Monitor pontoons for the proposed Great Landing

The Great Landing was meant to exploit an Allied advance at Passchendaele by putting troops ashore between Westende and Middelkerke, cutting off German troops as the land force advanced. Three 2,500-ton pontoons were planned, each able to carry an infantry brigade, an artillery battery, and three tanks. One pontoon would be lashed between two monitors, and Lord Clive and Sir John Moore were modified in March 1917 to handle one of them. The ships rehearsed until mid-July, but the Allied army never made the required ten-mile advance. Field Marshal Haig rejected Admiral Bacon's more limited September alternative, so the operation was cancelled. Even before enemy action, coupling two six-and-a-half-knot monitors around a loaded pontoon imposed a severe mobility penalty.