Devonport possessed several docks and a north lock suitable for earlier dreadnoughts, but their position between basins constrained access and enlargement. HMS Neptune measured about 166 metres, while HMS Hood grew to roughly 262 metres within less than a decade of procurement. Adding nearly 100 metres to the relevant docks would consume or obstruct the neighbouring basins. The inherited layout was the decisive obstacle because lengthening the docks would disable adjacent basin access.
Chapter · 35:27-40:51
Devonport's basins could not absorb rapid capital-ship growth
Devonport's interlocked basins show why the rapid increase from HMS Neptune to HMS Hood could require rebuilding an entire historic yard.