An official film from the Ministry of Supply provided by the Central Office of Information.
The test emplacement in which the engine firing is carried out under remote control, from a firing position a safe distance away. In the control room the safety link is inserted, without it the whole firing system is inoperative. An observer watches the bay where the firing will take place through a periscope. Pressurising the fuel and oxidant tanks. The firing officer receives the all-ready signal, starts the countdown and alerts all instrumentation points. Firing officer receives the all-ready signal, presses button firing the rocket engine. Engine is seen to ignite and build up thrust. Flame is deflected from the rocket "venturi" by a water cooled deflector plate into an outlet duct - steam can be seen rising from the duct and the haziness of chimneys in the distance is an indication of the heat intensity.