Can a ship tow a ship?

[Kukri]

I remember with great fondness (not!) Mr Len Maynard of P&O Safety Services, who had been on board the “Amoco Cadiz”, advising the Italian crew on safety matters, on the 16th March 1978, telling the Liberian Formal Enquiry into her loss that “The tug wasn’t towing. It wasn’t trying to tow. The tow line never came out of the water!”

The Liberian Government was engaged in trying to become respectable at this time as far as it’s maritime operations were concerned and the Formal Enquiry was headed by Sir Gordon Wilmer, QC….

Gordon Willmer - Wikipedia

Sir Gordon thanked Mr Maynard for his evidence with great courtesy, and proceeded to show exactly what he thought of it.

 

[Neeves]

My Fil an ex seaman once told me, it was the weight of the tow line that did the towing rather than the pull from the tug?

Sort of, but only sort of. The towing line describes a catenary curve between towing and towed vessels. The weight of the line tends to draw the vessels together; the towing vessel counteracts that tendency. So you can argue that the weight of the line pulls the towed vessel forward, and if the towing vessel were stopped, the towed vessel would (theoretically) continue until the towline hung vertically. But the towing vessel keeps the curve flat, so the process continues. However, if you look at the balance of forces, it is clear that the towline is transferring a force from the tug to the towed vessel.

This is the same technology that its the chain that holds the yacht - not the anchor.

Its refreshing to see the technology is so widely accepted and is, thus, obviously correct

Jonathan

Apologies - I had noticed a dearth of anchor threads, this was the best I could do

 

[Bilgediver]

I was just wondering, say a biggish containership, 10000 TEU broke down, prop fell off, so its drifting about, a passing oil tanker, big one, could it take the containership in tow?

The immediate problem would be what to tow with!!!!! What ship carries a towing line of 600 metres.

In the event that a safe method of towing is established you then come up against the problem of operating outside the propeller curve. You might mange a slow speed tow but it would be hindered by other factors such as turbo surge. I was once on a ship that while travelling at full speed was virtually stopped very quickly by an unusual sea. The turbos then certainly let us know they were unhappy as the governors applied more power to keep the propeller revs up.

If you look at a tug boat it has a much bigger propeller than a normal ship of the same size and also a much more powerful engine. This can be handy on the North Sea anchor handling boats when heading to port in a storm. Just a case of Home James and don't spare the horses. That is why they have no other windows on the front of the bridge apart from the bridge windows and those are protected by breakwaters. It can be exciting doing 14knots into a head sea in a force 10 but you need a strong stomach ! They have the power to do it and built accordingly.

 

[Bilgediver]

I remember with great fondness (not!) Mr Len Maynard of P&O Safety Services, who had been on board the “Amoco Cadiz”, advising the Italian crew on safety matters, on the 16th March 1978, telling the Liberian Formal Enquiry into her loss that “The tug wasn’t towing. It wasn’t trying to tow. The tow line never came out of the water!”

That is quite normal with a 2" steel towing line od 2000 ft or more.. Sometimes if towing in adverse conditions they tow using a line attached to an anchor and pay out enough chain so the anchor is between the tug and ship. This helps reduce snatching in heavy weather.

 

[Kukri]

That is quite normal with a 2" steel towing line od 2000 ft or more.. Sometimes if towing in adverse conditions they tow using a line attached to an anchor and pay out enough chain so the anchor is between the tug and ship. This helps reduce snatching in heavy weather.

Everyone in the room, most certainly including Sir Gordon Wilmer, and all the lawyers present, who were from the Admiralty bar, all very familiar with salvage tugs, knew that. But not Mr Maynard of P&O.

This was the tug; I knew her, her owners and her Master quite well as I handled her routine salvage claims. At that time, nobody had ever tried to tow a laden VLCC in a full gale. I remember with absolute clarity the owners’ salvage superintendent, a man whom I knew and liked, saying on the phone, around midday, “I don’t think we are going to do it.” As soon as the tanker’s Pan message had been received he had ordered her bigger sister which had sailed eastwards running light that morning to turn back at full speed to try to assist. She arrived an hour after the tanker grounded. If the tanker had issued her Pan message when she lost the steering gear, not after a long chat with Amoco’s Chicago office, she might have been in time.

Grrr!

 

[Bilgediver]

Everyone in the room, most certainly including Sir Gordon Wilmer, and all the lawyers present, who were from the Admiralty bar, all very familiar with salvage tugs, knew that. But not Mr Maynard of P&O..

Grrr!

All my towing experiences are with oil rigs. Some of these tows were over long distances until our Dutch friends introduced us to heavy lift vessels, Luckily non of the ships I sailed on ever required a tow even though for five years I was powered by 2 X 9 cylinder Ruston AO engines which had a habit of making life very interesting. Our sister ship was on on one occasion rescued by a tug.

 

[Kukri]

Off the subject, but I went from the world of salvage and long distance tows to the oil patch. It was very different. For instance in describing a salvage tug’s horse power we used “ihp” - not “indicated horse power” but “installed horse power” (add the generators to the main engine(s))
and no salvage tug master worth his salt in the 60s and 70s would dream of not sheering the deck edge under on a bollard pull test. The oil patch would have been horrified - not that they didn’t have their own cowboys, but they were a different sort of cowboy!

 

[AntarcticPilot]

Off the subject, but I went from the world of salvage and long distance tows to the oil patch. It was very different. For instance in describing a salvage tug’s horse power we used “ihp” - not “indicated horse power” but “installed horse power” (add the generators to the main engine(s))
and no salvage tug master worth his salt in the 60s and 70s would dream of not sheering the deck edge under on a bollard pull test. The oil patch would have been horrified - not that they didn’t have their own cowboys, but they were a different sort of cowboy!

I worked in oil exploration in my early career, and it was said that you measured the experience of a roughneck by the number of fingers he'd lost. That's not firsthand - I was never on rigs - but I remember being quite cavalier about explosives. When you've seen boxes of TNT being thrown about by a couple of guys with broad Somerset accents, it's hard to take the stuff seriously! But detonators terrified me. I always thought it odd that TNT (which is as safe as firewood and useless without a detonator) had to be locked away in a specially designed and licensed magazine, but detonators (which are really difficult to improvise, and can go off if you look at them the wrong way) were in a little box on the outside of the magazine where anyone with a hacksaw could get them! Explosives can be made by anyone with access to fertilizer and a cement mixer; detonators are the difficult bit!

 

[davidej]

While at school our chemistry master took us to the explosives place at Waltham Abbey (I think).

A kindly NCO gave me a handfull of detonators. I found that if you took a light bulb out and wired a detonator in it’s place, when the unwary came into the room and switched on the lights, they would be greeted by a large bang and electrity in the whole building would fuse.

oh! Happy days.

 

[Bilgediver]

no salvage tug master worth his salt in the 60s and 70s would dream of not sheering the deck edge under on a bollard pull test. The oil patch would have been horrified - not that they didn’t have their own cowboys, but they were a different sort of cowboy!

That paragraph sends shivers down my spine. Childhood memories of an incident in Cardiff Docks. I had no idea life on a tug boat was so dangerous.
There is actually a piccy on Ebay.

1951 British Railways Tug “earl” Sinks In Cardiff Docks While Escorting Campania | eBay

 

[AntarcticPilot]

That paragraph sends shivers down my spine. Childhood memories of an incident in Cardiff Docks. I had no idea life on a tug boat was so dangerous.
There is actually a piccy on Ebay.

1951 British Railways Tug “earl” Sinks In Cardiff Docks While Escorting Campania | eBay

And more recently https://assets.publishing.service.gov.uk/media/547c7010ed915d4c0d000073/FlyingPhantom.pdf

 

[AntarcticPilot]

While at school our chemistry master took us to the explosives place at Waltham Abbey (I think).

A kindly NCO gave me a handfull of detonators. I found that if you took a light bulb out and wired a detonator in it’s place, when the unwary came into the room and switched on the lights, they would be greeted by a large bang and electrity in the whole building would fuse.

oh! Happy days.

While it's the sort of thing we all would have done when young and carefree, detonators really shouldn't be treated lightly. They contain an explosive charge that can easily blow your hand off - indeed, I was taught to hold them by the wires so that they were held several inches away from a closed fist. The idea was that if it did go off, you MIGHT keep your hand.... And they usually have metal cases, which turn into shrapnel on detonation. That NCO would have faced some very hard questions if you or your mates had lost a hand or eye.

Dynamite, TNT and so on don't worry me - but detonators terrify me.

PS. I made a mistake in my earlier explosives post - it was dynamite being chucked around, not TNT. But all bulk explosives are pretty safe - the last thing you want is for them to go off at the wrong time. Ammonium nitrate and ANFO are a bit touchy (remember the explosion at Beirut?).

 

[Kukri]

And more recently https://assets.publishing.service.gov.uk/media/547c7010ed915d4c0d000073/FlyingPhantom.pdf

That was a girting. The usual cause of disaster with conventional tugs. Water tractors are immune to it.

 

[fisherman]

I like to watch the series of UK TV programmes about RNLI rescues. They sometimes tow moderately large ships, and tow lines break. I don't remember them saying how they cope with I presume how the two broken ends fly towards the vessel to which they are still attached with the stretch energy...

Your RNLI crewman gets broken ribs, in the local case here.
Extra Master Graham Danton details towing in his Manual of Seamanship. Hawser parcelled up with canvas and copper sheet, if I remember. Lots of useful stuff in it.

https://www.libramar.net/news/the_theory_and_practice_of_seamanship/2021-06-19-4226

 

[fisherman]

I took a diver out to a wreck, to retrieve pig iron ballast, some of it had to be blown apart before lifting. (The Hansy, if you're interested).
He came up, popped his head over the side, "Cut off a couple of inches of the explosive and pass it over"
"Wh.......where's that?"
"It's that sausage lying on the deck, but don't worry about it , safe as houses, it's the dets you have to worry about"
"Wh... where are the dets?"
"I put them on the engine to keep dry...." ......that's the, very hot, aircooled Lister engine.

 

[R.Ems]

I know a guy who was casually crewing on an old retired minesweeper, on the front deck, under tow.
Something parted on the towing vessel, and the towline catapulted a D-shackle into his skull, turning half his brain into mincemeat.
He was a vegetable for weeks on life support, then the other remaining half of his brain fired into action, and he became himself again,just a bit groggy. An amazing result, the family were planning to have him switched off at some point.
I have seen the D-shaped hole in his head, since patched over with metal.
I am wary of lines under tension.

 

[AntarcticPilot]

I took a diver out to a wreck, to retrieve pig iron ballast, some of it had to be blown apart before lifting. (The Hansy, if you're interested).
He came up, popped his head over the side, "Cut off a couple of inches of the explosive and pass it over"
"Wh.......where's that?"
"It's that sausage lying on the deck, but don't worry about it , safe as houses, it's the dets you have to worry about"
"Wh... where are the dets?"
"I put them on the engine to keep dry...." ......that's the, very hot, aircooled Lister engine.

Sounds like the diver wasn't worried enough! I think you had a close shave then - heat + vibration + detonation could easily result in ?!

 

[Bru]

.
I am wary of lines under tension.

Rightly so!

An old friend of mine has a large chunk of his upper left arm missing and was very fortunate not to lose his arm altogether after a bracket failed whilst recovering a bogged down 4x4. The shackle onto the bracket came back through his windscreen, then his bicep and finally embedded itself in the bulkhead behind him

I had a winch cable part whilst recovering a dead road roller onto the bed of my truck. The cable whipped back with so much force that it cut more than half way through a 3" fence post (and people wondered why I got a bit annoyed by incursions into my safety zone when winching!)

Just two of many incidents involving winching and towing I've witnessed over the years including, sadly, a fatality but that involved that most lethal of devices, a kinetic recovery rope (a piece of kit originally developed for battlefield tank recovery under fire which should never have been available to the general public IMO)

 

[R.Ems]

I bet that kinetic tank recovery line would make a great snubber

 

[AntarcticPilot]

I bet that kinetic tank recovery line would make a great snubber

I think you gain the "Wooden Spoon" award for stirring!