Originally Posted by
the evil twin
Another point is that if you need to apply in excess of 9 tons of force to get a 3 ton vehicle moving that is sort of similar to trying to tow 9 tons of load (say, 1/2 a semi trailer with no wheels) with a 3 ton vehicle then some pretty average things are going to happen.
I usually dig out the bogged vehicle a reasonable amount and give it a try in low 2nd at about 1200 to 1500 RPM with 2 metres of strap laid down (1/2 a metre by a metre by 1/2 a metre in an S).
If that starts to work then you can go a bit harder or if it works then great, which it usually should.
If the stuck vehicle doesn't move then start digging some more.