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PeterSibley
06-27-2015, 11:09 PM
I'm not sure if I've asked this question before but here goes.

The design I'm thinking of building has a normal rudder stock construction and as per normal it is in one piece and not readily serviceable.

What I would like is the rudder to be removable at a slipway without the help of a travel lift, something common in developed countries but rare in some parts of the world. It would require a flange connection with a ring of bolts or something similar ( or the necessity of digging a 4 foot deep hole in the slipway yard) .

Has anyone seen such an arrangement ?

Here is the arrangement as drawn.

http://i1062.photobucket.com/albums/t487/PeteronTweed/Screenshot%20from%202014-07-03%20185404.png (http://s1062.photobucket.com/user/PeteronTweed/media/Screenshot%20from%202014-07-03%20185404.png.html)

Don Kurylko
06-27-2015, 11:38 PM
Make your own Peter. You know how. At the bottom of the page:

http://www.edsonmarine.com/ecatalogs/T1/00009.htm

http://www.edsonmarine.com/ecatalogs/T1/p/00009.jpg

PeterSibley
06-28-2015, 02:23 AM
Thank you Don, that or something very similar would do nicely. It would require a bit of exposed shaft but that should work OK.

Don, do you use something similar or are you going to rely on Travel Lifts in the unlikely event of needing to remove the rudder and shaft.?

Jamesh
06-28-2015, 03:03 AM
Another way is to weld two pipe flanges to the shsft and bolt together.
James

PeterSibley
06-28-2015, 03:12 AM
Another way is to weld two pipe flanges to the shsft and bolt together.
James

That is what I had in mind initially but the required diameter of the flanges is perhaps a problem ? They would require a bigger indent in the stern post.

andrewpatrol
06-28-2015, 03:48 AM
What about unbolting the rudder blade from curved shaft then just lift blade out then slide shaft down. Obviously you'd have to make the curved sections of shaft not housed into blade. Just thinking out loud. Also would do away with any probs with corrosion in any fitting on shaft. If bolts on blade give you curry just cut em off.

PeterSibley
06-28-2015, 04:03 AM
I've thought about that Andrew. I'd need to trust the welder who welded those curves onto the shaft , but yes, that could work and would be an easier fabrication.

suzyj
06-28-2015, 04:10 AM
Rather than the curved shaft, you could weld a tab on the shaft, say 200 x 200, and have a corresponding tab in the top of the rudder, then join the two together with bolts. That way you could unbolt the rudder from the shaft and have just the small tab sticking out.

andrewpatrol
06-28-2015, 04:15 AM
Any way you do it involves trusting a welder. I'll have a look thru some of my books and see if there's another way.
Suzi do you mean a tab sticking in the same plane as the rudder blade and bolted to side of blade?

did you get the plans Peter, I know you were waiting for them

suzyj
06-28-2015, 04:22 AM
Yah that's right. You could even have two tabs welded either side of the shaft, and sandwich the top of the rudder between them.

PeterSibley
06-28-2015, 04:27 AM
Good ideas Suzy and Andrew. I like the idea of just being able to unbolt the blade and pull it out.

shade of knucklehead
06-28-2015, 05:04 AM
Here is what we usually do, its two flanges. Because of the weight of these rudders and the closeness to the hull above you need a lift ring cut in the rudder so you can hold it up while bolting it. We usually use a bar long enough to go across the boat and a come-along on each side up to the deck.

http://www.flaniganbros.com/Projects/images/john%20c%20%281037%29.JPG

shade of knucklehead
06-28-2015, 05:07 AM
Also some of the boats I work on the owner wants more security than just the bolts so I bend 1/4 inch pieces around the outside diameter of the flange and weld them in place. That way I have welded it together, but I haven't actually welded the joint between the flanges. (If I did that everytime we removed it the flanges would need to be replaced. To remove we just grind off the tabs and unbolt. That rudder is half inch steel and about 3 1/2 foot by 5 foot.

PeterSibley
06-28-2015, 05:24 AM
Thanks, I've saved that photo too .

Figment
06-28-2015, 06:47 AM
Knucklehead, what's the purpose of the bar ahead of the rudder?

Ian McColgin
06-28-2015, 06:54 AM
Flanges are best fitted with a keyway to the shaft. This is both stronger and lets you get the flange off. Remember, the keyed flange is strong enough to connect the transmission to the shaft so it's just fine for a rudder. The lovely Edson rudder post extender is a cleaner, simpler and tighter installation.

I think that boat does not require a stuffing box above the horn timber but you'd have to cut away a bit of that timber leading up along the shaft to make room for the extender to swing. I see no problem with that except access for fitting it. Might require a very small person there.

Alternativly, you could slightly extend the straight part of the shaft further down the rudder and cut away space for the extender there.

Either way, the extender uses no more length along the shaft than two flanges and requires less other carving up.

OR, you could consider how infrequently you need to ship the rudder and settle for digging a hole. I've done that for a big Rhodes sloop. Took me a long afternoon with a six pack to dig and shore deep enough. Just remember to put some real lateral spread on the blocking under the keel ahead of the worm shoe and to push that blocking a bit further forward than might be normal.

PeterSibley
06-28-2015, 07:13 AM
Ian, re the stuff box ... why so ?

I had thought just to run a copper or glass reinforced tube up to deck level.

Ian McColgin
06-28-2015, 07:33 AM
Lots of ways to skin that cat. I've seen plenty of boats where the exit of the hole in the horn is enough above waterline that it was fine . . . unless the boat was down a bit. A tube is also a common solution. In this boat one might use a bronze tube and dispense with that support timber ahead of the rudder shaft.

My main thought, based on experience, is that given how rarely one should be shipping that rudder, digging a hole once a decade or less sure beats the expense and trouble of fitting some sort of broken shaft device.

Owner's call and after that (we hope by decades) it's a NOP*.

*NOP, my favorite acronym for Next Owner's Problem.

PeterSibley
06-28-2015, 07:35 AM
I guess Ian but every yard here seems to have concrete everywhere! It could be done at low tide on the sand though.

Don Kurylko
06-28-2015, 09:07 AM
Peter...I went around in circles on this issue with my rudder too and finally decided not to bother with flanges and other complications. It didn't seem worth the bother and opted for the shovel and deep hole solution. Hiring a travel lift might be way cheaper than the expense and labour involved in a complex set up, not to mention unforeseen problems. That's not something I would worry about. What Ian says. Keep it simple.

One thing you might consider is an easily removable heel fitting so that the rudder could be pulled while the boat is in the water.

Ian McColgin
06-28-2015, 09:45 AM
Shipping the rudder in the water is a nightmare. Diver to unbolt the worm shoe and that flanged hinge, some clever harness to guide it down and not lose it in the mud. And then reinstalling! Digging a hole is just not that hard so long as you have half a brain about shoring as you go. And if you don't, there could be a Darwin Award in it for you. Any place covered with paving where you can't dig will have a crane or travel lift and if you set up right it should be less than an hour, maybe less than a half an hour, to get it out.

How often do you think you need to remove the rudder? Do you expect to live that long?

Dan McCosh
06-28-2015, 10:09 AM
Faced with a similar problem maybe 15 years ago, rather than dig a deep hole, we sawed the rudder in half. Sounds a bit radical, but the rudder stock is a stainless tube. The project was a major rebuilt of the rudder, involving a steel armature faired with foam and then glassed over. When the rudder went back on the armature was redesigned to be bolted together, the stock was sleeved with a steel plug, then the rudder was foamed and glassed after the whole thing went back on and was fastened together. It's now possible to saw through the glass, unbolt the halves, and take it off without a hole in the ground. As Ian said, this is unlikely to happen in my lifetime.

Canoeyawl
06-28-2015, 10:27 AM
Ian, re the stuff box ... why so ?

I had thought just to run a copper or glass reinforced tube up to deck level.

I have a similar construction and used a square wooden box from deck to keelson. One side of the box, above the waterline, is accessable from the cockpit by removing a "door" held on to "cleats" in the box forming a rebate with screws and bedding. You could place a shaft coupling just inside the door.
That particular curved rudder stock as drawn should be a casting. Make it long enough so the majority of the curved bit can be cantilevered off the end of your lathe supported by a steady rest. Or find a large enough lathe. Only the bearing surfaces need to be trued. When you cast it make them slightly proud to avoid having to turn the entire length to a diameter.

(I used the old school wooden rudder and stock, like a friendship sloop might have. African Mahogany (Kahya) drifted and bolted together with 1/2" drift bolts. A 3" id copper pipe serves as the bearing surface, slipped over the stock, bonded on with Sika and pinned with a 1/2" pins and the bushing on deck is the corresponding next size up pipe. 20 years, I've never had it apart. I can get bottom paint in the box through the "door". I expect it to last another 20 at least, in fact I may never see it again!)

Jamesh
06-28-2015, 11:08 AM
Here I the uk you can get pipe couplers which come in a variety of sizes.
They have grub screws which would need replacing with machine screws. But might work certainly affordable.
Corrosion would be an issue.
http://www.themetalstore.co.uk/products/tube-clamp

Cheers james

shade of knucklehead
06-28-2015, 06:37 PM
Knucklehead, what's the purpose of the bar ahead of the rudder?

That's called a strong back and keeps the skeg from bending when the boat bounces off the bottom. These oyster boats hit shallow bottom a lot.

PeterSibley
06-28-2015, 07:03 PM
I have a similar construction and used a square wooden box from deck to keelson. One side of the box, above the waterline, is accessable from the cockpit by removing a "door" held on to "cleats" in the box forming a rebate with screws and bedding. You could place a shaft coupling just inside the door.
That particular curved rudder stock as drawn should be a casting. Make it long enough so the majority of the curved bit can be cantilevered off the end of your lathe supported by a steady rest. Or find a large enough lathe. Only the bearing surfaces need to be trued. When you cast it make them slightly proud to avoid having to turn the entire length to a diameter.

(I used the old school wooden rudder and stock, like a friendship sloop might have. African Mahogany (Kahya) drifted and bolted together with 1/2" drift bolts. A 3" id copper pipe serves as the bearing surface, slipped over the stock, bonded on with Sika and pinned with a 1/2" pins and the bushing on deck is the corresponding next size up pipe. 20 years, I've never had it apart. I can get bottom paint in the box through the "door". I expect it to last another 20 at least, in fact I may never see it again!)

I won't cast the stock myself Jake, unless it's in two sections as It would be too much metal for my little set up. I could cast it in two sections though although I'd probably buy a bit of aluminium bronze for the top section.

Is your rudder removable the way you have built it ? Meaning sufficient wriggle room to drop it out ?

Canoeyawl
06-28-2015, 07:14 PM
Well yes, it will drop out no problem. You have to have clearance beneath the hull but once it is clear of the garboards it will go sideways. So maybe three feet under the keel to remove it? I'll see if I can get a picture...

http://i1045.photobucket.com/albums/b457/canoeyawl/image.jpg1_zpsgx2lzver.jpg (http://s1045.photobucket.com/user/canoeyawl/media/image.jpg1_zpsgx2lzver.jpg.html)

Canoeyawl
06-28-2015, 07:45 PM
The edit is being glitchy at the moment... f#%*in apple
Here's another

Note; the rudder heel fitting is a casting on the keel, and a fabrication on the rudder ( a 1" dia pin fitted about 6" up into the stock, wrapped with bronze plate and through riveted. You can sort of see the lines where the pieces are fitted to the stock.

On deck;

http://i1045.photobucket.com/albums/b457/canoeyawl/image.jpg4_zpskvso6bld.jpg (http://s1045.photobucket.com/user/canoeyawl/media/image.jpg4_zpskvso6bld.jpg.html)

Canoeyawl
06-28-2015, 07:50 PM
Another; showing the tiller pivot. Note the 1/2" pin riveted through the stock securing the copper pipe

http://i1045.photobucket.com/albums/b457/canoeyawl/image.jpg5_zpsscaft55a.jpg (http://s1045.photobucket.com/user/canoeyawl/media/image.jpg5_zpsscaft55a.jpg.html)

Canoeyawl
06-28-2015, 07:53 PM
Another showing detail of heel fitting. I think it is important to drill the hole through so that sand and etc cannot be trapped in there and wear it out.

http://i1045.photobucket.com/albums/b457/canoeyawl/image.jpg2_zpswjnzsxib.jpg (http://s1045.photobucket.com/user/canoeyawl/media/image.jpg2_zpswjnzsxib.jpg.html)

Canoeyawl
06-28-2015, 08:00 PM
This shows the details of the keel piercing and a bit of movement of the individual pieces show where they were assembled. It is still wet from our cruise a few weeks ago.The rudder is about three inches + thick at the stock and the stern post is concave to keep a clean and fair foil. (The keel itself is a foil with max chord about ten inches wide just aft of amidships, tapering to the end of the rudder about 1" that was a bit of work, not in the plan... But it does give some advantage at slow speeds in shallow water)

http://i1045.photobucket.com/albums/b457/canoeyawl/image.jpg3_zpszdiuqfcx.jpg (http://s1045.photobucket.com/user/canoeyawl/media/image.jpg3_zpszdiuqfcx.jpg.html)

PeterSibley
06-29-2015, 03:46 AM
Thank's Jake ... I'm just back at the computer . The photos are great and much appreciated ... I don't think I can find stock copper tube but casting tubes that size is easy enough.

So just 2 bearings , the deck level and the one at the heel ? Is there a bit of slack where the stock passes up into the hull to allow it to wriggle sideways to drop out ? Or would you drop off the heel casting ?

That offset prop makes all this a LOT simpler, I've been thinking about the little detail today.

Ian McColgin
06-29-2015, 06:21 AM
Rather than sweating bullets over a rudder that should not be dropped in the next twenty years, put some major effort into ventilation of that tiny stern and preventing moisture from causing rot in the horn under the mizzen step, as is all to common on certain yawls. While at it, perhaps you can improve access to the area.

G'luck

PeterSibley
06-29-2015, 06:26 AM
Don't worry Ian, ventilation is a high priority for me, I've seen the very unpleasant results of it's lack up close.

donald branscom
06-29-2015, 09:59 AM
If you think you will dig a hole to unship the rudder think about this:

When you are on the hard it is often covered in slippery mud and so you think you will just put down some plywood.
Then the plywood starts to act like a slippery ski.
Also I have had the plywood sink down into the mud.
The digging down is harder than you think and you will be sorry you ever thought up such a plan.
Especially out in the hot sun.

Build the rudder properly and think it out so that you will never have to pull the rudder unless you are at a boat yard.

Never weld a rudder shaft.
They almost always fail or break no matter how good the welding is.
When you weld the metal it degrades the metal .
I am a certified welder.

Most of the problems can be eliminated by designing it right in the first place.

The flange connection will be the best, but use Grade 8
steel bolts or bolts that do not set up a corrosion problem.

It is hard to talk about all of the different possibilities.
But wood boats,fiberglass boats, and steel boats, all may need a different design for the rudder.

Always provide a way to lift the rudder and make sure the lifting point is located so
the rudder will be upright and help you to position the rudder.

Canoeyawl
06-29-2015, 10:29 AM
Remove the heel casting. 8 # 16 screws.

PeterSibley
06-29-2015, 05:05 PM
Thank you Donald, good advice and your words about digging holes are noted and also the reason for this thread.

Also noted your comments on welding.... thus I will use bronze castings.

Don MacLeod
06-29-2015, 05:23 PM
Peter, if you wish to be able to drop the rudder right out, lift the boat up higher.
Use a travel lift or jack it up and place on blocks or 200 l steel drums.
For the small number of times that it will have to be done, the extra cost is nothing.
Plus working under a raised hull is a lot better on your back!
Jake's boat on the trailer can be driven over a vehicle pit.
Do not make your work to complicated.

rogue
06-30-2015, 11:13 AM
I have seen a few vessels lifted higher to remove their rudders; seems simple enough. On my 1932 cutter, the bronze rudder stock was two piece, with a long curved upper and a short straight lower, both through bolted to the rudder with 1/2" bronze bolts, separated by about 20" where the aperture is. The wood of the rudder supplied the strength where there was no stock; I used some 80 year old AYC instead of oak. The rudder was already off when I bought the boat, and I built the new just like the old but thicker. To install you left off the lower until the upper stock was up into the bronze pipe and held with a pipe wrench at the tiller head. The lower then slid into the socket on the shoe, and the lower bolts were tapped in through the rudder and nuts/washers applied. I also punched the bolt thread so the nut couldn't come off. Worked for 30 years, although I did notice that one of the lower bolts was a bit loose last time I put her up on the beach to clean her bottom. As Ian says "NOP".

PeterSibley
06-30-2015, 06:18 PM
That sounds like a nice simple solution Rogue, thank you.