Saturday, September 10, 2011

Steering Sheaves in Cable Systems aboard Yachts

(Written a few years ago.)
This spring, I was concerned about a Coast Guard alert for a CSY 37 that a few weeks earlier had been anchored near me. The vessel was reported as missing on on a crossing to the Bahamas. All ended well luckily but I feel compelled to spread the word again as to why there was a problem; a problem not rare to 25 year old boats.

Obviously no one wants to loose steering, no one; but reasonable maintenance should prescribe disassembly of our simple cable systems to check components. We know of failures and near failures and the fix is straight forward.

The steering failure that caused the CSY 37 to go missing for awhile and luckily nothing worse, was a rusted through steel bracket under the binnacle where sheaves attach. It crumbled, collapsed! The problem was beyond surface rust. A basic check of this bracket should be high on the maintenance list of any owner. These brackets came in bronze as well and should be sound if they are.

At left, photos (taken of my gear!)show a near failure of the bronze sheave pins. Edson now makes the replacement pins of stainless steel/a harder material!
Plenty of time has been spent on projects in my lazarette but I did not catch the wear on the sheave pins until I took the cable system apart to INSPECT.. Disassembly of the cables to work in the lazarette allowed me to feel the sheaves, now without tension on them, and the obvious 'wobble' scared me. The TOP photo shows a tilting of the sheave. Visually, that should alert anyone that there is a problem. The MIDDLE photo shows the pin was ALMOS; the evidence of ONE sheave pulling one way and another pulling against it....but almost worn completely through. This would have been disaster.  The BOTTOM photo shows 2 Fair pins, 1 Bad pin and 1 absolutely Dangerous pin.

Replacement of the Oilite bushings in the sheave costs only a few bucks, so have a shop to that for you as well.

OK, so your not going to cruise far. How about when you are turning into your marina under power and you have to turn past a few of those nice expensive power boats. Want to loose steering then?

(originally posted 9/20/06)

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