Retro fitting Bilge Keels...Discuss

[Applescruffs]

New to this so please bear with me....

I've just bought a Mirror Offshore that for whatever reason I thought would have a triple keel, (don't they all?), enough said; it has a long stub keel which is great for 'slightly' improved sailing but not so good for sitting on the mud when the water goes away.

Anybody out there got an idea what angle these little fellows lie over to when they hit the mud, (I have a half tide mooring), and if it will damage the hull every time it takes the ground? My mooring is not quite the classic Essex mud and does have a few stones scattered about.

Any advice welcome on retro-fitting bilge keels, where I could get them or if indeed it can be done, I guess that the hull would have to be strenghtened for a start?

Cheers!

 

[Fantasie 19]

It should have a triple keel - if it hasn't you've got to wonder why....

Best advice would be to ask around locally for someone who has a complete one so you can do some checking...

 

[oldsaltoz]

Removing the single and fitting bilge keels would not an economic alternative, better to sell it and buy what you want / need.

Perhaps a change in mooring?

The work and cost to convert would involve:
Locating a replacement keel.
Stripping the inside of the boat the lay up the strengthening required, providing you can get this information. Then the cost of replacing what was stripped out.
It may be possible to this on the outside of the hull but you might end up with odd underwater profile.
Locating of the new keel will critical, perhaps measuring another of the same model will help.
All this will also mean no use of the boat or any sailing for quite some time.

Good luck.

 

[Seajet]

Well I'm surprised it's taken this long to get him a mention, but Dylan Winter ( of his films 'KeepTurning Left' fame ) has done his best to go around Britain in a Mirror Offshore, I should think quite possibly the most experience anyone has clocked up in one - he's normally on Scuttlebutt, it would be well worth finding one of his posts - if not on page 1 the last one was quite recent, and sending him a PM; he may well have other contact details on his posts too.

Like Fantasie I can't help wondering why you haven't got the bilge keels, the big question is, is there any sign they were ever fitted ?

If the answer should appear to be anything like ' never fitted, she was a special ' you'd need to make very sure the hull actually is reinforced to take their loads.

One would expect the hulls to be standard, but remember in the days when she was built it was relatively easy to do 'custom' spec's.

Another good reason to talk to Dylan is he may well have formed ideas on types of underwater profile and any possible increases in performance.

For example if she were mine I might be tempted to fit minimal bilge keels to reduce wetted area drag - she frankly needs all the help she can get, settling on mud the bilge keels would mostly sink straight in, on firmer ground ( only under occasional, controlled conitions I hope, for any boat )even small bilge keels should keep her upright if they're correctly positioned.

Increasing lateral resistance keel area, deeper than the present central keel, would be a great help to the boat especially to windward - but difficult to organise easily !

If I was keen to do that - ie owned one - I might be thinking on the lines of leeboards, but we're getting away from your original question.

Good luck, and please let us know how you get on .

 

[jellylegs]

You want what Eventides have, I would say. Two keels cut from sheet metal with a top on it that fits the shape of the hull so it can be through bolted to the hull either side of the keel itself (a 'T' shape) On the bottom a piece of round pipe, blocked at each end will stopp her falling over on most mud, but in very soft stuff if it goes in it needs to come out again without pulling it from the boat, it has happened! Also, keep them shallower than the central keel by an inch or so. this will reduce the stress and strain on them when taking the ground and swinging.

Inside, I guess it needs some glass layers to stiffen it, but taper it so you dont get a stress line. Maybe shape a wooden plate to go inside, ply wood, big backing plates.

Should be ok, lets face it people build WHOLE boats!

 

[Applescruffs]

Hi Guys and many thanks for the replies and info,

As part of my purchase I got the original paperwork and sales brochure for the Mirror,(any one want a copy?), and the pictures and spec definatley show the Offshore to have only a single stub keel, I can only guess that the bilge keels were not fitted as standard? although the sales info doesn't even show them as an option, maybe later variations did?

Having read your comments and guidance I have decided not to fit additional bilge plates, although I may be thinking along the lines of bolting a length of, say, 4"x2" through the hull on either side at an appropriate place. This would a) stop the hull coming into direct contact with the shingle whenever it grounds and b) stop the boat leaning over too far. Option c) would be to just leave the thing alone and learn to live with it. After all the boat is 40 odd years old and has survived this long without mishap! Love to hear what you may think of this as an idea. BTW I have pretty thick skin so if you think it's the daftest idea please let me know, I'm not too happy about drilling holes in the bottom of boats!

RE: Dylan Winter. Dylan has the misfortune to 'know' me via his excellent KTL 'Brotherhood', (+ one sister!). We have discussed this over a metaphysical glass or two of plumb wine and I have, (probably) decided that option c is best, back to school to brush up on tidal heights for me then!

 

[Searush]

She draws so little water that a pair of swivelling or removeable legs may suit for the odd grounding situation.

You could home make a pair from alloy tube or scaffolding & bolt them thro the rubbing strake. Use 2 tubes one inside the other with holes & a peg to adjust the length & allow storage aboard in 2 parts. Have a plate on the bottom as a foot.

Then you can go anywhere Dylan goes & possibly point better & go faster!

 

[Applescruffs]

Thanks for that Searush; but do you think that I could leave them fitted on a daily basis, I'm thinking of when I'm not about and as the tide makes and receeds there could be quite a twising motion and it looks the legs could buckle or even worse. I'm mostly looking for some way to keep the hull from making contact with the 'oggin twice a day....every day and the possible damage that may inflict. That said it's a great plan for whilst I'm aboard and with a bit of thought could be easily deployed, yeah! thanks for that, looks like I could get a good nights sleep and have a brew in comfort!, Cheers.

 

[Ubergeekian]

Thanks for that Searush; but do you think that I could leave them fitted on a daily basis, I'm thinking of when I'm not about and as the tide makes and receeds there could be quite a twising motion and it looks the legs could buckle or even worse.

Jumblie spent two years on a drying mooring, supported by Yacht Leg Company legs, and seems to have survived fine, bar a bit of abrasion to the underside of the keel. She was moored fore and aft, though - I don't think I'd want her drying out unaccompanied on a 360 swinging mooring.

 

[Seajet]

Applescruffs,

I'm sure Searush would agree legs are NO WAY for daily use, especially unattended ! There's a very high likelihood of one leg -foot digging in ( wind / tide pressure, softer patch of mud, etc ) then if the boat leans on it the leg would put a truly horrible strain on the hull.

Like you I'm not at all crazy about drilling holes in hulls either.

Legs are usually fitted & used with specially strengthened topsides, and even then as I say a temporary measure for when you're around.

Handy for when on a cruise though.

Don't know if you've tried it, but as the boat begins to settle in the mud you should be able to keep her level; one trick is to stand on deck holding onto the mast and rock her side to side, which should speed up the settling level process.

Must say I thought triple keels were standard too.

I wouldn't have thought the central keel is very deep ?

If the mud is soft, bits of stone and shingle should just get pushed under by the boat; if there are any remotely large or pointy ones I'd redistribute them somewhere harmless.

Have fun !

 

[Applescruffs]

Jumblie spent two years on a drying mooring, supported by Yacht Leg Company legs, and seems to have survived fine, bar a bit of abrasion to the underside of the keel. She was moored fore and aft, though - I don't think I'd want her drying out unaccompanied on a 360 swinging mooring.

She's on a swinging mooring on the Blackwater and the tide can come in a bit quick. I have a club mooring and the rate is more that reasonable, not really inclined to move the boat. It is the abrasion to the hull that concerns me.

 

[VicS]

As you say the Mirror was not originally fitted with bilge plates, although I am pretty sure I have seen a Mirror with small bilge plates, but not the full depth of the keel.

I have also seen a small boat, possibly a Mirror, with one of the bilge plates bent back in under the hull

Should you decide to fit them not only make sure the hull where you attach them is suitably reinforced but also that they are themselves stout enough!

There are several Mirrors in the yard. Must take a closer look next time I am there. They will be on drying moorings.. not many of our moorings dont. Even the Macwester Rowans are on drying moorings.

I'll take the camera and get some photos if they will be useful.

 

[Applescruffs]

ohhh dear, I had a McWester Rowan at Canvey Island and never launched her because she had the long keel and I was paranoid about the boat falling over on the tide...loverly boat , but I felt unsuitable for the East coast. Since then I have bought a sucession of small bilge keelers, and a Dauntless.

Perhaps I worry too much ??

 

[VicS]

Perhaps I worry too much ??

Maybe

"Marie of Itchenor", a Tamarisk 24 I believe, on what was her mooring for a number of years before being sold and moved away

 

[Applescruffs]

Hi,and thanks for going to the trouble of finding the picture, She looks kind of ok to me , but could you sleep on her and have a decent brew??..dont think so, maybe that's why she has been moved or sold?

 

[nathanlee]

Then you can go anywhere Dylan goes & possibly point better & go faster!

Having raced the man, I can confidently say... he probably let me win, haha, but failing that being true, Kudu beat the slug.

 

[Applescruffs]

I think a blindfold penguin with both it's flippers tied behind its back would have beaten the slug in a race ...ha ha ?

 

[Searush]

I think a blindfold penguin with both it's flippers tied behind its back would have beaten the slug in a race ...ha ha ?

I agree that speed is not Dylan's prime concern when he goes sailing. He is a true born cruising man - a fast passage simply means that you haven't had the time to see the sights.

 

[VicS]

Hi,and thanks for going to the trouble of finding the picture, She looks kind of ok to me , but could you sleep on her and have a decent brew??..dont think so, maybe that's why she has been moved or sold?

True you could not have spent the night on board, at least not on her own mooring.
Sold because the owner bought a larger boat!

However I took a close look at some of the other pictures taken the same morning (23 May 2009)

Just two boats up from me looks like a Mirror ( with a lifting rudder !)

And sitting upright at low tide so I guess that's one that must have bilge plates.

And another nice picture taken just after sunrise on the same morning

 

[Applescruffs]

Lovely pictures, just about sums up why we do it ! Could be a Mirror up front but she has spreaders fitted to the mast and along with the hinged rudder make these 'add-ons', unless this is a Mk2 ?