Why shipyard expansion depends on trained workers

Does maximum shipyard output depend more on the skilled workforce than on the number of slipways?

Yes. A yard needs trained workers to use its berths, and developing those skills takes longer than expanding the physical facilities.

A yard cannot use all its slipways without enough skilled workers. Training that workforce takes years, while enlarging or modifying the physical berths can be done more quickly. Compulsory purchase offers a way to obtain land for expansion where neighbouring buildings obstruct the work. Compensation can ease the opposition to acquiring that land, but it does not shorten the time needed to train shipyard workers.