Is the wood frozen? What species? Are you dogging both sides, totaling 4 dogs?
I haven't tried this, but if it is a real bugger and won't say still, a chain over the top and anchored securely to the cross bunk with a small bottle jack under it pressing it into the chain. Again, I have not tried this and can't fully describe it in detail, you will have to play with it. I've seen it done a while ago, just poor memory.
Tim
