The Type 1942's proposed three-shaft diesel plant concentrated much of its machinery instead of distributing it evenly. Each outer shaft was to receive one directly coupled engine, but both engines occupied the same machinery room. Four 24-cylinder diesels arranged in pairs, with two Vulcan transmissions, drove the centre shaft. The Vulcan transmission was considered fairly reliable by this stage, so the objection concerns the arrangement rather than a demonstrated transmission failure. Two engines per shaft would have balanced the load more evenly in the preferred alternative. Separating the outer-shaft engines would also have avoided placing both in one room. The concern is that concentrated machinery and power could leave the ship vulnerable to damage or mechanical trouble.
Notable Point · 25:52-29:47
The Type 1942's diesel layout concentrated machinery risk
The proposed three-shaft plant put both outer-shaft engines in one machinery room and four engines plus two transmissions on the centre shaft, creating concentrated points of failure.