How Britain could scale dry docks for larger warships

How large could British dry docks become if the country needed much bigger ships?

As large as Britain was willing to finance, with Mersey expansion offering a plausible site for very large facilities.

Physical size was not the decisive British constraint because sufficiently large docks could be built if government and industry paid for them. Proposals associated with Cammell Laird would extend facilities into the Mersey, including docks capable of opening at both ends. Such infrastructure could support much larger ships during the Second World War. Capital-ship ambition depended on financing yards, docks, and waterfront engineering first.