Crankshaft

Try putting the car in third gear and then nudge it forward or backward to turn the engine over a bit at a time (with the ignition off of course). The crankshaft pulley moves the belt, not vice versa. If it is a petrol engine you could also take the plugs out to remove the compression pressure which would make turning much easier. Don't move the shafts too far out of line though or parts of the engine will touch other parts that they are not supposed to. This is why a broken cam belt can cause so much damage. Make sure that this is not the reason why you can't move it now.

The cambelt has not snapped but a washer had jammed between the crankshaft and the housing thinking that the timeing belt might of jumped. The engined was turned on then stoped on its own.What damage could of been caused.. Many thanks for any help given

You could have major problems if, as you say, the engine ran. If the belt did not actually jump any teeth then you should be OK, but if it did then you may well have had an expensive collision of pistons and valves. The experts on here will tell you more but I suspect that the only way you can be sure (assuming the belt did move) is to open it up and look.