T&T: ABYC and Canadian TC1332 spec

[2elnav at netbistro.com]

>>Anyone know where I can get a copy of the standards at minimal cost?
>
> As I have posted before:
>
> Transport Canada has "Construction Standards for Small Vessels" document
> that seems to follow the ABYC standards fairly closely.  If you don't want
> to pay for the ABYC documents, this seems to be a pretty good place to
> look
> for information on "proper practices".
>
>           http://www.tc.gc.ca/MarineSafety/tp/TP1332/menu.htm
>
> Steve

REPLY
<VBG>  ya dem canucks be good guys! But!......   I found a little
peculiarity in TP1332.
Seems Transport Canada recommend  placing all rotary  engines with the
crankshaft parallel to the keel;  NOT transverse like I see a lot of
generators installed '42 Krogens.
Being naturally curious I kept digging and finally phoned a TC inspector I
 met.  The answer is  "precession".

Remember the gyroscope experiments you did back in high school or maybe
with the spinning top children toys? When you push on  the shaft of a
gyroscope, it moves at right angles to the direction of the push.

A generator or engine is in effect a gyroscope. If you mount the engine
with the shaft parallel to the keel line the effect of a rolling motion is
minimal.  Mount the genset in a transverse orientation and every  time the
vessel rolls even a little bit; the spinning shaft tries to precess. This
in turn causes additional wear on the shaft bearings.

I doubt you will ever see this as a significant source of wear in any
recreational boat but in commercial fishing boats that stays at sea for
months on end,  it must have shown up enough for a Transport Canada
inspector to note and report.

Cheers
Arild