loss of helm control

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loss of helm control

Postby sdecarteret » Tue Sep 30, 2014 9:05 pm

I lost helm control on my hc 38. Fortunately only 100 urns from the marina. Upon inspection the cables are in place on the flywheel attached to the rudder so I am concluding it's a cable snapped or jumped a flywheel somewhere in or beneath the binnacle pedestal.

There does not seem to be any inspection access ports in the masters or navigators bunk area only a rear hatch to get to the rear rudder fly wheel.

Anyone have any advice ?

Thanks

Steve
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Re: loss of helm control

Postby scleary » Wed Oct 01, 2014 12:58 am

I had a similar experience on my own HC 48T (prior boat). In my case there was sufficient slack and the cable slipped a sheave, literally one second after tying up to a dock at the mouth of a river at night in December in Boston (my maiden voyage). On the 48's that were built by Transworld, they installed a TV cabinet in the aft cabin which stuck out into the engine room. As a result the steering cables that would normally have been at 90^ angles, were at at 45. I ended up buying 'guides' that bolted onto the sheaves so that even with slack they could not come off.

Now to your situation. Go back to the rudder quadrant (flywheel) and see if you can pull the cables, if either comes a significant distance without resistance you have a break. If you just get some slack, then most likely they jumped a sheave at the base of the pedestal or the chain has come off at the wheel. One other possible, you may have a roll pin on the sprocket at the wheel that snapped (so the wheel spins and the sprocket doesn't). You can take the compass off the binnacle to see the chain on the sprocket at the wheel. I'm not familiar with the 38, but I'm guessing there is a way to see the sheaves where the cables exit the base of the pedestal from below. On my 43T (current boat), I can see the sheaves at the base of the pedestal from a compartment at the base of the companionway steps.

The #1 cause of cables coming off the sheaves is trying to steer against the autopilot. Even with properly adjusted cables, if someone pulls on the wheel thinking the pilot is disengaged and it's not, that action can create enough slack that the cables come off a sheave. If you have a pilot connected directly to the quadrant the boat can still be steered, but with a wheel pilot you are completely out of business.

I hope this helps your find the issue, I'm glad there was no damage to people or boats, best of luck!

Steve

A picture is worth a thousand words...
steering_failure.jpg

steering_failure_cable.jpg
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Re: loss of helm control

Postby mimoza » Thu Oct 02, 2014 9:51 pm

The #1 cause of cables coming off the sheaves is trying to steer against the autopilot. Even with properly adjusted cables, if someone pulls on the wheel thinking the pilot is disengaged and it's not, that action can create enough slack that the cables come off a sheave. If you have a pilot connected directly to the quadrant the boat can still be steered, but with a wheel pilot you are completely out of business.


A small point, but this is much less likely to happen with a wheel pilot, since one is working against only the pilot, and not the cables. The cables are getting worked from only one end, not both.
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Re: loss of helm control

Postby scleary » Mon Oct 06, 2014 1:54 pm

Brian makes a great point. Those were meant to be two separate thoughts, but they certainly don't read that way (i should proof read my posts!). What I meant to say was that an advantage to a quadrant attached pilot is that in the event of a steering loss due to steering system failure (as opposed to rudder problem), you can still steer the boat.

One other thing I should have mentioned, the 48T is a center cockpit boat and as such the cable runs from the pedestal to the stern are many times longer than the rest of the HC's. This provides more opportunity for problems. The newer 48's got hydraulic steering, which makes much more sense. Had I kept the 48, I would have converted it to hydraulic. The big argument against hydraulic steering is that you lose the feel of the boat in the rudder, but I can tell you from experience that the 30-40' of conduit involved does the same thing and makes the boat much harder to steer due to all the resistance in the conduit.
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Re: loss of helm control

Postby sv_pacific_pearl » Sat Oct 11, 2014 8:39 pm

Hello

I have a 48 and installed hydraulic steering. It was the best upgrade done thus far. It needs a bypass valve to attach the emergency tiller - but other than that, it is unreal.

Under motor, I can let go of the wheel and it doesn't move. It just holds its course, whatever that course is.

I had cable steering and had an issue one night at sea in big weather. I remember when I was lying in the back bunk listening to the cable starting to fray and was waiting for it to break. It didn't part but it was close. The previous owner also put on one of those wooden spoke steering wheels. It was was also starting to fall apart. Not a good combination and a night I won't forget for some time.

I look at your pictures of wires and sheaves and think, not the best design on boats like ours.

Many HCs have been running around with a cable system successfully for many years. But I keep thinking about: Calculate the static moment on the rudder shaft from the huge rudder area and the huge sideways force on the shaft, due to your boats huge displacement and you will see that your cable is under quite a bit of load. Then think about the dynamic effects due to the velocity in a a storm and mass of the rudder. You can apply that to any boat but on boats like ours the problem is compounded due to our heavy displacement.

Anyway, just some things to think about I suppose.

Steering and chain plates and mast supports need to be super strong.
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Re: loss of helm control

Postby sdecarteret » Mon Oct 13, 2014 5:16 pm

Hey Guys - I finally had a chance to disassemble the binnacle and sure enough the chain had popped off but much to my dismay at least 3 teeth were shattered off the gear, it looks like this has been in that state for a while vs. my recent mishap. I am not sure how that gear is place on the horizontal shaft . . maybe pressed on?


Steve
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Re: loss of helm control

Postby scleary » Mon Oct 13, 2014 11:27 pm

I've not had one apart (i'm quite sure others have), but my bet would be either keyway with a set screw or roll pin holding the sprocket on the shaft. Bearings are often pressed, but I don't think a gear/sprocket assembly would be pressed...just not reliable to resist the mechanical force involved. If you spin the wheel 360 and you don't see a roll pin to drive out, my $ would be on a keyway just like what is holding the wheel on the shaft.

I'm very surprised the teeth would break off like that as I would think other parts of the system would have given out first, I would have to believe the chain was stretched and not riding on the teeth correctly, catching them at the very tip instead of the base to cause that type of break. You'll likely want to replace the chain and the sprocket at the same time, or at least make sure the chain is not stretched in a way that will ruin your replacement sprocket in the same fashion.

Best of luck, not too bad in the scheme of things that go wrong. Hopefully some that has had one completely apart will chime in with some definitive answers/advice for you.

Thanks,
Steve
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Re: loss of helm control

Postby sdecarteret » Sat Oct 18, 2014 5:52 pm

Thanks Steve - Solid advice and I will do some more inspection. One thing that concerns me if this would have happened out at sea, how would one have jury rigged something for steering?
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Re: loss of helm control

Postby scleary » Sat Oct 18, 2014 9:28 pm

You should have an emergency tiller (both the 48 and 43 have one) with a cover that threads out of the deck to get access. If you don't have one, you'll want to get one for sure.
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Re: loss of helm control

Postby mimoza » Mon Oct 27, 2014 7:01 pm

I know of one 43 whose quadrant disintegrated while rounding Cape Flattery in heavy weather. They were prepared with an emergency tiller, and hand steered all the way down to the San Francisco Bay. After that event I took my quadrant to be shot blasted, and then I filled a few voids and coated the entire thing in epoxy. Still looks good.
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Re: loss of helm control

Postby stuartm80127 » Sat Jun 23, 2018 4:32 am

'79 HC38 MK II .

Was going to Channel Islands for weekend and fortunately my steering completely failed while in harbor. I had replaced the cables and cleaned and serviced the Pedestal and throttle/shifter linkages a year ago. Upon getting back to dock I centered the wheel and the quadrant was centered too. The Radial drive was secured to the rudder post /quadrant yet the rudder blade was far from centerline. I took a boat hook to the rudder while the wheel brake was set thus locking the quadrant and was able to move the rudder from side to side without much effort and the flange with bolts appeared to track with the rudder so the flange and below into the Rudder appears ok. I won't get a good idea of the actual problem until she is hauled out in two weeks. I suspect that the rudder shaft may have sheared above the flange bolts or up inside of the log as it seems to be held in place given that there is a "shoe" at the bottom with no other lateral support.

Any other owners had this issue? Any advice on pulling the rudder on a HC 38 MK II? See Attached picture of the last tine she was out of the water for reference as to the rudder design.

Any other HC38 MK II owners remove their rudders or rudder log?

Thanks,

Stuart
S/V Sugata
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Re: loss of helm control

Postby bazzer69 » Sat Jun 23, 2018 4:46 am

My guess is that a lot of these problems are just due to operator error by failing to disengage the autopilot and standing on the wheel in order to try and steer the boat manually. Either way you should regularly check the steering system visually for wear and tear. Nothing lasts forever.
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Re: loss of helm control

Postby bazzer69 » Sat Jun 23, 2018 4:52 am

sdecarteret wrote:Thanks Steve - Solid advice and I will do some more inspection. One thing that concerns me if this would have happened out at sea, how would one have jury rigged something for steering?

Your boat does have a emergency tiller, you should have checked that out before leaving dock. Try disengaging the autopilot before leaning on the wheel this breaking the teeth on the gear.
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Re: loss of helm control

Postby stuartm80127 » Fri Jul 13, 2018 4:53 pm

As a follow-up to my earlier post on my lack of steering control. The rudder post to lower flange weld corroded away. It looked like this was re-done by previous owner, likely in 2004 in MX. The weld itself had just corroded away and taking 3/16" of the post in pitting along with it. Upon scraping away all paint and arriving at the metal surface, there looked to be only two original tacks about 3/4 inch each used to hold the lower rudder post to the lower flange. The rest of the upper and into the quadrant is in great shape but I was going to get the upper flange re-welded too, change out the quadrant log to make it all new. Dang rudder weighs over 100lbs and was built to last. Fortunately, in their design, despite this failure, the rudder was not going to drop out. This is because both the upper and lower flanges are about 1/2 inch thick and have a hole in the center to accommodate the solid SS Rudder post so that the post lies flush with the opposite side of the respective flange thus giving it 1/2 inch of support. So a word to all, closely check those welds on your flanges the next time you haul out. Pics attached.
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Re: loss of helm control

Postby bazzer69 » Fri Jul 13, 2018 6:21 pm

Stuart, that’s one of the worst welds I have ever seen. Looks like chicken sh-t
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