"Mr Sissons started in June of 1988. He started off as a class 1 driver, though it is fair to say that the work involved class 2 and 3 driving. He delivered frozen food to various Co-op outlets around the countryside, mainly southwards and westwards (sometimes eastwards). As any lorry driver knows (and anyone with knowledge distribution knows) there is no such thing for a lorry driver when he is on a variable delivery run of [sic as] a fixed working day. The driver will simply have to start in accordance with what was the most logical start time for his delivery run and finish when the delivery was over and done with. Sometimes he might be out for 12-15 hours, other times he might be out for 5 or 6. Mr Sissons was no exception. He made a regular weekly run to the west country. Having emptied one particular lorry a truck driver would then deliver him another lorry and he would carry on his deliveries.
"First, where there is a fixed number of compulsory working hours, and thereafter overtime is voluntary on both sides - so that the employer is not bound to employ the man for any overtime and the employee is not bound to serve it - then, although the overtime is worked regularly each week, nevertheless, being voluntary, it does not count as part of the normal working hours. Such a situation is covered by paragraph 1(1).
"That case makes it clear that it is not enough for an employee to show that over a period he has regularly or usually worked hours of overtime in order to have them included in a computation of his normal working hours. What has to be shown, in order that what is usually described as "overtime" can be included, is that it is obligatory upon the employer to provide the overtime, that it is obligatory upon the employee to do it and that that obligation on both sides is to be found in the terms of the contract of employment."