Replacement rudder for Mull 28

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bad
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Joined: Sat Jul 09, 2011 11:14 am

Re: Replacement rudder for Mull 28

Post by bad »

I thought Jim Antrim took over and managed most if Gary's designs.
https://antrimdesign.com/index.html.

GMT may give you a copy of the drawings and layup schedule. If not, I would not hesitate to ask Jim for help. Excellent structural guy and very straight forward.

You don't need the exact same rudder. It just has to fit the boat (shaft diameter, angle between the rudder shaft, hull, and top of rudder. Etc) that's not to hard to measure. Its has to be strong enough - you have info in the needed strength of the shaft. Layup schedule of the foil is partially dependent on the core and the shaft engagement. Profile and foil section... you have experience with hire the boat steers, rudder pressure, weather helm... it is a great time to make a better rudder. Not necessarily the same.

Best of luck!

walterg
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Re: Replacement rudder for Mull 28

Post by walterg »

Drove down to the boat last night (she's stranded about 2 hours away) and pulled out the rudder stock. Not a huge deal, just 2 bolts through the shaft, loosen the cables on the steering quadrant, unbolt and separate the quadrant halves, and then a little more pounding than I anticipated but it did come out. No signs of any other damage and the plastic bearing sleeves seem fine.
I called Jim Antrim and although he did some work for Gary Mull's widow, he doesn't have any of the drawings. Meanwhile I have asked if GMT would be willing to share the drawings that they have for a fee. Erik, take your point that the rudder doesn't have to be exactly the same and maybe can be even better, but I do want to be sure I have the fit right between the rudder and the hull. I made some cardboard templates but if I can't get the drawings, I might try to use a piece of PVC pipe and some thin plywood to mock up the top section of the rudder.

rudderpost3_small.jpg
rudderpost3_small.jpg (19.61 KiB) Viewed 1535 times
Walter Gotham
Salem MA USA
'87 Freedom 28-Mull #33 "Nova Vita"

bad
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Re: Replacement rudder for Mull 28

Post by bad »

Sorry about my misunderstanding re Gary's drawings.

Is the shaft fiberglass with st. steel wear sleeves? And do you have a bushing or a bearing on the bottom in the hull?

Errik

walterg
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Re: Replacement rudder for Mull 28

Post by walterg »

No problem, I am looking for any leads I can get! I hope to make a decision Monday on getting someone started to build a new rudder.

The outside of the shaft is FRP but I think that overall it is a mix of FRP and carbon. Where it's broken off at the base it looks like you can see strips of carbon. There is foam inside the shaft, but it only extends about 10" or so from the base, above that it is hollow. There are 3 stainless collars; one at the base, one at the top, and one in the middle. The top and bottom collars ride in bushings set into the hull and deck, I think they are HMWP but not sure how they are bonded in. The middle collar is where the steering quadrant attaches. There are two 3/8" bolts, one through the quadrant at the middle of the shaft, and one at the top. I think that the middle bolt takes all of the load, and the top bolt is only to serve as an attachment point for the emergency tiller, and to act against the stops to limit the lateral travel of the rudder.

As discouraging as all of this is, it could have been worse. Thank goodness I lost the rudder when I was several miles offshore and didn't have anything to run into. If this occurred in one of the canals or in Woods Hole, it could have been much messier.

Could this have been prevented in advance? I'm not yet sure. I have never dropped the rudder, but I did inspect it visually every off-season and wiggled it back and forth as hard as I could. The surveyor who looked at it suspects that it could have been cracked for some time based on the discoloration of the foam around the break and the marine critters swarming inside. Not sure if I will ever know.

The other lesson I learned is to know what your towing coverage is before you need it. I didn't, and got a little screwed as a result.
Walter Gotham
Salem MA USA
'87 Freedom 28-Mull #33 "Nova Vita"

bad
Posts: 160
Joined: Sat Jul 09, 2011 11:14 am

Re: Replacement rudder for Mull 28

Post by bad »

Interesting build if there is carbon and glass in the shaft. I've been told that because the carbon is so much stiffer than the glass, it takes all the load until it fails, and then the glass is to weak and fails right away, too.

Look at your lower bushing and check for wear. You really want the rudder shaft loaded right where it exists the hull, to minimize cantilever loading. I think HMWP is very low friction, but also a soft material. There may be better bushing materials for this as application.

sailorchris
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Joined: Wed Apr 06, 2016 11:04 pm

Re: Replacement rudder for Mull 28

Post by sailorchris »

F28 hull #46 reporting in. We had an identical failure and loss of the rudder today in Buzzards Bay. Sailing on a broad reach in approx. 20 kt wind, a big wave hit, and we abruptly lost steering. The boat hasn't been hauled yet, but when feeling it under water the remains of the rudder post felt like your picture appears: fragments of fiberglass and not much else.

Walter- do you think CCI will do a 2-for-1 deal? ;) Seriously though, thanks so much for the info about your progress. We were worried about the boat being a total loss, but we get to start dealing with the insurance claim tomorrow.

Chris
Mull F28 #46 Paragon

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mike cunningham
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Location: Jacqueline, F30 #3, Discovery Bay, California

Re: Replacement rudder for Mull 28

Post by mike cunningham »

I have a spare F30 rudder from an F30 which was parting out in Mass. a couple of years ago. I paid $500 for it and would sell it for same if someone could use it. II was doing some ocean racing and did not want a broken rudder to get in the way of my goal to do the singlehanded transpac in 2016. Two of my SSS colleagues had lost rudders. The rudder is is excellent shape. You would have to figure out shipping from California Bay Area.

I went on Boston Craigslist and found a couple who were looking for a rider to help with gas to California. I told them my rudder would be their rider and they strapped it to their roof rack, brought it out here for about $150 if I recall correctly.

Did the same with my gunmount pulpit. A gal drove it down from the Seattle area jammed into her Subaru Impreza believe it or not. I was impressed. I was also impressed with the cloud of pot smoke that came out of her car when she arrived at our place with her boyfriend and my pulpit. Ha ha. All's well that ends well, who am I to judge?
Mike Cunningham
Freedom 30 (Mull) Hull #3
Build date...June, 1986 . Freedom Yachts USA, sloop, shoal keel
Gun Mount and pole retrofitted (purchased from a Hoyt Freedom 32)
Yanmar 2gm20F , 1600 hrs fixed two blade prop
e-rud and ocean racing equipment

sailorchris
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Joined: Wed Apr 06, 2016 11:04 pm

Re: Replacement rudder for Mull 28

Post by sailorchris »

Hi Mike - thank you for the offer, but I think the F30 rudder may be larger than the F28 one. This thread from 2005 mentioned that the F28 and F30 have different rudder stocks and were built in different shops.

Maybe somebody may be able to shed some light on it?

Those are some great stories about clever ways to do shipping logistics. Glad to hear that it all worked out and that you were able to get the gunmount!

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mike cunningham
Posts: 368
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Location: Jacqueline, F30 #3, Discovery Bay, California

Re: Replacement rudder for Mull 28

Post by mike cunningham »

sailorchris wrote:
Tue Aug 04, 2020 11:00 pm
Hi Mike - thank you for the offer, but I think the F30 rudder may be larger than the F28 one. This thread from 2005 mentioned that the F28 and F30 have different rudder stocks and were built in different shops.

Maybe somebody may be able to shed some light on it?

Those are some great stories about clever ways to do shipping logistics. Glad to hear that it all worked out and that you were able to get the gunmount!
Maybe not the end of the road. When I received my spare rudder I noted the shaft diameter was different (smaller) than my installed rudder. I figured I could modify it if it was ever needed.
I am going out to the garage to measure it right now.
OK back - the topmost sleeve for the quadrant attachment is 3 inches OD, The two rudder bearings are also 3 inches OD. The GRP shaft is 2.75 inches diameter.
I have the thing tucked away in the garage behind a bunch of heavy stuff. If these shaft dimensions look promising I can pull it out and provide more detailed measurements and pictures.
I often wondered about the rudder shaft dimensions. I never got round to measuring and comparing the actual blade. Could the guy have inadvertently been parting out a 28?

BTW, a colleague in the SSS lost his rudder 200 NM offshore a couple of years ago. I believe he was sailing a Wilderness 30. He had a new rudder built in Santa Cruz. The folks down there basically designed the new rudder from scratch and, from all reports, improved boat performance to boot. So, even if you don't have drawings you should be able to get a rudder built, my understanding is performance modeling is vastly improved from when our boats were built. Note that David went on the win the Singlehanded transpac in 2016. David also provides a pretty good technical analysis of the failure in the below posting. If you have insurance or extra boat bucks then a new build, with performance and competent engineering as a top priority, would probably be the best way to go.

https://www.mercurynews.com/2014/07/02/ ... reaks-off/

https://www.sfbaysss.org/forum/showthre ... t=herrigel

Mike
Mike Cunningham
Freedom 30 (Mull) Hull #3
Build date...June, 1986 . Freedom Yachts USA, sloop, shoal keel
Gun Mount and pole retrofitted (purchased from a Hoyt Freedom 32)
Yanmar 2gm20F , 1600 hrs fixed two blade prop
e-rud and ocean racing equipment

walterg
Posts: 38
Joined: Tue Aug 30, 2016 6:48 am
Contact:

Re: Replacement rudder for Mull 28

Post by walterg »

Hi Mike,

Thanks for the interesting info....from the few drawings or other info I have been able to track down, the F28 rudder shares the same rudderstock dimensions, with three 3" OD SS collars that go through the upper and lower bearings, and the middle collar that attaches to the steering quadrant. The overall shaft length is about 39", the width of the rudder from the cutout for the skeg to the trailing edge is 17-3/4", and the width at the bottom is 10-5/8". The overall length of the rudder proper exclusive of the shaft is 54-1/4". If you actually have a F28 and not a F30 rudder on hand, it might help Chris but not me as I have already committed to having a replacement built, despite the fact that I have neither adequate insurance or extra boat bucks. Nevertheless, I have to get her home somehow.
Thinking about the idea of bringing a spare rudder offshore.....and wondering how one could install it? You would need to get the old rudderstock out, which shouldn't be that hard, but it would be a trick to get in the water and re-install the replacement. When my rudderless boat was towed in, an old-timer told me how you could use a bucket towed astern and tied to your winches to keep steering with a lost rudder.

Walter
Walter Gotham
Salem MA USA
'87 Freedom 28-Mull #33 "Nova Vita"

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