How to: Build a replica Cannon Part Four

Projectiles

In Parts One to Three of this "How to:" series we established the background to and how we went about building our scale replica cannon. In Part One we described the typical firing sequence and the equipment needed to service the gun. The one key element we have not discussed is what naval guns in the Age of Sail actually fired. So, in Part Four we explore the types of projectiles discharged from naval guns, their intended use, and how we attempted to recreate them.

Background  The earliest known European depiction of a cannon appeared in a manuscript by Walter de Milemete dated to AD 1326 [1]. The cannon is drawn loaded with a large arrow emerging from its muzzle. It seems, however, that these arrow-like projectiles were quickly replaced with round shot and grapeshot. Later more specialised projectiles were developed for use against personnel on the battlefield and at sea.

Fire arrows were, like their Mediæval predecessors, thick dartlike incendiary projectiles.  Their barbed points were wrapped with pitch-soaked canvas that ignited when the gun was fired.  The point stuck in sails, hulls, or spars and set fire to the enemy ship.

Round shot, also known as "solid shot", a "cannonball" or simply "ball", were solid spherical projectiles, without an explosive charge, fired from a gun.  The early versions were made from dressed stone but, by the 17th-century, cast iron was the preferred material.  Round shot was sized slightly less than the bore, the internal diameter, of the gun barrel.  They were the most accurate projectile that could be fired by a smooth-bore cannon and were used to batter the wooden hulls of opposing ships, forts, or fixed emplacements, or as a long-range anti-personnel weapon [2].

Heated (or hot) shot involved a solid iron ball being heated to red hot in a specially-designed wood- or coal-fired furnace.  The shot was carried from furnace to gun on a specially designed iron barrow or two-man litter.  In the era of black-powder charges contained in cloth bags, great care was taken when conveying the shot as the red-hot projectile would easily ignite any carelessly handled loose powder.  The heated shot was loaded into a muzzle-loading cannon, cushioned by a substantial thickness of water-soaked wads to prevent it from setting off the powder charge prematurely.  While still red hot, the ball was fired at flammable targets with the intention of setting them on fire.   This was a much advocated tactic (and many times a very successful one) for shore-based forts defending against attacks by wooden warships.  The hot shot lodging in a ship's dry timbers would set the ship afire.   Heated shot were seldom used aboard ships, however, because of the danger of fire.  Moreover, the eventual adoption of iron-hulled ships by most navies generally made these projectiles obsolete.

Chain shot (or Split shot) had two sub-calibre round shot (a good deal smaller than the bore of the barrel) linked by a length of chain.  They were used to slash through boarding netting, and the rigging and sails of an enemy ship so that it could no longer manoeuvre.  Chain shot was inaccurate, however, and only used at close range.   Variations of chain shot included:

●  Bar shot which, as its name implies, had two balls joined by a solid iron bar and was used to the same effect as chain shot.  Two-headed bullets (or "angels") were similarly constructed but made of two halves of a ball rather than two solid balls.

●  Expanding bar shot had the two shot connected by a telescoping bar that extended upon firing.

●  Spider shot is a chain shot, but it has many chains instead of just one.  It was not often used, despite its effectiveness against small ships.  Something similar was Link shot, a series of long chain links that unfolded and extended upon firing.

Canister shot was developed as an anti-personnel projectile that encased dozens of small iron round shot or lead musket balls in a canvas container or, later, a metal can that just fitted the bore of the gun.  When fired, the container burst open during passage through the bore or at the muzzle, scattering the shot throughout the enemy personnel, like a large shotgun.  Some artillery commanders used a technique of firing canister at the ground in front of advancing troops.  The effect was to bounce the canister shot into the formation and cause more injury.

The canister was made of iron galvanized with a coating of tin, with joints soldered together. A wooden disc, known as a "bottom", formed the canister base. This was probably made of end grain wood so that it would fragment on discharge.

Pre-filled with the correct size and weight of shot, the can was tacked onto the bottom with copper tacks. The bottom was partly inserted in the can leaving visible a deep groove cut into the wood. The propellant was contained in a flannel cartridge. The open mouth of the cartridge was choked (tied) on to the bottom with a cord which forced the material of the cartridge into the groove, so that it could not slip. The canister shot was then covered with cartridge paper or, in the early part of its period of use, with parchment, which was varnished, the varnish being later replaced by painting, because it was found to give better protection against rust. The image above shows canister shot from the US civil war period, much later than the Age of Sail, but it remains a good example of one way these projectiles were constructed.

At times when the supply of balls was limited, naval gunners might resort to Langrage, a type of irregularly shaped shot also known as "scrapshot". Nails, scrap iron or lead, wire, and other similar metal objects were packed into a case and fired at enemy ships to damage rigging and sails, and to maim or kill the crew. In 1718 Edward Teach, aka Blackbeard, armed his guns with a range of makeshift weaponry including langrage. Several of his cannons, still loaded with spikes and shot, have been recovered from the wreck site of his flagship, the Queen Anne's Revenge. According to an article in The Daily Telegraph (May 2011), archaeologists also retrieved conglomerations of lead shot, nails, spikes and glass from the site.

Grapeshot was another anti-personnel weapon, similar to canister shot, but with three or more layers of shot being contained in a canvas bag, and generally of a larger calibre. Grapeshot was so called because of its resemblance to a cluster of grapes on a vine. Some grapeshot was made with thin metal or wood disks between the layers, held together by a central bolt. The packages broke open when fired and the balls scattered with deadly effect. In one variation, the shot was held together by a coiled bar, and was spread by a fused charge in the same way as a shell.

Grapeshot was often used against the enemy quarterdeck to kill or injure the officers, or against enemy boarding parties. Grapeshot was also very effective against land-based infantry, although its range was rather short and it was largely ineffective against personnel protected by hardened cover. Canister and grapeshot were the starting point for the creation of shrapnel.

Spherical Case Shot (or "Shrapnel") was a thin-walled, hollow, iron anti-personnel projectile first developed in 1784. The interior cavity was packed with lead or iron round balls around a small bursting charge of just enough force to break open the case. A powder train in a thin iron sleeve led to a time fuse inserted into a holder at the outer edge of the projectile. The fuse was designed to be ignited by flame from the propellant charge. Ideally the case shot fuse would detonate the central bursting charge when the projectile was six to ten feet above the heads of the enemy showering them with the iron balls and fragments of the casing. The popular name "shrapnel" comes from the case shot's inventor Lt. Henry Shrapnel of the Royal Artillery.

Exploding shells worked like a grenade, exploding and sending shrapnel everywhere. The hollow iron shot was packed with a high explosive bursting charge of powder (but no small round shot or musket balls). The charge was ignited either by a burning fuse cut to a calculated length depending on the range, or (after 1861) on contact with the target using an impact fuse.

And finally, there was Double shot. As the name suggests, two round shot or other projectiles were loaded in one gun and fired at the same time. Double-shotting lowered the effective range and accuracy of the gun, but could be devastating within pistol shot range[3]; that is, when ships drew close enough for a pistol shot to reach between the two ships. To avoid bursting the gun, reduced powder charges were used. Guns sometimes were double-shotted with canister or grape on top of ball, or even triple-shotted with very small powder charges which still were enough to cause horrible wounds at close range.

The Replicas

Round shot  Cast iron round shot can still be found in antiques and collectibles shops. We have a nine pounder and a selection of pistol and musket balls for artefact handling in our history workshops. However, for the purposes of practising gun drills with our replica cannon, we purchased 100 mm diameter (Ø) polystyrene balls from an art and craft supplier. These "shot" were sealed with a 50/50 solution of water and PVA glue before being spray painted to look like cast iron [4].

Chain shot  To recreate Chain shot, two 100 mm Ø polystyrene balls were glued at either end of a 320 mm long chain. Metal staples similarly glued into each ball were used to secure the connecting chain. As before, the resulting Chain shot projectile was sealed with PVA glue before being spray painted black to look like cast iron.

By replacing the plastic chain with a 230 mm long, 15 mm Ø, PE-X (cross-linked polyethylene) pipe produced a replica Bar shot. The "bar" can be longer or shorter depending on the overall scale of the replica gun, Each end of the connecting "bar" was recessed 15 mm into each "shot" and glued in place.

By cutting a single polystyrene ball in half and gluing one half to either end of PE-X pipe, then a type of Bar shot known as Two-headed bullets (or "angels") can be made.

Canister shot  To recreate canister shot, a large 500 g drinking chocolate can was glued to a 95 mm Ø plywood disc. A canvas disc was cut out slightly larger than the can; a 10 mm hem is more than sufficient. Allowing for a 10 mm hem, a strip of canvas sufficient to wrap round the can was cut to size. A width of about 40 - 50 mm allows for a hem to which the canvas disc was sewn, plus extra material that can be gathered together and tied.

A second version was made to reveal what went into Canister shot: musket balls and sawdust, the latter used to tamp the projectiles firmly in place. The "musket balls" were 10 mm Ø unvarnished wooden beads commonly used to make jewellery. Each bead had a hole through its centre for threading onto a string. Each hole was therefore stoppered with wood filler before the beads were sprayed painted a grey colour to imitate musket balls.

Rather than fill it with hundreds of beads, however, we decided to insert a false bottom into the can. By so doing, fewer beads were needed which, when combined with homemade sawdust, created the desired effect for display purposes.

Grapeshot  From the image of actual grapeshot shown above, the solid iron balls are clustered round a central spine set into a circular base. So, to recreate grapeshot, a wooden dowel (15 mm Ø, 150 mm long) was glued perpendicular to, and centred on a 100 mm Ø plywood disc. Small polystyrene balls, approximately 40 mm Ø, were sprayed to look like cast iron and glued around the dowel.

Two versions were made: one with and one without a canvas bag cover. As with original examples, the canvas bag was bound with jute rope, which would have acted to hold the balls in place.

Next...  In describing the typical firing drills in Part One, a number of pieces of equipment were needed for the crew to serve the gun. In Part Five, therefore, we explore how to recreate the gunners' equipment.

Notes:

1.  De Nobilitatibus, sapientii et prudentiis regum (Concerning the Majesty, Wisdom, and Prudence of Kings).
2.  A bouncing round shot, skipping across the ground and ploughing into the massed ranks of 18th or 19th-century infantry caused multiple casualties.
3.  Some flintlock pistols had effective ranges of a few yards, while others may be reliably effective out to 20+ metres.
4.  Spray painting directly onto the polystyrene ball caused the material to dissolve and dimple. It was suspected that the chemical composition of the paint had caused the deformation. Subsequently, each polystyrene ball was coated with a 50/50 solution of water and PVA glue before being painted once the wash had hardened.