Fitting accommodation, subdivision, landing-craft capacity, weapons, and magazines required more than improvised wartime enthusiasm. Before conversion, officers also had to identify a suitable hull, verify its plans, calculate stability, and secure approval through the Sea Lords. Spending and requisition then required Treasury and possibly Cabinet authorization before a yard could begin the physical work. This chain could not credibly begin from nothing and deliver an operationally useful conversion within four months. Ready designs and preselected commercial hulls are therefore the likelier explanation, perhaps with Japanese amphibious operations in China helping advocates justify plans they already wanted.
Chapter · 15:35-18:45
What a four-month conversion implies about prior planning
The scale of the conversion and the normal approval chain suggest that plans and suitable hulls had been identified well before the ships entered naval service.