Footage of onboard AHTS vessel

If I remember correctly from reading the accident report a few years back, the engineer on the Dolphin was spraying a water hose on the bow thrusters to keep them cool because the vessel dp system was asking for so much turning force to change the ships heading with the pins in the raised position.

I think we can agree it’s more about the fact that you need to avoid getting into irons than odds of surviving if you do. You can bail out of a worse situation with the wire free than locked in pins, and you can’t always prefect when a WAFI will require you to take a hard turn or the barge take an unruly sheer. Some of the oil barges I’ve had the “pleasure” of towing would have caused many accidents if the wire was pinned all the way aft… What’s that abeam of us? Oh just the barge we’re towing. No problem with a good barge though.

Excellent report. There WAS a link in english for the full report but Bob’s summary is excellent and can be found at:

[QUOTE=tengineer1;181615]https://www.regjeringen.no/en/aktuelt/report-on-the-loss-of-the-bourbon-dolphi/id505100/

Excellent report. There WAS a link in english for the full report but Bob’s summary is excellent and can be found at:

https://maritimeaccident.wordpress.com/2008/03/29/bourbon-dolphin-report-released-tug-stability-captains-competence-not-checked/[/QUOTE]

[video]https://youtu.be/WZ4h1p6gbeI[/video]

[QUOTE=z-drive;181613]I think we can agree it’s more about the fact that you need to avoid getting into irons than odds of surviving if you do. You can bail out of a worse situation with the wire free than locked in pins, and you can’t always prefect when a WAFI will require you to take a hard turn or the barge take an unruly sheer. Some of the oil barges I’ve had the “pleasure” of towing would have caused many accidents if the wire was pinned all the way aft… What’s that abeam of us? Oh just the barge we’re towing. [/QUOTE]

I watched that video and speak form not having run anchors before but could the entire accident have been prevented by just stopping the vessel and allowing the wire to just drop to the seafloor? Secondly even if the wire wasn’t held by the pins, how would the DOLPHIN not have tripped when coming to port like it did? Would the master have not taken the wire right up onto the rail and rolled her over regardless? Was not the best course to leave everything pinned down and just stopped driving ahead?

no idea, I don’t work anchors. Without dropping the pins and getting steering power to come bow to the current the only other thing would be to go stern to the current , and abandon the heading? Some of the towing astern I do the tug is pointed nowhere near where a regular person would think logical. If you stopped the boat it would have to be both propulsion and heading; then nature and physics could select the the path of least resistance: stern to wind/current in an arc relative to the wire until about 3-o’clock in the video??? With pins released I would think a boat like that would turn bow to the wind/current especially dumping tension on the winch even temporarily and utilizing leverage from the wheels in a twist and the fwd thrusters. With tension on the beam in that case the current is fore/aft which I imagine to be the dominant force???

No disrespect to the poor souls there and I don’t have time to read the report but it sounds like an over reliance on button mashing?

but if you just pull everything back to zero doesn’t the anchor wire drop to the seafloor and then in effect anchor the tug stern to?

I always say to mates, if in doubt about anything, pull the fucking throttles back to zero if necessary then call me…many shit situations can be made much better without speed or thrust.

I’d agree. The important thing was to probably say fuck the heading! If they headed out at say 2230 vs 0001 it would likely have been a non issue.

One of the factors listed was the crew’s lack of experience. I would think that experenced captains and crews would develop an intuition with regards to loads, forces and so forth such that they would recognize that an unfavorable situation was developing well before it reached a critial point.

Once the situation got out of hand a boat handler that lacked the experence and intuition to stay out of trouble would likely also not have the instinct needed to recover.

1 Like

[QUOTE=c.captain;181621]I watched that video and speak form not having run anchors before but could the entire accident have been prevented by just stopping the vessel and allowing the wire to just drop to the seafloor? Secondly even if the wire wasn’t held by the pins, how would the DOLPHIN not have tripped when coming to port like it did? Would the master have not taken the wire right up onto the rail and rolled her over regardless? Was not the best course to leave everything pinned down and just stopped driving ahead?[/QUOTE]

Running anchors, you must be in the pins, paying out wire must be on the stern roller for that. I ran anchors for the Transocean Rather on several occasions, and they pay out fast as hell on dynamic - making steering is a little more difficult. You certainly do not want anything over the rails at that point. There is about 4,500’ of 3-1/2" chain, and 12 ton anchor hanging between you and the rig, not to mention the wire weight - that far out. It’s a lot. The only thing the Bourbon Dolphin could do at that point, is decrease power, the catenary will pull you back to the rig - thereby gaining some manuerability, get the rig to pick-up, or both. Put yourself in a recovery position, and screw the wire if it touches bottom and possibly gets damaged. There are a lot of moving parts. There are risks of the rig cutting the bolsters or pontoon if wire touches that during pick-up, or even cutting the other anchor wire the boat was near on top of. I am sure there was some pressure exuded from the coordinators on the rig, and it really pissed me off to read this report, because I have been in those situations. Never falling off line like that, but telling the rig “look guys, we gave out best effort, but holding this line in these condition is not going to work, stop paying out and I will relax the wire - keeping it off bottom - and hold into the weather”. The office will call, I explain the situation, and got a “good call” carry-on type conversation, and that was it. Never mind if the rig is $500,000 day, not counting services and boat costs. It is what is.

In reference to the video, having the wire locked in the down current guide pins is not too smart to start with - that just makes it worse to have any angle of attack - if you were going to turn port (when it was feasible). If they started with the wire in the outboard port pin while the rig was behind them, and not beside them, the chances would be much better of saying on line.

[QUOTE=Kennebec Captain;181629]One of the factors listed was the crew’s lack of experience. I would think that experenced captains and crews would develop an intuition with regards to loads, forces and so forth such that they would recognize that an unfavorable situation was developing well before it reached a critial point.

Once the situation got out of hand a boat handler that lacked the experence and intuition to stay out of trouble would likely also not have the instinct needed to recover.[/QUOTE]

Exactly. My educated guess on how they got in this position.

  1. Vessel was operated in DP assist, using the Auto-head and sway function (maybe to a point) to hold the line with no angle of attack consideration, with the assumption the thrusters will hold the line.
  2. As the vessel started moving, as the Rather pays out fast, the thrusters became less efficient and could no longer hold.
  3. Lack of experience did not allow them to recognize this fault for a long period, and then the rig is on the radio asking what is going on while trying to gain situational awareness yourself.
  4. They tried and tried to get back on track using nothing but the thrusters, and no telling how this is scaled in DP or what operator settings were in use, or even if full thrust was even achievable.
  5. All thrusters were taken out of DP as it was apparent that it was more of a detriment than a solution.
  6. But, now we cannot turn - at all. Well, if we let the wire move over, we can drop the pin and that will allow us to turn to port. Game Over. Waited to long, wrong set-up, too much weight out,… really pisses me off thinking about all the scenarios. Did not need to happen.

Have you read the report? I have no experience in anchor handling but the report was very thorough.

[QUOTE=Kraken;181635]Have you read the report? I have no experience in anchor handling but the report was very thorough.[/QUOTE]

Several years ago I did, but even with testimony not everything comes out, especially when relying on testimony of an inexperience crew. NMD came out with a risk analysis template not long after that I based some manuals on. A DNV SCAT was done as well, but not part of the final report that I remember.

[QUOTE=c.captain;181626]but if you just pull everything back to zero doesn’t the anchor wire drop to the seafloor and then in effect anchor the tug stern to?

I always say to mates, if in doubt about anything, pull the fucking throttles back to zero if necessary then call me…many shit situations can be made much better without speed or thrust.[/QUOTE]

Cannot go to zero with that much weight behind you. You can gradually come off, but will need to maintain some sort of power.

[QUOTE=anchorman;181639]Cannot go to zero with that much weight behind you. You can gradually come off, but will need to maintain some sort of power.[/QUOTE]

fair enough but would that have saved the BOURBON DOLPHIN tow pins or no?

[QUOTE=coldduck;181605]If I remember correctly from reading the accident report a few years back, the engineer on the Dolphin was spraying a water hose on the bow thrusters to keep them cool because the vessel dp system was asking for so much turning force to change the ships heading with the pins in the raised position.[/QUOTE]

I don’t think anybody use the DP system to control heading while running anchors. Manual operation of thrusters would be norm.
The fact that power is taken from the shaft generators to run the thrusers reduce the power to the propellers correspondingly, thus reducing the Bollard Pull available and the tension on the tow line/ anchor pennant.

Are you sure about that??

There is a long, contemporaneous thread on the Bourbon Dolphin capsize at boatdesign.net:

http://www.boatdesign.net/forums/stability/bourbon-dolphin-capsizes-16860.html

Earl

[QUOTE=coldduck;181656]Are you sure about that??[/QUOTE]

Sure about what??
That when power is taken from shaft generators the max. BP is reduced? Yes.
If anybody use DP mode when doing A/H? Not so sure, but I would think that heading control in Joystick mode would be more appropriate?

[QUOTE=ombugge;181643]I don’t think anybody use the DP system to control heading while running anchors. Manual operation of thrusters would be norm.
The fact that power is taken from the shaft generators to run the thrusers reduce the power to the propellers correspondingly, thus reducing the Bollard Pull available and the tension on the tow line/ anchor pennant.[/QUOTE]

There can be some limiting, but the shaft generators (and main engines) are normally rated high enough for all consumers, which include the winch & thrusters, under normal operating conditions.

DP or manual, the shaft generator doesn’t care where the command is coming from. The reality is, thrusters are generally in joystick (auto head), and possibly with sway axis, or athwartship - depending on DP terminology. Normally, but at times, full manual control may be required if situation dictates it, but that is more handling the vessel versus power consumption.