Ordnance QF 25-pdr on Carrier Valentine 25-pdr Mk 1, Bishop
Design and service history:
The Bishop SPG, more formally known as the Ordnance QF 25-pdr on Carrier Valentine 25-pdr Mk 1, was a British Self-Propelled Gun, based on the Valentine tank, which was armed with the ubiquitous QF 25-pounder gun-howitzer. The vehicle was a rushed attempt to create a self-propelled gun that could keep up with the mobile warfare found in the North Africa campaign. This hasty development resulted in a design with numerous problems, resulting in the Biship being produced in only limited numbers before it was replaced by better designs like the Priest and Sexton.
The rapid manoeuvre warfare that developed in the North African Campaign necessitated self-propelled guns, so it was inevitable that an artillery vehicle equipt with the 25-pounder gun-howitzer would be developed, as the 25-pounder was the standard howitzer in service at the time. The Birmingham Railway Carriage and Wagon Company was given the requirement for designing a self-propelled vehicle carrying the 25-pounder in June of 1941, and they produced a prototype based on the already existing Valentine MK II which was ready for trials by August and based on these sufficient results 100 of the vehicles were ordered by November of 1941.
The design of the vehicle was that of a Valentine II hull, with the turret replaced by a large fixed box shaped super structure with rear doors, which earned it the nickname Bishop due to the Mitre-like appearance of the superstructure. The 25-pounder howitzer was then fitted in this superstructure, creating a vehicle with a very high silhouette, which would be disadvantageous in a desert warzone. This design also limited the maximum elevation for the gun to 15 degrees, reducing the range of the gun to only 6,400 yards (5,900 m), which was about half the range of the same gun on a wheeled carriage. To get around this crews would build large earthen ramps, and drive the Bishops onto them, in order to tilt the vehicle backwards and increase the elevation. The depression of the gun was 5 degrees, which had a traverse of 8 degrees and was supplemented by a Bren gun for infantry and anti-air defence.
By July of 1942, 80 Bishops had been produced with the final 20 under construction. Their service showed them as fit for purpose if not ideal, but even so an order for a further 50 was placed with a further 200 on tender, but this was soon abandoned in favour of the American 105 mm Howitzer Motor Carriage M7, which was now being provided under lend-lease. This did not prevent the Bishop from first seeing action in the Second Battle of El Alamein in North Africa, from which point they remained in service until the early part of the Italian Campaign, though its limitations such as slow speed made them poorly received by the troops. The Bishop would ultimately be replaced by the M7 Priest (105 mm) and Sexton (25-pounder) when those became available in sufficient numbers. Surviving Bishops were then diverted to training in self-propelled gun tactics, and a group of 488 were sold to Turkey in 1943.
Mass 17.5 t (38,580 lb)
Length 18 ft 6 in (5.64 m)
Width 9 ft 1 in (2.77 m)
Height 10 ft (3.0 m)
Crew 4 (Commander, gunner, loader, driver)
Elevation -5° to +15°
Armour hull: 0.31–2.36 in (8-60 mm)
superstructure: 0.51–2 in (13–51 mm)
Main armament QF 25 pounder gun-howitzer with 32 rounds
Secondary armament 0.303 inch Bren light machine gun
Engine AEC A190 diesel 131 hp (98 kW)
Power/weight 7.4 hp/tonne
Suspension coil sprung three-wheel bogies
Operational range 90 mi (145 km)
Maximum speed 15 mph (24 km/h)
Additional historical photos:
- Bishop (artillery) - Wikipedia (Wiki page for Bishop)
- QF, 25 Pdr, self propelled gun, Bishop (1940) (additional history)
- Bishop | Weaponsystems.net (Additional specification)
- Bishop Artillery in the desert | A Military Photos & Video Website (Additonal historical photos)