Re: [PSUBS-MAILIST] A few questions from a newbie

[VBra676539@aol.com]

I've seen nylon bushings perform adequately on rudders, although delrin holds up better and seems to last longer. Stainless on bronze works fine, too, but probably isn't necessary. The rudders on the Perry boats were 36" X appx. 12" and used a thin delrin pushing set in aluminum and rudder posts of stainless and that worked the best. My Kittredge has a pivoting main motor and the pivots are SS and fit into delrin and that's with 3 horsepower against it.

On your hydraulics question:  Flanges? What do you mean by flanges? Most shallow boats use 2X or better pipe nipples welded into either the hull or, for multiple pens (say, for a manipulator package) through a penetrator plate that is welded into the hull or bolted into a support frame. You then use standard hydraulic fittings to tie the inside system to the outside system, generally attaching hull stops in the form of ball valves or somesuch on the inside to isolate problems on the outside. You can also machine a single plate for O-ring penetrator fittings on either side, which works very nicely.

On a historical not, the Pisces boats routed several tubes through a single taper fitting filled with silver solder so that you had several pigtails only in SS to tie depth gauges and emergency shears through the hull.

Vance