Straight Line’s commitment to excellence. They include
lapping couplings to shafts, dry fitting complete shaft
assemblies in the shop for precision, checking and then
stamping the parts to ensure that they are reassembled
in precisely the same orientation, and the use of torque
wrenches and grade 8 fasteners, where called for, for all
running gear assemblies.
When I nodded approvingly at the mention of the
torque wrench, Chris intoned, “We always use torque
wrenches and thread locking compound, even on
cutless bearing set screws. If you overtighten those,
the shafts will sing.” In fact, they go so far as to dimple
the cutless bearing shell where the set screw lands, to
reduce the pressure that’s necessary. Loose or loosening
fasteners simply aren’t tolerated in this shop. It’s the
machinists’ equivalent of the Bushido Code—all
fasteners shall remain as they were installed, period.
Finally, sea trials are mandatory for all Straight Line
Next, Chris took me on a whirlwind tour of some
of the projects they were currently working on, from
classic wooden commuters and sailing catamarans to
modern, super yachts and trawlers. Chris commented
that 20 percent of Straight Line’s work is on new boats.
With the yard tour finished, it was time for me to leave
Straight Line. It was an enjoyable and enlightening
Straight Line Marine
sojourn through the world of precision running gear
repair. As I was preparing this article and peppering
Chris with still more questions, he excitedly shared
with me a new graphic representation program he
developed for detailing and recording the alignment and
measurements on any boat. The visual nature resonated
with me and I voiced my approval. He also indicated
that he was very close to obtaining ABS approval
for shaft weld repairs. The standard is quite rigorous;
however, he’s confident his team has the requisite skill
set to meet the requirements.
As I mentioned at the outset of this article, alignment
is often overlooked or simply given cursory attention at
best. The next time your vessel is hauled, have a close
look at the shaft and bearings. Turn the shaft, if you
can. If your feet come off the ground, well, you know
the rest of the story. If you find you have a persistent
running gear or vibration problem that no one else
seems to be able to figure out, consider giving the folks
at Straight Line Marine a call. I suspect there isn’t too
much they haven’t seen, or fixed, when it comes to
Steve owns and operates Steve D’ Antonio Marine
Consulting ( www.stevedmarine.com), providing consulting
services to boat buyers, owners, and the marine industry.
ZMI Now At Herrington Harbour North!
ZIMMERMAN MARINE now provides a full range of boat repair services at Herrington Harbour’s outstanding
marina facility near Deale Maryland, just south of Annapolis. Our new facility can handle haul outs to 70 tons
and includes 4,500 sq feet of climate controlled work space.