Bridge jack mortar

[guncobbler]

I was looking in the trash by the river the other day and found this big chunk of steel. With cannon fever my eyes always stray towards big chunks of iron It's a hydraulic bridge jack and stamped on its side was it's rating of 300 tons @ 8,700 psi. The bore is about 9 inches and overall dia is 12 - 13. OAL is about 2 ft. Must weigh 250 - 300 lbs. Has anyone ever taken one apart? This looks like a nice start to a mortar. With a rating of 8700 psi this should be safe for emailling short chunks of telephone pole in the back 40. GC

 

[Wes/Tex]

Phew, for a minute you had come up with a use for that Bess barrel! :rotf:

 

[ichabod]

Never actually seen one up close like that, so can't tell ya' much.
But hey, it's always good to recycle! :grin:
May work. If all the in's and out's are good with it.

 

[guncobbler]

Hi Wes - I'm drying the walnut for the stock for the bess barrel right now. Had to remove a walnut tree this spring and my son and I used the chainsaw to cut the planks.

A bridge jack is a big piston with hydraulic fittings on the bottom and top to pump it up and down. We brought the truck up to it today and tried to lift it in. The two of us each grabbed a handle loop and could not budge it. We could roll it but only a little. Will have to come back with the come-along and slide it up a ramp. With the cylinder fully retracted it is essentially solid steel. How much does a cubic foot of steel weigh? 489 pounds. Dad taught us how to move big rocks out of the garden when we were young and impressionable. Got a few tricks to pull on this jack... Just hope I can get the piston out.

GC

 

[Bountyhunter]

Take pictures if you can.

Bill

 

[peter]

" Get the piston out?" Thats what black powder is for! Only kidding, but....hmmm...?

 

[guncobbler]

So I got the jack home the other night. Rather than lift I set up a ramp into the side door of the van and used a come-along to slide it up. 1/4 inch at a time up the ramp that was wet from the rain. Water is a good lubricant on wood! Got it in the van and tied it down real good to five seat attachment brackets. No loose cannons for me. Getting it our was somewhat easier. Makes me wonder what holds it together. There's only one bolt head showing on the working face. There's a threaded blind hole in the face of the piston. Just wondering if the piston is captured or not. May try to pull it out with the come-along. What's nice is that the outside has some rust but the seals all look pretty good. As soon as I can get my camera to computer cable I'll try to post some pictures. GC

 

[Story]

Just to be the Devil's Advocate, this source notes that a bowling ball's minimum diameter is 8.5" and the maximum is 8.595". [url] http://www.bowl.com/Downloads/pdf/USBCequipmanual2005_sectionIII.pdf[/url]

Have fun shelling the local Lanes. :thumbsup:

 

[guncobbler]

Got a better look at the working face of the jack and it looks like the piston is captured by a threaded ring about 1" thick and maybe 2" high. Sort of like how the Dan Wesson pistol barrels are secured at the front only the threads are on the sleeve not the barrel. The bore diameter looks like it is 9.75". This may be too big for a bowling ball but I could use a sabot. Hopefully that would not be untraditional unless I made them out of plywood

The ring has two threaded holes in it that look like you would attach a large spanner to it. Makes me wonder how much force it will take to budge the rings. Just don't want to break the screws off in them. GC

 

[guncobbler]

Well I finally got the piston out of the cylinder. The trick was to cut the last 5 threads off the end of the cylinder and give it a tap with the hammer. The long lever screwed to the face of the threaded capture ring just jumped and my son and I took turns walking around the jack unscrewing the ring. With that off we drained the leftover hydraulic fluid and a couple days later lifted the piston out. The cylinder is 9.5 inches bore. Have to use a sabot on the bowling ball... does that make it not PC? Amazed how heavy this still is even with the piston removed. I think it is at least 200 lbs now. The walls are 1.5" thick and the base plug is at least 2" thick. Not that I'm going to overload this thing but I think I got some safety built in. This can will hold over 8500 psi for long periods of time. A momemtary load of that much should be a bit easier and I don't intend to load it up that high. Wish I had a crusher gauge that I could screw into the side of this. Anyone work with peizo gages? Have to work up a wooden base for this and figure out how to load pictures on the site. GC