Anti-tank blocks
Usworth (HER 5851),The most common anti-tank blocks were concrete cubes, with sides of either 3 feet 6 inches or 5 feet. Other designs included “coffins”, pyramidal “pimples” and cylinders. They were designed to stop the progress of a tank, often in conjunction with pillboxes, traps, or other defences, so that the stationary tank was in the field of fire of antitank weapons. Should that tank attempt to mount the obstacle, it would expose the unarmoured underside of the chassis (Lowry 1996, 85-7)
West Boldon (HER 5850)
Site of WW2 concrete roadblock. In vicinity of Addison Road. Stop-lines included permanent and moveable road barriers. The most substantial works were formed from square or cylindrical concrete blocks entwined with barbed wire and fitted with explosives. Moveable obstacles consisted of horizontal or vertical bars or poles of steel, set between concrete blocks. Bent steel girders could also be slotted into sockets cut into the road surface. Modern road improvements are removing evidence for both, but some of the original blocks or aperatures have been observed in-situ. Cylindrical blocks have been used to line private roads or placed on river banks to combat erosion {Defence of Britain Handbook 1995}.
From this RAF picture taken in 1946 (Reproduced by permission of Historic England Archive) to the top left of the cross roads which would be the junction of Addison and Hylton road, what could be possibly seen is some concrete foundations. Is this the afore mentioned checkpoint or maybe the location of a pillbox/defence as described as being near here in another source. It is certainly an important defensive position being on the main Sunderland to Newcastle Road. The site was later occupied by Bank top Garage and associated bungalow and now a new housing development.
Grid Reference:NZ352610
Spigot Mortar Emplacements
29mm Spigot Mortars, also known as “Blacker Bombards”, only started to be introduced into defensive planning in the summer of 1941. Before this time, antiinvasion measures had been based around static lines of pillboxes. Even as early as 1941 many had questioned the utility of such inflexible defences. In February 1942 Home Forces declared that recent experience ‘points most strongly to the fact that the pillbox is not a suitable type of fortification for either coastal or nodal point defence’. The new defensive arrangement focused much more on earthworks and more flexible defences than on conventional fortifications. The Spigot Mortar fitted into this system perfectly. These mortars were very simple devices, and were issued to the Home Guard to use against enemy vehicles. They were set up in 4ft deep dug-outs, with a ‘pedestal mounting’ - a large concrete pillar with a steel pin in the top, to which the mortar could be attached. Each mortar would be issued with four kits for making emplacements, meaning that four alternate positions could be provided for each weapon, giving much more flexibility of deployment than under previous defence arrangements. These mortars were given priority in coastal regions, but were also often placed near bridges and road junctions, and wherever an ambush would be most effective.