (6) with a substantially vertical axis, and wherein a) to cause the section of the flexible conduit (3) whereon the accessory is mounted to pass through the said tensioning means (6), the said rigid accessory (21) is connected to auxiliary tensioning means (19, 20), so as to take up the pull exerted by the flexible conduit (3) by the said auxiliary tensioning means (19, 20), while the flexible conduit (3) is lowered through the free space between the said laterally moved-apart tensioning means (6), b) the outer surface of the flexible conduit (3) is gripped ahead of the rigid accessory by the said tensioning means (6) after they have been brought together, so that the pull exerted by the flexible conduit (3) is again taken over by the said tensioning means (6); c) after the auxiliary tensioning means (19) have been released, the unrolling of the flexible conduit (3) is resumed by the said tensioning means (6), the latter comprising the last means for guiding the conduit at the level of the floating support. ... 3. A device for operating the process according to any one of the claims 1 and 2, comprising; - linear winch-type tensioning means (6) with a substantially vertical axis, capable of ensuring the normal lowering of the flexible conduit (3) by gripping the outer surface of the flexible conduit (3) and capable of being laterally moved apart, the said tensioning means (6) comprising the last means for guiding the flexible conduit (3) on board the floating support (1), - auxiliary tensioning means (19, 20) comprising at least one elongate movable traction element (20) capable of being connected to the rigid accessory (21, 21 a , 21 b ) mounted on the flexible conduit (3)." 14. Construction - Four issues arise, three raised in the notice of appeal and one in the respondent's notice. They are: 1. What is meant by the words "flexible conduit"? 2. Does the claim require all or only some real part of the pull to be taken by the tensioning means? 3. What is meant by the words "comprising the last means for guiding the conduit at the level of the floating support"? 4. Should the words "

A device for operating" in claim 3 be construed as meaning that the device is suitable for operating or as meaning a device when used for operating? I will deal with issue 3 when I come to infringement. 15. Section 125 of the Patents Act 1977 makes it clear that interpretation of claims has to be carried out using the description and drawings. In essence they have to be interpreted as part of the document as a whole. But as the Protocol on Interpretation of Article 69 of the EPC makes clear a literalist approach is inappropriate as is an approach using the claims only as guidelines. They must be interpreted as defining a position between those extremes so as to give fair protection for the patentee and a reasonable degree of certainty for third parties. With that in mind I turn to the issues. 16. What is meant by the words "flexible conduit"? - It was agreed at trial and found by the judge that at the priority date of the patent the industry recognised two types of pipes namely "rigid pipes" and "flexible pipes". They were terms of art referring on the one hand to steel pipes and on the other to composite pipes. However the term "flexible conduit" was not a term of art. It follows that its meaning must be ascertained from and in the context of the specification. 17. Stolt submitted that the term should be construed as covering all conduits which were flexible. If so, it encompassed small diameter steel pipes which were flexible enough to be reeled. Coflexip supported the judge's conclusion that the words would be understood by the skilled addressee as referring to conduits known in the industry as "flexible pipes" and other structures having similar flexing qualities, but not conduits known as "rigid pipes". 18. The judge was right. Page 1 of the specification describes systems of laying flexible pipes. There follows at page 2 lines 1 to 20 an account of the problems that occur when those systems are used. Immediately thereafter is a reference to a European patent application concerned with rigid pipes. The specification draws a distinction between flexible conduits and rigid pipes. It then goes on to describe the invention and it is clear that what is being described is the laying of flexible pipe as opposed to rigid pipe. It ends with the passage at page 10 lines 21 to 29, set out above, which at its outset makes it clear that the invention had been described by reference to "tubular flexible conduits" meaning flexible pipes. There follows the statement that the invention is to cover "the laying of cables, for example traction cables and above all electric cables. Electric cables are understood to mean any cable comprising electrical conductors, as well as power cables and cables carrying information." That passage establishes that the words "flexible conduit" should be interpreted as including more than what was known as flexible pipe, but not so widely as to cover what was known in the industry as rigid pipe. 19. Does the claim require all or only some part of the pull to be taken by the tensioning means? - Stolt referred to the requirements of the claim that the auxiliary tensioning means is connected "so as to take up the pull exerted by the flexible conduit" and that the main tensioning means grips the pipe "so that the pull exerted by the flexible pipe is again taken over by said tensioning means". They submitted that "the pull" referred to was the same pull, and that all that the claim required was that a real part of the pull or tension had to be taken up by the main tensioning means and by the auxiliary tensioning means when operated. 20. Coflexip submitted that the judge was right to reject that submission of Stolt. The words used were "the pull" not "some or a real part of the pull". As the specification explained, the object of the invention was the laying of flexible conduits at depths greater than had been feasible before. This was achieved by inter alia the main tensioning means taking up the tension exerted by the portion of the flexible conduit "suspended on the tensioning means between the laying vessel and the bottom" (page 2 lines 49 to 52). It was that tension which was taken up by the auxiliary tensioning means and which was again taken over by the main tensioning means. 21. In my view Coflexip are right. The pull referred to in the claim is that exerted by the flexible conduit seaside of the main tensioners. Thus the words "the pull" refer to all the tension caused by the part of the pipe seaside of the main tensioners. The sentence bridging pages 2 and 3 of the specification, relied on by Stolt, does not suggest a contrary meaning. All that is said is that, if the seaside pull is taken by the main tensioners, the tension in the pipe after the main tensioners "is very low and preferably virtually negligible". There will inevitably be some tension due for example to the weight of the pipe and friction, but that does not detract from the teaching of the specification that the tension from the pipe seaside of the tensioners is to be taken by the main tensioners or, when an accessory is passed, by the auxiliary tensioner. 22. Of course, the words "the pull" have to be construed in context. As Lord Diplock pointed out in Catnic Components Limited v Hill & Smith Limited

(1982) RPC 183

a word such as "vertical" had to be construed in context; in that case in the context of manufacture of lintels for the building trade. Thus the requirement that a metal beam should be vertical did not mean that it should be exactly 90o to the horizontal. A similar approach should be adopted in the present case so that the requirements as to "the pull" should be construed in the context of pipe laying from a ship. 23. Should the words "A device for operating" in claim 3 be construed as meaning that the device is suitable for operating or as meaning a device when used for operating? - Before the judge Coflexip maintained that claim 3 was a valid claim. However both parties concentrated their submissions on claim 1. The result was that the judgment, handed down on 22nd January 1999, did not deal with claim 3. That omission was remedied in the unreserved judgment of 22nd January 1999. 24. Mr Miller QC, who appeared for Coflexip, submitted to the judge that the normal meaning should be given to the word "for", namely "suitable for". He referred to Adhesive Dry Mounting Co Ltd v Trapp

[1910] 27 RPC 341

and Instituform Technical Services v Inliner UK

[1991] RPC 83

to support that submission. Mr Watson submitted that the words in claim 3 should be construed as meaning "when used for". He submitted that if the construction suggested by Mr Miller was adopted, the claim was invalid upon the findings made by the judge in his main judgment. The judge accepted that argument. He said:

"If I may say so, I think this argument is right. I also accept Mr Watson's submission that the meaning of the claims has to be arrived at by looking at the claims in the context of the specification as a whole. It would have been easy to have drafted a claim which defined the pipe laying vessel simply by reference to the various mechanical integers it contained, but this claim does not. The words "for operating the process according to one of the preceding claims 1 and 2", in the particular context of this patent must have a limiting effect. The invention here is not really so much the hardware but the way in which the vertical pull is distributed as between vertical tensioners and horizontal tensioning devices, whether they be tensioners or powered reels. In my view, Mr Watson is right that claim 3 means the device when operating in the manner set out in the process claims -- that is to say, when it is operated so that all, or substantially all, of the tension is taken in the vertical direction." 25. That approach to construction is, in my view, wrong. The meaning of the claim cannot depend on whether a certain construction would mean that the claim was obvious. The inventive idea was in reality the process, but that does not prevent a patentee claiming a device which is suitable for operating the process, provided that such a device was disclosed in the specification and satisfied the requirements as to patentability in the Act. There are strong reasons for concluding that that is what happened in this case. 26. The patent, as the title and specification state, relates to a method and a device. To construe claim 3 in the way suggested by Stolt would in effect mean that there was no device claim. At page 5 lines 30-32 it is stated "

The characteristics of the method of the present invention form the objects of claims 1 and 2. The characteristics of the device in accordance with the present invention form the objects of claims 3 to 9." Clearly the patentee had in mind both method claims and device claims. His intention is carried through into the claims. For example claim 4 claims "A device according to claim 3 ...". That also indicates that claim 3 is a claim to a device not to a device when used. 27. In my view the normal and natural meaning should be given to the words "A device for operating" in claim 3, namely that the device is suitable for operating. Infringement 28. The alleged infringing acts involved the laying of flexible pipe in 1995 from the ship known as the Seaway Falcon. To enable the issues to be dealt with, Stolt prepared a "Process Description" which included four drawings. In two of them a moonpool base deflector plate was shown. The description did not describe their use, but it was contended by Stolt that their presence avoided infringement because claim 1 required the main tensioning means to comprise "the last means for guiding the conduit at the level of the floating support". In the Seaway Falcon that did not happen as the base deflector was below the main tensioning means and therefore the main tensioning means was not the last means for guiding the conduit. 29. The judge rejected that. He said:

"65. By the end of the trial, only one issue on infringement remained. Claim 1 ends with a requirement that the vertically disposed tensioning devices are "the last means for guiding the conduit at the level of the floating support."

Similar wording is to be found at the end of Claim 3. This wording reflects the fact that since the patented system delivers the flexible conduit at the same angle as the catenary below the vessel, no further guides, such as stingers or overboarding wheels or chutes, are required. As the drawing in the patent (Figure 14 above) illustrates and the text describes, below the lowest tensioner there is the working table (7) and the moonpool (8). Neither the table nor the sides of the moonpool are described or referred to in the specification as guides. In normal and stable conditions, they do not even touch the conduit. 66. The layout of the Seaway Falcon , the Stolt Comex vessel which is alleged to infringe, is essentially the same as that illustrated in Figure 14. It includes bumpers or deflectors located below the tensioners to prevent pipe which is being laid from hitting the moonpool or moonpool doors. It was accepted by Stolt Comex that in normal use these devices do not touch the pipe. They are used to prevent the pipe from being damaged, for example by smashing against the edge of the moonpool doors during stormy weather. Mr. Willis, who had never seen the Seaway Falcon in operation, said that the pipe would touch the deflectors "every other second". I do not accept that evidence. When the whole of his cross examination on this subject Transcript Day 3 page 392 line 15 et seq. is reviewed and read in the light not only of Mr. Seeley's evidence Bundle I tab 1 page 38 para 130. but also Mr. Coutarel's evidence Bundle D tab 1 paras. 98 to 104., it is apparent that the vessel is designed to be operated without the pipe contacting the deflectors at all. The same point comes out of the written instructions given to the operators of the Seaway Falcon . They are told to set up the vessel to ensure that there is no "clashing with the bottom edge of the moonpool" Bundle L2 page 266.. Those instructions go on to explain that if the pipe does come into contact with the bottom edge:

"This will not cause any damage to the [pipe] if performed in a fully controlled manner as the base of the vessel moon pool has a 7.5 metre radius"

Bundle L2 page 266. This means that because the edge of the moonpool is rounded (because of the presence of the deflectors) pulling the pipe past it will not cause damage if done carefully. 67. I do not accept that the deflectors in the Seaway Falcon can reasonably be called guides. They are no more guides than the bumpers at the front of a car or a crash helmet worn by a motorcyclist. The defendants infringe." 30. Mr Watson sought to resurrect the evidence of Mr Willis. However the judge was entitled to come to the conclusion he did. That being so, the conclusion he reached was inevitable and right. I therefore reject the submission that infringement was not established. Validity 31. Stolt alleged that the patent was invalid because it was obvious. Their attack started from two sources. First the prior use and description of pipe laying as carried out on the ship known as the Apache as patented in US patent No. 3982402 (Lang). Second, common general knowledge of laying rigid pipes using the J lay method. 32. It is accepted that the issue of obviousness is best determined using the structured approach suggested by Oliver LJ in Windsurfing International Inc v Tabur Marine (Great Britain) Ltd

[1985] RPC 59

at 73. "There are, we think, four steps which require to be taken in answering the jury question. The first is to identify the inventive concept embodied in the patent in suit. Thereafter, the court has to assume the mantle of the normally skilled but unimaginative addressee in the art at the priority date and to impute to him what was, at that date, common general knowledge in the art in question. The third step is to identify what, if any, differences exist between the matter cited as being "known or used" and the alleged invention. Finally, the court has to ask itself whether, viewed without any knowledge of the alleged invention, those differences constitute steps which would have been obvious to the skilled man or whether they require any degree of invention." 33. As Laddie J pointed out in Brugger v Medic-Aid Ltd

[1996] RPC 635

the inventive concept must apply to all embodiments falling within the claims. It is therefore not legitimate to define the relevant concept as something narrower than the claims. It follows that it must be taken from the claims, in this case claim 1. 34. Claim 1 relates to a process for laying flexible conduits which have rigid accessories mounted on them. The process involves two tensioners: a main tensioner and an auxiliary tensioner. The main tensioner is mounted vertically and takes the seaside tension with the result that there is no tension or virtually negligible tension boatside. When an accessory is passed, the seaside tension is taken by the auxiliary tensioner and the operating parts of the main tensioners move apart to allow the accessory to be passed. Thereafter the main tensioner takes over again. It is the last means for guiding the conduit. 35. For the purposes of this part of my judgment, I will assume that the common general knowledge was that described in the extract from the judge's judgment I have set out at the beginning of my judgment. 36. The Apache was a rigid pipe layer using the J lay system. It is shown in Figure 4 above and described in paragraph 11 of the judge's judgment. 37. The differences between Apache and the invention claimed in claim 1 are clear. First it laid rigid pipe. Second the major part of the tension was taken by the reel boatside of the tensioners in the pipe ramp. The tensioners on the ramp were used to straighten the pipe not to take the seaside tension. Third no auxiliary tensioner was used to take up the seaside tension if an accessory was passed. Fourth, there was no disclosure that the tensioners on the ramp were constructed to pass an accessory. I am doubtful whether the ramp ever became vertical, but in view of the statement in column 2 of the Lang patent, I will assume that it did in very deep water. 38. Examination of the differences between the inventive concept of claim 1 and that used in Apache show that the two processes are completely different. Apache was designed to lay rigid pipe and to deal with the problems of overbend requiring large stingers. That problem did not arise with the laying of flexible pipe where overboarding accessories and the size of wheels or chutes were the problems. 39. Mr Watson submitted that the skilled addressee would realise that the Apache could be used to lay flexible pipe. In fact, he submitted, it was obvious to do so, as was demonstrated by the evidence that Apache was used in 1992 in that way. If so, the ramp would be raised to the vertical position and of course the tensioners would have to move apart to let the accessories through. That was the way it was carried out in 1992. That left the question of whether the tensioners on the ramp would be altered so as to take the seaside tension rather than the reel. To establish that that was obvious Mr Watson relied upon certain passages in the cross-examination of Mr Nash. 40. For my part I do not understand Mr Nash's evidence as accepting that, in the light of the disclosure of Apache, it was obvious to alter the tensioning arrangement on Apache so that the seaside tension was taken by the tensioners that were used to straighten the rigid pipe. In any case I did not find the evidence relied on as persuasive to establish that claim 1 was obvious. The cross-examination was a classic example of the type rejected by Lord Diplock in Technograph Printed Circuits Ltd v Mills & Rocky (Electronics) Ltd

[1972] RPC 346

at 362. 41. Once the idea of solving the problem of overboarding and crushing by the use of main and auxiliary tensioners which took the seaside tension was known, the step by step route to the invention became apparent. The judge was right. "There is nothing in Apache or Lang which would suggest that the standard S lay of flexible pipes, or even S lay with a supplementary vertical tensioner, should be discarded in favour of an arrangement where all the tensioners are in a vertical array." As he pointed out the advantage of the claim 1 process was that it solved both problems associated with the laying of flexible pipe at the same time. 42. Apache does not suggest or render obvious the inventive concept of claim 1. A person seeking to lay flexible pipe would, with the knowledge of Apache, either do what in fact happened in 1992 or go back to the known way of laying flexible pipe. As Mr Beavers explained, the tensioners on Apache were not suitable for gripping flexible pipe. Thus when flexible pipe was laid in 1992, they were only operated to guide the pipe after the flexible pipe had been led over the ramp. To enable accessories to be passed, the ships' A & R winch was used with airbags to lift the pipe at the top of the ramp. The tension was taken by the reel. In essence the known system of laying flexible pipe was used with the equipment available on Apache. Improvement would have involved altering the ramp and adopting a system for passing accessories as had been proposed in the prior art. 43. Mr Miller submitted that at the priority date the problems solved by the process of claim 1 were not appreciated to be problems such that a fresh approach was needed. For that reason also, the inventive concept was not obvious. He submitted that the evidence was that the only obvious way forward was to update the known process for laying flexible pipe by increasing the size of the wheel or chute and designing better means for overboarding. However the evidence established that, as it had become necessary to lay pipes in deeper water, the problems associated with crushing and overboarding accessories became more acute. Solutions were needed as the patent specification suggests, but even so I believe the obvious way forward was bigger and better, not that claimed in claim 1. 44. Mr Watson's second approach to obviousness started from the known concept of laying rigid pipes by the J lay method. At the priority date that concept was known, but the Apache was the only vessel which had used the method. 45. The advantage to Mr Watson of starting his attack upon the inventive concept of claim 1 from J lay was that it was unencumbered by any detail. J lay was a concept advocated for laying rigid pipe. In deep water the entrance of the pipe to the water would be vertical or nearly so and no long stingers were necessary. Thus if he could persuade Mr Nash to accept that it was obvious to use it for flexible pipe, he could submit that he had established that the invention was obvious as the changes which would then be seen to be necessary would result in alterations which fell within claim 1. J lay solved the problems associated with laying rigid pipe in deep water, namely buckling so that overboarding gutters and chutes were not necessary. Thus once it was decided to use it for flexible pipe, all that was needed, he submitted, was the appreciation by the skilled person that the vertical tensioner would be sufficient by itself. The reason why the approach had not been adopted before was because of lack of investment. He again relied on parts of the cross-examination of Mr Nash which, he submitted, accepted that it was obvious to move from J lay to the process of claim 1. 46. Those submissions involve hindsight reasoning of the type that is unacceptable when deciding whether a patent was obvious. This can be demonstrated by adopting the structured approach suggested in Windsurfing . J lay had only been suggested for rigid pipes. It was not perceived as having any advantage for flexible pipes. Although tensioners could be mounted vertically, they need not take the majority of the tension as the method of use aboard the Apache demonstrated. The only features of similarity between J lay and claim 1 would appear to be vertical lay with tensioners; but the way the tensioners operated was not the same. In those circumstances none of the features of the inventive concept of claim 1 appear to have formed part of the common general knowledge which J lay was used. The two processes were essentially different. The J lay was for rigid pipe laying and the equipment used would be built for the purpose. It is only when you know the answer can it be seen how to use the process for laying flexible pipe. 47. J lay did not suggest the inventive concept of claim 1. It could be useful for rigid pipe laying and would be seen in that context. The judge was right when he said in paragraph 63 of his judgment:

"63. The argument based on common general knowledge was that it was known that J-laying was advantageous where rigid pipes were being laid at great depths. If a flexible pipe was to be laid at great depths, it was obvious to use J-lay for this also. It would avoid the difficulties associated with crushing the pipe and overboarding accessories. It appears to me that the case of obviousness based on common general knowledge alone is no stronger than that advanced on the basis of the Apache and the Lang patent. Once again, it may well have been obvious on the basis of common general knowledge to arrive at the type of configuration illustrated in Figure 16 above but I am not persuaded that it was obvious to take all or substantially all of the strain vertically."

The judge was right to reject the attack of obviousness and to conclude that claim 1 was valid. 48. Claim 3 - I have already concluded that the claim should be construed as relating to a device suitable for carrying out the process of claim 1. The features of the claim define the movement towards and away from the conduit to enable it to be gripped and to pass accessories, and also the elements of the auxiliary tensioning means. 49. The judge believed that a claim so construed would be invalid. I disagree for two reasons. First it was not established that it was obvious to lay flexible pipe using vertical tensioners which took the seaside tension. Even when the Apache laid flexible pipe it did not use that feature. The apparatus on Apache was not suitable for use in the described method. Second, without knowledge of the inventive concept of claim 1, I cannot envisage why it would be obvious to construct a device having the features of claim 3 which would be suitable for carrying out the process of claim 1. The Application to Re-amend the Particulars of Objection 50. In January 2000, a copy of US Patent No. 3216636 came to the attention of Stolt. It had been found in a search conducted by a third party who then brought it to the attention of Stolt. Stolt believe that the disclosure in that US patent rendered the invention of the patent obvious and sought leave to re-amend their particulars of objections to enable them to rely on it. To make the US patent effective as an invalidating disclosure, they needed to rely upon new evidence. They therefore applied to re-amend their pleadings and to introduce fresh evidence to establish that the patent was invalid having regard to the disclosure in the US patent. As this Court would be unlikely to hear cross-examination on that issue, it was likely that a retrial, limited to the allegation raised by the re-amendment, would be ordered if leave was given to amend the pleading. 51. Stolt submitted that re-amendment and a retrial, limited to the issue raised by the amendment, was an appropriate course. They drew attention to the fact that none of the patent offices had found the US patent in the searches they had carried out when conducting a validity examination on applications for equivalent patents. They submitted, that in those circumstances, they had acted reasonably when deciding to carry out the limited searches for prior art that they had done. They submitted that Coflexip would not be prejudiced by a retrial because the injunction would continue in the meantime without a cross-undertaking in damages and that an appropriate order for costs could be made. In those circumstances justice between the parties could best be achieved by the amendment and the retrial. That they submitted was in the public interest because, if the patent was invalid, it was in the public interest that it should be revoked as soon as possible. They accepted that upon the evidence before the court it was not possible to conclude that the US patent rendered the patent invalid, but submitted that at the very least it might be held to do so. 52. Coflexip resisted the amendment and disputed the relevance of the US patent. Their evidence established that if a full search had been made, the US patent would have been discovered. That being so, they submitted that the US patent would not have been admitted under the principles laid down in Ladd v Marshall . They submitted that it would not be right to circumvent those principles just because the application was one to re-amend a pleading. In any case, there was a duty upon a party to bring forward his whole case to ensure finality in litigation. Stolt had decided to carry out a limited search for prior art and it would be contrary to the public interest and to the interest of Coflexip for the matter to be reopened. Coflexip had a legitimate expectation of finality. 53. This Court has a discretion to allow the amendment. It is a general discretion, but it should be exercised to secure the overriding objective laid down in of the Civil Procedure Rules in rule 1.1:

"1.1 - (1) These Rules are a new procedural code with the overriding objective of enabling the court to deal with cases justly. (2) Dealing with a case justly includes, so far as is practicable- (a) ensuring that the parties are on an equal footing; (b) saving expense; (c) dealing with the case in ways which are proportionate- (i) to the amount of money involved; (ii) to the importance of the case; (iii) to the complexity of the issues; and (iv) to the financial position of each party; (d) ensuring that it is dealt with expeditiously and fairly; and (e) allotting to it an appropriate share of the court's resources, while taking into account the need to allot resources to other cases."

In my view the application to re-amend does not satisfy that objective and should be refused. It follows that the applications to introduce fresh evidence must also be refused. 54. To ensure expeditious and fair resolution retrials must be avoided. Thus a defendant in a patent action must decide the extent of any search he wishes to make and, except in very unusual circumstances, will be held by this Court to the decision he takes. To conclude to the contrary would encourage applications to introduce fresh prior art to meet conclusions reached by the trial judge with consequent delay and increased cost. Further a retrial cannot be an acceptable allotment of an appropriate share of the court's resources except in very unusual circumstances. None arise in this case. 55. It is not for the court to decide whether a search for prior art carried out by a defendant was reasonable. What is reasonable depends on a variety of factors, such as cost, importance of the result to the defendant, and its resources. To ensure that litigation is carried out efficiently and fairly parties must bring before the court the case that they wish to rely on. That Stolt did in this case. They carried out searches which they believed were appropriate and which they believed and still believe were reasonable. It was their decision not to search more widely and it is not right to allow them to reopen their case in this Court. There are no exceptional circumstances which would make this an appropriate case for amendment requiring a new trial. The Injunction 56. After copies of the main judgment had been supplied to the parties' legal advisers, it was officially handed down on 22nd July 1999. For the purposes of the hearing on 22nd July 1999, the parties had prepared and supplied to the judge a draft order together with an agreed note indicating the issues that would arise from argument. The draft order contained an injunction in the usual form which restrained the defendants from "infringing European Patent (UK) no. 0478742". The terms of the injunction were not in issue between the parties. At the hearing on 22nd July, the judge indicated that he was considering granting a different injunction and invited submissions upon his idea. Coflexip sought to maintain the injunction as in the draft order, but counsel for Stolt, no doubt realising the way that the judge's mind was working, withdrew his consent to the injunction in the draft order. 57. Having heard counsel for Coflexip at length and counsel for the defendants briefly, the judge decided to put his judgment on this issue into writing. That judgment was handed down on 29th July 1999. In his detailed judgment the judge concluded that the injunction should not be in the usual form. He proceeded to hear submissions as to the form it should take so as to satisfy the conclusions reached in his judgment. He then ordered that the injunction should be in these terms:

"The Defendants and each of them be restrained ... from using or offering for use in the United Kingdom (or in an area designated by Order under section 1(7) of the Continental Shelf Act 1964) a process for laying flexible conduit employing a Flexible Lay System of the design installed in the Seaway Falcon and described in the Defendant's Product and Process Description dated 27th March 1997 which process includes at least one occasion on which the flexible conduit being laid incorporates a rigid accessory (whether made from joined end fittings or not) within its length."

He gave the parties liberty to apply in respect of the injunction. 58. That injunction makes no reference to the patent nor to the right stemming from the patent. Thus it applies whether or not the patent lapses or is revoked and, unless an application is made to the court, it will continue even when the patent expires. It therefore needs some modification. I will come later to the reasons why the judge believed that an injunction of that width, albeit restricted to a particular description of a process, was appropriate; but before doing so will deal generally with the reasons why injunctions in patent actions are usually granted in the form which prevents the defendant from infringing the patent. 59. The court has under s. 37 of the Supreme Court Act 1981 a general power to grant an injunction "in all cases in which it appears to the court to be just and convenient to do so." Section 61 of the Patents Act 1977 provides for "a claim for an injunction restraining the defendant ... from any apprehended acts of infringement." In so doing the section accords with the general law prior to the passing of that Act. An injunction is a remedy against further injury and the Court will not make the order if satisfied that no such injury is likely to occur. It is not because a defendant has done a wrong that an injunction will be granted against him. Where a patentee has conclusively established the validity of his patent and that it had been infringed, as a general rule an injunction will be granted. However that will not happen as a matter of course as an injunction is a discretionary remedy. It is for that reason there have been cases where injunctions have been refused, for example, where the defendant satisfied the court that further infringement was not likely. In the present case the judge was not satisfied that no further infringement was threatened and therefore concluded that an injunction was an appropriate remedy. The contrary was not suggested in this Court. The issue argued concerned the terms of the injunction. 60. It is important that an order, such as an injunction, is drafted so as to set out, with such clarity as the context admits, what may not be done. It is for that reason that the standard form of injunction is in the terms restraining the defendant from infringing the patent. Such an injunction is limited in term and confined to the right given by section 60(1) and (2) of the Patents Act. It also excludes acts, carried out by the defendant and which fall within the ambit of the monopoly, but are excluded from infringement by the Act; for example private use coming within section 60(5)(a) of the Act. Such an injunction is confined to the monopoly as claimed. The claim has been construed by the court with the aid of the parties and in the context of the acts alleged by the plaintiff to infringe and any other potentially infringing acts which the defendant wishes to bring before the court. Of course a dispute can arise as to whether acts, not brought before the court, amount to a breach of the injunction. But such a dispute arises against the background where the ambit of the claim and therefore the injunction has been the subject of consideration by the court and has been construed by it. 61. I turn next to consider the injunction which was granted at the judge's suggestion. It suffers from 3 basic deficiencies. First as I have pointed out is not linked to the term during which the patent exists. That no doubt could be corrected by adding such words as "during the lifetime of the patent". Second it exceeds the statutory right given by section 60(1) and (2) in that it fails to exclude acts which are, under the Act, excepted from the right. Third it raises considerable difficulties on construction. 62. The injunction granted by the judge has incorporated into it the "Defendants' Product and Process Description". That comprises three pages of typescript and four pages of diagrams. Such documents are normally produced, and this document appears to be no exception, to describe the alleged infringement in terms, using uncontroversial words, sufficient to enable the court to decide whether or not there was infringement. In this case it includes a considerable amount of detail which is irrelevant to infringement. For example the process which has been injuncted requires use of a vessel crane fitted in a particular way and moonpool doors. There is no reason why an injunction should be so limited as the crane and doors are not limitations which appear in claim 1. The injunction is also limited by the drawings which are said to be drawn to a particular scale. What deviation from those drawings would avoid the injunction is not clear. 63. The injunction as granted is incorrect in ambit and is unclear and therefore it should be discharged and a more appropriate form of injunction substituted. 64. When deciding what is the appropriate form of injunction in a patent action, it must be borne in mind that the injunction is being granted to prevent apprehended use of the patentees' statutory monopoly, as defined in his claim. The decision as to form is taken against the background of the claim having been construed by the court as between the parties. That of course does not happen in other intellectual property cases. An injunction which just restrained breach of confidence would not be appropriate for many reasons, including because the extent of the confidential information would not have been determined. In passing-off cases a change of circumstance can alter the representation made and therefore the injunction normally sets out the act which is to be prevented, qualified by such words as "so as to pass-off". 65. The judge seemed to believe that injunctions which restrained infringement of a patent were broad injunctions: but they equate to the statutory right given, a right which has been held to have been validly granted and infringed. The injunction granted by the judge would allow the defendant to do other acts even though they may infringe. The defendant in those circumstances would be better off in that a change from that which is described and shown in the process description would allow him to continue in business without having to seek guidance from the court before adopting the change. The advantage to the defendant of only having the injunction cover a particular article or process is clear. If he makes a change he will not be in breach and it will be up to the patentee to bring another action. However the disadvantage to the patentee is equally clear. To obtain an injunction he has to established his monopoly and that it has been infringed, and the judge must conclude that further infringement is apprehended. From his point of view, it is the infringer who should seek guidance from the court if he wishes to sail close to the wind. In the normal course of events that would be reasonable. 66. The usual form of injunction which protects the right established by the patentee, with its ambit construed by the court, does in general provide a fair solution. However each case must be determined on its own facts and the discretion exercised accordingly. 67. In the present case, nothing has been brought to my attention which would suggest that anything other than the usual form of injunction would be appropriate. The injunction suggested by the judge was in my view inappropriate. Conclusion 68. The judge was right to hold the patent valid and infringed. However I would set aside the injunction granted and make an order in the usual form. I would refuse the applications to amend and to adduce further evidence. CHADWICK LJ: 69. I , too, would refuse the application to re-amend the particulars of objections and the related application to adduce further evidence. I agree that the injunction granted by the judge should be replaced by an injunction in the usual form, restraining the defendants from infringing the patent. Subject to that the appeal should be dismissed. The application to amend 70. The application to re-amend the particulars of objections must fail for the reasons given by Lord Justice Aldous. This is not a case in which it can be said that the prior art on which the appellants now wish to rely – US Patent No 3216636 – would compel the court to hold that the respondents’ patent is invalid. The most that can be said is that the US Patent provides a further basis for the appellants’ attack on the validity of the respondents’ patent. In those circumstances it is clear that, if the appellants cannot succeed without relying on the prior art which they seek to introduce by amendment, permission to re-amend would, necessarily, lead to a re-trial. 71. In deciding whether or not to make an order which would have that effect, the court must have regard to the overriding objective set out in CPR 1.1. In particular, the court must have regard to the need to allot to this case an appropriate share of the court’s resources while taking account of the need to allot resources to other cases. Where the court’s resources have already been allotted to one trial of the issues between the parties, a party seeking a second trial to raise new issues has a heavy burden to discharge if he is to persuade the court that further resources should be allotted for that purpose. The court is entitled to expect that parties will bring before it for trial, at one and the same time, all the issues upon which they wish to have a decision. Two bites at the cherry is wasteful of resources. 72. I agree with Lord Justice Aldous that it is not enough for a party in a patent action to say that he acted reasonably in deciding what limit to place upon his searches for prior art when preparing for a trial. It is accepted by the appellants, as I understand it, that more extensive searches than those actually carried out would have revealed the additional prior art upon which they now seek to rely. Such an acceptance is inevitable, as it seems to me, where it cannot be disputed that the additional material was there to be found. In such a case the test is not whether a party did what was reasonable; it is whether he did what was necessary. 73. It is no answer for the appellants to say that the respondents would not be prejudiced if there were to be retrial. That is to ignore the interests of other court users; who will be prejudiced if time and resources which could be used to hear and dispose of their cases have to be devoted in the re-trial of a case which has already been heard. The limited number of nominated patent judges, and the heavy demands on the Patents Court, gives the point particular force in patent cases. 74. Nor is it any answer for the appellants to say that if, as they contend, the respondents’ patent is invalid, it is in the public interest that it be revoked as soon as possible. The court cannot assume that, if there were to be another trial on the new material, the respondents’ patent would be held invalid. The appellants are driven to say that, because they might succeed at a retrial, it is in the public interest (as well as in their own private interests) that they should be given that opportunity. But, if the monopoly conferred on the respondents by the continued registration of the patent is really operating to the public detriment, then it may be expected that the patent will be challenged by another party in other proceedings. If that were to be the effect of refusing the appellants’ present application, then the refusal of that application in order to avoid a waste of resources would have been pointless. The resources which would be expended on a retrial would be expended in any event; because (absent a retrial) they would have to be allotted to the other proceedings But that is not this case. The appellants have made no attempt to establish that (absent a retrial) the respondents’ patent will be challenged by another party in other proceedings. In those circumstances the court must address the appellants’ present application on the basis that there is a real risk that to allow the application will lead to a waste of resources, contrary to the public interest; and that there is no public interest in giving the appellants a further opportunity to test the validity of the respondents’ patent at a retrial sufficient to justify taking that risk. Unless the court can see that (absent a retrial) it is really inevitable that there will be a challenge by another party in other proceedings, it should leave events to take their course. The court should not allow a party to pursue its own private interests in a way which is wasteful of the court’s resources under the guise of promoting an alleged public interest in challenging the monopoly conferred by the patent. The attack on the validity of the patent in suit 75. There is little that I wish to add to the reasons which have led Lord Justice Aldous to the conclusion that the substantive appeal should be dismissed. But I will explain shortly why I agree that the appellants’ attack on the validity of the patent in suit should fail. 76. As this Court pointed out in Windsurfing International Inc v Tabur Marine(Great Britain) Ltd

[1985] RPC 59

, at page 71, the question to be decided when an objection to a patent is made on the ground of obviousness is – to adopt the phrase used by Lord Justice Jenkins in Allmanna Svenska Electriska A/B v The Burntisland Shipbuilding Co Ltd

(1952) 69 RPC 63

, at page 70 – “a kind of jury question”. It is a question which has to be answered, . . . not by looking with the benefit of hindsight at what is known now and what was known at the priority date and asking whether the former flows naturally and obviously from the latter, but by hypothesizing what would have been obvious at the priority date to a person skilled in the art to which the patent in suit relates, who is assumed to have access to what was known of the art . . . immediately before the priority date. 77. In answering the jury question “would it have been obvious” the court should adopt the structured approach described by this Court in the passage of its judgment in the Windsurfing case (at pages 73-74) which Lord Justice Aldous has already set out. The reason why that approach should be adopted, as it seems to me, is that it helps the court to avoid the error – into which Mr Watson’s skilful submissions on behalf of the appellants in this appeal might have led the unwary – of holding that, because the concept embodied in the patent in suit can be seen, with the benefit of hindsight, to be a natural development of what was known immediately before the priority date, it must have been obvious at the time. 78. I agree with Lord Justice Aldous, for the reasons which he gives, that the inventive concept in the present case comprises the following elements: (i) it relates to a process for laying flexible conduits to which rigid accessories (of a bulk greater than the diameter of the pipe itself) have been or are to be attached, (ii) it provides for the pull to be taken by a tensioner (“the main tensioner”) mounted in a vertical axis on the seaward side of the chute or guide over which the pipe or conduit must pass between the basket in which it is stored on deck and its entry into the sea, (iii) it requires that the operative parts of the main tensioner can be moved apart or opened, so as to release the pipe and allow the accessories to pass through it; and (iv) it provides for the use of an auxiliary winch to take the pull, again on the seaward side of the chute or guide over which the pipe must pass, when the accessory is passed through the main tensioner. The combination of those elements solves two of the problems associated with the laying of flexible pipe. First, by taking the pull on the seaward side of the chute or guide over which the pipe must pass between storage on deck and entry into the sea, it avoids the danger of crushing associated with the passing of flexible pipe over a curved guide under tension. Second, again by taking the pull on the seaward side of the chute or guide, it avoids the danger of local buckling, at the interface between the flexible pipe and the rigid accessory, associated with overboarding accessories in a flexible pipe under tension. 79. Save that, in the J-lay system for laying rigid pipe the ramp on which the tensioner was fixed could be raised into the vertical, or near vertical, position, the prior art relied upon by the appellants has none of the features which I have described. Neither J-lay as first used, nor the development of J-lay as used in the ship “Apache” were seen as solutions to the problems associated with the laying of flexible pipe. They were seen as solutions to solve the different problem associated with rigid pipe; that is to say, the danger that rigid pipe would buckle under its own weight if the overbend was not supported by a stinger. The problems of crushing, and the problems associated with overboarding fixed accessories, did not arise in laying rigid pipe. There was no need for a facility to open the tensioners, or to take the pull on an auxiliary winch. In J-lay the sections of rigid pipe were welded together on the ramp. The pipe did not pass over any guide or chute between storage and entry to the sea; so there was no place for a tensioner on the seaward side of a guide. In the “Apache” system the pipe did pass over a wheel between the reel on which it was stored and entry to the sea, and there was a tensioner on the ramp on the seaward side of that wheel; but the pull was taken by the wheel, not by the tensioner. The purpose of the tensioner was to straighten the pipe, which had been deformed by storage on the reel. It is, I think, of significance that, when the “Apache” was used to lay flexible pipe in 1992, the seaward side tensioner was not used to grip that pipe – a task for which, in any event, it was not suitable. 80. It is, of course, possible to construct a series of logical steps by means of which, with the benefit of hindsight, it can be said that the inventive concept embodied in the patent in suit is a natural development of the prior art embodied in the J-lay system and the “Apache”. But that is the trap which the court must avoid. The correct question is whether the inventive concept embodied in the patent in suit would have been obvious at the priority date to a skilled, but unimaginative, person knowing that the J-lay system, and the system developed for use in the “Apache”, were available to overcome the problem of buckling at the overbend associated with laying rigid pipe. The judge, having heard the evidence, held that that question should be answered in the negative. In my view that was a conclusion that he was entitled to reach. There is no basis on which this Court can be asked to interfere. BUXTON LJ: I agree with both judgments.

Figure 7: (a) (b) (c) (d)

Figure 8

Figure 9

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Figure 11

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Figure 15 Figure 16 Figure 17 Figure 18

Order

Appeal dismissed with costs; interim payment ordered in the sum £100,000 within 28 days; permission to appeal to the House of Lords refused. Respondents to lodge a draft minute of order. (Order does not form part of approved judgment.) Figure 1: . Figure 2: Figure 3: Figure 4: Figure 5: Figure 6: