“(1) where the assured is over – insured by double insurance, each insurer is bound, as between himself and the other insurers, to contribute rateable to the loss in proportion to the amount for which he is liable under his contract. (2) if any insurer pays more than his proportion of the loss, he is entitled to maintain action for contribution against the other insurers, and is entitled to the like remedies as a surety who has paid more than his proportion of the debt.”
“… as soon as the loss has occurred… the primary obligation is broken, giving rise to the secondary obligation to pay damages.”…“Whether contribution claims between indemnity insurers fall within the scope of the Act must depend upon which of these views is preferred, and, as in the case of co-sureties, it is likely that the answer will usually turn on the wording of the relevant policies.”