Tow rope specification

[jasavo]

Its about time I had a decent tow rope. What are your recommendations for the diameter, length and material of a tow rope I should carry. My boat is a HB31, an IOR half tonner, and I sail out of Falmouth in the South West and across the channel.

 

[Mirelle]

Gosh! Something I know about!

Three strand Nylon.

Ideally with chafe protection in way of the fairleads - in big ships the "chafe protection" is a length of chain, spliced in, with most of the tow rope being wire with a nylon shock absorber included.

It can be as long as you feel like, the longer the better. If the breaking strain (not the safe working load) is the same as your displacement, you cannot go wrong.

 

[Stemar]

Is there any reason why you'd choose 3-strand rather than octoplait? I keep a spare 30m anchor warp in my locker with towing in mind. It's more than strong enough (about 1in diameter, for a 2 ton boat), but is it unsuitable for towing, and if so, why?

 

[geem]

I used a 100 ft of 3/4 inch 3 strand to tow a pals Centaur 20 miles up the coast when his motor failed. In the middle of the tow rope was a knot joining the tow rope together. In the 4 hours it took to tow the boat the knot dodnt even go tight. The catenary effect of the long rope took all the strain out of the tow. I wouldnt like to tow with anything shorter, especially if the sea was a bit bumpy

 

[Mirelle]

"Unsuitable" is much too strong a word!

Harbour tugs tow ropes are usually octoplait.

But the elasticity of three strand is rather better, so "theoretically" a deepsea tow rope should be three strand. The nylon buffers in the tow ropes of dee sea tugs are normally three strand, doubled.

If you have a warp that can be paid out without trouble, and is strong enough, you are already better equipped than most yachts.

 

[Stemar]

I think that if I had to tow someone any distance in lumpy conditions, I'd want to help the catenery by hanging a spare anchor from the middle of the tow.

Good idea or bad one?

 

[Talbot]

something heavy - a good idea

an anchor, only a good idea if the water is deep enough and when slack the anchor doesnt get to drag on the bottom. /forums/images/graemlins/wink.gif

 

[Mirelle]

Theoretically, good, but you will want to heave the tow line in, at some point, and a big anchor hanging off it can be rather awkward!

Since the operation may be taking place under "less than ideal" conditions, simplicity is good.

 

[andy_wilson]

Easy - one I can answer....

Your tow rope shoud be exactly the same length, diameter and material as your kedge warp.

 

[GMac]

Re: Easy - one I can answer....

Get a rubber band and stretch it until it breaks, what happens? Pain baby. Use Nylon and you have exactly the same situation. Nobody involved with towing uses nylon as they all know it's bloody dangerous. Nylon can stretch 40 odd % at break and do you want the end of that coming back and taking out anyone on the stern, I think not. If you really want to use a Nylon make sure it is that big there will NEVER be a chance of it breaking. Nylon tow ropes have put people in hospital.

Use a multiplait of some description so it will not spin and un-lay under load.

You will find tugs and so on use Spectra and/or Dyneema. It has no stretch so you have a lot more control over the tow. Deep sea towing is done on big long wires with chains in the line and some now use Spectras as well.

Obviously Spectra is cost silly for an occasional job so get a nice bit of multiplait or braided Polyester. Don't go to small a size as polyester stretches as well and you don't want that doing a rubber band on you either. Polyester does not stretch as much as nylon so the broken bit flinging back at the boat will be moving a bit slower. Polyester also has superior chafe resistance.

Don't make the tow rope to short, increases loads and chances of breaking.

We have just outfitted our Coastguard with Dyneema tow ropes as they keep getting handed the end of the nylon anchor rode. They will simply not tow using a nylon rope full stop and will only use polyester if pushed. For their own crews safety they have spent the money getting their own tow ropes.