Do engine fires happen? Naturally aspirated, small diesels.

[Jeff on Aurora]

Does anyone have first hand knowledge of an engine compartment fire caused by a small (say under 100-ish hp) non-turbo diesel on a sailboat?

I'm about to replace the the 20 y/o Fireboy automatic halon extinguisher in my engine compartment. Wow! Talk about sticker shock!! A new extinguisher and cable are almost $1k. I will spend the money to have a safe vessel, but there may be other issues to address where the money is better spent. I'm not feeling a huge risk of engine compartment fire.


Personally, I have first-hand knowledge of two engine room fires, but both were on large hp diesels (approx 45' sport fish boats) and turbocharger failure was the suspected source of ignition. One of these boats went from "Hey, do you guys smell smoke?" to a completely engulfed vessel in less than five minutes.

I have been around diesel powered sailboats for three decades and have yet to hear of a serious engine compartment fire. Sure, there have been plenty of fuel system leaks that resulted in a complete mess and the engine stopping, but none led to a fire. How would one ignite diesel anyway unless 1) fuel or compressed fuel vapor was spilling and 2) there was some very hot ignition source like an electrical fire?



Thanks in advance,


Jeff