The Consol Portable Shelter was manufactured by Constructors Ltd at their Nickel Works, Erdington, Birmingham. It was constructed of bullet-proof steel plate and could provide protection against splinters, shrapnel (sic), falling masonry and glass etc. It was fully portable with a strong 'eye' for lifting purposes. It was supplied in three sizes for one, two or four men. Diameter 3ft (1 man), 4ft (2 men) and or 4ft 9in (4-men). Weight, 9 cwt, 10 cwt and 14 cwt. Although not used on the operational RAF stations, they were used at the aircraft factories. I remember seeing one at Radlet and others at Leavesden and Hatfield where they had been used at night for observing incendiary devices being installed on the factory roof.
Picture below from the company catalogue - now in the archives