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Large ships do very poorly in waves. The last thing you want happening in a storm is to lose power. Without power you can't angle yourself perpendicular to th

by pp19dd 7y ago

Large ships do very poorly in waves. The last thing you want happening in a storm is to lose power. Without power you can't angle yourself perpendicular to the waves. When that happens, broadside waves make the ship bob like a corkscrew. If you don't capsize, this makes the situation beyond recovery. Waves tend to make large ships lose power easily because the engine oil sloshes in the pan, or the sump pit. The oil pump or inlet is located in a fixed place and can't be moved around. We're talking large engines here. Anyhow, the pump can't keep up with the flow due to this sloshing effectively cycling its flow rate and the engine starts overheating and it has to be throttled down then later shut off so it doesn't seize up. Once the engine is shut off and the vessel is no longer under command, the sloshing gets worse. Emergency battery power drains quickly. Meanwhile the fuel - bunker oil - cools off and turns into asphalt - it needs to be heated up to 120+ degrees F to be usable. Even if you don't shut the engine off, in stormy weather the fuel filters get clogged up faster and have to be constantly cleaned. The fuel itself, bunker oil, is chunky to begin with and the additional sloshing somehow gunks up the filters faster. In one famous case, the engineers had to do it every few minutes in a storm and that required complete enclosure disassembly and reassembly. That particular ship survived that storm, but not another.

YeGoblynQueenne 7y ago
The ship that didn't survive- was that the El Faro? I didn't realise this kind of malfunction of the oil pump was common. I thought it was particular to the design of the pump on that vessel.
- pp19dd 7y ago
  Aye, El Faro. Remember few months ago when the Norwegian Cruise ship lost power and 1,300 passengers had to be evacuated by helicopter? That wasn't the only disabled ship in the area due to the storm. Once NTSB releases a report, you might see this as a cause, fuel sloshing. Large ships are just not designed or meant to be in waves and it's not economical to design them to be. So you check weather far in advance and steer clear of it. El Faro's master looked at an old weather report regularly delayed by 12-18 hours or some such due to additional processing from BVS (his preferred software for checking weather) and didn't cross-check it with another source like NWS throughout the days, despite being challenged by the crew. He ended up steering the ship right into the eye of a hurricane.
  - YeGoblynQueenne 7y ago
    Oh, yes- I remember the Norwegian ship. I don't remember the details- I'll keep an eye out for the report. Thanks. >> He ended up steering the ship right into the eye of a hurricane. I know. I've read the NTSB report. And the bridge transcript. Most harrowing thing I've ever read. I got the feeling though that there was fault with the land crew who tied down the cars in the holds inappropriately. If I remember correctly, first there was water in the holds, possibly from a burst pipe hit by a car moving about freely; then the cars started slipping around on the wet floor; then they started listing to port; then the oil pump gave up; then the captain turned his port to the wind to counter the list; then they lost power; and by that time they were in the eye wall of the hurricane and they were lost. Perhaps, if it hadn't been an old ship and if the cargo had been secured properly, we wouldn't know there ever was a ship with that name. Despite the captain's mistakes.
    - pp19dd 7y ago
      It really was terrible. The audio transcription puts you right there and just wow. Like you said think it was a number of factors, but I think the other ones only compounded the situation after the master committed the ship to the float plan. He looked at an outdated weather report, didn't know the software options to plot the up-to-date hurricane overlay, company didn't permit any of the crew to have access to the ship's satellite phone (and presumably internet access that came with it) for a double check, then he dismissed a confrontation about the conflicting NWS report from the 2nd mate, then delayed pulling up updated information from his lagging weather report and went to sleep. The design of the ship played a factor too. It was a retrofitted RO/RO ship with waived safeties, and had ventilation hatches that apparently lowered the de-facto lowest-point-of-water-ingress (forgot the actual parameter name) underneath the unsecured hatches, which were - unsecured. Or unreliable. New engineer started doing maintenance mid-storm, lowering the engine's power output, and I think the loose cargo became a factor afterwards.
rtkwe 7y ago
Most current plans don't use ships as the basis of a seasteading at least not currently. Most designs that have actually been tried are something like this [0] spar platform reminiscent of the RP Flip [1] which is extremely stable passively in waves. They have very small cross sections to the waves so mostly just bob up and down with the motion of the waves. We already know how to build these pretty large (see oil rigs). [0] https://ocean.builders/wp-content/uploads/2018/10/spar.png https://ocean.builders/wp-content/uploads/2018/10/spar.png [1] https://en.wikipedia.org/wiki/RP_FLIP https://en.wikipedia.org/wiki/RP_FLIP

by pp19dd 7y ago

YeGoblynQueenne 7y ago

The ship that didn't survive- was that the El Faro? I didn't realise this kind of malfunction of the oil pump was common. I thought it was particular to the design of the pump on that vessel.

pp19dd 7y ago
Aye, El Faro. Remember few months ago when the Norwegian Cruise ship lost power and 1,300 passengers had to be evacuated by helicopter? That wasn't the only disabled ship in the area due to the storm. Once NTSB releases a report, you might see this as a cause, fuel sloshing. Large ships are just not designed or meant to be in waves and it's not economical to design them to be. So you check weather far in advance and steer clear of it. El Faro's master looked at an old weather report regularly delayed by 12-18 hours or some such due to additional processing from BVS (his preferred software for checking weather) and didn't cross-check it with another source like NWS throughout the days, despite being challenged by the crew. He ended up steering the ship right into the eye of a hurricane.
- YeGoblynQueenne 7y ago
  Oh, yes- I remember the Norwegian ship. I don't remember the details- I'll keep an eye out for the report. Thanks. >> He ended up steering the ship right into the eye of a hurricane. I know. I've read the NTSB report. And the bridge transcript. Most harrowing thing I've ever read. I got the feeling though that there was fault with the land crew who tied down the cars in the holds inappropriately. If I remember correctly, first there was water in the holds, possibly from a burst pipe hit by a car moving about freely; then the cars started slipping around on the wet floor; then they started listing to port; then the oil pump gave up; then the captain turned his port to the wind to counter the list; then they lost power; and by that time they were in the eye wall of the hurricane and they were lost. Perhaps, if it hadn't been an old ship and if the cargo had been secured properly, we wouldn't know there ever was a ship with that name. Despite the captain's mistakes.
  - pp19dd 7y ago
    It really was terrible. The audio transcription puts you right there and just wow. Like you said think it was a number of factors, but I think the other ones only compounded the situation after the master committed the ship to the float plan. He looked at an outdated weather report, didn't know the software options to plot the up-to-date hurricane overlay, company didn't permit any of the crew to have access to the ship's satellite phone (and presumably internet access that came with it) for a double check, then he dismissed a confrontation about the conflicting NWS report from the 2nd mate, then delayed pulling up updated information from his lagging weather report and went to sleep. The design of the ship played a factor too. It was a retrofitted RO/RO ship with waived safeties, and had ventilation hatches that apparently lowered the de-facto lowest-point-of-water-ingress (forgot the actual parameter name) underneath the unsecured hatches, which were - unsecured. Or unreliable. New engineer started doing maintenance mid-storm, lowering the engine's power output, and I think the loose cargo became a factor afterwards.

rtkwe 7y ago

Most current plans don't use ships as the basis of a seasteading at least not currently. Most designs that have actually been tried are something like this [0] spar platform reminiscent of the RP Flip [1] which is extremely stable passively in waves. They have very small cross sections to the waves so mostly just bob up and down with the motion of the waves. We already know how to build these pretty large (see oil rigs). [0] https://ocean.builders/wp-content/uploads/2018/10/spar.png https://ocean.builders/wp-content/uploads/2018/10/spar.png [1] https://en.wikipedia.org/wiki/RP_FLIP https://en.wikipedia.org/wiki/RP_FLIP