Runaway Diesel

[Bowserbc]

Hello everyone. I have been reading posts for a year now and learning all the time. I live in BC on Vancouver island and sail an Albin Cumulus28. A few years ago I stumbled on an article on runaway diesel engines. I read it twice and thought Wow! As it happens this article played an important part in my sailing life. I was motoring near Tenedous Bay in Desolation sound when I noticed my Yanmar YSM12 start to to sound different. With no warning it went from cruising rpm's to past full throttle out of control rpm. The noise and vibration was terrific and I tried to shut down the throttle but no response. The kill switch cord broke off in my hand. I went down pulled the access covers off and tried to block the air intake. I couldn't reach it. I tried to reach the compression release but the engine was already red hot. now we had lots of smoke and no sign of change. So next step shut off the fuel but no way to reach the shut off. There was no shut off at the tank. I grabbed a wrench and was cracking the nut on the bleed screw at the injection pump to cut off the fuel. At this point a guy in a big Bayliner saw the smoke and thought we were on fire and roared over to rescue me. The wake threw me into the engine and my hand hit the cooling fins on the alternator. I wrapped my hand in paper towel and went back to the bleed screw which I managed to open and the engine gasped itself to a grinding stop. The end result was a hand with severed tendons and major damage, a coast guard ride to the hospital, and a ten knot tow for my wife back to Lund BC. The end result of all this was a brand new engine, a repaired hand now fully functional, a big thank you to all who helped and all the necessary means to shut down a runaway engine. The cause was a fault in the injection pump causing the engine to speed up and when it got hot enough the mechanic said it was running off the crankcase oil. Since then I have met many sailors who have heard of or experienced this. Some really scary accounts. I was able to strip my old engine of all the good parts and gave it to a young couple heading for Alaska. They have enough parts for anything now as well as a lesson in how to stop their engine in an emergency. Happy sailing all!
Robert

[sailingunity]

Good post and a good reminder we need to assess how to address a situation such as this before it happens!

[Fence Man]

Good post, and good to have a plan. I've had three runaways in my life, and all on land. The last one was a bad turbo seal, and it was running on oil. I got a my sweatshirt shoved in the air intake and luckily only suffered one bent connecting rod. We are building a diesel powered airboat, and have been working through the mechanics of our emergency shut down and backup emergency shut down. Glad the hand survived!

[zeehag]

good work. my runaway i named ka lunk and made a write up here in cf... about 3-4 yrs ago now..2013-2014. is entitled ka lunk.
i am glad you fixed your ills. mine was due to bad high pressure pump.
compound with bad mechanic --before i found my rebuilder--hahahaha--and get runaway. i was raising anchor when my perkins ranaway. mine was stopped by cracking all 4 injectors.

[Suijin]

I have a 5" square piece of plywood faced with 1/8" rubber in the engine room to clap over the air intake if this ever happens. Fortunately my engine shutdown fuel shut off is manual as well.

[SecondBase]

Valuable post and made me think through multiple shutdown options. Thanks for sharing!

[Pete7]

As we dived for cover hearing the sound of the main battle tank engine suddenly scream up to full revs, one old mechanic picked up a small halon extinguisher, fired it off and tossed it in to the blower. Immediately the engine slowed down and finally stopped as peace was restored to the workshop.

That was 3 decades ago but the lesson hasn't been forgotten.

Pete

[rbk]

I keep a CO2 extinguisher on hand for smothering the intake. I have yet to plumb it for direct discharge at the intake bit that’s the goal, quick, effective and can still salvage the engine hopefully.

[Pauls]

Some of the old GM diesels had a spring loaded plate which would snap over the intake and choke the engine. All that was required was to pull a lever to actuate the plate. Positive, fast, and simple.

[Wotname]

Welcome aboard CF, bowersbc; nice first post

[UNCIVILIZED]

Good thread, quite a reminder for all of us!

[DenverSailors]

Wow! Once again I am incredibly grateful for a post on this forum! I’ve never even heard of this situation so THANK YOU!

[GordMay]

Greetings and welcome aboard the CF, Robert.
Wow! Great introductory illustrative story, well written.

[Fence Man]

Originally Posted by Pauls

Some of the old GM diesels had a spring loaded plate which would snap over the intake and choke the engine. All that was required was to pull a lever to actuate the plate. Positive, fast, and simple.

Guillotine Air Gates – Fair Valley Performance

This is what we have planned for the airboat project. Not exactly like the spring loaded plate, but this seems quite practical for a marine application. It could even double as an anti-theft device?

[zeehag]

i had known about this as a possibility for diesels as i was a gearhead before boat ownership. that however doesnot mean i knew what to do . the idiotic alleged mechanic whose denial helped cause the situation was the one who cracked all injectors instead of closing off air intake--was a more rapid solution. some air cleaners, such as k and n, are difficult at best to smother , meanwhile the potential for real damages and disaster increase as the rpms remain high.
perhaps a plastic bag over the k and n as well as cracking injectors might be next issue i face.,...
ka lunk looked initially beautiful and i though ti was off the horrific repair train, but the inside once the head was removed looked like an erector set town run over by a runaway freight train;. was impressive damage. was the worst mangled mess i have ever seen come out of an engine bay. outside perfect, inside wow....even piston heads and cyliners looked beautiful--no scoring or lipping-- before the complete dismantling.