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david_eastwood
Main Sheet Hand
124 Posts |
 Posted - 09 February 2006 : 9:30:42 PM
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Chris you're right - the "effective" WL length is the relevant length, but exactly the same theories apply whether the boat's upright or heeled. As you note the effective WL changes with heel.
Boats with fatter, and longer ends lengthen more as they heel than same length boats with finer ends - more buoyancy in the ends pushes the bow and stern waves apart as before. Consider an old style 30 square metre or a Dragon, those old boats have very fat ends relative to beam and they pick up heaps of length when they heel. Look also at a modern AC boat - same difference. They have relatively fat ends too, relative to the overall beam of the boat (AC boats are very narrow) - and they certainly aren't planing hulls at 24 tonnes displacement! See how much length this boat is picking up at the back end just by leaning over a bit.
Imagine putting Hagar on its side and holding it there, the bow and stern would be way out of the water as there's so much buoyancy in the middle. Then imagine putting a 30 square metre on its side the same way. The stern would be touching the water and the bow a short way above.
And, IOR boats are WAY SLOW upwind - that's an old wives tale! I've sailed 40 foot IOR, IRC and IMS racers. The IOR boats are a full knot slower upwind than modern equivalents. It's not all down to hull shape, but some of it is. IOR boats were also very tippy as IOR penalised stability heavily - and that holds them back. The issue with their off the breeze performance is the one we're discussin - it's all about the lack of length they pick up with their fine transoms. They dig a big hole in the water and sink into it!
Recall that the generation of IOR boats built after the late 70s had much fatter sterns. It was actually Bruce Farr that pioneered that trend (and, effectively, his career) with the all conquering 1 tonner hull that went on to become the Farr 1104 - of which there are plenty sailing around Syderny Harbour.
I've sailed rings around old style 30+ footers (East Coast 31, even S&S 34 for example) in my 26 too - but mainly in light air where wetted surface is more important than length. In any breeze it ought to be a no brainer - 30 footer always wins!
Given how well you blokes sailed Hagar 2 I'm sure you'll end up sailing this one faster than a 30 has ever gone before too! |
Shed boy #1, the one holding the stick thingy. |
Edited by - david_eastwood on 09 February 2006 10:26:17 PM |
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Chris Cope
Skipper
Australia
2350 Posts |
Posted - 12 February 2006 : 2:23:52 PM
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Early this morning I sneaked off without wakening the household or tell SWMBO'd and bought the Hagar IV into the work berth with Rod. Dave the diver arrived thereafter & opened the stern gland and repacked it with the cut pieces of greasy rope and then re-sealed the gland and ran the engine.
It was a simple operation which anyone could do and to my surprise the boat did not sink or even leak during the job.
Then our local Sparky, Bear, arrived and got to work on the non-working bilge pump. The pump worked fine, it was the flow switch which had given up. So I went off the Whitworths and procured an new switch which Bear installed, checked her out and all is fine.
Bear advised that when racing to switch off the Auto swith which will burn itself out with the constant movement of the hull, and especially when tacking.
I got a chance to tighten the deck mounted instrument panel as well as washing down the outer hull and the bilges with fresh water.
We took the Hagar for a run over to Manly & back and found that the stern gland was dripping slowly after half an hours motoring.
We will check her during the week.
Chris. |
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Splinter
Helmsman
Australia
500 Posts |
Posted - 12 February 2006 : 5:03:18 PM
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Chris, you have adjust the glan for a while but do not tighten it up too hard. It will settle down after a while. Then you only have to adjust it possible once a month.
cheers, |
"Splinter" |
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Colin Cole
Helmsman
Australia
676 Posts |
Posted - 12 February 2006 : 5:43:10 PM
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| It should leak a couple of drops every 5 mins or so whilst running. As Kev says its a bit of a tighten here and there but it will settle down. |
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Chris Cope
Skipper
Australia
2350 Posts |
Posted - 12 February 2006 : 9:29:13 PM
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Thanks for that Guys. Dave the diver could only get two pieces of the greasy rope into the removeable part of the gland and there may be some of the original rope still inside it because he could not get the removeable part back on with the three pieces of rope. We will be looking at it closely in the next week.
Colin, I sent an email to the chap with the new E30 on Lake Macquarie, but have had no reply. Would be happy to take a run up there one day to have a look at the boat. He probably just needs encouragement. We have been working on the Hagar IV now for nearly 11 months and still have some way to go. We are now making plans & lists of jobs to do when we slip her in April-May. Some of those jobs include undoing some of the things we did last year when she went up for the first time.
Chris. |
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Colin Cole
Helmsman
Australia
676 Posts |
Posted - 12 February 2006 : 9:42:32 PM
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have any of you guys got extra or added weight in the bilge area? This bloke removed 640kilos!!! His sail maker jumped on board and thought she was gunna tip over!!!
All sounds a bit bodgy, the boat was originally "Echo" from BBYC so I'll ask around at the club. |
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Chris Cope
Skipper
Australia
2350 Posts |
Posted - 13 February 2006 : 03:30:57 AM
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Try using a strong magnet over the keel. It might have had a window cut into it in a previous life and then found to be underweight with the lead added. The Hagar IV sits high in the water but not like you have described and there is no lead and the bilge which was cleaned yesterday. When she was up on the slips last year for the first time she had a few rust spots on the keel which we ground off, primed and treated before antifouling.
Chris. |
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Splinter
Helmsman
Australia
500 Posts |
Posted - 13 February 2006 : 6:10:21 PM
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Gee Col, dodgy sounds right.
I cannot see how you could pull that weight out of the boat. There is nothing there to do it. It could only be rubbish built up in the boat.
Would like to see the boat and it could now be a good one.
Looking forward to meeting the owners.
cheers, |
"Splinter" |
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Chris Cope
Skipper
Australia
2350 Posts |
Posted - 13 February 2006 : 7:14:09 PM
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If the Macquarie E30 boat does have a window cut into her keel it could be "shaved" and the lead re-inserted in the cavity. It would solve a lot of the boyancy problem and be sort-of make her legal? Well it does sound like a BBYC job.
Col, ask Mackay he might know about it.
Chris. |
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Colin Cole
Helmsman
Australia
676 Posts |
Posted - 13 February 2006 : 8:42:52 PM
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Now now, John MacQuilin is the owner, he says the weight was in the form of lead ingots of various weights - all stacked in the bilge!
Sonds a bit rough and ready even for Maca! sorry what am I saying - no it doesn't. |
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Colin Cole
Helmsman
Australia
676 Posts |
Posted - 13 February 2006 : 8:45:11 PM
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anyway weren't some (if not all) the 30s built with a cast iron keel?
Seem to remember some "feros oxside) weeping out of some! |
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Splinter
Helmsman
Australia
500 Posts |
Posted - 13 February 2006 : 9:21:09 PM
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Hi, Chris, Col etc,
Just had a long conversation with John "ECHO" McQuilin. Great guy, will stay in touch with him. He is restoring the Mark II and will be on the water shortly.
Re the weights, didn't go into it with detail just he got rid of them. I think the boys on Lake Macquarie should meet John as he want to Cruise and I think possible at last race later when the boat has been restored.
will be staying in touch with his progress as he could keep the forum informed as well.
That would now make 3 '30's on the Lake that could be active once Ando pulls his finger out.
cheers, |
"Splinter" |
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Sasha
Helmsman
838 Posts |
Posted - 13 February 2006 : 9:51:37 PM
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Cast iron keels were the "standard option...but anyone willing to pay the extra money can always upgrade to lead...so there are bound to be a few out there.
If the boat is now too tender, (and this should be tested extensively and under a range of conditions), then the solution would not be to put the weight back into the bilges, but to add a bolt-on keel bulb. This will mean that less weight does more and better work, and a well shaped bulb will improve the boat characteristics by getting rid of tip drag off the bottom edge of the keel. A badly shaped one will add to it considerably, but at E30 speeds, we are talking about .05 of a knot either way.
Sasha
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The more I know about horses, the more I love sailboats.
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Colin Cole
Helmsman
Australia
676 Posts |
Posted - 13 February 2006 : 11:56:04 PM
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| me thinks a good blacksmith could construct such a devise :) :) |
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Sasha
Helmsman
838 Posts |
Posted - 14 February 2006 : 02:39:44 AM
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You would need to take careful measurements and tracings of the underside of the keel. Contruct your sand or plaster moulds accordingly and cast the lead torpedo in two halves, with insets for the three or four through-bolts. You would then clamp both halves in place and carefully mark where the holes in the cast iron keel needed to be drilled and drill them using a rather torquey drill and extra long bits (frequently cooled, frequently sharpened, I fear).
It is then a matter of bolting the two lead halves onto the cast iron keel, Inclding coating the inside surfaces with an epoxy resin). The fill the bolt indents, fill the join to the main keel and fair everything to look pretty.
There are companies that work in this area, though mainly as a way of converting boats to a shallower draft. Suffice to say it is doable, and at a reasonable price. Trying to cast up the bulb sections in cast iron would not be a great idea, and much more expensive.
By the way, because the bulb sits on either side of the existing keel, the boat's draft is unaffected.
Sasha
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The more I know about horses, the more I love sailboats.
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Chris Cope
Skipper
Australia
2350 Posts |
Posted - 14 February 2006 : 04:22:25 AM
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Sasha,
Whats' your estimation of the cost of making and installing this add-on keel and what would the cost be for a complete new lead keel?
Chris. |
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david_eastwood
Main Sheet Hand
124 Posts |
Posted - 14 February 2006 : 08:52:24 AM
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A word of caution on keels: be sure to check that the boat's structure can cope with the extra load an enhanced keel would introduce. The floors of the boat need to be strong enough to cope with the extra load of a bulbed or other wise modified keel and the frames in that area may also need modifications to transmit the load outwards. I don't know what an E30's structure is like, but a 26 flexes like crazy around the keel so there's no way you would increase stability without some serious structural work.
Quite a few older offshore boats (IOR) have been so enhanced to improve their poor stability, and several in Australia have subsequently lost their keels and sunk as a result of the floors failing. At least one of the 98 S2H casualties was down to that issue.
Needn't be a show stopper, more stability is nearly always better than less, but important to get good naval architect's advice on the structural issues before proceeding. |
Shed boy #1, the one holding the stick thingy. |
Edited by - david_eastwood on 14 February 2006 08:57:17 AM |
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Sasha
Helmsman
838 Posts |
Posted - 14 February 2006 : 09:37:03 AM
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Add-on bulb, start ti finish (including the sundry materials to get it all the way finished) around $900-$1300.
Casting a hwole new lead keel and fitting it...Probably start at about $4500 and go up from there. I think $5500 would be more realistic. This is based on limited direct experience, mind you, so more guestimate then estimate.
While the comment on checking strength and such is fully valid, it is also worth noting that about 150kg at the bottom of the keel is worth the 550kg he took out of the upper bilges. so the advantages are obvious.
On the downside, too much weight all the way "down there" reduces seagoing comfort somewhat, as the boat is prone to sharp metronome type movement. The art is in the balance.
Sasha
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The more I know about horses, the more I love sailboats.
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david_eastwood
Main Sheet Hand
124 Posts |
Posted - 14 February 2006 : 11:40:15 AM
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Cast custom keel for a 40 foot racer ~2.5 tonnes = $25K - but that's a very different beast to an Endeavour.
Difference between 550kg in the bilge and 150 on the bulb is that the bilge weight doesn't stress the hull floors as there is no lever arm between the weight and the keel attachment point. The displacement difference is of course a huge advantage.
My offshore boat has a solid lead keel with a built in bulb. We have a new baby sistership on the water called Blackadder. This boat is the same hull and displacement as us but has a fabricated steel fin with a much larger bulb - and hence lower C og G. They rate 2% faster than us - and that's a lot! |
Shed boy #1, the one holding the stick thingy. |
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Chris Cope
Skipper
Australia
2350 Posts |
Posted - 14 February 2006 : 11:43:11 AM
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The keel will not matter that much if the owner only plans to cruise around Lake Macquarie. If that is the case the keel fixing could be put off and other more important work should be prioratised. Only if he intends to go offshore cruising or racing competitely should the keel become a worry. Alternatively he can procure more moveable ballast in the form of bigger or extra crew members.
Chris. |
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Topic |
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A New E30
