Author Topic: Controlling recoil (Read 1112 times)

Blaster · « **on:** July 13, 2005, 06:55:51 AM »

BillinOregon, if you will take a look at my post of Sept 27, 04 on page 9 of this particular forum, you will see some pictures of the Whitworth Deck Gun in 20 m/m that was made up for me. Got the 20 m/m barrel from Big Sky Surplus located somewhere in the Pacific Northwest. The descriptive details are in one of my posts in that thread. It did work but the only thing that really bugged me was the fact that it would make a complete somersault upon firing. Have to find some method of keeping the muzzle more controlable. I'm sure open for suggestions now that I have got the gun back! Anyone?

? :oops:
Blaster (Bob in So. CO)

Double D · « **Reply #1 on:** July 13, 2005, 07:19:53 AM »

Bob, forgive me but I felt your response to the rifled barrel topic would make a good discusion topic of itself, so I split it off.

Field guns mange flip from recoil with long trails. Deck guns have to be controlled differently.

If you look at pictures of cannons on ships you will see they have a block and tackle system that appears to be used for pulling them back into battery after firing. They are also used to control recoil.

Here is a picture of my 1841 boat howitzer before firing. I uses simple set of double blocks attached to a couple of spikes driven into the ground to keep the gun from flipping over.

Here is another angle prefiring.

Here is just after firing. Notice how far back it has recoiled even with the tackle. But it didn't flip!

BillinOregon, that gun is an Oregon built piece. Steel came from an outfit in White City that sold mill ends and shorts. The wood came out a of a large Locus tree grown in Silverton and the whole thing was constructed in my garage in Grants Pass and shop in Ashland.

GGaskill · « **Reply #2 on:** July 13, 2005, 08:45:15 AM »

The recoil force is above the center of gravity and resistance to the recoil force from the Marsilly-type carriage is below the C-O-G, forming a strong couple. If the back end actually digs in and prevents rearward motion, I would expect the gun to overturn. The Marsilly carriage uses the recoil force to increase friction against the deck to absorb some of the recoil but the gun has to be free to move or risk overturning. If you are firing the gun from a dirt surface, you should add rear wheels. Alternatively, you could put down a piece of plywood (something like the portable deck used by old time mortar crews) to prevent the carriage from digging in.

John N · « **Reply #3 on:** July 13, 2005, 09:11:00 AM »

Maybe we should check with the "experts" in Hollywood. Somehow they manage to virtually eliminate cannon recoil in their movies. (sarcasm off).

I really bugs me when I watch a movie like "Gettysburg" and the cannons "recoil" less then 6 inches.

My little commercial beer can mortar was prone to digging in under recoil and flipping due to poor sled design. Setting it on a piece of plywood really helps.

BillinOregon · « **Reply #4 on:** July 14, 2005, 05:09:09 AM »

Great thread, guys. Never gave that much thougth to recoil in mortars and field guns, but obviously the balance and firing surface are critical. Doug, that naval cannon is just gorgeous. Bet you got the metal from White City Steel, and you'd have to go a ways to find wood tougher than black locust. Beautiful work! Had no idea you were cannoneering here in the Rogue Valley.
Wish I had a local pal with a nice big lathe ....

Evil Dog · « **Reply #5 on:** July 14, 2005, 07:18:07 PM »

Rather than using any form of restraint, I prefer to just let my half scale Napoleon roll. 2 to 3 feet is normal for me depending on the ground surface.

BillinOregon · « **Reply #6 on:** July 14, 2005, 08:41:41 PM »

ED: Sweet half-scale Napoleon. Where'd you get the barrel and carriage?

Evil Dog · « **Reply #7 on:** July 15, 2005, 02:37:26 AM »

The barrel is from Hern Iron Works, the carriage from the local hardware store (built it myself). The wheels have since been replaced with heavier ones.

BillinOregon · « **Reply #8 on:** July 15, 2005, 04:52:03 AM »

ED: Are you happy with your Hern barrel? Did you have to have it lined or did it come that way?

Blaster · « **Reply #9 on:** July 15, 2005, 06:56:18 AM »

I may have already mentioned this in my post about the Casper, WY MORTAR/CANNON shoot, when thinking of recoil/concussion associated with the big guns, there were one or two bowling ball mortars at that shoot that would trigger vehicle burglar alarms. Those vehicles were parked about 50 yards away from the firing line. You could really feel the earth seem to move with those babies blasting away. Blaster (Bob in So. CO)

Evil Dog · « **Reply #10 on:** July 15, 2005, 08:30:21 AM »

Hey Bill..... I really have nothing to complain about with the Hern Barrel. It came with a seamless liner. About the only drawback I can think of is that it is a fairly lightweight barrel.... 2 1/4" bore that only weighs around 150 pounds. It does shoot very nicely though. Were I to do it over again, I think I would look more towards a golfball sized bore weighing 250 pounds or more.