Guns, Mortars, and Howitzers

From Guns of the Regiment, by Doug Knight. (Ottawa: Service Publications, 2016). Reproduced with the kind permission of Service Publications and the Author.

Gunners refer to their equipment generically as “the guns”, but the weapons can be separated into four main types: guns, mortars, howitzers, and rockets. Each type has specific characteristics, although the exact definitions have been modified and refined over the years. The Regiment did not use rockets until the Second World War, and these will be discussed later.

The distance to which any weapon can fire its shot is controlled and limited by the size of the gunpowder charge and the angle above the ground that the barrel makes with the horizontal – the elevation. The maximum size of the charge is limited by the strength of the barrel, and physics and gravity dictate that the longest range for any given charge will be achieved at an elevation of about 45º. Increasing the elevation beyond 45º will actually result in a shorter range.

Historically, the most numerous type of artillery is the gun. It has a long barrel and uses a relatively large propellant charge that has a fixed weight and has a maximum elevation of less than 45°. This gives the projectile a high velocity on firing, and a gun will normally have a longer range than the other types. However, the fixed size of the charge means that the trajectory, or path, of the shot can only be changed by changing the elevation of the barrel. This creates a problem when trying to engage a target behind a hill or other obstacle. The height of the hill will create an area behind it that the gun cannot hit. Lowering the elevation of the gun to try and engage a target immediately behind the hill will result in the shell hitting the crest or forward slope instead.

A carronade was a special variant of smoothbore gun and was designed to fire a heavy shot to a short range. It was much lighter than a gun and used a much-reduced gunpowder charge. The intent was to have a light gun with a powerful punch that could be mounted in small ships, which could not carry heavy guns.

Another variant of the gun was the “shell gun”. Normal smoothbore guns were designed to fire solid iron shot. This relied on the kinetic energy of the impact in order to damage the target. The shell gun was designed to fire an explosive shell, which was lighter but used the chemical energy of the explosion to do damage. Shell guns were more lightly constructed than a normal gun and could not fire solid shot.

The second type of artillery is the mortar. It operates solely at elevations above 45°, which gives the weapon a very high trajectory, and its projectile, or bomb, comes down almost vertically. It has a very short barrel, and a relatively long time of flight, and is somewhat less accurate than a gun. It was used to lob shells over the walls into a fortress, but it could be used equally well from the fortress, firing into the entrenchments and saps of the besiegers. In contrast to a gun, an early smoothbore mortar was mounted to fire at a fixed elevation and varied its range and trajectory by adjusting the size of the gunpowder charge. It used a smaller charge than a gun, resulting in a lower range. This was balanced by being able to engage targets behind walls or other obstacles. Mortars fired explosive shells and could not fire solid shot.

A howitzer is a gun-mortar hybrid. It is capable of elevating from the horizontal to an elevation of more than 45°, although its maximum range will be achieved just below 45° elevation. Continuing to elevate the howitzer above 45˚ will result in a lower range. The howitzer uses a selection of charges, each of which produces a different basic trajectory, which can then be finely adjusted by changing the elevation. The largest charge gives the greatest range and the highest muzzle velocity and has a similar trajectory to a gun. The progressively smaller charges each have a shorter maximum range. However, by arranging the charges to have some overlap in range, the howitzer can engage most targets using two or more charges. The lower charge will need the howitzer to be elevated to a higher angle than the higher charge to achieve the same range. This allows the howitzer to act like a mortar and lob a shell over the crest of the hill or over the wall into the dead ground. However, the howitzer has a shorter barrel than a gun and, even at the maximum charge, will have a lower muzzle velocity than a gun, and therefore has a lower maximum range. Howitzers fired explosive shells. Prior to the First World War, guns and howitzers were separate, but complementary, equipments. After the war, the gun-howitzer was developed, which combined the better features of both systems.

Nomenclature and Measurements

Not surprisingly, artillery definitions have varied over the years. For the barrel, the terms “ordnance”, “equipment”, and “piece” have, more or less, the same meaning, and define the gun barrel with reducing degrees of formality. Originally, gun types were given names such as “culverin”, “demi-culverin”, and the like, but the British eventually standardized their terminology based on the characteristics of the gun. The basic identifier included the nominal weight of the solid shot that the gun fired, and the construction material and nominal weight of the gun barrel. The weight of the shot was measured in pounds, and a gun firing, for example, a ten-pound shot, was soon called a 10-pounder gun. An example of the complete description would be “a 68-pounder cast iron gun of 95-cwt” (cwt = “hundredweight” = 112 lb (50.8 kg)). In this case, the gun fired a 68-pound (30.8-kg) solid shot, and the barrel was constructed of cast iron and weighed 95 cwt (10, 640 lb or 4,826 kg). Smoothbore shell guns, mortars, and some howitzers could not fire solid shot, and were identified by the diameter of the bore (“calibre”) in inches and the weight of the gun, such as “a 10-inch cast iron shell gun of 87-cwt”. Note that the weight of shot and gun were nominal values, and that the manufacturing process was such that the actual weight could vary either side of the norm.

Surprisingly, it can be equally difficult to determine the exact number and location of modern guns. There are relative few reports that summarize the guns in service for the whole of Canada – many of the early reports are by military district, with not all the districts reporting, and they are usually contradictory. Very few of the museum pieces still have their gun history books. There are two excellent censuses of the all the guns in service in 1912 and 1933 that include the serial numbers of the guns and sometimes the carriages. These have been used as baselines for the locations of equipment at those times. There are problems, both in the readability of the surviving reports and in typing errors, but they serve as starting points.

Guns used by the Royal Canadian Artillery 1871-2016

The Smoothbores 1871 – 1895

  • Bronze 3-pounder 3-cwt Smoothbore Gun
  • Bronze 6-pounder 6-cwt Smoothbore Gun
  • Bronze 9-pounder 13½-cwt Smoothbore Gun
  • Bronze 12-pounder 18-cwt Smoothbore Gun
  • Cast Iron 12-pounder 34-cwt Smoothbore Gun
  • Cast Iron 18-pounder (38-cwt and 42-cwt) Smoothbore Guns
  • Cast Iron 24-pounder (20-cwt, 48-cwt, and 50-cwt) Smoothbore Guns
  • Cast Iron 32-pounder (32, 42, 45, 56, 58, and 63-cwt) Smoothbore Guns
  • Cast Iron 56-pounder 97-cwt or 98-cwt Smoothbore Gun
  • Cast Iron 68-pounder 95-cwt Smoothbore Gun
  • Cast Iron 8-inch (52/54-cwt and 65-cwt) Smoothbore Shell Guns
  • Cast Iron 12-pounder 6-cwt Carronade
  • Cast Iron 18-pounder 10-cwt Carronade
  • Cast Iron 24-pounder 13-cwt Carronade
  • Cast Iron 32-pounder 17-cwt Carronade
  • Cast Iron 68-pounder 36-cwt Carronade
  • Cast Iron 8-inch 9-cwt Smoothbore Mortar
  • Cast Iron 10-inch (16-cwt, 18-cwt, 47-cwt, and 52-cwt) Smoothbore Mortars
  • Cast Iron 13-inch 36-cwt Land Service Smoothbore Mortar
  • Bronze 12-pounder 6½-cwt Smoothbore Howitzer
  • Bronze 24-pounder 13-cwt Smoothbore Howitzer
  • Cast Iron 5½-inch (24-pounder) 15-cwt Smoothbore Howitzer
  • Cast Iron 8-inch 22-cwt Smoothbore Howitzer
  • The “Russian Guns”
  • The Ottawa Time Gun

The Armstrong Rifled Breech-loading Guns 1873 – 1895

  • Armstrong 6-pounder 3-cwt Rifled Breech-loading Gun
  • Armstrong 12-pounder 8-cwt Rifled Breech-loading Gun
  • Armstrong 20-pounder 16-cwt Rifled Breech-loading Gun
  • Armstrong 40-pounder 35-cwt Rifled Breech-loading Gun
  • Armstrong 7-inch 72-cwt (110-pounder) Rifled Breech-Loading Gun

The Rifled Muzzleloaders 1873 – 1895

  • 7-pounder 2-cwt Bronze and Steel Rifled Muzzleloading Guns
  • 9-pounder 8-cwt and 6-cwt Muzzleloading Rifles
  • 13-pounder 8-cwt Muzzleloading Rifle
  • The Rifled Muzzleloading Coast Defence Guns
  • 64- pounder 64-cwt Muzzleloading Rifle
  • 7-inch 6½-ton Muzzleloading Rifle
  • 7-inch 7-ton Mk I Muzzleloading Rifle
  • 8-inch 9-ton Muzzleloading Rifle
  • 9-inch 12-ton Mk II and Mk III Muzzleloading Rifle
  • 10-inch 18-ton Mk II Muzzleloading Rifle
  • 32/64-pounder 58-cwt Palliser-Converted Rifled Muzzleloading Gun
  • 64-pounder 71-cwt Palliser-Converted Rifled Muzzleloading Gun
  • 80-pounder 5-ton Palliser-Converted Rifled Muzzleloading Gun
  • 32/64-pounder 54-cwt Canadian Palliser-Converted Rifled Muzzleloading Gun
  • The Gatling Gun

The New Breech-loaders 1895 – 1905

  • 12-pounder 6-cwt BL Mk I & Mk IV Gun on Mk I* Field Carriage
  • 12-pounder 8-cwt QF Naval Landing Gun
  • 15-pounder 7-cwt BL Mk I Gun on Mk I and Mk I** Field Carriages
  • 4.7-inch QF Mk IV* “B” Gun on Mk I Travelling Carriage
  • 5-inch BL Mk I Howitzer on 5-inch Mk I Field Carriage
  • 6-inch 30-cwt BL Mk I and Mk 1* Howitzer on Mk I Carriage

The Early Twentieth Century and First World War 1900 – 1939

  • 1-pounder QF Mk I (Maxim) Gun on Mk I* Field Carriage
  • 13-pounder 6-cwt QF Mk I and Mk II Field Guns on Mk I Carriage
  • 18-pounder QF Mk I & II Field Guns on Mk I, IR, II, IIR, & IIPA Carriages
  • 4.5-inch QF Mk I and II Howitzers on Mk I Carriage
  • 60-pounder BL Mk I & II Guns on Mk I, II, III, & IV Carriages
  • 6-inch 26-cwt BL Mk I Howitzer on Mk I Travelling Carriage
  • 8-inch BL Mk VI and Mk VIII Howitzers on Mk VIIA Carriage
  • 9.2-inch BL Mk I Howitzer on Mk I Carriage
  • 2-inch Muzzleloading Trench Howitzer (The “Toffee Apple” Mortar)
  • 6-inch “Newton” Trench Mortar
  • 9.45-inch Mk I Trench Mortar

The Second World War 1939 – 1945

  • 75-mm French M1897 Field Gun
  • 75-mm American M1917 Field Gun
  • 75-mm American QF M1A1 Pack Howitzer on M8 Carriage
  • 95-mm Centaur Tank Howitzer
  • 25-pounder C Mk 2 and C Mk III QF Field Gun
  • 25-pounder Sexton C Mk 1, C Mk 2, and C Mk 3 Self-propelled Gun
  • 105-mm American M7 Priest Self-propelled Howitzer
  • 4.5-inch BL Mk II Gun on Mk I Carriage
  • 5.5-inch BL Mk III Gun on Mk I and II Carriage
  • 6-inch BL Mk XIX Gun on Mk VIII Carriage
  • 155-mm American M2 “Long Tom” Gun on M1 Carriage
  • 7.2-inch BL Mk I and Mk VI Howitzer on Mk I Carriage
  • 9.2-inch BL Mk X and Mk XIII Railway Gun on Mk III Carriage
  • 12-inch BL Howitzer
  • Projector, Rocket, 3-Inch, No. 8, Mk 1 – The Land Mattress

The Cold War, 1945 – 1990

  • 81-mm C3 Mortar
  • 4.2-inch British Smoothbore Mortar
  • 4.2-inch American M-30 Mortar
  • 105-mm C1 and C2 Howitzers
  • 105-mm L5 Pack Howitzer
  • 155-mm C1 (M1A2) Howitzer on M1A2 Carriage
  • 155-mm M109 Self-Propelled Howitzer
  • Honest John Rocket

The Modern Era, 1990 and Beyond

  • 105-mm C3 Howitzer
  • 105-mm LG1 C1 Mk II Light Gun
  • 155-mm M777 C1 Howitzer

Twentieth Century Coast Defence 1900 – 1950

  • 6-pounder 8-cwt QF Mk I “Hotchkiss” Gun
  • 6-pounder 10-cwt QF Mk I Gun on Mk I 6-pounder Twin Mounting
  • 12-pounder 12-cwt QF Mk I Gun on Mk I Garrison Carriage
  • 4-inch QF Mk V Naval Guns on “P” Mk X and Mk III High Angle Mountings
  • 4-inch QF Mk XVI* Gun on Mk XIX High Angle Twin Mounting
  • 4.7-inch QF Mk IV “B” Gun on Mk III Garrison Carriage
  • 6-inch BL Mk VI Gun on Mk IV Disappearing Garrison Carriage
  • 6-inch BL Mk “G” Gun on Mk II CP Garrison Carriage
  • 6-inch BL Mk VII Gun on Mk II(L) CP Garrison Mounting
  • 6-inch BL Mk VII* Gun on Mk V Mounting
  • 6-inch BL Mk 24 Gun on Mk V or Mk VI Mounting
  • 6-inch QF Mk I “B” and Mk II “B” Naval Guns on “P” Mountings
  • 6-inch BL Mk XII/N Naval Gun on “P” Mk VII* Mounting
  • 7.5-inch BL Mk “C” Gun on Mk “A” Barbette Carriage
  • 7.5-inch BL 45-calibre Mk VI Naval Gun on Mk V CP Mounting
  • 8-inch American M1888 Gun on M1918 Barbette Mounting on M1918 Railway Carriage
  • 9.2-inch BL Mk X Gun on Mk V, Mk CVIa, and Mk VII Barbette Mountings
  • 9.2-inch BL Mk XV Gun on Mk IX Barbette Mounting
  • 10-inch BL Mk I Gun on Mk I Barbette Garrison Carriage
  • 10-inch American M1888 Gun on Barbette or Disappearing Carriage

The Anti-Tank Guns 1939 – 1952

  • 2-pounder QF Mk X Anti-Tank Gun
  • 6-pounder 7-cwt, QF, Anti-Tank Gun
  • 17-pounder, QF, Towed Anti-Tank Gun
  • 17-pounder “Archer” Anti-Tank Gun on Valentine Tank Chassis
  • American Gun Motor Carriage M10 and M10C “Achilles”

Anti-Aircraft & Air Defence Guns and Missiles 1916 – Present

  • .50-calibre Colt Browning AA Machine Guns on M46 (Mk 22) Twin Mountings
  • 20-mm, QF, Polsten Machine Gun on Quadruple Anti-Aircraft Mounting
  • 35-mm Skyguard Anti-Aircraft Gun System
  • 40-mm Bofors Light Anti-Aircraft Gun
  • 13-pounder 9-cwt, QF, Mk I Anti-Aircraft Gun on Mk I Motor Lorry Mounting
  • 3-inch 20-cwt, QF, Mk I* Anti-aircraft Gun on Mk II Travelling Platform
  • 3.7-inch C Mk 2/2 Anti-aircraft Gun on Mountings, 3.7-inch AA C Mk 3 and 3A
  • 90-mm M1A1 Anti-Aircraft Gun
  • Blowpipe Very Short-Range Air Defence Missile System
  • Javelin Very Short-Range Air Defence Missile System
  • Oerlikon Air Defence Anti-Tank System (ADATS)

Surveillance & Target Acquisition Systems 1954 – Present

  • AN/MPQ/501 Counter Mortar Radar
  • CU-172 BLACKJACK Small Unmanned Aerial System (SUAS)
  • ELM-2084 Medium Range Radar
  • Q-49 Light Weight Counter Mortar Radar
  • CU-173 Raven B Miniature Unmanned Aerial System (Mini-MUAS)
  • Halo II Acoustic Weapon Location System