[Rhodes22-list] Fractured stern plate.

[Michael D. Weisner]

Hi Pat,

As an engineer, the problem appears to be caused by one (or more) problems 
as follows:
    1.    Motor weight exceeds design specification
    2.    Live load (motor, waves, wind, etc.) exceeds design specification
    3.    Improper structural material formulation or specification
    4.    Damage or abuse (backed into fixed object, collision, etc.
    5.    Storm damage

Since I must assume that Stan built the motor lift and provided the engine, 
one must assume that #1 is out.  As good as Stan is, engineers do revise 
their designs to correct "oversights."  It is entirely possible that as the 
4-cycle electric start engine weights continue to increase, the design of 
the lift may need to be redesigned (#1, #2 & #3.)  An aluminum plate would 
seem to indicate that such a process has already been started at GBI.

If designed properly, you should not be capable of damaging the lift by 
having "raised the Yamaha too high."  IMHO, the only time that you could be 
at fault would be in cases like #4.

Is it safe to sail?  Well, make sure that your safety chain is in good shape 
and of the correct length so that you do not lose the motor should the plate 
fail.  You could also have difficulty raising or lowering the motor if the 
damage affects the mechanism.  Also, be careful since the cracked material 
can be very sharp.

Mike
s/v Shanghai'd Summer ('81)
Nissequogue River, NY

From: "Pat & Mary Ann" Tuesday, September 21, 2010 9:07 PM
> Hello all,
> This summer I notied a progresse, increasing series of cracks in the stern 
> plate.  I asked Stan about it and he thought it would be safe to sail til 
> Labor Day, then pull the plate and replace it with an aluminum replica. 
> Has anyone had a similar problem?  I wonder if it is because I raised the 
> Yamaha too high.  Any other suggestions for repair or replacement?
> Pat Devig
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