Churchill proposed a substantial naval squadron: three Revenge-class battleships, an aircraft carrier, five cruisers, two destroyer flotillas, submarines and supporting auxiliaries. The battleships would need to be significantly modified to resist air and submarine attack as well as pass through the shallow waters.
Royal Sovereign would have been fitted with very large bulges to her hull (making her 140 ft wide) to increase her buoyancy and so reduce her draught by 9 ft (2.7 m) even after the addition of 4 to 5 in (100 to 130 mm) of deck armour (some 2,000 tons of armour would be used in total). While only two of her main turrets would be retained, elevation for those guns would be 30 degrees. In this new state her top speed would have been about 13-14 knots in action.[2]
As well as cutting off German iron ore supplies, Churchill anticipated that this show of force would encourage the Scandinavian nations to join the war against Germany.