T&T: Fw: Emergency steering

[Larry N. Brown]

> <Mike wrote: This valve that provides a bypass is a source of real danger.
> Precautions should be taken to prevent the valve from ever coming open
> by itself. It should be locked if possible, if not then wired closed,
> tied or whatever is most feasible.>
> And it happened ...... to us. In our case the bypass valve body had a flaw
> and under pressure opened up. It was rated at 3000 lbs and our steering
> pumps don't put out more than 1200 PSI.
<SNIP>
>
> YMMV
> Dave & Nancy
> Swan Song
> Roughwater 58
> Puerto La Cruz

Dave makes a good point about the bypass valve failing. That valve is no 
weaker or apt to fail than any other part of the system- maybe less so. A 
tie wrap could protect it from accidental movement.

When Cigano was in the yard, I noticed some pitting in the tubing in my 
Hynautic steering system so I stripped it all out and replaced it with hose. 
I sent the upper and lower helm pumps and the tiller ram to a professional 
hydraulic steering place. Installed everything and bled the system and all 
seemed well. We were making some high speed runs on the river to check the 
propeller pitch and suddenly the boat wouldn't turn to starboard. It was 
like a ratchet; it would turn left but not right. I slowed down and steered 
with differential power until I could get down to the lower station; the 
steering was normal there.

We returned to the yard, bled the system and went out later. Two short runs 
and everything seemed normal. Until the 3rd run and the story repeated 
itself.

I sent the helm pump back to the guy who checked it out and said that the 
pump body was machined aluminum and the valves were steel. The shuttle/check 
valve on the upper pump, starboard side, had wallowed out the aluminum to 
the point that it allowed fluid to bypass it from time to time. Had to 
replace it and it wasn't cheap but I was lucky that it happened in 
relatively benign circumstances.

As the man said "if your boat is over voting age", during a winter lay-up it 
might not be a bad idea to have the hydraulic components rebuilt.

Gary at Marine Control in Franklin, NC did a good job 828.369.7572.

Regards,

Larry & Teri Brown
MV Cigano, 47' Prairie Sundeck
Still glued to the dock in Covington, LA