Friday 5 March 2021

Blister

The 10mm knitting needles arrived in the post and I immediately took one out to the workshop and cut an end off.

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Great… it’s both hollow and made of metal rather than the expected plastic.

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What is not so great is the internal diameter of the needle is smaller than the rope.  I’ve overcome that by removing some of the rope threads at the end to create a cone.  This was then taped together with electrical insulation tape.

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I now had a DIY Fid.  Unfortunately I couldn’t get the Fid down the core of the orange rope.  My suspicion is I’ve made too many previous attempts on this piece of rope and the inside is “hairy” which is snagging the inserted cord.

However my luck changed as the courier arrived with the 30 metres of blue Dyneema tow rope I’d ordered online. 

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The crazy part of this is it was cheaper to buy the complete tow rope than Dyneema rope by the metre.  Way cheaper!!!

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.My knitting needle Fid and 16 gauge wire “pusher”. 

It took some juggling around but I managed to get the Fid and rope through the centre of the Dyneema.

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No doubt you can see my error in the above photo!  I’ve managed to get the measurement wrong and there isn’t enough rope on the end of the Fid to tie a diamond knot.

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Got the tails the same length on my second attempt but they were very short making tying the diamond knot rather difficult.

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Second soft shackle with longer tails and some black protective sleeving I’ve recycled from the original tow rope.

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The finished product with lighter to provide a perspective of size.

Next I wanted to make a ‘Bridle Strap’.  A You Tube video explained how to make a simple “Longbury’ eye splice in Dyneema.  However this splice isn’t as strong as the more complicated ‘Mobius Brummel Locking Splice’.  I decided strength was important and opted to create my ‘eyes’ in the ends of the Bridle Strap using this latter method.

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My Bridle Strap connects to the recovery points on the 4x4 with two soft shackles.  Using the bridle strap means any load is being shared across the recovery points.  Less strain on the recovery points and hopefully minimising the risk of twisting the chassis.

At the end of the day all the Dyneema has been used and I have 11 soft shackles and two bridle straps.  Plus one blister!

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I might now have a further attempt at creating soft shackles from the orange rope.

My thanks to readers who sent suggestions on how I might achieve all of this.

4 comments :

Alf said...

Don't know how much your 4x4 weighs but having had some experience of towing dead rally cars out of ditches/gullies I would personally like a much beefier rope or even a wire or chain capable of pulling at least twice the weight of the vehicle.

Tom and Jan said...

Alf 10mm Dyneema has a breaking strain of 10,700kg. Low stretch, high abrasion resistance and floats. If it breaks under load there is minimal whiplash.

[Quote]
Switch to a synthetic winch rope
If you want to increase your safety factor, synthetic winch lines have higher Minimum Breaking Strengths than steel cable. Where 5/16" steel winch cable breaks at 9800 lbs, MasterPull's 5/16" standard winch rope breaks at 12,300 lbs which is an okay strength increase. Their 5/16" Superline, however, breaks at 21,700 lbs which is more than double the steel winch cable and a huge improvement in the safety factor. You can also reap large strength benefits by using a 1/16" larger winch rope that has a slightly shorter length. There is little doubt that for most fourwheelers synthetic winch line is going to be safer.
https://www.roundforge.com/articles/all-about-winch-cable/#:~:text=If%20you%20want%20to%20increase,is%20an%20okay%20strength%20increase.
[unquote]

I used to think steel wire was stronger than synthetic but I'm a convert :-)

Alf said...

Fair enough, I, like you were, am obviously out of date on such matters, (& many others no doubt !!) Too much experience & not enough research ? :-)

Tom and Jan said...

Alf I was with you thinking steel rope would be much stronger!