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Old 22 February 2007, 04:25   #1
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towing a rib safely

Does anyone here have any experience of towing a rib behind a larger boat?

The larger boat has two kleats either side of the stern,the rib has towing eyes facing seaward on the rib (I asked RC to put them there for this purpose) positioned 4ft back from the bow each side.

My concern is firstly loading, in relation to snatch, when both boats are out of sequence on waves, also the direction of pull if two fixed bridles are used.

Initally I thought (and still think ) climbing rope doubled up for stretch as the main line but thats as far as I've got, a rope bridle similar to the one used by skiers on the back of the transom is also an option but It think there will be a significant difference once again in loads, is there a larger capacity one out there ..?

Originally had a 4SR this was easy to tow,I tied the line to one side and raised the engine revs on the same side,everything tracked straight.

But this RC is a lot larger/heavier.

Any idea's would be appreciated.


Another one for you JW
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Old 22 February 2007, 04:54   #2
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You should not have a problem. Make a bridle between the two cleats on the larger vessel, then make a bowling in your tow line, or have a spliced eye made up with a stell ring in the cntre. This will ditribute the weight of the tow evenly and will prevent the tug from pulling to one side.

The attach the tow line to the bow eye which will be on the stem of the hull. This will be a strong point and will also prevent rubbing of the tow line on your sponsons. If you dont have a bow eye then make another bridle between the cleats which you refer to, and again attach the tow line to the bridle to spread the load.

With regards to snatch, make sure that the tow is as long as possible, and that the boat being towed is in the same wave trough as the boat towing. If you are getting snatch then you have attach some chain to the centre of the tow line, or even use a bucket.

May I also suggest that as you will not have any steerage on the towed vessel that you use a towing drogue that will be deployed from the stern.

Hope this helps

Simon
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Old 22 February 2007, 04:58   #3
mdt
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I would say that rigging a line on the “big boat” from one cleat to the other cleat with a block running in it, to which you could attach your climbing rope to this. Then copy this at the other end for the RIB, this should keep the pull strait and as much as possible keep the pull even on the points of each eye on the rib. And the longer the rope the more give it has.

Take it you are not talking of towing at a high speed
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Old 22 February 2007, 05:02   #4
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Quote:
Originally Posted by Simon Hawkins View Post
You should not have a problem. Make a bridle between the two cleats on the larger vessel, then make a bowling in your tow line, or have a spliced eye made up with a stell ring in the cntre. This will ditribute the weight of the tow evenly and will prevent the tug from pulling to one side.

The attach the tow line to the bow eye which will be on the stem of the hull. This will be a strong point and will also prevent rubbing of the tow line on your sponsons. If you dont have a bow eye then make another bridle between the cleats which you refer to, and again attach the tow line to the bridle to spread the load.

With regards to snatch, make sure that the tow is as long as possible, and that the boat being towed is in the same wave trough as the boat towing. If you are getting snatch then you have attach some chain to the centre of the tow line, or even use a bucket.

May I also suggest that as you will not have any steerage on the towed vessel that you use a towing drogue that will be deployed from the stern.

Hope this helps

Simon
Thanks simon,

The steel ring concept has answered most of the issues I had in relation to pull distribution. my only concern with something heavy enough to sink the rope at that point, is the possibilities of the rope getting round the prop of the larger boat.

Do you have a reason to attach to the bow eye on the rib? my searider used to steer/weave about when pulled from this location, RC suggested the rings positioned further back under the tubes may cure this...it's also a theory to ensure not losing the rib if towing at night when you can't see if it's still there.

Whats a bowling? and what do you think of the climbing rope idea?
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Old 22 February 2007, 05:05   #5
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Sorry I meant Bowline. Climbing rope is good as it is very strong.

Simon
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Old 22 February 2007, 05:14   #6
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Quote:
Originally Posted by mdt View Post
I would say that rigging a line on the “big boat” from one cleat to the other cleat with a block running in it, to which you could attach your climbing rope to this. Then copy this at the other end for the RIB, this should keep the pull strait and as much as possible keep the pull even on the points of each eye on the rib. And the longer the rope the more give it has.

Take it you are not talking of towing at a high speed
Nope, no high speed stuff,

I've looked for blocks etc, the problem is the the size of rope I'm planning on using for the bridle 16mm the block would have to accomodate this and as yet I've not found one large enough to do it..
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Old 22 February 2007, 05:26   #7
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Waterski bridles have a float which usually has the pulley inside,
Adding a float like this would reduce risk of tangling the rope round prop on the tug.

Quote:
Originally Posted by IBWET View Post
Thanks simon,

The steel ring concept has answered most of the issues I had in relation to pull distribution. my only concern with something heavy enough to sink the rope at that point, is the possibilities of the rope getting round the prop of the larger boat.
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Old 22 February 2007, 06:18   #8
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Quote:
Originally Posted by IBWET View Post
Nope, no high speed stuff,

I've looked for blocks etc, the problem is the the size of rope I'm planning on using for the bridle 16mm the block would have to accomodate this and as yet I've not found one large enough to do it..
Have you looked at snatch blocks?
e.g. http://en.lewmar.com/products/index....umber=19830500
They go past 16mm. Be prepared to loose an arm and leg though. It will cost around 70 squids.
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Old 22 February 2007, 06:24   #9
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Cleats aren't for towing, you need u bolts in the transom.
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Old 22 February 2007, 09:28   #10
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Quote:
Originally Posted by Mark Halliday View Post
Have you looked at snatch blocks?
e.g. http://en.lewmar.com/products/index....umber=19830500
They go past 16mm. Be prepared to loose an arm and leg though. It will cost around 70 squids.
Minan gotten! 70 squids...... actually couldn't get your link to work, so googled ,the lewmar snatch block I did find for 16mm, was £300!.

So cheers, but the best option so far is still a S/S ring that can float along the bridle both big and small boat. I,m thinking about fitting a float at the ring to keep the bridle (BB end) up and out the way of the props.
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