Da, da da da..,
Here it is in action. We just so happen to get a barge load of sawdust in at the sea wall today to test out the new clamshell. Sand is okay, but if a small pebble gets caught in the jaws and holds it open a bit, the dry sand pours out around it. Hence the need for a screener.
Wet sand is okay too, but neither one fills the bucket. I think in such a small scale the clam is just not going to dig in very well.
I did try it in the canal, dredging sand off the bottom. I was able to get a good enough load that my counter weight on the crane was not enough to keep the crane in position. I think the bucket turned out a bit too large. Not sure if a bit more narrow might dig better?
I would like to try another one with teeth for wet sand and not so wide.
http://youtu.be/8ouiHyJ_mvg
Jim