Frank's Blog - Yes, Finally
Alarms - 26 January, 2016
my training in the military. I spent fifteen years in the Navy as an engineer. I stood a lot of watches on a lot of equipment and
I have seen equipment come apart just from use.
In all the time we have owned Rockhopper, I have only had one of those alarms come in because the condition it was
monitoring occurred. We were off-shore, running from Saint Augustine, Florida to Beaufort, South Carolina, when the high
bilge water alarm came in. I investigated and found that a potable water line had split and the potable water pump had been
left on. This pumped the contents of one of our water tanks into the bilge. Luckily, we had another tank of water and plenty
of spare bottles of water on board. Pumping the water out of the bilge solved the problem.
However, we have had many of the other alarms come in spuriously and this is very worrisome. We have had the propane
alarm for the stove go off late at night, both the forward and aft carbon monoxide monitors go off when we were not running
any CO producing equipment and the smoke detectors go off randomly. In all of these cases, I have investigated and
determined that the problem was not what the system was supposed to be monitoring. There was no propane leak, no
buildup of carbon monoxide and no fire. In most cases, I believe that the problem was that we have had the boat closed up
for a few days - either because it was very hot or very cold out and we were running the heating, ventilation and air
conditioning (HVAC) systems rather than letting air flow through the boat.
Each of these alarms has a "silence" mode, but the alarm only silences for a period of time. In addition, if I clear the alarm
and it resets, but the "non-emergency" condition still exists, it will come right back in, usually just after I have gotten
comfortable under the covers. After the second or third time, I have ended up either pulling the fuse, for systems that are
wired into the boat's 12 volt system, or pulling the batteries for the ones that are not wired in.
This creates two problems, obviously. First, for the period of time that the power is removed, the system is useless. If a
problem did develop, I would have no warning of it. I have to offset this fear with my need to sleep. Usually, but not always,
sleep wins. Second - and to my mind, more importantly - I have to remember that the system is off-line. Now, for the propane
system, this is not a big problem. When the propane alarm system is off-line, we cannot open the solenoid valve to the
stove, so we can't cook. That is an incentive to put the fuse back in as soon as possible. On the other hand, neither the CO
nor the fire alarms give any indication that they are not working and I have had it happen that I have discovered a random
battery rolling around loose, only to remember that it is out of one of the alarm units. Sometimes, i cannot even remember
when I took the battery out.
The only thing worse than having an alarm that comes in spuriously is one that does not alarm when it should. I have high
temperature alarms on the main engine and the generator. Recently, I had the raw water pump impeller fail on the
generator. When I finally figured out what the problem was, I discovered that the heat exchanger on the genny was almost
completely blocked and almost no water had been flowing. The generator kept shutting down on high temperature, as it
should, but it has no gage or alarm to indicate why it was shutting down. I was also getting no warning from high outlet water
alarm. I don't know if the problem is that the system doesn't work, the sensor was placed wrong or the temperature never got
up to the trip point because the generator shut off first. Any way I look at it, the system did not do what I expected of it.
Most of the alarm systems on my boat can be checked and should be on a regular basis. I blow a candle out near the smoke
detectors, release a little butane gas from a lighter near the propane detectors and the high bilge alarm has a "test" lever.
Checking these on a regular basis (every three months usually) is on my preventive maintenance log. But it is very difficult to
simulate a high temperature or high CO condition, so I can't be sure those systems will work properly. I try not to think about
it. Otherwise, I would never get any sleep.