Making Ship Gun Carriages
By Don Howe (Navarone)

I was building my model, the Enterprise of 1799, and after I assembled the gun carriage and cannon, I did not like how they appeared. The bed was too wide, the carriage axles consisted of brass wire and the steps were cut wrong. I didn’t like the look and decided to make my own. Shown in the photo below are the kit supplied side pieces, trucks and bed.



I did some research into early 18th century cannons and I discovered that there is a lot of information and numerous books covering the construction of ship guns and their carriages. Before you decide to make your own gun carriages do a little home work and determine what time period your ship was built in. Gun carriages are not all alike and many differences exist in there construction. This is especially true of English and French gun makers.
 
Among the more note worthy contributors to this work are John Muller – Treatise of Artillery, Benjamin Robins – New Principals of Gunnery, Captain Lawrence L. Bruff – A Text Book of Ordnance and Gunnery and Albert Manucy – Artillery Through The Ages.
 
I also learned about the history of the Enterprise and in doing so I came across an article by Michael L. Bosworth that was originally published in the winter 1999 issue of the Journal of the War Of 1812, entitled The U.S. Navy Schooner Enterprise – A prestigious History – and Recently Rediscovered Plans. The article is an extremely detailed historical account of one of the famous small warships in the US Navy.
The article gives a description of how the Enterprise was outfitted at the time of her construction. Among the many details, the Enterprise was a double topsail schooner of 135 tons and armed with 12 six – pounder cannons and she was commissioned for service in December 1799.
 
I decided to build my gun carriages according to the construction methods outline by John Muller in his Treatise of Artillery. The material I used was basswood which I found at my local craft store. My ships scale is 1/51.
 
The first task I set out to do was to determine if the kit supplied cannons were accurate and if not what I would do about it. This led me to learn about the design and construction of real cannons. The cannon length and the thickness of the metal around the bore as well as the dimensions of the gun carriage are all interrelated to the diameter of the shot. The diameter of the shot or cannon ball for an English 9 pounder was 4 inches. This can be mathematically proven by taking 4 and dividing it by 2.08, the cube root of 9 pounds. The quotient is 1.923 or the diameter of a one pound ball. If you continually multiply the quotient by the cube root of the given weight you will get the diameter required.
 
The Enterprise was outfitted with 12 six pounder cannons. The diameter of the shot for a 6 pounder cannon was 3.494 inches or 1.923 multiplied by 1.817, the cube root of 6. Knowing this number we can calculate the length of 6 pounder cannon and compare that length to our kit supplied cannons.
 
The general rule for iron and brass guns is that the length be 15 diameters of the shot. Therefore, multiplying 3.494 x 15 gives us 52.41 inches or approximately 4-1/2 feet and at 1/51 the scale of my kit the cannon length should measure about 1-1/32. Amazingly the length of my cannons supplied with the kit are fairly accurate measuring 1-1/16 and though lacking in some details like a vent, a proper cascable and the correct bore diameter, I figured I would use them. As a matter of interest my kit came with 14 cannons. (See the photos above)
 
To approximate a more realistic cascable I used small beads about .08 inches in diameter and CA glued them onto the ends of my cannon. The beads are similar to crimping beads used to make jewelry but are more round. My trunnions run through the center of my gun which is another detail that is accurate. I used 16 gauge brass wire cut 3/8 inches long to form my trunnions.

 

Since the Enterprise was commissioned in December 1799, I did not add a breech ring to my cannons as that feature did not appear on ship guns until the late 18th and 19th centuries. Now that my guns were in order I proceeded with the gun carriages.
 
The major parts of the gun carriage consist of the side pieces, the front and rear axles, the transom, the stool bed, the quoin, the trucks or wheels and other related hardware.
 
To begin take the diameter of the shot and divide it into 24 equal parts. Using the diagram on page 4 we can construct the gun carriage. The front of the side piece labeled “a” is 4-3/4 diameters of the shot and half that height behind. If you take 1/2 the length “b” and divide it into 4 equal parts, beginning at the end you will have the steps.
 
The thickness of the side pieces was a diameter of the shot. So for a 6 pounder the diameter of the shot was 3.494 as stated above the height measures 16.59 real inches and at 1/51 scale measures .325 inches or about 5/16 plus a little extra.
 


To find the length of the gun carriage, establish a line AB take two points CD, C being the center line of the trunnions. Make the distance between them 3/7ths1 the guns length or 6 diameters of the shot plus 10 parts. Remember we divided the shot into 24 parts so the length is 6 diameters and 10 of those parts. Through point C draw a line at right angles CE and CF, each equal to 34 parts and at point D likewise draw a line at right angles DG, DH each equal to 39.5 parts. Draw lines from EG and FH, this will determine the width within the carriage.
 
The distance DB is a diameter of the shot plus 12 parts or alternately1 the length of the cascable. The distance AC is 2.5 diameters or half the diameter of the trunnions plus half the diameter of the trucks. The distance AB is the length of the carriage.
 
Using these formulas I calculated the height and length of my side pieces. Each side piece measured 3/4 x 5/16 using 1/16 inch thickness basswood strips. Since I have 14 cannons I needed to make 28 side pieces.



To help cut the pattern of the side pieces I made a brass template with the steps, axle and trunnion positions as well as a radius relief. I also numbered each of the side pieces and cut them together as a set.



I placed a set of side pieces with my template in a small one inch vise careful not to crush them and making sure the template and side piece edges matched up. I used my X-ACTO fine saw blade and carefully cut the trunnions and steps into the side pieces. This is somewhat delicate work and if care is not taken you can easily break the wood. Make sure you have a sharp saw blade. A dull blade will cause more breakage and tearing of the wood.
 
Then keeping the side pieces and template together I flipped them over and cut the axles. To cut the radius I glued some 100-C grit sand paper around a 3/16 inch dowel rod, which made easy work of the basswood and sanded a relief about a 1/16 deep centered between the axles.
 
I made a jig to assemble my carriages and the center piece is actually the shape of the inside of the carriage taken from the drawing on page 4. Before I made the center piece for my jig, I measured my cannons largest diameter and the diameter of the muzzle and cut the piece about 1/32 bigger than these diameters along the entire length.

This was done to ensure that my cannon would fit inside the carriage. I also cut a good swath of relief in the piece so that when I glued my axles there was plenty of clearance and not to much chance of things getting stuck together. For my axles I used 3/32 square basswood strips. I repeated this process for each carriage until I had all the carriage axles assembled.







The next step was to add the transom. I set my transom straight and centered over the front axle. This was a personal choice but I feel it makes for a stronger connection and a more consistent look.



I used the same 3/16 inch dowel rod that I had wrapped in 100-C sand paper to cut the radius of the transom. I temporarily placed the cannon in the carriage and tipped the breech end of the cannon up in the air to determine the depth of the transom radius which for my gun carriages was about 1/16 of an inch.
 
Having set all the transoms in place I moved on to make the trucks or wheels. According to the rules set up by John Muller, The thickness of both front and rear trucks is equal to one diameter of the shot. The diameter of the front trucks is equal to 4 diameters of the shot and the rear trucks 3-1/2 diameters of the shot. However, if the gun ports are made higher or lower than prescribed, then you’ll need to make some adjustments to these diameters.
 
The best way to insure the trucks are the correct diameter is to make a template as I did here. As you can see in this photo the cannon is almost touching the top sill of the gun port.



What you want is for the cannon to be in the center of the gun port. I recommend you check both side’s; port and starboard of your ship as I found in my situation, a slight variance in heights. Using a sharp X-ACTO knife I cut the bottom of the template as needed to place the cannon as near to the center of the gun port as possible. After some trial and error and some fudging of numbers I settled on 3/16 inch dowel stock for both front and rear trucks.
 


I assembled one gun carriage and did a final check of all my gun ports to make sure everything was going to fit correctly. When I was satisfied with the results I cut the remainder of the trucks. I painted the trucks using a flat black paint, leaving a small somewhat square unpainted area on one face so I had a good clean surface for gluing when I attached them later.

The next step in the construction was to add the stool bed, the ring bolts, eye bolts, cap squares, quoin and final assembly. For the stool bed I used 1/8 x 1/16 inch basswood strips cut about 3/16 inches long.



I placed the end of the stool beds flush with the rear axle and the quoin was made from 1/8 inch square basswood strips cut in 1/4 inch increments and then cut in half diagonally to form a wedge.





 The cap squares were made from heavy black construction paper and pinned to the top of the side pieces covering the trunnions. I painted my gun carriages with brown paint and glued on the trucks. After everything was dry I assembled the remaining pieces.



I hope this article is helpful to anyone wanting to make their own gun carriages. I learned a lot and had fun making them.