Maybe a silly Q but - how does one stop a Diesel Engine running ?

[rogerthebodger]

On a boat, many small engine air intakes are baffle types at the inlet and would be difficult to seal e.g. my Perkins 4236 has a mushroom air inlet filled with a filter material, so shoving a rag over it would not be effective nor could it have a bung inserted without removal of the filter element from the manifold.

This is the reason I considered fitting a valve under the inlet filter that could be moved into a closed position without removing the air filter.

If could also be used as a anti theft device preventing any possibility of starting the engine without opening the valve

 

[adamstjohn]

Covering the air intake stops them.

this is exactly how i can stop mine too, have done this many times.

 

[Gary Fox]

No air = no compression, engine will stop.
I think it's a good idea to have a handy bit of metal lashed near your air filter, just like tapered wooden plugs near the seacocks. You are unlikely to need it, but if you do..
A suitable size baked bean tin cut in half, that sort of thing.

One slight digression: to stop my Beta, there is a stop button which cuts off the fuel. Just above it is a large 'ignition' key, which switches on the panel and, in particular, the charging system.
I ordered the basic panel but I now wish I had ordered the button-only one without the key.
If someone instinctively tries to stop the engine with the key, like a car, it won't stop, and will probably damage the alternator diodes.
I will probably make a cover for the key, which needs to be lifted up before turning the key.

 

[scottie]

I'm remind of an old Stuart Turner single that we couldn't stop. The kill lever had rusted solid. a rubber ball placed over the air intake and operating the decompressor eventually worked. It took me three hours to free off the stop lever working with a tin of WD40, a small tap hammer and a mole grip.
[asuming that it was a Stuart diesel rather than the Sole they marketed was skipper called Noah?

 

[rogerthebodger]

No air = no compression, engine will stop.
I think it's a good idea to have a handy bit of metal lashed near your air filter, just like tapered wooden plugs near the seacocks. You are unlikely to need it, but if you do..
A suitable size baked bean tin cut in half, that sort of thing.

Good Idea

If someone instinctively tries to stop the engine with the key, like a car, it won't stop, and will probably damage the alternator diodes.
I will probably make a cover for the key, which needs to be lifted up before turning the key.

Unless the key will disconnect the battery from the main alternator positive terminal disconnecting the charging light connector will not danmage the alternator.

If you turn the battery isolator switch off while the engine is running this will blow the diodes just turning the key switch will not

 

[Tamar]

On my boat which has twin Sabres, the air intakes are at deck level, and they have airtight flaps to close which in theory will cut off the air supply. I've never tried it.

 

[Bilgediver]

Mostly replaced with strain gauge pressure sensors now. The young today have no idea about the names of stuff that used to be common place: The F*&% Stick, Cows C*&^, Poor Boy, Possum Belly, Worms, Kelly Cocks. Last year I was in USA, Permian area of West Texas. It was a time warp with old rigs and old ways of working, even the new rigs were built as if they had just time warped from the 1960's.

Happy days, In latter years I was innvolved with the Jackup Bennevis which is not that long retired. Built alongside the QE2 1971 was like a living museum and built long before the age of modern elecrtonics and of course contrary to Roger's comments had Rig Savers on the 5 Cats doing hotel services and auxiliary pumps etc, the 4 Alcos driving DC generators for 600 VDC for drilling motors plus the emergency generator . All required by legislation in order to prevent runaway in the event of gas leaks from drilling activities.

 

[Bilgediver]

Well as an Professional Engineer I tend to look for proof and anm not into blind faith.

There has been sever posts where blocking the air inlet is a safety requirement and in some cases a legal requirement

So forgive me if I find it difficult to understand and believe you as its been considered an acceptable way of stopping a runaway diesel.

If you have a video of this happening I am willing to review and get comments from the wealth of knowledge on the forum

You obviously have not looked very far Roger. You will not find a single offshore oilfield installation that does not have Rig Saver valves fitted on the air inlets. They work perfectly satisfactorily and in the event of a runaway due to the presence off methane gas effectively stop the attached diesel. In most countries you cannot operate unless these basic items are installed.


Google is your friend as below would come to your screen with many others. Possibly not a requirement in wineries etc.


11" Rigsaver air shut off Valve - Safety Bulletin

 

[rogerthebodger]

You obviously have not looked very far Roger.

I wanted to see is a video of a diesel overspeeding with the air inlet totally blocked with a valve like the Rigsaver you posted.

11" Rigsaver air shut off Valve - Safety Bulletin

Yes that the kind of thing but 11" is a bit bid for the 60mm diameter air inlet on my boat diesel.

 

[Deleted member 36384]

I wanted to see is a video of a diesel overspeeding with the air inlet totally blocked with a valve like the Rigsaver you posted ...

Not over speeding but testing of a shut off device.

Runaway diesel and bloke slaps a disc over the air intake.

 

[Capt Popeye]

Well its all very interesting reading up on the various Ways to STOP a Diesel when running; some way out of my interest or activities; so with a basic Small Diesel mounted in a Small Boat guess it would be a good idea to have a Fuel Line On /OFF Tap before the switch operated Solenoid just in case the Solenoid chooses to get uncoperative at any difficult time
This extra Fuel Line tap could also be an anti theft device as well if not a standard fitting; am I right pl ?

 

[penberth3]

........with a basic Small Diesel mounted in a Small Boat guess it would be a good idea to have a Fuel Line On /OFF Tap before the switch operated Solenoid just in case the Solenoid chooses to get uncoperative at any difficult time
This extra Fuel Line tap could also be an anti theft device as well if not a standard fitting; am I right pl ?

Can't see any problem with that. One day you'll try to start the engine with the tap OFF, but you'll soon work out what you've done!

 

[rogerthebodger]

Not over speeding but testing of a shut off device.

Runaway diesel and bloke slaps a disc over the air intake.

Both of your videos show that blocking the air input will stop a diesel which is what I know

Boater Sam was saying that even if you blocked then air inlet the diesel would create a vacuum and suck air and lubricating oil from the ump to continue running.

This in my view is nonsense and others have agreed. I asked Boater Sam to provide a video of a Diesel engine running away even with the air inlet blocked so he could prove his statement.

The first video shows what I was considering fitting as an emergency stop as butterfly valve just like a choke flap on a petrol engine.

 

[PaulRainbow]

Well its all very interesting reading up on the various Ways to STOP a Diesel when running; some way out of my interest or activities; so with a basic Small Diesel mounted in a Small Boat guess it would be a good idea to have a Fuel Line On /OFF Tap before the switch operated Solenoid just in case the Solenoid chooses to get uncoperative at any difficult time
This extra Fuel Line tap could also be an anti theft device as well if not a standard fitting; am I right pl ?

It's such a rare event it' s hardly worth much effort, but up to you. You'll be surprised how long the engine might keep running after you turn the fuel off. If your solenoid operates a rod or linkage to stop the engine you can manually operate that in an emergency. If it's hard to reach, tie a length of string to it and secure in a reachable place.

In the event of a runaway, safest bet is to join in, run away. Last place you'd want to be is in the engine compartment trying to stop it.

 

[Capt Popeye]

It's such a rare event it' s hardly worth much effort, but up to you. You'll be surprised how long the engine might keep running after you turn the fuel off. If your solenoid operates a rod or linkage to stop the engine you can manually operate that in an emergency. If it's hard to reach, tie a length of string to it and secure in a reachable place.

In the event of a runaway, safest bet is to join in, run away. Last place you'd want to be is in the engine compartment trying to stop it.

Hi Mr PR thank you yes maybe I am worrying too much over nothing much at all; anyways I now know how / why to stop a Diesel Inboard engine; I do like a tad of over done safety though recon that it pays off eventually

Thank you to all who posted info for me (and others apparently) now we ALL have a better understanding of How to stop a Diesel engine

 

[179580]

With exceptions of those who understand stop solenoids and statuary requirements of the oil/gas industry, I cannot remember in the 72 years I have spent on this planet reading such a load of bow locks.

 

[Gary Fox]

With exceptions of those who understand stop solenoids and statuary requirements of the oil/gas industry, I cannot remember in the 72 years I have spent on this planet reading such a load of bow locks.

At least reading through all the posts gave you some satisfaction..

 

[RichardS]

With exceptions of those who understand stop solenoids and statuary requirements of the oil/gas industry, I cannot remember in the 72 years I have spent on this planet reading such a load of bow locks.

I definitely would not risk posting any specific details of what it is that you disagree with as that would expose you to being horribly wrong.

Richard

 

[Beneteau381]

You obviously have not looked very far Roger. You will not find a single offshore oilfield installation that does not have Rig Saver valves fitted on the air inlets. They work perfectly satisfactorily and in the event of a runaway due to the presence off methane gas effectively stop the attached diesel. In most countries you cannot operate unless these basic items are installed.


Google is your friend as below would come to your screen with many others. Possibly not a requirement in wineries etc.


11" Rigsaver air shut off Valve - Safety Bulletin

I know and you know that Rig Savers were fitted, we worked on them and with them.

 

[Beneteau381]

Well its all very interesting reading up on the various Ways to STOP a Diesel when running; some way out of my interest or activities; so with a basic Small Diesel mounted in a Small Boat guess it would be a good idea to have a Fuel Line On /OFF Tap before the switch operated Solenoid just in case the Solenoid chooses to get uncoperative at any difficult time
This extra Fuel Line tap could also be an anti theft device as well if not a standard fitting; am I right pl ?

Both my Beneteaus are fitted with fuel taps attqched to a T pull cable with Emergency Stop marked on the T