Tow rope thickness

rigi36 · 08 May 2012, 20:03

Is 10mm tow rope as shown below too thin for a boat towing the average 5m rib?

What would you recommend?

High visibility floating security / tow rope 10mm canoe | eBay

Thanks.

thomas · 08 May 2012, 20:27

A decent braided 10mm rope from the chandlers would be fine but wouldn't trust a floating rope with the same diameter for the same job.

Starovich · 08 May 2012, 20:49

been using a canoe throw bags for 20 yrs now same rope thickness (multiple bags) worked for me all the time.
OFC depends what you are towing.

njensen · 08 May 2012, 20:56

Quote:

Originally Posted by maxhar

Is 10mm tow rope as shown below too thin for a boat towing the average 5m rib?

What would you recommend?

High visibility floating security / tow rope 10mm canoe | eBay

Thanks.

be careful about thin nylon ropes... they stretch and it hurts and burns when it breaks. I would not tow a 5 meter rib with anything less than 12-14 mm unless the sea is flat.

Gentiana · 08 May 2012, 21:12

Good quality 10mm or 12 mm braided rope, for small boat to 5m rib. Use a shock absorber. Small tire --O----, especially if lumpy conditions.

P

jyasaki · 09 May 2012, 05:34

Ideally, you want something other than nylon for towing, unless you take a lot of care to prevent backlash should it break. Nylon stretches, and if it goes, it tends to snap back with a lot of force. The cutting someone in half thing has been proven wrong, but it will still break bones or leave a decent welt. Tying a large piece of cloth (towel or similar) every 20 feet or so will increase drag through the air and slow it down pretty well.

If you anticipate having to tow, get a dacron or polypro rope of adequate thickness. Of course, if it's an emergency, use what you've got and hope for the best, but anticipate the worst.

That said, I think the USCG generally use nylon tow ropes as a cost point type thing, but they clear decks while towing.

jky

chewy · 09 May 2012, 08:28

I'd use 10mm nylon, the stretch will act as a shock absorber and take the strain off the fittings.
Regards it snapping you should never be towing that quick to have such a great strain on it....

rigi36 · 09 May 2012, 08:43

Should add that most of our towing will be done on the non-tidal thames where the water is almost always flat.

jyasaki · 09 May 2012, 15:08

Quote:

Originally Posted by chewy

I'd use 10mm nylon, the stretch will act as a shock absorber and take the strain off the fittings.
Regards it snapping you should never be towing that quick to have such a great strain on it....

Not a matter of quick, it's a matter of the rope failing.

jky

chewy · 09 May 2012, 18:22

Quote:

Originally Posted by jyasaki

Not a matter of quick, it's a matter of the rope failing.

jky

Whenever we tow anything the rope is just under tension, I've never worried about it snapping.
If its tight like a piano wire then I would but done properly you shouldn't have any troubles.

I got a Series 3 Landy pulled out of a ditch with 14mm 3 strand rope, the rope was fine, it did stretch but then the Landy pinged out.
If you have any concerns wrap some other rope around it so it breaks the whip effect.

hobbit555 · 09 May 2012, 18:53

The longer the better really. Nylon will snap back on parting and has on occasions killed people on decks of tugs. I have happily used 10mm climbing rope and floating rope to tow 5 mm ribs in a variety of conditions. Unless your rib is set up as a tow boat it is unlikely you will have dedicated rope. The rougher the conditions the longer the tow.

rigi36 · 09 May 2012, 18:59

Quote:

Originally Posted by chewy

If you have any concerns wrap some other rope around it so it breaks the whip effect.

Suppose you could pass a second tow line over too to share the load.

m chappelow · 09 May 2012, 19:10

10 or 12 mm braidline would be fine for general small boat towage and as was said earlier in the thread nylon even though it can stretch up to half before parting does have great shock loading propeties,and yes i have seen a couple of bad incidents where nylon has been used under load ,
worst was a smallish speedboat that was swamped the novice owner tied his nylon anchor line to a 4x4 hoping to drag it out of the water when the chrome bow fitting broke out and hit the owner in the face him nearly loosing the sight in one eye
just as a matter of intrest braid line of 12 mm has a breaking load somewhere around 2 tons on a decent length of line ,
as phil (chewy) said its sometimes the snatch loading on fittings that can fail as much as the rope.

pic of our Atlantic75 when we lent it to phil (Chewys ) station for a few weeks whilst their boat was in for a refit ,
and my own y boat sib towing back a broken down boat using 10mm braid .

dont forget that if towing a much heavier boat you will most likely need a bridle set up that can slide about from the transom otherwise you cannot get steerage proper unless you have a samson post set up infront of the propeller .
last pic my tow line and bridle set up for towing off the transom.

chewy · 09 May 2012, 20:33

Quote:

Originally Posted by maxhar

Suppose you could pass a second tow line over too to share the load.

You'd never manage to get the ropes the same length to share the strain... would having two ropes double the risk on whipping back.......

Our Atlantic has towed a Tyne class lifeboat which is 47ft of steel and weighs 25 tonnes, Mart may be able to tell you the size of tow rope used on the Atlantics?

m chappelow · 09 May 2012, 21:57

Quote:

Originally Posted by chewy

You'd never manage to get the ropes the same length to share the strain... would having two ropes double the risk on whipping back.......

Our Atlantic has towed a Tyne class lifeboat which is 47ft of steel and weighs 25 tonnes, Mart may be able to tell you the size of tow rope used on the Atlantics?

think its 14mm and about 36 metres long

m chappelow · 10 May 2012, 10:37

[QUOTE=chewy;461370]
Our Atlantic has towed a Tyne class lifeboat which is 47ft of steel and weighs 25 tonnes, QUOTE]

found an old pic of Redcars Atlantic 21 with 60hp engines towing a Tyne.