Why a stop solenoid?

[Reef Wanderer]

How to Start - How to Stop

A few years ago, wife and I were looking for a boat and a youngish (late 30's) boat broker was showing us over a 38 footer with twin Perkins. The broker knew everything about boats, we couldn't stop him talking about the attributes of this naval architect designed vessel and it's beautiful lines, absolutely faultless motors and the boats sea keeping qualities. He had been around boats all his life and thought that of the hundreds he had sold that this was the perfect crusing boat. The boat, on quick inspection seemed ok, it was in the water so I asked could we hear the motors running? Sure says the broker who turns the key and nothing happened. So I said possibly the Colhersee switch is off. His reply, "what is a Colhersee?"
I searched and found a power panel and switched on the two Colhersee switches and she fired up. First motor took a bit too long to start and puffed blue smoke continuously for the 10 minutes it ran for which sounded alarm bells with me. The other started easier and ran clean after a minute running. The 'broker' said he thought one motor needed an oil change? I said I think it needs an overhaul!
Ok, we have heard enough thanks, you can turn them off now....
The broker turned off the keys, nothing happened... then came to the Colhersee's (his new favourite word) and switched those off... but both motors still kept running.
I wanted to leave the boat and leave the broker to figure where the stop solenoids or cable were, but my wife who is much kinder hearted than me, said "oh come on he's only a young guy, he doesn't know how too turn them off" My reply was that surely one of the hundred of boats he sold were mechanical diesels?
I jumped back on and he was on his phone trying to contact the owner. I pulled the two stop levers, clearly marked next to the Colhersee switches and jumped off. He learned two things that day. Colhersee and Stop Lever!!

 

[2savage]

Stop solenoid here, front starboard on the 671 Detroit Diesel. Original from 1969.

 

[rgano]

He learned two things that day. Colhersee and Stop Lever!!

And that any potential buyer may know a lot more about boats than his young years allowed.

 

[Nautica]

My diesel has an ignition key and a stop button. The key alone will start and stop the engine, but the manual says to use the stop button and then turn off the ignition. I haven't investigated it yet, my guess is the ignition switch turns off the fuel pump and injectors and the button operates a kill solenoid to stop the fuel. I use the button since that's what's recommended, but I haven't found it makes a difference if I don't.

If you turn the key off first you are isolating the alternator, which can blow it up (Extreme case). If you stop the engine with the stop button (Cutting the fuel) the alternator is still connected and OK.

 

[BruceK]

Heavy Duty Switches and Electrical Products – Cole Hersee

 

[NEtrawler58]

If you turn the key off first you are isolating the alternator, which can blow it up (Extreme case). If you stop the engine with the stop button (Cutting the fuel) the alternator is still connected and OK.

Thanks Nautica. I hadn't thought of that possibility. I always use the stop button now that I know that's recommended. I suspect the previous owner never did but don't know for sure.

 

[rslifkin]

It depends on how the alternator is wired. If turning off the ignition cuts the field current, the alternator should stop outputting power and it shouldn't hurt anything. But if the output gets disconnected by a solenoid or something (not very common), then there's a risk.

 

[diver dave]

On many boats, including my last two, the main engine ON/OFF master does not break the alternator circuit. The alt output goes directly to the isolator system.

 

[SteveK]

On many boats, including my last two, the main engine ON/OFF master does not break the alternator circuit. The alt output goes directly to the isolator system.

The alt are self exciting? The key switch is just to turn on the starter. The alt keeps charging until motor is stopped.

 

[diver dave]

Not self excited. Had to put a resistor across the isolator to provide some tickle current.

 

[C lectric]

I

I guess my question stems from why wouldn’t GB simply energize the fuel solenoid when that engine on switch is turned on. That way it energizes everything and simply to press a start button to start….. pressing the off button could then isolate the fuel solenoid for as long as it is pressed and the engine will shut down. Releasing it leaves the engine energized and buzzer buzzing, but engine shutdown.

As you have found many engines were arranged that way. Came from more commercial useage. Once the engine was started they did not want it to shutdown due to some switch failure or even a solenoid failure.
Get the engine running and keep it running.

Once you need it to stop then the fuel can be shut off and it will run out in a minute or two. Or depending upon its mounting there is a linkage that can be pushed/pulled to override the fuel flow.

 

[ronobrien]

If you gave not done so already, it is a good idea to find the stop solenoid on the engine in case you ever need to operate it manually in case an electrical connection fails. You want to know where everything is on the engine anyway, but this is a good one to prioritize, easier to look around a cool and quiet engine than that is one hot and noisy.

This is why I like my "old school" diesel. Strictly mechanical with a stop cable, given the likelihood of an electrical connection failure in a salt water environment. And we all know that will only happen at the worst possible moment.

 

[NEtrawler58]

I think it would be easier and safe to close a fuel line valve in an emergency than try to manually operate a solenoid on a running engine

 

[Gdavid]

I think it would be easier and safe to close a fuel line valve in an emergency than try to manually operate a solenoid on a running engine

It really depends on the nature of the emergency, it would have to be a situation where every second counts for me to consider it an emergency and in those cases I wouldn't want to wait 1-3 (guessing) minutes for the engine to run out of fuel after closing a valve.

1. Transmission stuck in gear in close quarters
2. Exhaust system failure, engine room filling with exhaust and raw water discharge
3. Cooling system failure
4. Person in water and out of sight

The likelihood of the stop solenoid failing at the same time as you are experiencing one of the above on a well maintained boat, is very low, but in my opinion, outside of these situations, the failure of a fuel stop solenoid isn't an emergency. It would instead come down to whatever is most convenient.

 

[psneeld]

On my Lehman, I could crack a floorboard, reach down with hand (very safe) or a ruler (extraordinarily safe) and move the lever to the stop position.

ALL engine rooms should be safe enough to enter and work around an engine (at least critical components) when running. If not, the critical components should be able to be observed and if the type, manipulated from closest safe point (or remote manually) to mitigate emergencies.

Sure it depends on the diesel, but some setups may run for a longer than you may want if the only thing you shut off is the fuel cut off valve.

 

[NEtrawler58]

It really depends on the nature of the emergency, it would have to be a situation where every second counts for me to consider it an emergency and in those cases I wouldn't want to wait 1-3 (guessing) minutes for the engine to run out of fuel after closing a valve.

1. Transmission stuck in gear in close quarters
2. Exhaust system failure, engine room filling with exhaust and raw water discharge
3. Cooling system failure
4. Person in water and out of sight

The likelihood of the stop solenoid failing at the same time as you are experiencing one of the above on a well maintained boat, is very low, but in my opinion, outside of these situations, the failure of a fuel stop solenoid isn't an emergency. It would instead come down to whatever is most convenient.

I get what you are saying, and of course I would want a working solenoid always, but in those instances, leaving the helm and jumping into the engine compartment with running engines and trying to manually operate a solenoid just sounds like things could end up worse. I know from experience (of forgetting to open a valve) that my engine will not run for very long. In all but your last case, it's really just minimizing boat damage. Best not to put that ahead of personal safety. Especially #2. No thanks!

 

[Gdavid]

I get what you are saying, and of course I would want a working solenoid always, but in those instances, leaving the helm and jumping into the engine compartment with running engines and trying to manually operate a solenoid just sounds like things could end up worse. I know from experience (of forgetting to open a valve) that my engine will not run for very long. In all but your last case, it's really just minimizing boat damage. Best not to put that ahead of personal safety. Especially #2. No thanks!

The configuration of boat and engine room would certainly be a factor. Like psneeld, my shut down solenoid is accessible via partially opening one hatch which is right at my feet when at the lower helm. I have more of an engine "compartment" rather than room. I'm also usually running from the flybridge anyway so I would try the shut down button from the lower station in case the problem is somewhere between the upper station and lower station. I have a fuel tank selector valve near the lower station, I don't know if there is a position that would stop the flow, but it is something I will look into thanks to this conversation.

On an old headboat I worked on during college, the larger of the two generators had an inoperable shut down solenoid for years. It was just part of the routine to climb down to the engine room and shut it down after returning from each night's run. The boat should have been maintained better, but it was just a minor hassle.

I think the important thing is to consider your response to potential faults ahead of time when you can carefully consider the pros, cons and decide with a clear head rather than when in the middle of a "emergency". Fortunately, most of us have limited experience operating in a crisis.

I'm most certainly on a tangent at this point (sorry), the best "crisis" response I saw on the water last year was a sailboat that lost forward gear when headed out of the marina. I was following him and unsure what was happening as he gradually slowed to a stop (tide was high so he had plenty of water), he shifted over to the inbound side of the channel and just commenced reversing his way back to his slip without a look of stress on his face. As he passed by he casually mentioned that he lost forward and asked for my pardon for the inconvenience. It would have been slightly more impressive had he remembered to sound three horn blasts, but it was still a good recovery in my mind.

 

[NEtrawler58]

Thanks GDavid. Since we are off topic anyway, I'll add a couple more tidbits. I'm sure all boats have some positive fuel shut off somewhere in the lines between tanks and engines. Possible more than one. The easiest for me are on a rear bulkhead, aft of the engine next to the Racors. There is a valve for Engine and one for generator, so that would be my first and easiest choice w/o getting too close to the engine. Another thing I learned kind of by chance, but maybe I should have paid closer attention, is that my main battery switches near the helm do not kill power to the thrusters. They have their own battery switches that are below deck under hatches. Makes sense now that I know it, but would have been bad if one was stuck on. (note the engine battery switch does kill power to the thruster controls and also shuts them down unless the high current solenoid got stuck closed)


Regarding your sailboat story, I chartered a 46' bareboat in the BVI for a vacation with some friends. Pulling into the Bitter End mooring field, the shaft decoupled from the engine and I had no engine control at all and no thrusters. One guy grabbed a line, cleated it to the bow, and jumped over and secured us to a nearby mooring. It's good to be young and lucky.

 

[C lectric]

I think it would be easier and safe to close a fuel line valve in an emergency than try to manually operate a solenoid on a running engine

Depends on access which the owner must determine.

I shut a friends boat down by doing exactly that when the ign. switch failed to do it.
But the linkage was right in front of me and I was on the back deck.

I have crawled around my own engine while it runs although in these cases it was for something else. I wear headphones to kill the noise.

 

[Bongi]

Folks, as the originator of the thread, I’m delighted by the education on emergency shutdown.. My original question is more than adequately addressed, but the wisdom from those who have thought through - or have dealt with - emergency shutdowns, is priceless.

I am adding this to my list of “what to do if…” scenarios!

That list is by no means complete only a few months into ownership on our GB42C.

I would also add that getting comfortable by practicing backing up and reversing into confined quarters is clearly a worthwhile endeavor, and what made the sailboat owner in question confident and relaxed in dealing with that “emergency “.

 

[catalinajack]

Thanks GDavid. Since we are off topic anyway, I'll add a couple more tidbits. I'm sure all boats have some positive fuel shut off somewhere in the lines between tanks and engines. Possible more than one. The easiest for me are on a rear bulkhead, aft of the engine next to the Racors. There is a valve for Engine and one for generator, so that would be my first and easiest choice w/o getting too close to the engine. Another thing I learned kind of by chance, but maybe I should have paid closer attention, is that my main battery switches near the helm do not kill power to the thrusters. They have their own battery switches that are below deck under hatches. Makes sense now that I know it, but would have been bad if one was stuck on. (note the engine battery switch does kill power to the thruster controls and also shuts them down unless the high current solenoid got stuck closed)


Regarding your sailboat story, I chartered a 46' bareboat in the BVI for a vacation with some friends. Pulling into the Bitter End mooring field, the shaft decoupled from the engine and I had no engine control at all and no thrusters. One guy grabbed a line, cleated it to the bow, and jumped over and secured us to a nearby mooring. It's good to be young and lucky.

Just curious, what was the cause of that shaft decoupling on that sailboat you chartered?

 

[SteveK]

Just curious, what was the cause of that shaft decoupling on that sailboat you chartered?

Single lever per engine?
Maybe too many shifts from high rpm from FWD to reverse etc by previous charter folk.

 

[catalinajack]

Single lever per engine?

Maybe too many shifts from high rpm from FWD to reverse etc by previous charter folk.

That would explain a transmission failure but how did the shaft separate from the transmission? What did I miss?

 

[NEtrawler58]

Just curious, what was the cause of that shaft decoupling on that sailboat you chartered?

I didn't watch the repair and was not that interested at the time. A mechanic came out to the boat and repaired it at the mooring. Just seemed like some coupling in the drivetrain became loose. At that time I had owned a couple sailboats, but not one with inboard power so I was not familiar with the systems.

 

[SteveK]

That would explain a transmission failure but how did the shaft separate from the transmission? What did I miss?

Thinking Drivesaver.

 

[diver dave]

Set screws into SS shafts without dimpling the shaft first will eventually be problematic.

 

[ronobrien]

Set screws into SS shafts without dimpling the shaft first will eventually be problematic.

I had the same issue some years back. I dimpled the shaft and never had a problem again.