This vehicle takes its name from the inventor, Mr Robert Gladstone of Liverpool, who made several innovations in protecting the police from violent attack. In about 1914 he developed a steel hand-shield to ward off bricks and similar missiles, a fore-runner of the plastic shields used today to counter mob attacks.
By 1929 he had developed this bullet proof shield to combat the increasing use of firearms in criminal activities. A rubber wheeled truck was fitted with an armoured steel shield and wheeled into position by two constables sheltering behind it. The armour was said to stop a bullet from a service revolver at five yards (4.75m), although this was not guaranteed by the manufacturer. Narrow eye-slits for vision were provided and an aperture for a revolver could be opened to allow the police to return fire. In service, a sledgehammer and crowbar were carried on the truck to break through barricaded doors. As the shield was rather top-heavy the upper part folded down for travel when not under fire.