Hood needed a global network of longer dry docks

How could Britain build HMS Hood but lack the infrastructure to support ships of her size worldwide?

A few bases could handle one Hood, but Britain lacked enough long dry docks across its global network to support a class of equally large ships.

Britain had dry docks in home and Mediterranean waters able to support Hood, but the network lacked enough long docks across the empire for a squadron of similar ships. Enlarging an individual facility could take only months and need not breach naval treaties, because a dock is infrastructure rather than a warship. Building long passenger liners for the Australia route could also provide a legitimate commercial reason for the same dockyard expansion.