Double D, We have roughly calculated the muzzle energy and have found it to be 83,925 Ft. Lbs. This is based on a SWAG in that it uses a velocity of 200 fps of the 135 Lb. projectile. ME = M x (V squared) / 450,400 = 83,925 Ft. Lbs. So, not being engineers we merely take the mass of the projectile and the mass of the bed and platform and sprung trailer weight to get a really rough ratio and then calc to see how much energy is imparted to the trailer.
Projectile weight……135 Lbs
Tube wt. total …720 Lbs.
Weight of bed….650 Lbs.
Platform wt. …..450 Lbs.
Sprung Tl wt. 1,250 Lbs.
Total wt. 3,070 Lbs. 135 = 1
3,070 23
So we figure that the recoil effect should be very, very approximately one twenty-third the energy of the projectile’s ME or 83,925/23 = 3,649 Ft/ Lbs. energy. We think that may be enough to make the trailer bounce noticeably and may be enough to tweak the trailer’s angle iron frame if it is supported only by corner jacks. We intend to block it with four cribs made of all those cut off timber pieces, 4” X 6” X 18” that we have in piles all over the shop. We figure we will place them under the trailer at the four corners of the mortar platform on leveled pieces of plywood. Large wedges will get 80% to 90% of the weight off the trailer tires.
Victor3, Can’t wait to see big mortar platform and bed constructed like a corporate jet interior. I hope someone has a good quality video camera there. Our company has a very basic one which we will have there of course, but no slo-mo capability.
George, If we decide to use those stainless steel eye bolts with 5/8” Dia. cross section, we will have our friend with the huge Lincoln welder fill those gaps. Good suggestion, thanks!
We finally got the shell hoist assembled, but all our help was busy today, so we have only a few pics when my son became available. Looks like it works, but our rope is a bit short. DD knows where we can get a really authentic, old-time, but strong, rope. We will give him a call. I braved the crawling things and did all the hardware installation under the trailer. Mike has been so helpful on this project, that I didn’t want to tick him off.
Newest development, although Mike has had many spectacular ideas over the years which benefitted our company greatly, the latest one yours truly dreamt about and actually remembered the critical part of that dream, to put it to use. For the vent piece, which has to be about 9” long, why not use a .22 barrel? So I thought, I will machine an old .22 cal. barrel stripped off a Ruger 10-22 to bridge that big gap between the Chamber Piece and the Cosmetic Shell. It has the correct I.D. and enough meat to run a ½”-20 die on the O.D. of one end. Try to find tubing with those dims.!! It ain’t easy!
Enjoy the pics,
Mike and Tracy
The two old farts haul the heavy Shell Hoist lifting arm toward the top plate.
Heave Ho!
With .030” clearance, it was a couple minutes to find the center of the hole; the 6” flange blocked our view!
Mike, Please HOLD THAT LADDER!! The eye was 10.5 feet off the platform.
The FIRST projectile is hoisted. It works!
This is just about the right position to enter the Monster Mortar’s Bore.
Mike hams it up a bit, but he is happy to see something ENTIRELY done.
