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Old 27 August 2013, 05:02   #21
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Originally Posted by Downhilldai View Post
Unless this slipway was at the bottom of my garden, I'd be looking to use a different one......
That's exactly where it is

The winch idea would be great, but then I'd have to run power to it. I don't fancy the idea of another battery to keep conditioned.
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Old 27 August 2013, 08:46   #22
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If the weinch is on the car - if you donlt already have one or a 13 pin trailer socket - fit a 23S. Plenty of power there.

If on the trailer a 2 pin Bulgin Buccaneer will take the same current as a 23S and keep the brine out when you are on the water.


But yeah, do not underestimate the power or utterly random direction-ness of a rope / cable snapping under tension. If you are talking danger zone, assume it snaps right at the trailer at the lowest tide. Then plot a circle the length of that bit of rope from the block. You won't be far off the danger zone if you do that. Then add a rectangle the width of your car x the distance it will travel based on you revving & trying to keep it not stalled with the handbrake on then get someone else to drop the handbrake & see how far you actually travel......


Also as I assume you will be needing to set this all up, the rope wil lbe lying on the ground where it will pick up grit that will not seem like much (if you can even see it) until it takes out a couple of strands & the rot sets in - the rest have a higher load and suddenly the 3T rated cpacity is halved?..... (Think how often climbers change their ropes!)
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Old 27 August 2013, 12:46   #23
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I can understand the wire rope flailing around when it snapped. Take a wire rope of a winch and all it wants to do is curl up again. So when it snapped.. it was flying through the air and trying to curl up. That is why I removed the wire from my electric winch and replaced it with a tape. Wire ropes are very dangerous if abused.

Having spent a great part of my lifetime working with the thompson capstan winch..and ropes of all sorts.. when they snap..and we broke them very regularly.. trying to haul heavy lead cables into the ground.. they generally travelled back in a straight line and dont flail around like the wire ones. However Im sure there are exceptions to every rule so dont take it as gospel. We used gate guards with their face flat on the pavement to help contain the rope if it did break as Joe Public were always walking past.

Quote:
Originally Posted by jlanng View Post
That's exactly where it is

The winch idea would be great, but then I'd have to run power to it. I don't fancy the idea of another battery to keep conditioned.
Here are another couple of ideas for you.

I was once a member of a small boat club .. and they had a similar problem. They over came it by installing a large hand winch at the top of the slipway..something like the one in the photo below. The club has long gone though..as Im sure health and safety laws would have wanted the winch tested regularly and small clubs would have found that and the insurance issues associated with it too much to deal with.

As it is in your own property..you wont have these issues and a hand winch pulling in a straight line ..is very much safer that pulling in a dog leg with a vehicle.



Another idea..if you dont want a battery operated winch on your trailer ..why not use the hand winch that is already on it ?

I do this often too..if I forget to charge the battery for the electric one. I haul a 350kg boat and engine over stoney and often steep beaches this way. (I realise your boat is probably twice this weight..but perhaps your trailer winch is suited to it too)

I attach a 9mm rope to my tow ball.. and winch the boat up this rope using a "jumar" left over from my mountaineering days. The tapes from the boat winches are not long ..so when I wind them up.. I chock of the trailer wheels ... unwind the tape and slide the jumar up the rope ready for another pull. The jumar bites tigher into the rope the more it is pulled..so wont slip. Its slow but steady work with the trailer winch but it has very little risk as you have a hands on feel for the tensions.

I was shown how to thread the rope through a shackle..and it also locked on the rope ..in a similar fashion to the jumar. I just cant recall how the "knot" was done now as I didnt pay much attention.. but Im sure I could find out if you wanted to try it that way.



best luck however you decide to do it..at least you now know some solutions and also the dangers ... so you are in a far better position to decide how to do it.
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Old 27 August 2013, 13:31   #24
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That sounds like a Prussic knot (which predates Jumars/ ascenders etc)!
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Old 27 August 2013, 15:13   #25
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Hi BumbleAbout.. the prusik knot is similar in concept..but it wasnt the one I was thinking about. Problem with the use of the prusik in this situation is the rope that locks onto the main rope has to be a lot thinner for the knot to work. Hence we loose rope strenght for winching.

The one I am trying to recall was made with the use of a shackle. I have fiddled about with a shackle and rope to try and work it out..but I cant get it correct.

It is something like shown below..in that the main rope will lock on itself if the pull is applied in one direction..but will easily slide if tension is removed and the shackle pushed along the rope.

Anyone know the correct knot ? below is not correct...but its that type of idea

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Old 27 August 2013, 23:02   #26
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Are you thinking of a Blackwall hitch?
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Old 28 August 2013, 01:24   #27
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Quote:
Originally Posted by The Gurnard View Post
Hi BumbleAbout.. the prusik knot is similar in concept..but it wasnt the one I was thinking about. Problem with the use of the prusik in this situation is the rope that locks onto the main rope has to be a lot thinner for the knot to work. Hence we loose rope strenght for winching.

The one I am trying to recall was made with the use of a shackle. I have fiddled about with a shackle and rope to try and work it out..but I cant get it correct.

It is something like shown below..in that the main rope will lock on itself if the pull is applied in one direction..but will easily slide if tension is removed and the shackle pushed along the rope.

Anyone know the correct knot ? below is not correct...but its that type of idea
Do you mean an Italian hitch?
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Old 28 August 2013, 03:57   #28
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I use 10mm dyneema for my Valiant 520. Works well so far, no complaints here.
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