Pontoon bridge transport soldiers and artillery across rivers in the South. In 1872 at a military review before Queen Victoria, a pontoon bridge was thrown across the River Thames at Windsor, Berkshire, where the river was wide. The bridge, comprising 15 pontoons held by 14 anchors, was completed in 22 minutes and then used to move five battalions of troops across the river. It was removed in 34 minutes the next day. The British Blanshard Pontoon stayed in British use until the late 1870s, when it was replaced by the "Blood Pontoon". The Blood Pontoon returned to the open boat system, which
Pontoon effect Pontoon effect The pontoon effect refers to the tendency of a vessel whose flotation depends on lateral pontoons to capsize without warning when a lateral force is applied. The effect can be sudden and dramatic because pontoon boats usually cannot rely on the righting effect of a keel (which contains ballast). The vessel is stable and self-righting up to the point that the centre of gravity shifts past the centre of buoyancy of the ship and the vessel rapidly capsizes. The pontoon effect is theoretically possible whenever the vessel's entire weight exceeds the buoyancy of the pontoon(s) on either side.