Following the Korean War, complaints started to be received about the liner of the Mk 4 helmet (see here). Soldiers complained that the liner and shell span around each other due to the central lift the dot fastener. As the helmet was used, the rubber shrunk slightly, losing its grip on the helmet shell so if the soldier turned his head suddenly and then stopped, the helmet shell carried on spinning independently! A new liner was designed and introduced in 1956 and the ‘Mk 5’ helmet was created:Technically the term ‘Mk 5’ was never an official designation, the helmet remaining a ‘Mk 4’ with an upgraded liner. However the nomenclature seems to have been universal enough that when the steel helmet was replaced, the army called the new ballistic nylon helmet the ‘Mk 6’. The steel shell of the helmet is identical to the earlier Mk 4 and Mk III helmets, but a new liner with foam padding and a knitted nylon stockinet liner improved comfort:The Mk 5 liner, the name adopted in 1959, was held securely by a series of rubber pads:The same simple elasticated chin strap was retained:This example is in typical cold war condition, painted a matt mid green with a helmet net and nylon fabric scrim:A number of accessories were developed for the helmet, including a torch which clipped onto the rim and was powered by a separate battery pack and a riot shield for use in Northern Ireland. The helmet liner was generally well regarded as being comfortable, indeed having tried this one I have found it far more comfortable than the later Mk 6 I was issued in the RNR, but there was a danger of overheating in warmer climates that was never satisfactorily resolved. This was the last steel helmet to be used by the British Army and had a long service life, not being phased out until the late 1980s.