RML 8 inch howitzer

RML 8 inch howitzer
RML 8 inch 46 cwt howitzer diagram, pub. 1879 (HMSO)
Type	Howitzer
Place of origin	United Kingdom
Service history
In service	1872 - 1902
Used by	British Empire
Production history
Designer	Woolwich Arsenal
Manufacturer	Woolwich Arsenal
Variants	46 cwt Mark I and II 70 cwt Mark I and II
Specifications
Weight	46-long-hundredweight (2,300 kg)
Crew	9
Shell	180 pounds (82 kg) (common shell) 180 pounds (82 kg) (shrapnel)
Calibre	8 inches (203.2 mm)
Action	RML
Breech	none – muzzle-loading
Muzzle velocity	1,330 feet per second (405 m/s)
Effective firing range	3,500 yards (3,200 m)

The RML 8 inch howitzer was a British Rifled, Muzzle Loading (RML) Howitzer manufactured in England in the 19th century, which fired a projectile weighing approximately 180 pounds (82 kg). It was used in siege batteries and in fortifications.

The gun consisted of an 'A' tube of toughened steel, over which was shrunk a 'B' tube of wrought iron and jacket. A cascable was fitted at the end.

The original 46 cwt howitzer was rifled on the "Woolwich" pattern with 4 spiral grooves in which studs protruding from the projectile engaged to impart spin; the later 70 cwt howitzer was rifled on the "Polygroove" pattern with 24 grooves and projectiles had "Automatic gas-checks" attached to the base which engaged the grooves.

Three planes were machined on the upper surface of the Howitzer, for use with quadrants enabling it to be elevated to 30 degrees. This enabled the gun to be sighted for indirect, or direct fire.

46- and 70 cwt guns differed in number and type of rifling grooves so studded projectiles were only available for 46 cwt guns, and different automatic gas checks were required for studless projectiles.

Guns were fired using a silk bag containing a black powder propellant. They used three types of ammunition – Common shell (for use against buildings or fortifications), shrapnel shell (for use any Infantry or Cavalry) and case shot (for close range use against 'soft' targets). Ignition was through a copper lined vent at the breech end of the gun. A copper friction tube would be inserted and a lanyard attached. When the lanyard was pulled the tube would ignite, firing the gun. A number of different fuzes could be used enabling shells to either burst at a pre-determined time (and range), or on impact. A typical rate of fire was one round per minute.

The Howitzer was normally deployed in batteries of four guns. Each gun was pulled by a team of elephants. It had a crew of nine men. In addition to each gun, a limbered ammunition trailer was also deployed with each gun.

Rifled Muzzle Loading howitzers were selected by the Royal Artillery in the 1870s to replace obsolete smooth bore Mortars and howitzers, as they had great range and accuracy. They were only semi-mobile and were used by Garrison batteries of the Royal Artillery in India, drawn by elephants, or kept in fixed emplacements or fortifications. For example by the 1890s Fort Widley had two howitzers on travelling siege carriages that could be moved to wherever they were needed.