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a little stringy thingy... Could be right up KM's alley.


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I recently replaced the tramp lashing on the GBE, finishing it off on the day of the rum race.

 

That same night some of the line broke, quite badly chafed. I had plenty of spare so simply re-tied it all pre-race.

 

Does anyone have any suggestions on which cord/string is best for this? I use continuous lashing for each area, rather than individual loops.

 

Would D12/ Lightning/ whatever it's called here (plaited dyneema with no case) be a good choice or would it not offer enough chafe resistance? And if so, where's a good place to buy it? 

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Thanks KM, that's what I suspected.

 

I've worked with dyneema before (used to run a chandlery in the UK) but couldn't remember what the chafe resistance was like. I probably should have given that a little more thought, given that I use it on the Laser cunningham through the sail. Doesn't move much but wears through some other types of line.

 

We also sold some so-called liquid crystal in 4mm which was crazy strong, but went for something like GBP 4 per metre. Never found out what it was meant for, but the director/owner seemed to love it, and sold lots of it. I don't think I ever sold any! It was called "black gold" in reference to both it's colours and its revenue ability!

 

edit - just remembered that stuff was called Vectran. Ring any bells?

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Vectran is a sort of cousin to Kevlar. KM will tell you more details on the rope itself, but Kevlar was developed way back in 1965 by DuPont from an aromatic polymide. There is a closer cousin to it that was developed by Azko and starts with T, but the name escapes me. The development of the co polymer's opened up a whole new area of technological developments and from that base range of Co polymers came a Liquid Crystal Polymer which the fibre made from it was called Vectran.
Synthetic fibres are all pretty much a form of plastic. They come from the same base, being Ethene. But then a lot of spookery is done to make some real fancy mixes. Much of it being complete accidents too. Like for instance, one of the most famous being superglue. The inventing chemist of that one was trying to make a superior optical sight for Rifle Scopes back in WW2. Later on, a lightly different version was made for pulling wounds together and stop the bleeding during the Korean war. Anyway, that's a tangent.
So the flashy rope fibres are actually forms of plastics. But the Molecular chains are just arranged slightly differently to gain the various properties. Vectran fibre actually has one of the same key ingredients in it's make up as the clear plastic fizzy drink bottle does. That particular clear plastic is what makes Polyester. You can have LDPE (low density Polyethylene) HDPE (High density PE) and UHMWPE (Ultra high Molecular weight Polyethylene, or also commonly called Umpfee by engineers) And that is what Dyneema is spun from.
When it comes to these Chemical Engineers, I had a guy I used to talk with a lot that was working in some Chemical Field, but the stories he told make your hair stand on end. Like sometimes a lab would be demolished because some mix didn't quite work out as expected. They often had no idea what to expect when 1 part 19456alpha was mixed with 2 parts of 5q471074gamma. (* I made those up)
 

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Individually tie the tramp at every hole, this limits the amount of string movement and wear. This also insures that the whole lot doesn't come undone at once. Dynema is good, doesn't break, the small diameter string will cut through plywood.

 

I keep a few lengths of string in my pocket and try and  replace a few every time I go out. Ken from Voom splices each individual string. Most of us don't have time to do that.

 

The rods in our tramp continually creep out of place when the boat is moored and getting battered with wind and waves, like right now. Does anyone have a great way of keeping the rods in place?

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I also tied each hole individually and am not surprised you've chaffed through so quickly. I went with poly for the lacing because I prefer that they are a little more "springy" than the hmwpe and uhmwpe ropes.

 

I used small sail batten ends 'glued on' with silicone so they could be removed and whipped them in place but had limited success with that idea. Really need a longer and better fitting sleeve - I'm going to turn a few out of ally on the lathe - perhaps even with a thread though I think the batten might be a bit small for that. The other thing I've done is to run a grub screw into the rod tube to act as a gate.

 

I would be interested in how others tie each lacing off - I simply went round twice and reef knot - but it's hopeless for holding tension until the knot bights. Tramps hopefully go onto Ballistic in two weeks.

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The main reason I switched to continuous lacing is exactly that reason. There is not enough space to tie and tension individual lashings at present. On the sides, the tramps touch the hulls all the way along the outsides, and also touch the pod in the middle. I'll wait and see how much chafe happens there. On the plus side, the rods haven't moved since the switch. 

 

That said, it was the back end of the front tramp (along the main beam) that chafed through, which is where the most gap is, and probably also the highest point loadings as the lashings are further apart. I'll re-do that part with dyneema singles.

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Yeh - they have stretched over the years. Was going to get Bill to shorten them in Feb. but just didn't get round to it - sorry! Pin the front one home as tight as you can crosswise, then pin to the main beam - also as tight as you can, then tension to the forebeam - the weave crimp might give a bit more crosswise tension. You won't be able to do too much more with the aft tramps without a trim.

 

I use long nose pliers masked with sparkie tape to get them as tight as possible.

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Tried marling hitching?

 

That's what I've done all round. The failure was at the cross-over. 

 

It's probably to be expected really, given that my four year old uses it as a, well, trampoline! The flexing of the hull sides is pretty scary to watch, so I usually just look elsewhere :)

 

Of course, it's always possible that I just lucked out, and the core had a weak point There wasn't any noticeable chafe elsewhere nearby.

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That's how Euphoria was originally and it chaffed everywhere - still have nightmares about discovering that issue! If you're going hitch like that then you really need grommets in the tramp I think. Grommets don't work on Ferrari tramps unless they're through a solid pocket which is welded to the base fabric.

However it looks like KM's R&D department is about to answer this ongoing question happy to enter the T into the program!

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I'm absorbing all the info here as best I can.

 

Short term plan is to get her race ready and clutter free.

 

Long term ambition is to make her easily demountable and trailable so those distant regattas are easier. Also so I can take her home for the off season.

 

That requires somewhat of a redesign in the tramp area to avoid the lashing each time, so when new tramps are needed I'll start drawing.

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Think KM is your man for that - they used to race a trail-able GBE back in the days of square wheels!

rushman - I think you are bang on the money - especially with Ferrari tramps - but I think they do need to be "squarish to be really effective".

You get the added advantage of the yarn span being 40% longer as well which will give them a little more give. They'll cost more though as the build labour would go up significantly (bill rubs his hands again). They'll look a bit kooky too but on a Race boat I don't think that's an issue

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Have seen some small race cats in europe where the tramp has a line running around the whole outside, and basically hung just from the four corners. Am thinking something similar with zips over the pod hatches.

 

Have got preliminary design work for trailer which allows loading of boat fully rigged, then folds in for trailing. Suspension design was a head scratcher as hulls need to lift over wheels in the folding process.

 

Luckily I had a bit of downtime at work, so out with the pencils!

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Have seen some small race cats in europe where the tramp has a line running around the whole outside, and basically hung just from the four corners. Am thinking something similar with zips over the pod hatches.

Have got preliminary design work for trailer which allows loading of boat fully rigged, then folds in for trailing. Suspension design was a head scratcher as hulls need to lift over wheels in the folding process.

Luckily I had a bit of downtime at work, so out with the pencils!

Transoms to the front of trailer?

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Have seen some small race cats in europe where the tramp has a line running around the whole outside, and basically hung just from the four corners. Am thinking something similar with zips over the pod hatches.

 

Have got preliminary design work for trailer which allows loading of boat fully rigged, then folds in for trailing. Suspension design was a head scratcher as hulls need to lift over wheels in the folding process.

 

Luckily I had a bit of downtime at work, so out with the pencils!

I'm interested in how you solve the trailer folding. I am considering doing the same thing with my cat and have a few basic sketches. Ends up being pretty tall if you keep it all above the wheels but a lot simpler.

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Plenty to comment on here but I will dig out a few photos over the next while and post up some solutions. I've seen and tried most methods but always come back to individual lashings around fibreglass rods. I'm definitely not keen on a single line lashing for an entire side, unless it's for a very short term. Even then I would rolling hitch every metre or so.

Bias cut bolt rope tramps never get tight no matter how hard you pull 'em, they also travel around on the bolt ropes as they stretch more in the centre which changes the edge length - result is they are always noisy to walk on as the bolt rope slides back and forth, even though it's only a meter on mm.

To stop the battens migrating on pvc tramps is reasonably easy, drill a hole in o e end of the batten and sew it in, also add a goop of 5200 right where it's sewn. Leave the other end to free range. To stop battens in hull tubes migrating I reccomend a similar approach, always have one end of the tube bogged and glassed closed and make an extra lashing cutout at the other end. Snot this gap up with 5200 and there it shall stay. I've got pics of lashings somewhere.

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