I recently witnessed a possible accident with the autopilot in my boat.
While going under autopilot a guest accidentally put her arm into the
wheel among the spokes and was caught at a wheel turn between a spoke
and the tiller post. The servo is quite powerful so that she was able
to withdraw the arm only after switching off the unit which took few
seconds - still too much. Fortunately only few bruises and some panic
but I fear that it could have gone worse. Any experience? Wouldn't it
be safer to put a panic shut-off switch somewhere? I mean the little red
mushroom to push in case of problems. I have never seen such things
mentioned in autopilot manuals.

Daniel

Daniel wrote:

I recently witnessed a possible accident with the autopilot in my boat.
snip

Is that a cable steering system? I'm trying to remember if I've ever
been on a boat where the autopilot movements feed back to the wheel.
Must be that I have not been around an autopilot on anything but
hydraulic steering systems.

I like being able to rest my forearms on the wheel while the autopilot
is engaged. And if you need to grasp something to steady or brace
yourself, you can grab the wheel because it ain't doing nothing.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

Raytheon actually recommends this. Occasionally their units will freeze and
you would be unable to turn the wheel (not a good idea with a freighter
bearing down). they recommended a cutoff switch ( has to cut the main power
to the unit that controls the rudder). I opted not to do it, but I have
practice diving below to hit the switch on the electrical panel

--
Dennis Gibbons
dkgibbons at optonline dot net
"Daniel" wrote in message
...
I recently witnessed a possible accident with the autopilot in my boat.
While going under autopilot a guest accidentally put her arm into the
wheel among the spokes and was caught at a wheel turn between a spoke
and the tiller post. The servo is quite powerful so that she was able
to withdraw the arm only after switching off the unit which took few
seconds - still too much. Fortunately only few bruises and some panic
but I fear that it could have gone worse. Any experience? Wouldn't it
be safer to put a panic shut-off switch somewhere? I mean the little red
mushroom to push in case of problems. I have never seen such things
mentioned in autopilot manuals.

Daniel

Jack Erbes wrote:
Is that a cable steering system? I'm trying to remember if I've ever
been on a boat where the autopilot movements feed back to the wheel.
Must be that I have not been around an autopilot on anything but
hydraulic steering systems.

yes, there is an electrical servo-motor under the pedestal linked
through a chain directly to the shaft of the helm wheel (there are two
parallel chains inside the pedestal). The servo includes an electric
clutch that engages/disengages the motor shaft to its sprocket wheel.
When the clutch is powered the helm wheel is locked to the autopilot
movement and its torque is quite high, believe me.

Daniel

Daniel wrote:


Is that a cable steering system?

yes, there is an electrical servo-motor under the pedestal linked
through a chain directly to the shaft of the helm wheel (there are two
parallel chains inside the pedestal). The servo includes an electric
clutch that engages/disengages the motor shaft to its sprocket wheel.
When the clutch is powered the helm wheel is locked to the autopilot
movement and its torque is quite high, believe me.

Oh yeah, chain and a servo motor. No slippage there. The panic button
sounds like a good idea if the autopilot's off or standby button is not
prominent or obvious.

And it might be a good idea that engaging the autopilot disengages the
servo motor clutch. If you can't use the wheel for "dodge steering"
when the autopilot is on, there is really no good reason to have the
servo motor clutch engaged. For quick dodge steering I'd like a
prominent switch (momentary contact?) that disengaged either the
autopilot or the autopilot drive.

As you add more pieces it gets to be more complicated and more to
remember but it seems some safety override would be good on that.

I like if a spin of the wheel induces a dodge. Up here in Maine they
have magnetic lobster pot bouys that cause autopilots to home in on
them. A spin of the wheel at the last second will fool them on some
boats.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

Might not be a bad idea, but there are many ways to get hurt on a sailboat.
Sticking one's arm through the wheel is definately a risky move even when
not using an autopilot.

Doug
s/v Callista

"Daniel" wrote in message
...
I recently witnessed a possible accident with the autopilot in my boat.
While going under autopilot a guest accidentally put her arm into the wheel
among the spokes and was caught at a wheel turn between a spoke and the
tiller post. The servo is quite powerful so that she was able to withdraw
the arm only after switching off the unit which took few seconds - still
too much. Fortunately only few bruises and some panic but I fear that it
could have gone worse. Any experience? Wouldn't it be safer to put a
panic shut-off switch somewhere? I mean the little red mushroom to push in
case of problems. I have never seen such things mentioned in autopilot
manuals.

Daniel

Seems to me that the best way to free the wheel is not to worry about some type
of kill switch just disingage the lever. If that's not possible I recomend the
simple solution of installing the autopilot breaker in the cockpit. I mounted
mine alongside the Yanmar control panel. Having access to the breaker in the
cockpit also allows you to turn the thing off and not leave it in standby
without going below.
S/V Express 30 "Ringmaster"
"Trains are a winter sport"

That will work in some of the wheel mounted autopilots but not
necessarily on a below deck system. Ours doesn't lend itself to
any such solution. Our remote control for the autopilot has an
instant shutdown button. Turning off the autopilot doesn;t release
the wheel though. Just freezes it where it is. Must activate the
hydraulic release to return to cable steering.

Doug
s/v Callista

"SAIL LOCO" wrote in message
...
Seems to me that the best way to free the wheel is not to worry about some
type
of kill switch just disingage the lever. If that's not possible I
recomend the
simple solution of installing the autopilot breaker in the cockpit. I
mounted
mine alongside the Yanmar control panel. Having access to the breaker in
the
cockpit also allows you to turn the thing off and not leave it in standby
without going below.
S/V Express 30 "Ringmaster"
"Trains are a winter sport"

That will work in some of the wheel mounted autopilots but not
necessarily on a below deck system.

Right. I was thinking of the self contained types that have the
engage/disengage lever at the wheel.
S/V Express 30 "Ringmaster"
"Trains are a winter sport"

Those can be disengaged quickly. In addition, I don't think they are
powerful enough to seriously hurt someone. My hydraulic one can swing the
rudder from stop to stop
in 3-5 seconds and probably wouldn't know if you arm was there or not.

Doug
s/v Callista

"SAIL LOCO" wrote in message
...
That will work in some of the wheel mounted autopilots but not
necessarily on a below deck system.

Right. I was thinking of the self contained types that have the
engage/disengage lever at the wheel.
S/V Express 30 "Ringmaster"
"Trains are a winter sport"