Replacing tramp tensioners

[Jaycb]

I need to replace the white plastic trampoline tensioners on my Dart (the "Erling" tightening method has served me well but every time I do it I fear some of my rather perished ones will snap) and I think I'm right in assuming I'll need to take one hull off in order to do this..?
I've never had to remove a hull before and am worried about breaking something or not being able to put it all back together again. Could anyone advise on the easiest way or if there any handy tips for doing this please? Also, how long do you think it would take and will I need help to do it or can it be done single-handed?
Thanks.
J.

[Martin Searle]

Hi,

On some boats there is a gap in the slot where the tensioners are you can replace them using that gap so check first saves lots of hassle!

But to answer the question of removing the hull:

The rigging manual for the 15 is here: http://www.sprint15.com/manuals/rigging_manual.php

Removing the hull:

You can do this singlehanded but its easier with 2 persons! Do it on a piece of soft flat ground (ie not a concrete area!)

1. Remove Mast
2. Remove Trampoline
3. Choose which hull you need to remove (the fixed central tensioner for the traveller dictates which one)
4. The retaining spring on the back beam needs to be moved to one side to allow the locking plate to slide up and from there you should be able to pull the hull out enough to allow the locking plate to slide slightly into the rear beam housing to keep it unlocked (as it were). To do this singlehanded: Stand inside the boat next to the rear beam lean over and move the spring and locking plate with your hand and push the hull with your thighs\knees (well its how I do it).
5. You should be able to slide both beams out by gently pushing each end of the boat (much easier to do this with 2 but with one ease one end then the other). Be careful when you reach the point when the last part of the rear beam is about to come out of the housing ensure you support the hull (I use my leg again if singlehanding) and then hold the rear beam to prevent it falling.
6. Ease aside the hull and put the beam down on the ground

I have seen it done so that you can get to the point of getting the rear beam out of the housing and then pushing the front beam back in the slot so you don't have to remove the entire hull just gain access to the end of the rear beam.

That should only take about 15 mins or so in the worst case. Just follow the rigging manual to put it all back together.

Have fun!

Martin S.

[Jaycb]

Thanks Martin, I'll have a look for that slot tomorrow. If there isn't one I may try to cut my own. Do you know if it was the early boats or later ones that had the slot?
Seems odd that the instructions don't advise to slide on the tensioners before fitting the hulls together - bet that's led to a fair bit of cursing over the years

[Erling]

Only the newer ones had the slot, my first boat 1704 didn't but 1959 did.

[Bob Carter]

Hi

This is what the slot looks like.

http://www.sprint15.com/pics/viewer.php ... &imgid=831

The one in the picture is on a new boat from South Africa. It was just the more recent boats that have this feature. It would be quite difficult to cut it on an assembled boat - it really needs a milling machine to do it neatly. I reckon on an older boat it is better to just take the boat apart and replace the sliders properly. It is good for the soul to take the boat apart* every so often and it gives you a good chance to inspect the bits you don't often look at. The shrouds and the strop at the hounds are worth checking closely.
Cheers
Bob

PS * Erling does it in about 20 minutes

[Bob Carter]

Another thought.
Don't just change one change the lot. It is also a good idea to put on a couple of spares too (one each side). They do not do any harm and you never know when will come in handy..................
Cheers
Bob

[Jaycb]

Thanks Bob, good idea re. putting in spare ones - I think I bought a few extra so will do this.

[George Stephen]

Hi,

The mast and beams are made from anodised aluminium alloy. The anodising skin prevents corrosion of the aluminium alloy. If you cut the mast or beams you will leave unanodised edges and surfaces to corrode. Corrosion will be all the more rapid if you sail on the sea, as salt water reacts more strongly with the metals in the alloy than fresh water.

If you've ever seen the corrosion on the mitred joints of aluminium replacement windows that have been poorly/cheaply fitted to seaside properties, you'd know that cutting into beams or mast could lead to trouble.......

[Chris Black]

A simple metod which I have used is to cut one of the sides off the tensioner (so it is a L section rather than a T). You then insert it into the slot with the remaining side upwards. The lacing tension then holds it in place.

[Charles]

Hi Jason

I had a boat your age & somone has tried to make a slot with an angle grinder... I'd recommend not repeating that process, looks poor for the sake of a very little effort.

[robinl]

Hi

The tramp and tensioners are very important on a 15 as they provide stiffness to the platform in lieu of bolts.

When buying replacement tensioners, avoid the white ones and buy the 'clear' ones. They are stronger and don't go brittle.

All the best

Robin

[Jaycb]

Thanks for the words of advice guys. Managed to do the job yesterday. It needed two people to get the hulls apart but I got it all back together on my own. Put spare tensioners in as Bob suggested so shouldn't need to do it again for a while.
I'm impressed by the mechanism used to keep the hulls together - simple but effective

[Steve Sawford]

avoid the white ones and buy the 'clear' ones. They are stronger and don't go brittle.

Steve`s boring boat building Knowledge

Only use the Allen Brothers part A89 .These were manufactured in clear High grade nylon but now have a white pigment in them.(exactly the same part).
The nylon is injected in the mould and released into boiling water to cool down slowly so they are not brittle. Other manufacturers are not as strong and were all white.

Allen Brothers WHITE is good