Today was a dock day here at HAWSEPIPER's Afloat Global HQ/Centres for Excellence in Breaking Important Mechanical Stuff.
I went to bed after midnight yesterday, and after 30 minutes or so of reading, had slept for all of 30 minutes when Muscle Man, my OS tankerman, knocked and poked his head in my door.
"Hey, cargo crane won't swing, man. I can't get the hose back."
The part of me that stays conscious of sea state, pump and generator load and list and trim of the hull while I was sleeping told me that we were done pumping cargo, and that the hydraulics had been on for a while.
When the swing motor doesn't swing, and there isn't an explosion of hydraulic fluid, I know that we sheared off the 2-inch thick short shaft in the swing motor unit on the crane. We've done this before. The crane was replaced with a boom 10' longer than the original that came with the base, and the increased torque this causes when there's a ton or of 100 feet of of oil hose hanging and swinging around 60' away can be too much on the swing motor's shaft, which acts as a brake when the hydraulic motor is not in gear. The swing motors last about 2 years. First time it happened to me, I was lucky enough that I had just handed off the cargo hose to a ship, and when they disconnected the hose sling from the headache ball at the #1 (the wire at the very tip of the crane), the boom swung rapidly like a giant propeller, completely unstoppable... only thing to do is to raise the boom vertical, take away the momentum.
Last night, when I walked out on deck, and saw the hose leaning against the hull of the ship we wanted to sail away from, I knew we'd lucked out... and I got to make Muscle Man think I was either psychic or an insanely old salt. I told him to drop the #2 headache ball (which was holding up about a 25' loop of cargo hose), and listen for the clunk of the 25lb piece of steel scrap that would fall into the inside of the base of the crane when I swung the crane manually.
Since I set the #2 whip about 40 feet from the base of the crane, there's a lot of leverage there, no matter how heavy the load on the crane. With a big loop of hose to drag on to, plus zero list on board, I dragged the loop of hose to the crane's boom cradle, and had O lower the boom and put the crane home. I heard the clunk of the broken shaft and the gear it was attached to as it fell out of the geared ring of the crane's base. Since we had no orders for later on, I just called the night guy and told him we were out of service until I could talk to a port engineer- we don't carry spare swing motors.
BY noon we were all fixed and all was well again. The engineers used a shoreside crane to put the new swing motor up, and with access to the shore, it's given us a chance to get groceries, load up on supplies and offload waste and scrap, stuff like that. It's a rare chance- we don't get to the office dock more than once every 4-6 weeks, so since we're overnighting here tonight, too, tomorrow will be another dock day, too, God willing.