Forestay

15/08/2011 12:22:26
Russ B.
Just trying to get to grips with a Merlin following many years in an Enterpise. It's a late composite  NSM2 with alloy spars. I've had various minor disasters, two of which involved the mast falling down, one on land de-rigged and one while racing, both of them probably my fault. My boat has no forestay, and, from reading through posts on the forum, I gather that this is not unusual. However both dismasting incidents would have been avoided had the boat got a forestay. 
Why don't most Merlins have a forestay?
What are the issues I should consider about fitting one?

15/08/2011 12:56:28
Chris Rathbone
Dear Russ,
I think that the main reason is that the forestay would entangle with the spinnakeras it was coming in and out of the chute. Back in the 1960s, when Merlins were somewhat more basically rigged, once the jib was in tension, the forestay just flopped around and didn't do anything until the jib was taken down.

Many of the NSM2s used to control mast bend by an alloy or stainless steel strut- have you got one of these? If so,just attach the strut to the mast, making sure that both the fitting being attached to the mast and onto the lever under the deck are well attached by either a decent rivet or screw.

With regards to fitting a forestay, I am sure it can be done in the normal way but suspect that it will chew your spinnakers quite nicely! Some boats such as New Potato had the jib tack right on the bow with the chute immediately behind. I can only surmise that the hoist and recovery would be slower because of the jib foot being in the way.

Good luck,

Chris

15/08/2011 12:56:46
Alistair
Most Merlins don't have a forestay because, other than stopping the mast falling down, they would just get in the way and be one other thing for the spinnaker to tangle itself with. The function of 'stopping the mast falling down' is undertaken by the jib luff-wire which nowadays doesn't get hanked on to the forestay. Some classes - Ents, Albs, etc - do still have a requirement for a forestay which, for a deck-stepped mast, isn't such a bad idea but which is totally redundant whilst sailing. However, the Merlin does have a 'puller' which, when tensioned, acts as a very good substitute in lieu of the jib being hoisted. You can also rig the spinnaker halyard as a temporary forestay when the boat is left in the dinghy park - I tend to leave the boat with puller tensioned and spinnaker halyard as forestay when it's alone in the dinghy park.
If you were to fit a forestay you would have to ensure that the spinnaker wasn't going to get between it and the jib luff and you woud also need make sure that it would accommodate the range of rake on the Merlin rig.

15/08/2011 12:57:44
Alistair
...and what Chris said, too!!

15/08/2011 14:28:38
Russ B.
Blimey, that was a quick response, it was like you were hovering just waiting for the questions. Thanks guys. 
No I don't have one of those struts, Chris. I hadn't really thought about the puller doing the job, obvious really. The onshore dismasting came about by my poor knot using the spinnaker halyard. The sailing one was a failure of the pin connecting the jib to the halyard: no jib halyard - mast falls down.
I can see the argument re.snagging spinnakers though.
I am sure all my calamities are out of the way - they are all learning experiences if painful/expensive so I can get on with learning to sail the boat. All things considered, I think I'll stay without a forestay and be more careful.
Thanks again.

15/08/2011 14:42:04
Rob H
Russ B, where do you sail ok of? I'm sure that there must be someone around MR wise who would be very willing to run through things with you.

15/08/2011 14:42:05
fribbs
You should also tape the shackles/pins used to attach the jib to the bow and to the halyard.  The tape does the double job of ensuring the shackle pin / pin stays in place and smooths the area to stop the spinnaker/sheets/halyard snagging.

15/08/2011 19:17:48
Russ B.
Thanks Rob. I am the only MR sailor at Hollowell (nr. Northampton). I think the boat is reasonably sorted, it's just that I'm not. I hope to have a decent autumn and winter getting used to it, then try the training weekend at Rutland next May (assuming it's an annual thing)and a couple of Midlands open meetings.

16/08/2011 06:56:34
Pat2121
Most older boats won't have a puller. If the mast is hog stepped, add a mast gate retainer - we have a simple luggage style strap which clips across and holds the mast from falling but allows it to move within the gate.

04/05/2013 10:47:59
Andy Hay - Business as Usual
Simple answer is as long as the distance between hog and underside of deck, less the height of the blocks. I actually think that we now have too much as we were able to go to extreme rake at the inlands, which looked plain silly!

It is more a function of the rake that the boat can handle with the limits being full upright to just being able to clear the hoop with the kicker on.

I'll crawl under BAU when I get the chance (she is in the same state as the Dream Machine!) and stick a tape over her.

03/06/2013 04:59:34
Andy Hay - Business as Usual
We (and some others) have an 8:1 "one string block" so that you eliminate the 4:1 down the case sides (still giving the 16:1 though).

This is effectively a quadruple back to back block.

Works well if you cannot arrange for the 4:1 blocks to pass down the side of the case or if you cannot get the full range of travel on the one string block with the length of the case.

03/06/2013 04:59:34
Andy Hay - Business as Usual
Forestay tenstion controlled by the shorud tension. Nothing seperate on the forestay although I think that Miles has this on his magic lever system. We also have a jib cunningham which, although not affecting luff sag, is remarkably effective at changing the jib shape / depth.

Seperate controls on the lowers and shrouds though.

03/06/2013 04:59:34
Andy Hay - Business as Usual
That was the same problem I had with BAU (made worse with the aft tank now though). The Winders have a nice gab at the aft end of the case to bring the tails around.

Just watch the "one string" block rocking as it is quite chunky, but this is cured when you tension the system up fully. You also need to watch the size of the sheaves you use in the block, I have seen the HA 16mm high load ones used which although made the block more compact (= more travel) it did cause a bit more friction. We have the 25mm diameter old Proctor wore sheaves (best with the V groove to stop jumping). Carbon cheeks of course.

If I was making another, I might try the 16mm Harken air block sheaves (noting my earlier comment about small blocks & friction) but as that sheave is really free running, it might be OK.

23/08/2013 04:36:04
Gareth Griffiths Notting Hill Rigging Co
Cheers Andy

Had a really good play with Terabyte today, made a few measurements and checked out the system which is the standard Winder one string with the 2:1 and 4:1 purchases.

I am trying to work out a way to maximise the distance i have which is reduced on The Dream Machine because the daggerboard case continues forward. I think you had similar on your old boat...?

Looking at Terabytes length of travel i think I am ok... but will have measuring sticks out a bit tomorrow...

28/11/2013 10:25:25
Gareth Griffiths
Cool cheers Andy. I noticed something like that on photos I found of your yacht.. Tidy looking boat...!

Sorry I hadn't emailed you those pics of thimbles. Been away with work. Back Friday hopefully and my GF is working so I can spend plenty of time on the Dream Machine.

28/11/2013 10:25:25
Gareth Griffiths
Just wondering...!

Do you still have a tweaking control for the forestay adjustment as well as the one string...?

Do the shroud tensioners act as your sole means on increasing rig tension?


I was thinking of setting up the one string raking system then having separate controls to adjust lowers, shrouds and forestay. But if you think that is unnecessary I'll not bother.

Cheers for all the thoughts ideas and advice guys

28/11/2013 10:25:25
Gareth Griffiths
Cool cheers Andy.

I think your suggestion of the opposing 8:1 system will be ideal for me. I have the space to run a 4:1 down each side but crossing the leads to the opposing sides was going to mean I had to make a hole through something g and retro fit a double block for the lead. This works much better.

I agree on jib cunning hams being a great idea. Just designing a new bow fitting and forestay halyard lock/sheave block at the moment.

28/11/2013 10:25:25
Gareth Griffiths
Hopefully I should have a pretty cool new forestay system for you all to see in the next few weeks. I think it might interest a good number of you.

It's not been done on a merlin before. It's adapted from a system we used on 16 ft skiffs in Australia a few years back.

Should reduce weight and compression massively.

10/01/2014 21:39:08
Gareth Griffiths
How much purchase are you guys using on the forestay?

And what purchase is there on the one string side?

I can't find any info on how or where the one string forestay part works

All hep much appreciated...!

11/01/2014 09:18:55
Mags
These photos are about as clear as you can get, I'm afraid.

http://www.merlinrocket.co.uk/gallery/default.asp?folder=gallery/rigging_guide/3683
11/01/2014 09:19:06
Mags
There is a little detail here too.

http://www.bluelightning.co.uk/Merlins/MRTechnical.shtm
11/01/2014 09:28:42
Miles
have seen it vary between 12:1 to 16:1

11/01/2014 12:12:16
Chris M
2:1 at the top of the halyard, 2:1 on the control car, then 4:1 along the case side in both directions.

so you have 16:1 over the jib halyard (not that this means a great deal on a one stringer, the rig tension is automatic), and 8:1 over the car itself.

Most older wooden boats have 2:1 at the top, then 4:1 at the mast step giving 8:1 overall. Older Winders had 6:1 at the mast step increasing purchase to 12:1. I found 8:1 to be adequate, it's not often that you move it under tension as you let the shrouds off first.

13/01/2014 01:21:39
[email protected]
Cheers guys

18/01/2014 06:05:06
[email protected]
Hey Andy what's the distance of the travel you use for full to no rake at the king posts...? 

How much do I need?

Going to be fiddling around with the rake system on terabyte tomorrow but was having a bit of a measure up earlier and I think I'm ok but would be great to get some numbers.

Cheers

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