What's the easiest way to cut a chunk out of a buried railroad tie?

Question

I'm in the process of digging holes for concrete piers (for a small deck - nothing fancy) and on my last hole I came across what appears to be an underground railroad tie (or some other huge piece of wood with a sticky tar on it).

Here's a picture:

I tried to just avoid the wood by moving the hole down a bit but then it becomes misaligned with the rest of the holes (which in turn messes up my plans for the deck foundation).

I don't relish the idea of having to re-dig 8 other holes just to workaround this. Is there an easy way to cut into this piece of wood? It's not associated with any large structure so cutting a piece out of it won't cause any structural issues in the surrounding area.

I tried using a simple chisel and that yielded little results. I'm thinking perhaps a sawzall? Or chainsaw? Cutting in vertical lines... then chiseling that off?

Answer 1

I've used a sawzall type reciprocating saw with the 14" long demolition style blades for similar type wood removal in the ground.

Be prepared to replace the blade a few times as cutting into dirt can mess up the teeth after a while.

With the saw like this you should be able to cut completely through the old timber without having to do any chiseling in the hole. Just enlarge your hole enough to give access to permit cutting the wood back far enough so that it does not interfere with your pier form.

Answer 2

Do you really need to remove it? If this is in a mild climate, you could simply place the deck pier on top of it and secure it, perhaps by drilling into the tie and attaching with spikes, cable, etc. to get more stability. If the frost level is mid-tie, I think that having the tie partially below frost level is good enough to ensure stability.

Otherwise, that doesn't look too deep and if it really is a railroad tie (which is quite common), it is no more than 9 feet long. Digging it up would be a great ambitious kid project (say for $20 cash), or it could simply be dug around enough at one point to get good saw access. I'd favor a sawzall with an aggressive and disposable blade. Sawzalls can be obtained at most tool rental stores.

Answer 3

If you want a new toy, a dual blade circular saw would fit in the hole and easily eat through the wood and nails.

http://m.harborfreight.com/5-in-double-cut-saw-68316.html

You'll still need to get new blades afterwards, and a new lubricating stick most likely, but it'll be safer than a chain saw and less time and a better working angle than a reciprocating saw.