As you walk-in along the Croesor haulage adit and pass over the false floor of the main haulage incline (flooded) there is a slight left bend /dog-leg where you can see some winch/engine mountings.
At this point there is a short hand over hand old rope to get past that to a smaller scrappier incline (with the big smoke pipe). As you progress up the incline at what seems the top are heavy iron bars. CRTT turns left there for the first pitch. The incline continues a short way behind the bars (bars installed when it was used as ICI/Cooke's explosive store) and that is the bottom of the shaft.
Originally there was the largest sized Robey portable steam/wining engine at the top of the incline and the smoke went up the shaft. However as the main incline (now flooded) is out of sight of the engine operator, it got moved down the incline (with smoke pipe) so that the operator could see the main haulage incline. The manager at the time (Moses Kellow) gives an account in his autobiography as the chain broke during lowering and it came down the incline but luckily for Moses (who was standing half way up the incline below the engine) it jammed on the wall at half way.
Anyhow the shaft is 340' and coated in many years of soot, so don't wear your finest crisp white caving suit or white dinner jacket discussed in other thread. There was originally a small portal and short adit leading into the shaft at the top and I think that enters 10m??? down, although collapsed at entrance there is some kind of ledge or feature of note just down the shaft. I hear there were spit anchors there but maybe they need replacing. If they are confirmed as old I may be able to put in some 12mm stainless coeur in Feb? for there you have 100m or a touch less to the bottom. Nearish the bottom there are tunnels to East and West. One to West comes out high above the big lake chamber you will have seen to your right when you came in. One to East comes out into the large unstable chamber of first pitch of CRTT and can be used to continue instead of having to slither through the bars at bottom. Unless you are a racing snake (and a thin one at that) they may be a challenge. I don't know the current condition of anchors there either, can review in Feb some time but if you go before that feedback from others useful.
What also interests me is the very top. While there are whopper winding wheels to anchor, how easily (or wisely?) they could be used as a pull through is of interest, otherwise someone is going to have to walk back up the side of Moelwyn Mawr to get the rope again