Small-tube boilers were technically possible when Jellicoe considered machinery for the Queen Elizabeth class, but they had not accumulated enough testing to be judged viable. As Third Sea Lord, he could ask what machinery was ready but lacked discretionary money to commission the missing trials. The counterfactual gives him the option of paying for a batch of boilers and demanding results within the design timetable. An illustrative schedule allows two months to build them and another two months to test them, making a decision after four months conceivable. A private firm would be more likely to run a few boilers over a longer period because it would carry the loss if the trials failed.
Notable Point · 39:14-42:11
Jellicoe's boiler decision and the cost of proving machinery
Discretionary funding could let Jellicoe commission the missing small-tube boiler trials before the Queen Elizabeth machinery decision.