The panel riffs on using an R-class at St Nazaire and then describes the more serious British contingency for a German invasion. Older battleships positioned around the coast could run into a landing area, beach themselves if necessary, and become improvised fortresses. Their heavy guns, armor, and embarked Royal Marines could create a durable strongpoint even after the ship ceased to be maneuverable. The discussion links this logic to purpose-sunk breakwaters such as Centurion off Normandy and the earlier Hood at Portland Harbour.
Notable Point · 45:46-48:09
The emergency plan to turn R-class battleships into coastal fortresses
In an invasion emergency, an old battleship could be deliberately grounded to place heavy guns and Royal Marines directly inside a threatened landing area.