Yacht with engine out of control - R Medina above Cowes thus morning

[superheat6k]

Felt very sorry for the chap on the green hulled yacht who's engine had apparently decided to overspeed on his way down the river, just south of Cowes opposite the power station.

Plenty of boats slowed to offer assistance, and initially it looked like he was on fire.

The Folly HM / river taxi arrived to assist, along with a small dory.

I trust everyone was OK.

 

[rafiki_]

Sounds like the engine was running on its own lube oil. You can't stop the engine when it starts to run away like this. Will be a terminal result too. Not good.

 

[rosssavage]

And if this happens to anyone here, DO NOT try and stop the engine. Stay well clear - the engine will either seize or worse let go in a big lots-of-hot-metal-and-fluids-going-everywhere type fashion. Injury can result.

 

[henryf]

We had a Range Rover diesel do this once going down the M3 to the boat. Obviously in a car you can simply use the brakes to stall the engine.

I would imagine it would run out of engine oil and stop. Pull fuel stop immediately.

Henry

 

[vandy]

I was told the ONLY thing one could do is to block the air inlet of the engine (not an easy job on yachts).....

 

[Pinnacle]

We had a Range Rover diesel do this once going down the M3 to the boat. Obviously in a car you can simply use the brakes to stall the engine.

I would imagine it would run out of engine oil and stop. Pull fuel stop immediately.

Henry

I don't have a fuel stop on my boat (at least I dont think I do).

I do have a decompression lever - I guess that should stop it?

 

[Neil_Y]

I had a Mercedes horse lorry that did it, either block air intake or take off rocker box/oil filler cap to reduce crankcase pressure. But you want to do it very quickly. It used to do it after we stopped for fuel, hot engine start up. It made it another few hundred miles starting it in 2nd and quickly driving off. On a yacht/boat it could be quite dangerous as someone above said.

 

[Cardo]

I do have a decompression lever - I guess that should stop it?

On Tinkerbell I have to lean over the engine to get to the decompression lever.

 

[starfire]

I was told the ONLY thing one could do is to block the air inlet of the engine (not an easy job on yachts).....

Or choke it with a CO2 fire extinguisher up the air intake, it needs oxygen to run.

 

[henryf]

I don't have a fuel stop on my boat (at least I dont think I do).

I hope you do.

I was under the impression a fuel stop was a pre-requisite to comply with construction standards and safety regulations just as an engine fire extinguisher is.

Henry

 

[GrahamHR]

For emergency runaway situations like this, I'm surprised that marine diesel engine don't have a spring loaded flap on the air inlet; held open by a pin; along the lines of pull an emergency cord, it withdraws the pin and the flap springs shut, closing off the air supply. A very easy thing to make, it could even be made of a high grade plastic so not susceptible to corrosion/ seizing in the open position.

 

[Firefly625]

I hope you do.

I was under the impression a fuel stop was a pre-requisite to comply with construction standards and safety regulations just as an engine fire extinguisher is.

Henry

Indeed, i also thought all boats had to have a fuel cut off valve..

I have witnessed a runaway diesel engine once, on a BMW. The vehicle came into our forecourt engine screaming, now on this occasion it appears the engine had been slightly overfilled with oil (chap admitted afterwards he had just topped up the oil at halfords..) and as I understand it oil was being sucked through the crankcase breather into the air intake, and thus into the engine, bypassing the injectors... With this situation having a fuel cut off valve I don't believe would have solved the problem as it was burning engine oil as fuel. Very quick thinking to block the air intake or have an fire extinguisher to hand may have saved the day... however it was just too late and everyone was scared and just stood pretty far away from the thing as it basically destroyed itself in a huge billowing cloud of smoke which totally obliterated the road and everything within a couple of hundred yard radius.. the owner stood totally bemused with the car keys in his hand wondering why the engine had not switched off when he took the keys out!

 

[Divemaster1]

For emergency runaway situations like this, I'm surprised that marine diesel engine don't have a spring loaded flap on the air inlet; held open by a pin; along the lines of pull an emergency cord, it withdraws the pin and the flap springs shut, closing off the air supply. A very easy thing to make, it could even be made of a high grade plastic so not susceptible to corrosion/ seizing in the open position.

A bit like the 2 stroke Detroits have had for decades you mean ... Positive Air Shut-off valves exists for most engine air intake sizes... ....

 

[GrahamHR]

A bit like the 2 stroke Detroits have had for decades you mean ... Positive Air Shut-off valves exists for most engine air intake sizes... ....

I bow to your greater knowledge, I don't know anything about those Detroit engines ( apart from their reputation for high fuel consumption), but if the potentially ( very expensive) problem and solution was identified many years ago why wasn't the solution implemented on a much wider scale ? Cost/ penny pinching ? Or is the incidence of such problems actually rather low ? It must be a rather cheap retrofit, even if the OEMs do not want to fit it.

( I don't know much about marine diesels really, having petrol engine in my boat and car, but I did have a D5 Volvo V70 once; I sold it due to persistent problems with the engine management electronics !)

 

[l'escargot]

I hope you do.

I was under the impression a fuel stop was a pre-requisite to comply with construction standards and safety regulations just as an engine fire extinguisher is.

Henry

i have never had a fuel stop on a boat engine, unless you mean a stop cock where the fuel line meets the tank. Nor are there any regulations requiring a non commercial boat to have an engine fire extinguisher.

 

[GrahamHR]

i have never had a fuel stop on a boat engine, unless you mean a stop cock where the fuel line meets the tank. Nor are there any regulations requiring a non commercial boat to have an engine fire extinguisher.

Neither of my 2 most recent (inboard petrol engine) boats; a 1999 one and a 2004 one, have had stop cock on the fuel supply. Both have had anti syphon valves at the fuel tank outlets so in the event of a downstream leak, in theory the fuel flow stops.

 

[Beamishken]

Or choke it with a CO2 fire extinguisher up the air intake, it needs oxygen to run.

+1 we carry a co2 extinguisher for this very reason

a failed turbo or overfilled crankcase can start an engine running on its sump oil & unless you stop it first it will continue to run at overspeed until it either seizes or flys apart big time but a co2 extinguisher down the air intake will stop the engine before it does catastrophic damage

once stopped you only need rectify the original fault not replace the engine

 

[Lakesailor]

You won't have the excitement with a petrol engine.
There was a nasty accident in Hull many years ago when an LPG wagon stopped in an underpass where a compressor was being used. The Wagon was leaking LPG and the compressor ran away. Some people were killed in the explosion and fireball.

 

[Latestarter1]

A diesel engine runaway is both rare and more often the result of error or omission. On a properly maintained engine installation you are more likely to be struck by lightning.

Overfilling the lube on a badly worn engine can be one cause.

Another cause on turbocharged engine can be a partially blocked air filter, compressor side is hungry for air, restriction of air filter causes turbo lube oil to be sucked past the oil seals. However turbomachinery has to be in pretty poor state for this to happen.

Just a case of you reap as you sow.

Second point, on diesel engines it is bad pratice to fit valves on flow and return.

 

[superheat6k]

Second point, on diesel engines it is bad pratice to fit valves on flow and return.

Could you amplify your last comment. Being able to isolate both fuel supply and spill return in the event of a fire and without entering the engine space seems perfectly sensible to me. However on my boat only the supply can be operated from the cabin, but I would like to know the thinking behind this.

Thanks