I found this in a post about the disposal of waste. Hope this helps you!
The ash hoists were used when the ship was in port and the ash ejectors were used at sea. The hoists were basically a block and tackle powered by a steam cylinder that would lift bags of ash from the boiler room up to E-deck, where they could be disposed of through doors in the ship's side to the pier or a barge. I assume that they lowered the ash buckets down to a man waiting below, but I don't know for sure. The reason that the "ash place" was on E-deck is the need for the door and the fact that it had to be above the bulkhead deck. In all cases, the ash hoists were located next to and above an ash ejector.
The ash ejectors used a jet of pressurized water to carry ash from a hopper in the boiler room up a tube with a curved top and shoot it away from the side of the ship. The fact that they sprayed a slurry of ash and water is doubtless why they were not used in port.
About every four hours a fireman would clean each of the three furnaces under his care, raking the ash and clinkers onto the stokehold plates. The duty of moving the ash from there to the ash ejector or hoist was that of the trimmers. The ash was probably loaded into a wheelbarrow and trucked to the ejector/hoist. I some cases this meant wheeling it through the passage between the boilers. The trimmer might have to break up the clinkers to get them to fit into the ejector.
You will note that in most cases the ejectors were in the aft end of the large boiler rooms. This makes sense, as the pumps that ran the ejectors were also on the aft side of the boiler rooms. The exception is boiler room #4, which had it, ejectors, forward (the pump is still aft)--I can't tell you why the difference.
The single-ended boilers in boiler room #1 were intended for use in port, so they weren't too concerned with access to the ash ejectors. In port, the ash from #1 was wheeled to the ash hoist in #2 or perhaps #3 (if they were disposing of ash from the port side). Apparently, they didn't generate so much ash that the distance was a big problem. If boiler room #1 was used at sea they had ready access to the two ejectors in #2, via the watertight door in the bulkhead.