The Arizona, Fuso, Stier, and Sperrbrecher 15 now all carry the Arizona gun system. This is very simple and reliable gun that any skipper can build with minimal tools and skill. This "how to" article will give the details on the construction of a single barrel Arizona cannon. More cannons can be chained together to create a secondary battery where all cannons are fired simultaneously as on the Arizona or Fuso. All four ships use this style gun for guns under 8 inches, while the Arizona and Fuso also use this style gun for their underwater non-reloading torpedoes.
Note: Originally called just a “single barrel gun system”, the gun has been called the Arizona Cannon since Steve Mielke used it in the Arizona with great success during the 97 and 98 battle season.
REQUIRED MATERIALS FOR ONE GUN:
1 inch coppers tubing and two end caps
One 1/8 inch NPT coupler per gun (part # A-715 from Home Depot)
One 1/8 inch Pipe to 10-32 Clippard 15006-1
Two 10-32 to 1/16 inch Hose Fitting Clippard 11752-2
One MJV-2 Poppet Valve
One MPA-3 Actuator
One MAV-2 Firing Valve and 11916-3 button
¼ inch I.D. Plastic tubing you can get from home depot
Hose Clamps
Tie Wraps
Miscellaneous fittings and vinyl tubing from Clippard as needed
Brass tubing with same I.D. of gun caliber
Gun barrels
Cost: around $15 to $20 per gun depending on what you have lying around your shop.
REQUIRED TOOLS:
Pipe Cutter
Propane Soldering Torch
Steel Brush/Sand Paper
Flux
Teflon Tape
Drill and Drill Bits (#21 drill bit and #U drill bit)
Tap Set (1/8 -27 tap bit and 10-32 tap bit)
ACCUMULATOR:
Start out by cutting a length of copper tube. Three to four inches makes a good length for a single barrel gun. Drill a hole with the #U drill bit into the center of one of the copper end caps or into the pipe. You also need to drill a #21 hole into the other end cap or into the pipe. These holes are where the 1/8 inch NPT coupler and hose fitting will be eventually be screwed into the accumulator. Placement of the coupler and hose fitting will depend where you wish to place the firing valve assembly and fill line. Threads can now be cut using the #1/8-27 tap and 10-32 tap. If you don't have a tap, you can over drill a bit to make it fit.
Now it is time to fire up the propane torch. Before soldering anything together, the pieces must be very clean. Take your steel brush or sandpaper and clean the surface of the copper pipe, end caps, and 1/8 inch NPT coupler, and 11752-2 hose fitting. You know it is clean when it shines. The cleaner the better. Dirt, oil, or even a fingerprint will make it difficult to make a good solder joint. (Use flux to help you solder) You can now solder the coupler and hose fitting to one of the end caps (or pipe) and the end caps to the copper pipe. You now have a copper accumulator that will last forever. No need to worry about exposure to sunlight or over pressuring (good to 1200 psi) one of these babies.
Copper accumulator
FIRING VALVE:
This part is real easy, even my Grandmother can do it. Now screw the MPA-3 onto the MJV-2. Now screw one of the 11752-2s onto the MPA-3. Wrap some Teflon tape to the coupler and screw the MJV-2 onto the coupler. That was easy. You now have an accumulator with a firing valve. This is a good time to test for leaks. Pressurize the accumulator and place it under water. This test will show even the smallest of leaks.
LOADING ASSEMBLY:
This is the hardest part to build and best not left to your Grandmother. I'll give instructions, put it is easier to just look at the drawing to get a better idea on how it is made. You need some brass tubing with the same I.D. as your ammo. You need to take two of these pieces and make a feeding tube. One piece needs to have a hole drilled into the side of it and the other needs to be soldered into it at an angle around 30 degrees. Now make sure a ball bearing will roll down the feed tube and out both ends of the breach tube. If it does not, take a drill and cut out excess tubing and solder that may be blocking its path.
Forward Gun of Sperrbrecher 15 with view of loading tube and breach
AMMO BREECH
The next step is to fix the breach so only one ball bearing loads at a time. You need to drill a small hole into the side of the brass tubing were one ball bearing will come out of the feed tube and enter the breach. Insert a small piece of wire into the hole and solder it into place.
Now the last step. Drill out the Clippard 15006-1 so the brass tubing will fit into it. Now solder the loading assembly to the Clippard 15006-1. Screw this assembly into the top of the MJV-2. Your gun is now ready to accept rounds from a magazine. Rounds can be carried from the magazine to the breech using either brass tubing or a larger I.D. plastic tubing (my preferred method) with an end cap.
Use hose clamps and plastic tubing as needed to hold a barrel to the breach and to hold the magazine feed tube to the breach.
Final Note: While this method of gun construction works great for a single barreled gun, do not attempt to fire multiple barrels from the MJV-2. The MJV-2 does not have enough airflow to support a multiple barreled gun and you will be disappointed in the results.
A FEW EXTRA PHOTOS
Daisy Chained Guns on the Fuso
Hard to see, but there are underwater torpedoes and secondaries in there
Fuso underwater torpedo
Remote Accumulator on Sperrbrecher 15