Martin Baker Ejector Seats Plate

Martin Baker have been making ejector seats for jet fighters since the dawn of the jet age in the late 1940s. Ejector seats had first been developed in the 1920s, but it was the ever increasing speeds of fighter jets that made them essential safety devices. Previously it was possible for someone to fall free of an aircraft to escape in an emergency. Jets travelled too fast for this and so it was necessary for an escaping airman to be propelled clear of the aircraft before a parachute deployed. Today we are looking at a commemorative plate issued by the Martin Baker company:

The design of the plate is an unusual teardrop shape and at one end is a picture of an ejector seat, the company name and the Queen’s Award for Industry dated 1966 and 1967 which dates this plate to 1967:

The back of the plate gives some context to this souvenir piece:

Martin-Baker investigated ejection seats from 1934 onwards, several years before Germany and Sweden proposed similar systems in 1938. The company concluded that an explosive-powered ejection seat was the best solution. In particular, Baker’s death in 1942 during a test flight of the MB 3 affected Martin so much that pilot safety became his primary focus and led to the later reorganisation of the company to focus primarily on ejection seats.

In 1944, James Martin was asked by the Ministry of Aircraft Production to develop methods for fighter pilots to escape their aircraft. Martin decided that the best method involved ejection of the seat with the occupant sitting in it, aided by an explosive charge. After ejection, the pilot would separate from the seat and open his parachute by pulling a ripcord in the usual way.

At that time there was little information on how much upward thrust the human body could withstand. Data relating to “g” forces in catapult launching of aircraft involved horizontal thrust and was therefore inapplicable to the new problem. Tests would have to be conducted to find out how much upward “g” force a person could tolerate. These were done by shooting a seat up a near-vertical path, loading the seat to represent the weight of the occupant, and measuring the accelerations involved.

A 16-foot (5-metre) test rig was built in the form of a tripod, one of the legs being in the form of guide rails. The seat was propelled up the guide rails by a gun, consisting of two telescopic tubes energised by an explosive cartridge. The guide rails were provided with ratchet stops every three inches (75 mm), so that the seat was automatically arrested at the top of its travel.

Studies were conducted to find the limits of upward acceleration that the human body could stand. The first dummy shot with the seat loaded to 200lb was made on 20 January 1945, and four days later one of the company’s experimental fitters, Bernard Lynch, undertook the first “live” ride, being shot up the rig to a height of 4 feet 8 inches. In three further tests, the power of the cartridge was progressively increased until a height of 10 feet was reached, at which stage Lynch reported the onset of considerable physical discomfort. The first seat was successfully live-tested by Lynch on 24 July 1946, who ejected from a Gloster Meteor travelling at 320 miles per hour (510 km/h) IAS at 8,000 feet (2,400 m) over Chalgrove Airfield in Oxfordshire. The first production Martin-Baker ejection seat, a ‘Pre-Mk 1’, was installed in the Saunders-Roe SR.A/1 prototype and the first use of an ejection seat in a practical application by a British pilot involved the Armstrong Whitworth A.W.52 flying wing experimental aircraft in May 1949.

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