RushMan 31 Posted August 31, 2016 Share Posted August 31, 2016 Just watched a video of a ship breaking up and sinking while under tow. What happens to the towline? Does someone release it from the towed vessel? Is the tow line allowed to run out from the towing vessel? Is it not attached to the end of the winch drum? Is there a quick method of cutting the tow line? How long is the tow line and what would it cost to replace? Who would have to cover that cost? Quote Link to post Share on other sites
Black Panther 1,579 Posted August 31, 2016 Share Posted August 31, 2016 i'm sure Rigger can answer those, he'll turn up presently. Quote Link to post Share on other sites
RushMan 31 Posted August 31, 2016 Author Share Posted August 31, 2016 i'm sure Rigger can answer those, he'll turn up presently. I am sure he will too Quote Link to post Share on other sites
Black Panther 1,579 Posted August 31, 2016 Share Posted August 31, 2016 In fact I'm looking forward to hearing his answers. Quote Link to post Share on other sites
grant 40 Posted August 31, 2016 Share Posted August 31, 2016 Good photos The tug would have some way of releasing or cutting the tow. Was talking to someone a couple of months back that had to replace the wire on a tow drum on a tug ( towing tug not a harbour tug), maybe a bit shorter/lighter than for that sort of job and he was talking $50k Quote Link to post Share on other sites
rigger 47 Posted August 31, 2016 Share Posted August 31, 2016 OK - towing on a bridle with fish / delta plate then pennant to towline. Situation: Not an emergency - Heave in the towline and lock the pennant eye in the forks / sharkjaw / pelicanhook, undo the shackle from towline to pennant, release the pennant. Situation: OH F$%^ - On the old dutch tug we could just dump the brake and the wire would run out. Worked on a couple of boats where the winch was secured on a dog - meaning you had to heave up to remove the dog then you could dump the gear. - If you could control the position of the wire - you could take the chance the pennant / stretcher would fail before something else - if the gog wire failed first you would be wishing you did something else..... did have a 16inch (I think - could have been bigger) rope snap once. - Always had cutting gear to hand. But... We had a spare tow wire on most of the boats. So my attitude was that we had a spare wire but no spare crew or boat to hand - in emergency dump the wire. In NZ the MNZ rules require the towline to be the weakest line in the the towing arrangement.... An example of gear in an arrangement, Ships Bitts / Panama - 64tonne SWL Tug Tow line - 300t MBL Tug Bitts - 100t SWL Winch brake render load - 180tonnes On who pays for it, depends upon the contract and how you lost it. KM can give you an idea of cost - how much for 1250m of 64mm wire rope A setup for a harbour tug (just the mainline) - maybe 50k for one with +60tonne Bollard Pull but depends on a few factors. Quote Link to post Share on other sites
RushMan 31 Posted August 31, 2016 Author Share Posted August 31, 2016 Thanks Rigger What does one use to cut 64mm wire rope in an emergency? Quote Link to post Share on other sites
rigger 47 Posted August 31, 2016 Share Posted August 31, 2016 Thanks Rigger What does one use to cut 64mm wire rope in an emergency? There are hydraulic cutters, but never had them only had gas gear or cut off discs on a big angle grinder - hence my preferred option of paying out the wire, after all if you have a 1200m wire and you cut off 400m you will most likely change it out so why risk people to save a bit of wire. Quote Link to post Share on other sites
too_tall 15 Posted August 31, 2016 Share Posted August 31, 2016 Under the tension that those tow ropes would be under, how safe would manually cutting it be? A Gas axe would get through rapidly enough, and at least allow a little distance between rope and the operator, but a grinder? I would be terrified!! Quote Link to post Share on other sites
TimB 7 Posted August 31, 2016 Share Posted August 31, 2016 Why did it break in half, incorrectly ballasted perhaps? I noticed they said at the end no environmental issues. Is that because as John Clarke famously said it was outside the environment.? That was in a skit about a ship off the coast of Australia whose "bow fell off"!!! Cheers Tb Quote Link to post Share on other sites
ScottiE 174 Posted August 31, 2016 Share Posted August 31, 2016 Clarke and Dawe actually! Oh and they would never be so comically unprofessional as to have called it the bow! It's the front you fool! 2 Quote Link to post Share on other sites
Mothership 6 Posted August 31, 2016 Share Posted August 31, 2016 One of the best skits, still Quote Link to post Share on other sites
rigger 47 Posted September 1, 2016 Share Posted September 1, 2016 Why did it break in half, incorrectly ballasted perhaps? I noticed they said at the end no environmental issues. Is that because as John Clarke famously said it was outside the environment.? That was in a skit about a ship off the coast of Australia whose "bow fell off"!!! Cheers Tb Vessel was in ballast being towed to china to get a new fore body fitted to the aft section - probably very little oils onboard. Vessel was built for service on the great lakes in 1978, sank in 2009 - that is old for a bulk carrier. A bulk carrier in ballast under tow in heavy seas.... the vessel had be aground in the past - was due to get the fore section replaced - fatigue, water ingress and so on. Quote Link to post Share on other sites
TimB 7 Posted September 1, 2016 Share Posted September 1, 2016 Thanks Rigger, so if built that long ago probably some serious corrosion issues as well. cheers Quote Link to post Share on other sites
rigger 47 Posted September 2, 2016 Share Posted September 2, 2016 Thanks Rigger, so if built that long ago probably some serious corrosion issues as well. cheers fatigue could be considered as well water ingress Quote Link to post Share on other sites
wheels 543 Posted September 2, 2016 Share Posted September 2, 2016 I worked for a Pom yrs ago, who was a retired Ships Cpt or Master he like to call himself. He had sailed Tankers around the World. He retired because it was at the time when cheap labor was being brought into the Industry, but his main concern was that the Ships were being Sailed way past their use by date and the corrosion was horrific. He said it was only a matter of time that a Ship he would command would break in two and he didn't want that. He commented about many having Steel structures almost paper thin in areas due to corrosion. Quote Link to post Share on other sites
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