Making a Cannon

By Jonathan Davies

“Tell them, whatever you do, don’t try and make a cannon.” That is the polite version of what my son said to me when I told him I was writing this blog. The project has taken twice as long and cost twice as much as I thought but it has also been fascinating and produced something beautiful and permanent. The following should still be considered a warning rather than an encouragement.

The project was the consequence of my retirement and a small windfall. I had led a re-enactment group for almost 20 years and had decided to carry on but on a much smaller scale. The focal point of the new ‘gun company’ was to be a cast bronze cannon from the reign of Henry VIII. This was a period of history where there are currently few re-enactment groups and plenty of excellent venues.

The Barrel

With limited funds we decided that it was far better to produce an accurate version of a smaller gun rather than a poor copy of a larger. Only major national museums, such as the Royal Armouries in the UK and the Vasa museum in Sweden could afford to produce large pieces of bronze ordnance. A steel barrel inserted into a fibreglass shell, although economical and practical, did not appeal to our sense of authenticity.

On simple grounds of cost and practicality the gun could only be a falconet, one of the smallest contemporary guns. The first gun we investigated was in the Musee de l’Armee. It was octagonal in form, some 1.06m long weighing 25.4kgs. Its shape, proportions and date, (ca1510), would suit our plans but we hoped to find a rather larger gun. The search led us to two bronze falcons held in the collection of the Royal Armouries, at the Tower of London and Fort Nelson. Both were early guns of octagonal form. With the approval of the Royal Armouries staff we made detailed measurements and drawings of both guns.

Comparison of key proportions of comparable faceted falcons and falconets.

FalconCa 1500Ft NelsonGenoa63mm2.54m40
Falcon1520Ft NelsonGenoese66mm3.05m46
FalconetCa 1526GlasgowScottish54mm1.71m32
An early 16th century Genoese falconet had a diameter of 46-47mm (1.8in) and would use a ball weighing one Italian libra. The later English falconets had a bore of two inches (51mm).

It was the falcon in Fort Nelson xix-14 which particularly took our fancy. The heraldry would suggest that it was cast prior to 1503. Renato Ridella suggests that the letter G, cast around the touch hole was the initial of the Genoese gun founder Gregorio I Gioardi, who died in 1518. Our gun would for obvious reasons have a cast D, in carefully researched Lombardic script. It would also have two shields on the facets as did the original. The cross of St George was used by Genoa and it seemed appropriate for us as well. My son was able to produce a falconet version of the design conforming to contemporary proportions.

The process of casting required the making of a precise two-part pattern. The mould would be horizontal but slightly tilted to ensure a free flow of metal into all corners of the mould. Ben Shutt a young pattern-maker was responsible for making the wooden pattern and a local foundry took on the responsibility for casting. The first gun was cast at 1.15pm on 1 February 2019 by a well-drilled group of seven men, the whole process taking little more than two minutes. Unfortunately, it soon became apparent that the core had slipped and that the thickness of metal at the breech was in no way uniform. This was a common contemporary problem even in a gun cast vertically. The gun was unsafe and could not be proceeded with. It was therefore back to the factory for the gun to be recast. With a new gun it was now down to a firm in Leighton Buzzard to drill a perfect bore.

The gun was cast with additional material around the trunnions in order to avoid cracking during casting. The facets of the gun, the heraldry and the mouldings all required considerable fettling, using files and cold chisels to produce the correct finish. It was important to avoid using modern tools as we wanted to replicate the original finish. Several visits to the Fort Nelson falcon and detailed photographs enabled us to establish exactly what the finish on the gun should be. Hundreds of hours have now been expended in this fettling process but the result is a beautiful gun.

This work revealed numerous small flaws, especially on the upper surface. Two small holes, filled with a sand/bronze mix were found, one near the touch hole and the other on the breech moulding. We decided that before proofing we should investigate the integrity of the barrel using X-rays. There were no voids in the casting, there were a few patches where the density of material varied. The horizontal casting was bound to produce such issues.

Proofing the gun presented significant problems. The Birmingham Proof House were unable to proof such a long-barrelled gun on its Birmingham site. Now for our very own Catch 22. You can’t hire a field to proof a gun without insurance and you can’t get insurance until your gun is proofed! Fortunately, I had a friend who owned a large field just south of Bristol. This is where the gun was eventually proofed, by two Proof House technicians, on what was one of the wettest days of the year. It did make a lovely bang. Result!

All this could only have been achieved with the commitment and hard work of Tom and Tim as well as the arcane skills of manufacturing firms both old and new.

The Fort nelson Falcon is in the centre of this photo. As you can see it is a very fine form without the reinforcements that will appear later. The polygonal design is associated with early cannons from c. 1500-1560, cast in France, Flanders, England and Italy.
Tom’s 3D version of the falconet using contemporary proportions and shape to produce a beautifully elegant design. His detailed engineering drawings were essential for the pattern maker to produce a precise model.
The pattern was very, very big. It was so precisely made that there was virtually no visible ‘seam’ when it was cast.
The gun was cast horizontally in sand. The mould was held together with a large number of heavy weights. Some 120kgs of bronze was poured of which over 80kgs constituted the cannon itself. It was an exciting and tense moment for everyone.
The gun as it came out of the foundry after the removal of the waste from the casting. The exterior was still very rough and required hundreds of hours of work by Tim and Tom.
The proofing was not an administrative technicality but a real test of all the work up to that point. It used a 4oz. proofing charge. I would have liked to have fired a few more rounds but the weather precluded it.
Not the final state of the barrel but most of the hard work has been done to clean up the casting, the mouldings and heraldry. Contemporary paintings show the barrels in their true colour, which contrasts with the muted greens of museum examples. In bright sunshine the barrel shines like a mirror!