in several expedient incendiary weapons. The only one fielded was the Grenade, No. 76 or Special Incendiary Phosphorus grenade, which consisted of a glass bottle filled with a mixture similar to Fenian fire, plus some latex. It came in two versions, one with a red cap intended to be thrown by hand, and a slightly stronger bottle with a green cap, intended to be launched from the Northover projector, a crude launcher using black powder as a propellant. These were improvised anti-tank weapons, hastily fielded in 1940 when the British were awaiting a potential German invasion after losing the bulk of their modern armaments in the Dunkirk evacuation. At the start of the Normandy campaign, 20% of American 81 mm mortar ammunition consisted of M57 point-detonating bursting smoke rounds using WP filler. At least five American Medal of Honor citations mention their recipients using M15 white phosphorus hand grenades to clear enemy positions, and in the 1944 liberation of Cherbourg alone, a single US mortar battalion, the 87th, fired 11,899 white phosphorus rounds into the city. The US Army and Marines used M2 and M328 WP shells in mortars. White phosphorus was widely used by Allied soldiers for breaking up German attacks and creating havoc among enemy troop concentrations during the latter part of the war. US Sherman tanks carried the M64, a 75mm white phosphorus round intended for screening and artillery spotting, but tank crews found it useful against German tanks such as the Panther that their APC ammunition could not penetrate at long range. Smoke from rounds fired directly at German tanks would be used to blind them, allowing the Shermans to close to a range where their armour-piercing rounds were effective. In addition, due to the turret ventilation systems sucking in fumes, German crews would sometimes be forced to abandon their vehicle: this proved particularly effective against inexperienced crews who, on seeing smoke inside the turret, would assume their tank had caught fire. Smoke was also used for "silhouetting" enemy vehicles, with rounds dropped behind them to produce a better contrast for gunnery. Later uses White phosphorus munitions were used extensively by US forces in Vietnam and by Russian forces in the First Chechen War and Second Chechen War. White phosphorus grenades were used by the US in Vietnam to destroy Viet Cong tunnel complexes as they would burn up all oxygen and suffocate the enemy soldiers