Railway sleeper strength

Suey

Hi I am a sculptor carving a stone that is 20 tons that is sitting on 3 railway sleepers , I'm cutting it wet with a saw on and off and I'm trapping the water around the base of the stone with a water trap so there is water constantly around the sleepers ... My question is will the water going rising up and down around the sleepers cause them to weaken so they might to split and fail ? If so is there anything I can put on them to stop this happening ?

Reindeer

Suey wrote: »

Hi I am a sculptor carving a stone that is 20 tons that is sitting on 3 railway sleepers , I'm cutting it wet with a saw on and off and I'm trapping the water around the base of the stone with a water trap so there is water constantly around the sleepers ... My question is will the water going rising up and down around the sleepers cause them to weaken so they might to split and fail ? If so is there anything I can put on them to stop this happening ?

You are asking an engineering question more than a forestry one. As an American forester, all I can say is the sleepers are likely made of treated douglas fir or larch; I do not know what Ireland would use for them aside from that. If this is the case, the water problem wouldn't exists any time soon so long as the entire 'structure' is at rest, and the sleepers are only compressed and not under tension. The '20 tons' is more likely to cause problems than the water is, would be my guess.

Nekarsulm

Water alone wouldn't have much effect on the sleepers, after all they have probably spent between 30 to 60 years lying out in all weathers. Lots are imported from other countries as railways move to concrete sleepers, and its impossible to know how old they are, or how sound.
I bought 6 to use as strainer posts in fencing, and one broke in half as it was rolled off the trailer onto the ground. The trailer is about 2 foot high............
So as long as you don't plan on using a crane to lift the 20 ton block of stone, using the sleepers as a cradle underneath you will be OK.

blue5000

Op if you are worried about not being able to lift the sculpture when you are finished because the sleepers have collapsed, could you put a chain or heavy duty strap(s) between the sleepers? But I don't think the sleepers will rot that fast.

Genghis Cant

Suey wrote: »

Hi I am a sculptor carving a stone that is 20 tons that is sitting on 3 railway sleepers , I'm cutting it wet with a saw on and off and I'm trapping the water around the base of the stone with a water trap so there is water constantly around the sleepers ... My question is will the water going rising up and down around the sleepers cause them to weaken so they might to split and fail ? If so is there anything I can put on them to stop this happening ?

Are the sleepers being used simply as skids under the rock, on a flat enough surface or spanning something?

Suey

Hi , the stone is sawn flat on the bottom , there is a concrete floor underneath it , it's under compression , the stone has been on the sleepers for about 7 months already , the sleeper in the middle isn't the best in my opinion but the outside ones look dense and sound , I'm just a bit paranoid il come in to work one day and it will have toppled to the side ,as I used to always carve the stone dry , now I'm doing it wet to suppress the dust . I will use a 20 ton forklift to get the stone out when it's done as I used that to get it in , even though it was scary getting it in the door

In reply to the first response , I couldn't find the engineering section .. Many thanks to anyone that has helped me so far on this thread as I would prefer to put my mind to rest

I would say I have cut away 3 tons of stone already so it could be half the weight by the time it's finished.

Genghis Cant

Suey wrote: »

I would prefer to put my mind to rest

Given what you say, my money's on the sleepers doing their job. They're generally pretty robust.
Hope your work turns out well.

Jonty

http://www.boards.ie/vbulletin/forumdisplay.php?f=431

Engineering Section :-)