Article by Capt. Steve Katz
I would like to take a moment and recognize the Schrawder family. Larry Schrawder of L&L Marine recently passed away, and his wife, Pat was a long time author of this Ship-to-Shore Colum. My thoughts and prayers are with his Family.
Fire. That’s a word we do not want to hear on board our boat. Thankfully, the statistics at the USCG Office of Boating Safety does not list fires as a major contributing factor of boating accidents, though it can happen and we need to be prepared.
While this article will not give you all the details on what and how to be sure your boats fire fighting systems meets the regulations, we will discuss some basic facts applicable to all boats.
Recently, I worked on a few boats where the owners or operators were not aware of the fire suppression system capabilities. I want to review this for the benefit of everyone.
Many mid-sized boats and most diesel powered boats are equipped with a fixed fire extinguishing system. A fixed system consists of a metal cylinder pressurized with a fire extinguishing agent, permanently mounted in the machinery spaces that will automatically activate in the event of a fire. There are additional requirements for other spaces on the boat that we will not review in this article.
The only other approved system on a larger boat is where a crew member would manually operate a single, appropriately sized fire extinguisher, and discharge it into the machinery space via a specifically designed “fire port” in the structure, without the need to open the machinery space. This manual alternative is not very feasible on most boats.
Boats with outboard engines and no enclosed machinery spaces have a different set of requirements that usually include multiple hand-held fire extinguishers.
The automatic system is designed to automatically activate in the event of a fire when the temperature exceeds approximately 175 degrees at the fire extinguisher. ABYC (America Boat and Yacht Council) requires that the engines, generator and blower automatically shut down in the event of a discharge of fire extinguishing agents.
This automatic shutdown is necessary to allow the extinguishing agent, usually a “clean” gas like FM 200 or FE241, to do its job in the machinery space and not get ingested by the engines, generator or blowers. If the agent were to be ingested, it would quickly run through the engine and out the exhaust, reducing the agent’s concentration or completely removing the agent from the machinery space, not allowing the agent to extinguish the fire. Additionally, the engines are automatically shut down so that the fire cannot be fueled by the continued operation of engine systems, for example a pressurized fuel leak.
A faulty engine shut-down system can also cause routine operational trouble if not properly checked and maintained. Most of these systems include an engine shutdown control (relay box) with a lot of electrical connections and a remote indicator panel. The relay box, usually mounted near the helm, has internal relays that open or close and can shut down the power to the engines, fuel systems, generators and bilge blowers. At or near the helm is an indicator switch panel connected to the automatic system. This panel typically has a switch that can be either in the normal or override position.
The normal position is the default position when operating the boat and allows the shutdown system to do its job in the event of a fire. The override position allows you to re-start the engines, generator and blowers as needed after a fire triggered the system to automatically discharge. A red light usually accompanies the alarm when the fire system is automatically activated.
If you were heading through a rough inlet and the automatic fire extinguishing system gets triggered, the engines would immediately shut down and not restart until you flipped the remote control switch to override. You would need to assess the situation to determine if it is safe to re-start the engines.
Here is the issue I often see in the field; operators have the switch set to the override position during normal boating operation. This is not a good idea since you lose the automatic shutdown features of the fire system. If the system is in override due to a malfunction, the system should be checked by a qualified individual.
Yes, that is all that switch on the remote panel does, it allows the system to work normally in the normal mode or bypass the automatic shut down feature in the override position. This switch does NOT trigger the fire bottle to open. The indicator light on this panel shows you the status of the fire bottle. Usually green means the bottle is fully charged and ready for operation. If the indicator light is red, the bottle has low pressure or has been fully discharged and should be serviced immediately.
Often a separate “T” handle is nearby on the helm. This handle is to override the temperature sensor on the fire bottle and manually release the extinguishing agent into the machinery space. This handle is often secured with a clip or pin to prevent accidental discharge. The current, clean extinguishing agents like FM 200 or FE241 are quite expensive, often over $1,000 for one extinguisher, and an accidental discharge can be expensive. If you were wondering, Halon is no longer available for our fire extinguishing systems since it is an ozone depleting substance. If you have one now, you can keep it, but you will not be able to refill if needed.
The shutdown system relay box could malfunction over a period of time. Since all of the important engine wires pass through this box, it should be checked annually, tested for proper operation and replaced if faulty. If this box is defective or contains bad wiring, this could cause the engines not to start during normal boating activity.
These systems should be periodically inspected by a professional. However, marine systems differ from typical portable fire extinguishers and not all inspection outfits understand or are able to scrutinize marine installations. Just because the inspection tag is initialed does not mean the entire system has been properly inspected.
There are two major companies that manufacture these systems, one is in Baltimore, Sea-Fire and the other is Fireboy. While they are independent companies, their systems are very similar and the information above is relevant for both brands of system. These companies have the system owner’s manuals and other literature on their websites if you need further information about your own system.
Captain Steve Katz is the owner of Steve's Marine Service and holds NMEA MEI, AMEI, NMEA2000 certificates, ABYC Master Technician certification and factory training from many manufacturers.