155 mm Creusot Long Tom

155 mm Creusot Long Tom
Long Tom being loaded during the siege of Mafeking
Type	siege gun
Place of origin	France
Service history
In service	1897 to 1901
Used by	Zuid-Afrikaaansche Republiek
Wars	Second Boer War
Production history
Designer	Probably De Bange
Designed	1876
Manufacturer	Schneider et Cie, Le Creusot, France
Specifications
Weight	6,500 kilograms (14,300 lb)
Length	7.5 metres (25 ft)
Barrel length	4.2 metres (14 ft)
Crew	Commander (warrant officer and six gunners
Shell	94 pounds (43 kg)
Caliber	155 millimetres (15.5 cm)
Barrels	1
Action	breech loader
Elevation	-13° to 28°
Traverse	None
Rate of fire	20 rounds per hour
Muzzle velocity	480 m/s
Effective firing range	9,000 metres (30,000 ft)
Maximum firing range	9,880 metres (32,410 ft)
Sights	Tangent sight and quadrant

The 155 mm Creusot Long Tom was a French siege gun (artillery piece) manufactured by Schneider et Cie in Le Creusot, France and used by the Boers in the Second Boer War as field guns.

Four guns, along with 4,000 common shells, 4,000 shrapnel shells and 800 case shot were purchased by the South African Republic (informally known as the Transvaal) in 1897. The guns were emplaced in four forts around the country's capital, Pretoria.

The Long Tom gun consisted of a barrel and a separate carriage (trail). The barrel was 4,2 metres long and weighed 2,500 kg (49 cwt). The carriage weighed 3,000 kg (59 cwt).

The gun was placed on a wooden platform, consisting of three layers of beams (deals) each measuring 7,5 cm by 7,5 cm by 4,5 m. The size of the platform was 4,5 m by 4,5 m by 22,5 cm. The layers were placed at right angles to one another. The platform weighed 5,200 kg. The platform had to be placed level in all directions to ensure that the range did not change when the gun pointed in a different direction. Near the "front" of the platform a pivot plate was securely attached to the platform. Recoil was controlled by a hydraulic cylinder which connected the trail to the pivot plate. Chocks were also placed behind the wheels to limit recoil.

To prepare the gun for transport a large tripod was placed over it and, using a block and tackle, the barrel lifted off the front trunnion cups and moved to the back trunnion cups. The trail was then placed on a limber. 16 to 20 oxen were required to pull the gun over hard soil. Two wagons were required to transport the platform and the ammunition was transported on another two wagons.

The propellant charge for the Long Tom was carried in a canvas bag which was about 56 cm long. Black powder was used and this caused a large cloud of white smoke when the gun was fired. The enemy immediately knew where the gun was.

The common shell was 42 cm long and weighed 43 kg (94 lb.) It was filled with an explosive called MC 30. The range was 9,880 m.

This shell weighed 41 kg and had a range of 6,800 m. It had a combination percussion cap and time fuse. During the first part of the war the time fuses did not work properly.

Case shot was used as a last resort when the enemy's foot soldiers were close to the gun. Case shot was effective up to 400 metres.