Prop, Shaft and Rudders on a 61' Marlow

The new owner and new Captain on a beautiful 61′ Marlow came into the yard.  The vessel had a major vibration that was most noticeable when driving from the lower wing station.

After removing props we went through our standard running gear inspection process – checking shaft run-outs, bearing clearance, seals and engine mounts.  The running gear all checked out within spec so no need to pull shafts and create a big bill.

The rudders were extremely loose with up to 0.125″ of play and slop in the tiller arm pins.  This was clearly a source of vibration with the prop wash rattling the rudders around.

Marlow’s were built using cutlass bearings as lower rudder bearings.  We believe that allows too much play and premature wear.  The lowers and uppers were replaced with Tides Marine UHMW bearings.  The machine shop re-bushed the tiller arms and made new pins for the tie-bar.  New Tides Lip seals and back together – all nice and tight.  We only traveled a hundred yards in the New River before the Captain declared the problem solved.  A month later he sent us the following update:

“Hi Chris,  Thought you should know that the boat is running better then the day we bought her, thank you. Less noise etc. And we can actually run over 1400rpm with out breaking plates. ”

Next time you have a vibration, try to listen closely to your rudders.  Don’t assume it is a shaft or alignment problem.  And make sure you use a contractor that will take the time to inspect before tearing apart.  We saved this owner a tremendous amount of money by recommending a “pass” on a full shaft job.

Tides Marine offers a very nice replacement rudder tube system.   A fiberglass rudder tube comes complete with upper and lower UHMW bearings and an upper lip seal.  The technical support team at Tides Marine were extremely helpful in working through the engineering details.  The existing rudder stock was tapered which created a few complications for the rudder bearings.  Not a big problem since Tides has a machine shop to handle the odd dimensions and custom specifications.

The replacement process requires the old tubes be removed from the vessel.    A sawzall and some patience allowed the old rudder tube to drop right out of the boat.  The new tubes were inserted, using the  rudders as an alignment jig, and fiberglassed into place.  Our friends at P & S Yacht Services did a clean, professional job fiberglassing and fairing the tubes in place.

After reassembly the rudders were tested – a light touch with one finger moved the rudders effortlessly.

Rudders on 111' Inace

One of our customers ran into a major problem with rudders that were seized in position.  The rudder hydraulics had failed due to overloading.  We knew it was a problem when a mechanic in the rudder room could not move the tiller arms using his legs and back.

Once hauled (the vessel had to be towed in) the rudders were removed.  At High Seas we like to meet our customers prior to haul-out in order to start the steering and rudder removal process.   After haul-out and during the pressure wash we complete the disassembly and can drop the rudders prior to final blocking.  Most rudders are too tall to remove once the vessel is blocked.  If we work efficiently with the yard crew we can avoid a second lift (which is an additional charge for our customers).

Once the rudders were removed the bearings were carefully inspected.  Everything was within specification (the vessel is only three years old).  The problem was in the packing.  The manufactured used Teflon packing in a traditional stuffing box.  The rudders were a constant leaking annoyance for the crew and someone had overtightened the packing gland.  It is possible to torque down the packing gland with Teflon packing to the point where the rudders will not move. 

We clean all components and repacked with more traditional flax packing.  Once everything was re-hung the rudders turned without any effort at all.