Towing and being towed

[zoidberg]

I note yacht' Vagabond', stranded on rocks in the Isles of Scilly, has been towed off. But to where? Bennet's of Bryher....?

I recall being on the receiving end of a tow twice - once twenty miles south of The Lizard in an easterly storm, and once in a 'mirror-calm' in the Dhorus Mhor. I also note 'Yachting Monthly' has an article on towing, and it's informative..... as far as it it goes. There is a lot to learn.

'Towing and being towed' has always been part of the reality of working life afloat, and I'm well aware that few production boats have mooring cleats adequately beefed-up to manage the very substantial 'jerk' loads encountered over and over during a tow at sea. The same 'integrity' question can be asked of the fixings of cockpit and anchor winches.

It was standard practice to spread the load around the hull, to everything that could carry a part.... midship and stern mooring cleats being favourite, using 'nippers' and strops fastened on with rolling hitches and similar. The base of deck-stepped masts proved a 'no-no'. The common practice of passing a warp horizontally right around the hull from the stern to a bridle forwards has much merit. Could we rig that today?

It's not just a theoretic exercise - just a couple of weeks ago a 'Jester Challenger' Folkboat lost its rudder and was towed+sailed the best part of 500 miles, by another 'Jester' boat. There's probably another 'Yachting Monthly' article in that, sometime.

 

[fisherman]

One strongpoint in extremis is a beam across under a deck hatch.
In the 2014 storm in Porthleven I had a job keeping hold of 14 ton boat. The steel hauler cabinet was crushed, corner alloy beads around the wheelhouse bent, hatch coaming pulled off the deck, but a beam under the deck beams in the hatch held.

 

[Stemar]

The base of deck-stepped masts proved a 'no-no'.

That would have been my first thought - a bridle with a turn round each forward cleat when being towed, aft cleat if towing, and made off round the mast, so why a no-no?

I've only ever towed alongside in harbour, but my "thought experiment" for towing with Jazzcat involved a big bridle attached as above, as long a warp as I can string together and a weight in the middle to take up slack when the tow catches up a bit, but I'd hate to try it in a bad sea.

 

[Boathook]

That would have been my first thought - a bridle with a turn round each forward cleat when being towed, aft cleat if towing, and made off round the mast, so why a no-no?

Deck step masts normally only have a few small bolts holding the base in place as it is in compression most of the time. The base of mine mast has 4 bolts holding it whilst the cleats have 6.
Keel stepped mast mast is another matter and is or was normally suitable to have a rope round it at deck level.

 

[fisherman]

That would have been my first thought - a bridle with a turn round each forward cleat when being towed, aft cleat if towing, and made off round the mast, so why a no-no?

I've only ever towed alongside in harbour, but my "thought experiment" for towing with Jazzcat involved a big bridle attached as above, as long a warp as I can string together and a weight in the middle to take up slack when the tow catches up a bit, but I'd hate to try it in a bad sea.

And much depends on adjusting the length to accomodate the wavelength: start the tow and veer away until comfortable. I saw someone get in a state coming up the harbour, very light boat towing a much heavier one off the extreme stern, so no hope of steering.
I towed a boat nearly twice my weight, when we got in I lashed alongside with my rudder well behind his stern, put him in his berth no trouble.

 

[Gary Fox]

Deck step masts normally only have a few small bolts holding the base in place as it is in compression most of the time. The base of mine mast has 4 bolts holding it whilst the cleats have 6.
Keel stepped mast mast is another matter and is or was normally suitable to have a rope round it at deck level.

I'm going to partly disagree:

Keel stepped masts are usually not rigidly fixed to the keel but sit in a shaped block. This block (there are a few variants) is designed to hold the foot of the mast in place, when the rigging is tensioned.
The foot of the mast may just rest in a recess, without actually being physically attached, by bolts for example. The arrangement is less than ideal, if you want to use the mast for towing.

Going up, many masts are designed to flex and bend in use, the hole the mast goes through may allow movement, and the mast is often lightly secured with wedges or other non-structural methods. Ideally these might transmit the towing jerks and forward pull to the deck, but very likely not, with unpredictable results.

We all know what rigging we have, but think of the direction of any towing loads; obviously all boats are different, but I bet 30% of you have an 8mm backstay going up at a steep angle; useless. It can not assist with towing forces, but does hold the mast down to keep the bottom end in place. Same goes for shrouds etc. If you have upper + lower running backstays, that's a bit better of course..

So: the middle of the mast would benefit from lines going back to strong points, above the deck maybe cleats, winches, the whole counter perhaps? Below deck, maybe the engine mountings or similar.
I hope these thoughts are useful. It all depends of course, on your individual set-up.

 

[Mudisox]

Strong connection on the towed boat is one thing but the forces that cause Yaw and sway has often been a problem, despite long tow ropes/chains if the rudder has gone and there is little to straighten up the towed boat with a single deep fin keel. It also has an effect on the towing boat. Happens even in calm water, but a swell and 1m waves even increase the problem.

 

[Gary Fox]

Strong connection on the towed boat is one thing but the forces that cause Yaw and sway has often been a problem, despite long tow ropes/chains if the rudder has gone and there is little to straighten up the towed boat with a single deep fin keel. It also has an effect on the towing boat. Happens even in calm water, but a swell and 1m waves even increase the problem.

Using a bobstay fitting looks like a partial solution to help, but they aren't strong enough unless welded onto a steel hull IMO.