Performing a complete running gear refit

2014 August 1
by Chris Brown

We were recently hired to perform a complete running gear refit on a very unique 120 foot Trinity Sport Fish. The refit included everything from realigning the strut bearings using a “line boring” machining process, realigning transmissions and installing new stern tubes.

This particular yacht also had very old Paxman engines and Christie & Grey engine mounts, both UK-manufactured products. The Paxman engines were going through a major overhaul with another contractor so we proposed replacing the old Christie & Grey engine mounts with a new type of adjustable isolating mount.  For this project we selected Vulkan mounts.

New Vulcan engine mount with CHOCKFAST

New Vulkan engine mount with CHOCKFAST

In order to install the new Vulkan engine mounts, we needed to fabricate all new sole plates, drilled new holes in the aluminum stringers and align with CHOCKFAST® ORANGE. CHOCKFAST is an engineered epoxy chocking material that is used to cast-in-place permanent machinery supports for all sizes and types of main engines and marine auxiliary equipment. Because it conforms precisely to any surface profile, CHOCKFAST eliminates the machining of foundation and mounting surfaces as well as the fitting of the old-style steel chocks.

We also installed new Vulkan torsional couplings.  This torsional coupling is found between the gear box and the engine and serves to dampen the torsional loads coming from the engine flywheel thus absorbing any twist in the shaft. The Vulkan torsional couplings have rubber or other material that does degrade with time and heavy use. After 10 years it is time to check your coupling. This one was well past due going on 17 years old.

Once the preliminary work and re-installation were complete, we performed a Ludeca Laser Alignment on the vessel. A Ludeca Laser shaft alignment uses a patented automatic CONTINUOUS SWEEP measurement mode which evaluates hundreds of readings during shaft rotation. This compares to shooting a movie vs. only taking flash pictures at certain intervals. The end result is less shimming and horizontal moves because you are measuring much more accurately.

This very unique Sport Fish is now ready to deliver many more years of sporting pleasure to its owners and crew.


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