|
|
|
|
|||||
|
||||||
Subject: Re: TWL: Fire-supression systems
From: Mike Maurice (mikem@XXX.XXX)
Date: Sat Feb 01 2003 - 13:59:14 EST
At 12:07 PM 2/1/03 -0500, you wrote:
>I suspect that those of us who have such a fire-supression system aboard
>should take a closer look at possible ways the system could be
>accidentally triggered.
>
>David
A couple of years ago I was on board a brand new vessel when the engine
room fire suppression system was accidently activated.
In this particular case someone was trying to remove the panel that the
emergency release lever was mounted on. The resulting pressure on the cable
triggered the release of gas, which was some kind of "Halon" type material,
probably FM-241.
There are several problems with the automatic fire extinguishing systems as
generally installed in boats.
The system should not be able to activate automatically when the engines
are not running and there is someone available to trigger it manually.
The control panel commonly used, with the green and red lights is poorly
understood, in that not one person in 100 can describe how it works, or
what the lights mean and what the state of the switch means in terms of
arming/disarming.
There is no reason such units should activate automatically if someone is
available to trigger them manually. The problem is switching the system
from manual to automatic mode, which must be done manually. And is itself,
an error prone operation, which if the system is left in the manual mode
when the system should be in auto mode, would defeat the purpose and
effectiveness of the automatic response.
What it boils down to is that as long as the units are unlikely to be
disabled during those times when they might endanger people, there is
always going to occasional accidents with loss of life.
In the case of an accidental discharge, no one should enter the
compartment, even to save someone until the compartment has been ventilated
to remove the gas or someone can effect a rescue while wearing some sort of
breathing apparatus.
There is no point in losing rescuers and failing to rescue the victim(s) at
the same time.
The compartment must be ventilated before rescue is initiated.
In the case of the accident mentioned in the original post, the automatic
system did not activate the unit. It seems that pressure on the manual
cable set it off. Such cables need to be well protected from accidental
pressure, run inside conduit and the lever handle should be mounted in such
a way that it will NEVER be moved or part of any panel that can be removed.
ANd the plate that it is mounted in, should be EXTREMELY well secured,
physically. Like a major structrural member.
IN the case where I was present, no one else vacated the area after the gas
went off, except myself, even though the manual stated that the gas was
hazardous.
The amount of complacency about these issues is just enormous.
Capt. Mike Maurice
Wilsonville, Near Portland Oregon
_______________________________________________
http://lists.samurai.com/mailman/listinfo/trawler-world-list
To Unsubscribe send email to trawler-world-list-request@XXX.XXX
Include the word "Unsubscribe" (and nothing else) in the subject or body of the message.
|