Do any of you power boat guys have a cable connected to the injection pump lever for an emergency shutoff? It is something that I have want ed to do. I have never had to thankfully, but, in the event of a fire or runnaway engine I can't immagine laying across the engine to actuate that lever. So, I was wondering how I might route it and where to mount the "T" handle. I have a CD28 Flybridge with the Volvo TAMD41A.
tony.raymond@worldnet.att.net
Volvo TAMD41, Emergency shutoff
Moderator: Jim Walsh
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Walt Bilofsky
Re: Fire extinguishers and engine shutoff
Tony -Tony Raymond wrote: Do any of you power boat guys have a cable connected to the injection pump lever for an emergency shutoff? It is something that I have want ed to do. I have never had to thankfully, but, in the event of a fire or runnaway engine I can't immagine laying across the engine to actuate that lever. So, I was wondering how I might route it and where to mount the "T" handle. I have a CD28 Flybridge with the Volvo TAMD41A.
I'm preparing to install an automatic fire extinguisher bottle in my engine room (as soon as it comes in off back-order), prompted by an article in the Boat/US insurance newsletter that 90% of boat fires start in the engine room, so have been thinking about this.
The automatic fire extinguisher bottle has an optional engine shutoff accessory that has to be wired into the engine (and blowers). The reason is that if there's a fire, the bottle triggers, and the diesel is still running, it will suck enough air to clean the extinguisher gas out of the engine compartment. Apparently this is not such a problem with gas engines, but diesels suck a lot of air.
According to the Volvo Penta folks, cutting off the engine requires applying 12 volts to the shutoff valve. This is done by what they said was the S terminal (but my diagram says is the R terminal) on the starter switch. In any event, it's in the 7 o'clock position on the switch and according to my wiring diagram connects to the number 2 pin on the engine wiring harness.
Unfortunately I can't say much about a mechanical cutoff, as the Volvo is designed for electrical cutoff. In the event of loss of electrical power, the engine is supposed to keep running. So if there is a fire that cuts off the 12v before the engine is stopped, the electrical cutoffs won't work. Since many fires start in the electrical system, I don't really know the answer to this one. Maybe wire the cutoff switch to both battery banks through an isolator diode, if you really want to be compulsive about it.
On my boat, the CD 30 power, there are access hatches in the cockpit to the fuel tank pickups. The hatches are under the steps to the sidedeck. Under each hatch is a valve allowing fuel to be cut off to the engine, as well as a mechanical indicator on the fuel gauge pickup. This valve is where I'd go in the event of engine runaway - though I really should try it some time to see how long it takes to cut the engine off.
There are accessory mechanical releases for the fire extinguisher system, which would also trigger the engine cutoff. In the event of a runaway engine, you'd shut the engine down but also have to refill the gas bottle - probably an acceptable inconvenience.
- Walt
bilofsky@toolworks.com