It was agreed that a Board of Inquiry would be convened to investigate the loss of Affray and while it was in session the First Sea Lord, Sir Bruce Fraser, met Admiral Sir Arthur Power to discuss the possible outcome. Together they agreed that if further investigations by divers confirmed that Affray’s snort induction valve was definitely in the ‘open’ position, it would be possible for the Board to conclude that the submarine had been lost as a result of the snort mast breaking off due to metallurgical faults. But they knew that if this were the case, the Admiralty would either be criticised for accepting a badly designed snort tube or failing to identify those responsible for welding the device to the hull.
Before the Board had an opportunity to deliver its findings, Sir Bruce and Admiral Power together agreed that water rushing into the submarine through a hole in the stump of the mast was ultimately responsible for the accident – and further investigation by divers no longer necessary. They claimed that the latest television pictures seen on Reclaim showed Affray listing at a greater angle, making it dangerous for divers to continue working on the wreck. Reclaim was scheduled to return to Affray on 25 July for eight days and future work on Affray was now in question.
The outcome of the conversation between the First Sea Lord and Commanderin-Chief, Portsmouth, was relayed to the three senior officers chosen to head the Board of Inquiry. They were also ordered to place proceedings on hold for the time being while an interim report was produced confirming their findings so far. This was delivered on 19 July.
Senior officers within the Navy’s engineering branch were quietly asking if the broken snort mast provided sufficient compelling evidence to confirm the real reason for the Affray’s loss. Many suggested that the accident might have been caused by a battery explosion triggering off shock waves throughout the submarine, which, in turn, resulted in the snort mast breaking away, sending the submarine to its doom.
Admiralty bosses knew that a battery explosion carried a different set of implications about British submarine design and workmanship failures – and potential embarrassment for the Royal Navy. A broken snort mast, however, would be more acceptable for relatives of those lost on Affray – and the British public – to swallow as the reason for the submarine’s loss.
The Admiralty had, therefore, made up its mind why Affray was lost long before the Board of Inquiry had presented its completed report, while witnesses were still providing evidence and naval engineers continued examining the fractured snort mast.
In a memo to the Secretary of the Admiralty dated 7 August, in which a copy of the Board’s full and final report was enclosed, Admiral Power stated:
As regards alternative causes of the accident, it can only be said that no evidence has been brought forward. Other theories about collision, explosion and so forth can be suggested, but as regards fact there seems no definite evidence on which to start a different line of investigation based on such possibilities as some weakness in the condition of the ship herself, failure to obey orders, indications of collision, folboat exercise or similar lines.
The recommendations put forward hold good whether or not the Board’s theory is accepted since they arise from the effects consequent on the positive fact that the snort mast snapped off and the recommendations are confirmed to those in connection with the breaking of the snort mast and to other lessons which have been learnt in the course of the Inquiry.