T&T: Ford Lehman 120 potential casualty

[Rich Gano]

While hunting around for a small leak in the closed-circuit portion of the
cooling system of my stbd engine, I was reminded of something that happened
about ten years ago with that engine.  I mentioned it then, but there are
lots of new folks here now...

The overheat alarm did not immediately sound when the elbow exiting the
reservoir (stbd side of the engine) burst.  We were alerted to something
unusual by a slight "tinkling" sound coming from the buzzer.  It was so low
in volume that only the helmsman on the flying bridge could hear it.  I was
a few feet away and could not - it could have been missed completely.

By the time I moved over to look at engine gauges, the temp needle was
pegged.  I ran below to the lower station (cannot shut down from bridge) and
shut the engine down at which time a lot of steam came shooting out the stbd
engine room cowl, and THEN the high temp alarm came on fully.

What I think happened is this:  The rupture in the old elbow was large and
allowed a lot of coolant to escape quickly followed by steam coming up from
the engine, through the left side of the reservoir (where the alarm sensor
is located), across the reservoir, and out the rupture in the elbow.  The
alarm sensor, set for something above 212-degrees F, which is about the temp
of the steam at near atmospheric, had not been "tripped" completely.  It
would have eventually sounded (as evidenced by the fact it came on right
after I shut the engine down) when ALL the coolant had been exhausted and
the engine was ready to seize up.

I spent a few anxious minutes ten years ago replacing the elbow and fluid
before I restarted the engine, with no further issues until now.  I suspect
the leak I am having is from the same area, but even if it isn't, the pipe
coming out of the elbow leading aft is awfully rusty where it is clamped
into the elbow.  Time for a thorough house cleaning and elbow replacement.
Think I'll do it now before I end up doing it in the heated ER like last
time.

A word to the wise - check that elbow and keep a good one in there, AND be
sure to keep an eye on your temp gauges.

Rich Gano
CALYPSO (GB-42 #295)
Southport, FL