Forestay help

[Seajet]

Sorry if I'm being dim, but apart from being adjustable to fit, what use is the bottlescew in that diagram ?

Tightening it in situ' might pull the deck down a smidge but that seems about it.

I'd have gone for what I think Daydream Believer meant, with a long eyebolt at an angle straight though from stem to deck.

As for mast rake, yours does look alittle excessive - of course every boat is different, and the boat must be at normal trim - allowing for the designed weight in the cockpit - people and engines, fuel etc .

In case of any use the rake on my 22' with 26' mast means when I use the main halliard as a plumb line it's 4" aft of the mast step centre.

 

[PuffTheMagicDragon]

I could be wrong, of course, but it seems to me that the wire that has been used for the forestay is of flexible 7x7 construction instead of the more usual 1x19. This means that it is prone to elongation and the problem is unlikely to go away. At a guess I would say that the diameter is 5mm at most and a replacement in 1x19 will easily go round a thimble and still allow for a simple swage; at that size it would be quite cheap, certainly less than the time that you will spend on the modifications (except for fitting a proper U-bolt with a backing plate which you'll need anyway).

 

[Seajet]

It's a thought,

I can't see what wire it is from the photo.

The crux of it is, none of us like the look of the forestay attachment or those for the bow roller.

I wonder if a Wichard U bolt - ( mentioned previously but I'm a fan too, all my chainplates have them ) might fit the bow roller lateraly, which if decent wood and penny washers could be fitted would sort everything - sorry if I'm repeating someone, it's late and I'm tired !

Tip to the OP - if doing this have a cutting grinder, eye protection and a vice handy as I would expect the penny washers might need corners cutting off to fit - or just mark off everything and take home to do it.

Top Tip; plastic breadboards are a good source of cheap non-rotting backing pads, as long as there are penny washers on top.

 

[VicS]

I could be wrong, of course, but it seems to me that the wire that has been used for the forestay is of flexible 7x7 construction instead of the more usual 1x19. This means that it is prone to elongation and the problem is unlikely to go away. At a guess I would say that the diameter is 5mm at most and a replacement in 1x19 will easily go round a thimble and still allow for a simple swage; at that size it would be quite cheap, certainly less than the time that you will spend on the modifications (except for fitting a proper U-bolt with a backing plate which you'll need anyway).
]

How have you come to that conclusion ?

I would expect the wire on a boat this size to be 3mm 1x19. ( thats what the standing rigging on my 19 ft Sea Wych is )

 

[PuffTheMagicDragon]

How have you come to that conclusion ?

I enlarged the part of the photo where there is the thimble and it appears to me that the strands are thick if compared to the wire diameter.

I did start my comment by saying "I could be wrong, of course..."

 

[anoccasionalyachtsman]

The crux of it is, none of us like the look of the forestay attachment or those for the bow roller.

Actually, I've asked twice if there's any sign of cracking because it looks perfectly OK to me if there isn't. This forum has an obsession for penny washers and ply backing pads when solid grp is very strong stuff if thick enough.

And I'll say it again. The geometry says that moving the stay forwards won't shorten it enough, spend a fiver on having it shortened and go sailing with a tight forestay and a transformed boat.

 

[Seajet]

Well you're living up to your forum name !

I wouldn't wait for cracking, a poorly backed rigging wire - especially the most highly stressed of the lot, the forestay - can pull straight through.

I was actually being conservative suggesting penny washers as the OP's boat is quite a low stress design, unlikely to take really heavy weather; my backing pads are sheets of stainless on top of 3/4" ply, which is well painted all over before fitting.

I disagree re the geometry too, moving the eye - and more to the point improving it, will very likely be all the tweak needed - at the moment it relies on two small welds when it ought to be a backed U bolt - as someone else mentioned Wichard would be good, all my chainplates are Wichard except the forestay which is a custom arrangement.

If you really insist backing pads are silly, please let me know your sail number so I can keep upwind of your rig...

 

[PuffTheMagicDragon]

I disagree re the geometry too, moving the eye - and more to the point improving it, will very likely be all the tweak needed -

If you know the dimensions of the fore triangle, Pythagoras will show that an increase of the base of the triangle by a small amount (100mm maximum?) will have little effect on the "tweaking". On the other hand, shortening the hypotenuse (the forestay) will certainly work, both for tightening the stay as well as for reducing the mast rake.

 

[Seajet]

You haven't considered if the mast step is moveable - it often is - and the rig only needs a small tweak - or backstay tensioners, which are generally vital anyway when a roller headsail is involved.

I say shifting the lower forestay tang will have the win/win if incorporating fastening the bow roller down too.

Remember it's getting towards the end of the season and the forestay runs through the roller system; so best to sort out the deck hardware now, and any rigging wire changes over the winter; an important point nobody has asked - inc me, I kept meaning to - is how old is the standing rigging ?

If over say 20 years old I'd replace the lot over the winter and, having sorted out the deck fittings, then decide if the forestay needs shortening.

 

[anoccasionalyachtsman]

Well you're living up to your forum name !

My forum name is about as useful a guide to my wisdom and experience as yours is. As a trained engineer, perhaps you can tell me why a decades old deck is about to suffer catastrophic failure right now? As for the geometry - have you actually looked at the picture of the boat? The upsweep of the foredeck at the forestay almost completely negates the effect of moving the attachment forwards.

 

[Seajet]

You're still at it, nothing to do with ' catastrophic failure of the deck ' - in fact my suggestion of decent backing pads is more likely to cause that, while your unbacked fastening would neatly pull through !

I am not going to spoil this thread any further - except to say yes I did a lot of work on Sea Harriers and took the photo in my avatar, the late, great John Farley.

 

[VicS]

Hi fellow boaters....

After all of your help and advice on work I needed to do on my Dockrell 17, I was hoping that I could pick your brains again now its on the water.

It has been noted by people who have sailed in her that the mast might be raked to far back and that the shrouds are too loose. I can adjust the shrouds, but I think the main problem is the forestay and its position.
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What do you guys think would be the best solution? I would really appreciate any ideas...are there any Dockrell owners that could tell me what they do on theirs?

Cheers in advance!

Tim

Think you will have to shorten the forestay. but be sure it remains long enough to accommodate the furling spar.

If Puff the Magic Dragon is correct about the type of wire then you should change it to wire with a 1 x 19 construction.

It would be nice to incorporate some method of adjustment. Maybe that could be a lashing to the deck fitting.

If you are unhappy with the pad eye type of deck fitting consider changing it to a U bolt like this .

with a suitable backing pad or plate to spread the load a little. I'd be happy with the welded pad eye. Neil's suggestion to move it forward and add a backing pad is a good one but it wont gain an awful lot over its present position.

As a temporary measure to get your boat sailing decently for the remainder of the season try a lashing to a narrow shackle through an additional hole drilled in the bow roller fitting as far back as reasonably possible.
Put a plate, or cropped penny washers, under the nuts of the foremost fixing bolts to spread the load if you think it is necessary.

Its only a small boat . the loads will be modest so there is no need to make it strong enough to tether a Harrier to the deck!

 

[PuffTheMagicDragon]

For adjustment of the new forestay you might wish to use something like what is used for dinghies for stays. There are various sizes and any size will be much cheaper than the equivalent rigging screws. Something like this:

Just to get an idea, this is the 60mm size and is sold at £3.82 including VAT plus delivery.

 

[PeteCooper]

For adjustment of the new forestay you might wish to use something like what is used for dinghies for stays. There are various sizes and any size will be much cheaper than the equivalent rigging screws. Something like this:

Just to get an idea, this is the 60mm size and is sold at £3.82 including VAT plus delivery.

I have something similar to that, essentially 2 stainless plates joined near one end then the 'short' end has 1 hole through, the other longer end has 7 holes. If the OP wants it I will cheerfully send it for the cost of postage.
Forgot to say … it's roughly 10cm long by 10 mm wide.

 

[suffolktim]

Wow! Lots to reply to! As people have said, I am going to really have to do a proper job when its on the hard again in the winter...but I think I am going to go as per last sketch and Ive found a second identical eyebolt, so I will also put an eyebolt on the port side aft bolt through the bow roller fitting to, as well as putting an eyebolt through the middle single hole in the fitting as well. Im also going to connect it and tension it up to the backnof the eyebolt that comes through the stem (for the trailer). I will use a sustantial delrin (thick chopping board) backing under the deck for all the bolts to go through.

According to the previous owner (who had the new forestay wire fitted by the rigger earlier this year), the wire cannot be physically shortened any further, which is part of the reason why I think the move forward even by 100mm or so will be a big help.

I havent seen cracking in the deck, but I was still amazed to see no backing behind the current fitting, and I would definately be backing whatever I did there anyway. I will hopefully get the job done tomorrow, but it will be done on the mooring, so it should be fun!

I was wondering how I can get an instant idea of how much further back I have raked the mast with the new position, and I think I will take my rig tension reader down with me and check the shrouds before and after....they are currently only slightly under tension, so any extra tension after should tell me it has at least done something in the right direction. The previous owner tells me that before he changed the forestay wire the rig seemed well tensioned and the mast looked right etc, so hopefully I can get it back to that!

Heres hoping!

Oh, and there is no backstay in my rig...I think that has covered everything in the comments from today! Thank you all so much for your help and advice...hopefully ive picked the best course of action that is the most practical while she is still on the water!

 

[suffolktim]

PeteCooper...just got your post - thats very kind of you, and I might well take you up on that! I will have a look in my bits box first, in case I already have one! Thanks again

 

[ProDave]

Can I add an alternative suggestion.

If the consensus is moving the forestay attachment further forward won't make much difference, and shortening it is not posible, then over winter when the mast is down, move the forestay to mast fixing point a little higher up the mast.

In fact I would move it sufficiently higher to get a turnbuckle in at the bottom of the forestay so you have some adjustment to play around with next year.

 

[VicS]

Can I add an alternative suggestion.
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And another. Put a hard wood block under the mast step to raise the mast sufficiently to get the forestay tight. If then necessary extend the shrouds with toggles.

 

[Seajet]

And another. Put a hard wood block under the mast step to raise the mast sufficiently to get the forestay tight. If then necessary extend the shrouds with toggles.

A good bit of lateral ( well, vertical ) thinking, along with all the other mods suggested that would be the mast step sorted and confidence building - at this rate she should be far better fettled than Gypsy Moth IV or Lively Lady

 

[DownWest]

Just a thought, provoked by Vic's block of wood. One assumes that the mast step is well supported? and the slackness is not the mast compressing something under it? Not unknown.