Steering cable snapped

Talulah

Talulah

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The steering cable snapped on our boat over the weekend so for those interested I've detailed further info below.
Overview: Mounted onto the steering wheel shaft is a sprocket over the top of which passes a length of chain. The chain hangs vertically down either side of the sprocket. Attached to each end of the chain is a length of stainless steel rigging wire.
This wire drops down through the steering pedestal into the engine bay below. Each of the wires then pass around a pulley and enter the rear cabin through a sleeve where they exit under the rear berth and are attached to the rudder quadrant.
The cable snapped where it goes around the pulley in the engine bay.
I imagine this constant bending and straightening of the rigging wire causes it to weaken and eventually break.
If you have a similar system it's worth checking in the pulley areas for broken strands of rigging wire.
The situation becomes exagerated when people engage the autopilot without realising and try forcing the wheel.
In our case it is possible to steer using the autopilot as the ram is mounted directly onto the quadrant at the rudder stock. For those with an autopilot that has a belt that goes around the steering wheel hub it won't work for obvious reasons.
In addition steering was possible with the emergency tiller but as this is mounted on top of the rudder stock in the rear cabin visibility is minimal. You need a crew member to give directions.

I haven't yet fixed the cable but removal and refitting at the rudder stock end is straight forward. The binnacle end is slightly more difficult as you have to remove the compass and top section of the binnacle. The compass is wired in and will have to be disconnected. You need a socket set to reach the bolts for removing the top section of the binnacle.
Once removed (corrosion of the bolts permitting) it is still not easy to get to the sprocket. If the Steering pedestal has side opening for speakers, engine control or power cable it may help to get access through there. Having extracted the chain with the wire attached take to a local rigger/chandlery to renew. (Arthurs or Kiwi Rigging in Gosport.) Refitting is straightfoward. I anticipate 2 hours to fix plus whatever it takes to get the cable made up.
Should be done in time for next weekends BBQ.
 
My wire cable steering also starts to break up at the final pulley before the quadrant but in my case (started to break strands on two occasions at 4 year intervals) the wear was caused by the pulley seizing up. The seized block could not be felt on the steering but was gradually wearing which showed as broken starnds. Best to use 7x19 stainless wire as more flexible and check that pulleys are adequately lubricated.
 
catalac08 said:
My wire cable steering also starts to break up at the final pulley before the quadrant but in my case (started to break strands on two occasions at 4 year intervals) the wear was caused by the pulley seizing up. The seized block could not be felt on the steering but was gradually wearing which showed as broken starnds. Best to use 7x19 stainless wire as more flexible and check that pulleys are adequately lubricated.
Click to expand...

Useful tip. Many thanks.
 
Talulah said:
The steering cable snapped on our boat over the weekend so for those interested I've detailed further info below.
Overview: Mounted onto the steering wheel shaft is a sprocket over the top of which passes a length of chain. The chain hangs vertically down either side of the sprocket. Attached to each end of the chain is a length of stainless steel rigging wire.
This wire drops down through the steering pedestal into the engine bay below. Each of the wires then pass around a pulley and enter the rear cabin through a sleeve where they exit under the rear berth and are attached to the rudder quadrant.
The cable snapped where it goes around the pulley in the engine bay.
I imagine this constant bending and straightening of the rigging wire causes it to weaken and eventually break.
If you have a similar system it's worth checking in the pulley areas for broken strands of rigging wire.
The situation becomes exagerated when people engage the autopilot without realising and try forcing the wheel.
In our case it is possible to steer using the autopilot as the ram is mounted directly onto the quadrant at the rudder stock. For those with an autopilot that has a belt that goes around the steering wheel hub it won't work for obvious reasons.
In addition steering was possible with the emergency tiller but as this is mounted on top of the rudder stock in the rear cabin visibility is minimal. You need a crew member to give directions.

I haven't yet fixed the cable but removal and refitting at the rudder stock end is straight forward. The binnacle end is slightly more difficult as you have to remove the compass and top section of the binnacle. The compass is wired in and will have to be disconnected. You need a socket set to reach the bolts for removing the top section of the binnacle.
Once removed (corrosion of the bolts permitting) it is still not easy to get to the sprocket. If the Steering pedestal has side opening for speakers, engine control or power cable it may help to get access through there. Having extracted the chain with the wire attached take to a local rigger/chandlery to renew. (Arthurs or Kiwi Rigging in Gosport.) Refitting is straightfoward. I anticipate 2 hours to fix plus whatever it takes to get the cable made up.
Should be done in time for next weekends BBQ.
Click to expand...

This should not be ordinary rigging wire? Confirm what you have is flexible wire . I am surprised it has failed at a sheave. I have a similar system except my wire has multiple turns over a drum at the wheel. my sheaves for direction change are about 4 inches dia for 1/4 inch wire and after 10 years service there are no signs of distress at any sheave. My only source of problems were the attachment points to the quadrant where the wire bent 90 degrees and had a swage to secure. This 90 degree bend was softened with radii. If the pulleys are correct for the wire there should be no real problems . It is good practice to check these cable runs every winter layup.
 
Bilgediver said:
This should not be ordinary rigging wire? Confirm what you have is flexible wire . I am surprised it has failed at a sheave. I have a similar system except my wire has multiple turns over a drum at the wheel. my sheaves for direction change are about 4 inches dia for 1/4 inch wire and after 10 years service there are no signs of distress at any sheave. My only source of problems were the attachment points to the quadrant where the wire bent 90 degrees and had a swage to secure. This 90 degree bend was softened with radii. If the pulleys are correct for the wire there should be no real problems . It is good practice to check these cable runs every winter layup.
Click to expand...

I had made the assumption is was just ordinary rigging wire so stand to be corrected. Is 'flexible' wire easy to come by and how would I identify it?
 
check the chain too

i had a gradual loss of steering due to what i thought was a a loosening of the cables on the quadrant steering section. it turned out that the rudder stops had loosened enough over 20 years that there was slack in the steer cables. i found this out in a heavy wind when i needed to apply sharp rudder to avoid a fisherman ilegally anchored in a narrow channel. the sharp application of rudder caused a cable to jump off the. sheave completely, locking the rudder to far port. could not free the jam, it was. at. night . could not use emergency rudder as the rudder itself was pinned against the stop . had to be to towed alongside by a professional towboat $$$$$$$. as without rudder, none of our sailing friends could assist.

to clear the problem, had to take off compass binnacle, needed stubby and offset screwdrivers.on inspection. the chain was. badly worn so decided to replace the chain , also replace the steer cables, adjust the rudder stops and lubricate the sheaves. the steer cables were begining to fishook, thalt is --run a bare hand down the wires and you will get pricked by little sharp pieces of wire starting to come out from the body of the cables. in the usa, edson manufactures complete quadrant drive steering parts and all they. needed was an old cable and the length of the drive chain. not expensive. to fix if you do it yourself.
 
Talulah said:
I had made the assumption is was just ordinary rigging wire so stand to be corrected. Is 'flexible' wire easy to come by and how would I identify it?
Click to expand...

Most places should sell steering wire. Normally it is galvanised as it will take the 'bending' better. I end up replacing mine every 4 or 5 years mainly becuase a pulley 'seizes' and frays the wire. Should sort out the pulley .....
 
Talulah said:
I had made the assumption is was just ordinary rigging wire so stand to be corrected. Is 'flexible' wire easy to come by and how would I identify it?
Click to expand...

Rigging wire is totally unsuitable for this application. Your local chandler or rigger should have the flexible wire. It is made to a similar construction as bigger wire ropes and will probably consist of 6 strands laid together where each of the six strands contains 26 to 36 small wires each not much bigger than your hair...Well maybe just a tad.

This flexible wire is sold for steering applications and will work quite happily on sheaves where the stiffer rigging will not.

Flexible stainess is fine and will last many years. In this size galv steel is no advantage.
 
Interestingly, when I took my running backstay wires in to be shortened, the rigger assumed they were steering cables. So you wouldn't get any special hair-thin dozen-bundles steering wire if he were speccing it.

Pete
 
Update: Talulah has now been fixed and is back out and about.
I'm at work but the guys on board took the old stuff to the chandlery and got a new wire made up. So I hope they got flexible wire. I just don't know and won't be able to check until next weekend. Hopefully the chandlery replaced it like for like.
 
catalac08 said:
My wire cable steering also starts to break up at the final pulley before the quadrant but in my case (started to break strands on two occasions at 4 year intervals) the wear was caused by the pulley seizing up. The seized block could not be felt on the steering but was gradually wearing which showed as broken starnds. Best to use 7x19 stainless wire as more flexible and check that pulleys are adequately lubricated.
Click to expand...

7 x 7 i think you mean
 
I had twice a breakage of my steering cable - both times after longish heavy weather sailing with the wheelpilot on. In my case they broke at the quadrant. The only way to avoid it, is tensioning the cables. When you feel the wheel has play: it's that time again, otherwise the strain of the rather sudden autopilot movements will be too much.
 
"The situation becomes exagerated when people engage the autopilot without realising and try forcing the wheel."

I have tried to put less stress on the system by both "people" and the autopilot drive by using a disengagement wheel.
See photos here https://picasaweb.google.com/clive.sparkes/Rudder
Also I replaced the steering cables as you describe and also the bearings in the pedestal.
Clive
www.sephina.org
 
auditdata said:
"The situation becomes exagerated when people engage the autopilot without realising and try forcing the wheel."

I have tried to put less stress on the system by both "people" and the autopilot drive by using a disengagement wheel.
See photos here https://picasaweb.google.com/clive.sparkes/Rudder
Also I replaced the steering cables as you describe and also the bearings in the pedestal.
Clive
www.sephina.org
Click to expand...

Great set of pictures. Looks like an excellent job. It was interesting to see as I have not seen a disengagement wheel before or greasers fitted to the cable conduit.
Many thanks. Every day's a school day.
 
sailorman said:
7 x 7 i think you mean
Click to expand...

7x19 is more flexible than 7x7 and perhaps more suitable for steering cable but I could imagine 7x7 to be more hard wearing, if not as flexible but there may be more work hardening in the less flexible wire?
 
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