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Old 22 February 2007, 11:24   #21
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Have towed a 7.3m Gemini with a 46' Sealine within the Solent for short periods.

Single line from one cleat on the Sealine to the bow eye on the Gemini. Outboards trimmed right up. Seemed mostly OK and we towed up to about 20 knots - the Gemini was stern heavy with two 200 optis on the back!

However, the tow rope did break when going ove the red jet wake and we did have one moment when the rib surfed outside the tow boats wake and nearly overtook us!

Would probably have been better with a bridle on the tow boat and someone in the rib to steer. We were only towing to give the RIB coxn a warm up and a cup of tea!
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Old 22 February 2007, 11:59   #22
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IBWET - New climbing rope does have stretch/elasticity in it to reduce the load on the climber and the hardware during a fall. It does go stiff and horrible though with prologned exposure to salt water and UV. It may be that the poster who said it has "no give" was referring to old out of condition rope.

However, I don't think you will find 16mm climbing rope - 8-11mm is standard.
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Old 22 February 2007, 12:13   #23
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Originally Posted by Polwart View Post
IBWET - New climbing rope does have stretch/elasticity in it to reduce the load on the climber and the hardware during a fall. It does go stiff and horrible though with prologned exposure to salt water and UV. It may be that the poster who said it has "no give" was referring to old out of condition rope.

However, I don't think you will find 16mm climbing rope - 8-11mm is standard.
My original plan was for the tow rope to be climbing rope, with the two bridles be 16 mm (mainly because I've got lots of it lying around) the age changing implication is now making me think more along the lines of normal rope as the tow, I can splice a large S/S hard eye into both ends with one or two mooring rubber/shock absorbers along it's length, also one two other idea's already posted.
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Old 22 February 2007, 12:14   #24
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I have been using old climbing rope for many years & yes it dose go hard over time, but then it was free!
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Old 22 February 2007, 13:12   #25
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If you go for 'ordinary' rope, make sure it's nylon, which is often used for anchor line I think, and mooring lines. Nylon line stretches - up to 20 per cent I think, Try to avoid polyester, it has little stretch. I wouldn't even think about polypropylene etc.
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Old 22 February 2007, 14:40   #26
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If you go for 'ordinary' rope, make sure it's nylon, which is often used for anchor line I think, and mooring lines. Nylon line stretches - up to 20 per cent I think, Try to avoid polyester, it has little stretch. I wouldn't even think about polypropylene etc.
Thanks,

Very usefull

Iain.

Incidentally, are you going on the Coryveken trip?
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Old 22 February 2007, 18:25   #27
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Thanks,

Very usefull

Iain.

Incidentally, are you going on the Coryveken trip?
My pleasure, thanks.

Re. the Corry. I'm hoping to go but much depends on the weather. I've spent too long floating around this part of the sea in cold, wet and gales to do it for fun these days. If it's half decent and not too windy I'm hoping to be there. Made it the deadline for getting the boat back in the water anyway. (usually kept afloat on a relatively exposed mooring. Slip at Ardfern Yacht Centre is excellent, but getting the boat back into the drive it's kept in is a major undertaking for lots of reasons, so I try not to do it too often) I'm just about to order the wherewithall to make a tent for the rib so I can sleep aboard in Argyll weather. Probably won't get that finished in time though. If it's too wild and woolly I'll drive over to Craobh and perhaps meet up in the evening.

Tony
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Old 23 February 2007, 04:14   #28
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Talking of climbing rope watch out for black or occasionally white rope about 16mm, there is a type of climbing rope called "static" and its exactly that, it has no give in it.
Its designed for abseiling or SRT (single rope technique) - ascending as well as descending). Basically jobs where you don't want bounce!
Also climbing rope is designed to take one major fall normally, just something to bare in mind.
hope it helps
James
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Old 23 February 2007, 09:20   #29
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Quote:
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the lewmar snatch block I did find for 16mm, was 300!.
That just goes to show the people I used to race with had more money than sense. Sorry for the bum steer.

On the rope front. 8 or multiplat is pretty damn stretchy. Its used for Kinetic recovery rope by off roaders. A scary recovery method involving a slack rope and as much speed as you can get before the rope goes tight. This usually happens when you get 1/4 to 1/3 further apart than the length of the rope.
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Old 23 February 2007, 11:41   #30
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Well that surprises me,the whole reason I was going down the climbing rope route was because the rope had give in it (so a falling climber dosen't get a broken back..) however it was an assumption I made.
Falling climbers aim to minimise the distance they can fall at anyone time to avoid breaking themselves, rather than relying on the stretchiness in the rope!

The thing is with "climbing rope" there are various different sorts for various different tasks. Principally, you can break them into two main types... static rope, and dynamic rope. Basically, one stretches A BIT (dynamic), and one doesn't (static). Personally, I can't see that either of them would be useful for towing boats.

Dynamic rope... which I'm assuming is what you've got is designed to be shock loaded once... and then binned. Although, admittedly that is where a second fall on the same rope would have potentially fatal consequences. Perhaps you feel that's an acceptable risk when towing on water?

Although I must say (as someone else has) I've never seen 16mm "climbing rope".

Cheers, WMM
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