Can diesel loco's stall?

[umontu]

Was on a 150 at St Anne's today, as it pulled away it felt like the engine was going to stall like when in a car you lift off the clutch without enough power.
I'm guessing all diesel loco's are automatic though so I'm wondering is it possible at all for them to stall?

 

[Oracle]

It is possible to stall an auto transmission with a torque converter. In the case of a diesel-electric surely the only way that it could stall is if the engine itself stalled...could it happen if the fuel injection system was faulty on opening-up?

 

[Zoe]

In the case of a diesel-electric surely the only way that it could stall is if the engine itself stalled...could it happen if the fuel injection system was faulty on opening-up?

150s are not diesel electric though.

 

[strange6]

It is possible to stall an auto transmission with a torque converter. In the case of a diesel-electric surely the only way that it could stall is if the engine itself stalled...could it happen if the fuel injection system was faulty on opening-up?

if it has a fuel pressure problem caused by something like a fuel pump that was about to fail, then it probably would stall. Would be intersting to see if there are any fitters that frequent these forums.

 

[driver9000]

That can happen with 15x units when opening up - they sometimes seem to 'miss a beat' when the engine is picking up. To stall one when taking power shouldn't happen as the input to the transmission (hydraulic) and engine is governed to prevent it, but there are a few things that can cause the engine to shut down - something that can happen when shutting off on a 150 for some reason. I've never had one shut down when opening up though.

A diesel electric shouldn't stall either when opening up, although most diesel locomotives have an overspeed governer that will shut the engine down should it exceed it's maximum rpm.

 

[dubscottie]

Dont know about sprinters but..

http://www.youtube.com/watch?v=zrz82x3_LkM


Warning.. The Lads in the background are VERY annoying..

 

[Jonny]

The only way that I can see a "stall" happening on diesel-electrics is if a loco doesn't move when it should on full power, and the lack of back EMF (back EMF is a back-current that is equivalent to electrical resistance) causes the amps to get too high and the system trips out (as long as it has a circuit breaker).

The term stall (for trains) seems to be used more often in terms of wheelslip preventing progress up a hill IIRC.

 

[Spagnoletti]

The only way that I can see a "stall" happening on diesel-electrics is if a loco doesn't move when it should on full power, and the lack of back EMF (back EMF is a back-current that is equivalent to electrical resistance) causes the amps to get too high and the system trips out (as long as it has a circuit breaker).

The term stall (for trains) seems to be used more often in terms of wheelslip preventing progress up a hill IIRC.

All depends on what the OP meant by 'Stall' - the whole point of the governor & load regulator on a D/E is to match engine speed to load, so it should be impossible to cause the power unit to stop unless there is a fault.
I've heard of load regs being set up wrong so the gen gets loaded up but the fuel racks don't open and the engine stops.

As pointed out above, wheelslip, overload etc will cause traction power to be cut or reduced but the engine would keep running.

Other transmissions would be different - the small Diesel/Mechanical shunters for example.

 

[lm321412]

I was on 150001 once and the centre coach kept randomly cutting out and had to be restarted at the next station!

So, I suppose this is "stalling" for you!

 

[driver9000]

I was on 150001 once and the centre coach kept randomly cutting out and had to be restarted at the next station!

So, I suppose this is "stalling" for you!

Engines shutting down at random on 150s used to be annoyingly regular. It seems to happen when returning the engines to idle - as soon as you move the handle to 'Idle' the Engine stopped lamp comes on! Generally it will start up again once you've stopped. They can also sometimes 'cough' (ie momentarily idle) when moving down between certain notches for some reason.

 

[Eng274]

I Don't know this for certain, but if the hydraulic fluid level is running low on a DMU's transmission it could cause the engine to cut out.

I was on a 158 circa 2008 that suffered this problem, at each station the driver had to restart the rear engine, only for it to conk out 15 seconds(ish) after leaving the station, necessitating a restart at each called station. This carried on from Dunfermline Town to Haymarket p0, where a fitter was waiting with a spouted can for topping something up. It may or may not have been for the transmission, but for the few seconds it was running the engine itself sounded okay.

 

[CarterUSM]

I Don't know this for certain, but if the hydraulic fluid level is running low on a DMU's transmission it could cause the engine to cut out.

I was on a 158 circa 2008 that suffered this problem, at each station the driver had to restart the rear engine, only for it to conk out 15 seconds(ish) after leaving the station, necessitating a restart at each called station. This carried on from Dunfermline Town to Haymarket p0, where a fitter was waiting with a spouted can for topping something up. It may or may not have been for the transmission, but for the few seconds it was running the engine itself sounded okay.

I thought it was just water, happens on the 156's all the time too.

 

[Eng274]

Engines shutting down at random on 150s used to be annoyingly regular. It seems to happen when returning the engines to idle - as soon as you move the handle to 'Idle' the Engine stopped lamp comes on! Generally it will start up again once you've stopped. They can also sometimes 'cough' (ie momentarily idle) when moving down between certain notches for some reason.

Sounds like the transmission had difficulty switching back to the fluid coupling hydraulic circuit (assuming it was doing a high-ish speed when returned to idle), meaning in this case it probably did 'stall'.
--- old post above --- --- new post below ---

I thought it was just water, happens on the 156's all the time too.

Maybe, could have been overheating that shut it down. Since 15x's don't have very vocal radiator fans (unlike the 170) its hard to identify if the engine's close to overheating.

 

[90019]

I was on a 158 recently on which the front engine kept cutting out and had to be restarted at the next station, it seemed to sort itself out after a few times though, but the exhaust was rather smoky.

 

[driver9000]

I Don't know this for certain, but if the hydraulic fluid level is running low on a DMU's transmission it could cause the engine to cut out.

That would cause the engine to idle rather than shut down. It would have to be low engine oil for the engine to shut down as they have a pre-set self preservation level.

I've seen reports in the repair books of engines shutting down when returned to idle and the fitter has remarked on low oil pressure and filled the engine oil up.
--- old post above --- --- new post below ---

Maybe, could have been overheating that shut it down. Since 15x's don't have very vocal radiator fans (unlike the 170) its hard to identify if the engine's close to overheating.

An overheating engine will return to idle and the fans will run until the coolant has returned below the temperature. Low coolant will bring about a shut down. First indication you get of 'boiled' engine is the slight nudge as the car stops providing traction followed by the drag and drop in speed.
--- old post above --- --- new post below ---

I was on a 158 circa 2008 that suffered this problem, at each station the driver had to restart the rear engine, only for it to conk out 15 seconds(ish) after leaving the station, necessitating a restart at each called station. This carried on from Dunfermline Town to Haymarket p0, where a fitter was waiting with a spouted can for topping something up. It may or may not have been for the transmission, but for the few seconds it was running the engine itself sounded okay.

That sounds like a typical low coolant situation. Did the fitter have to go below the solebar to top up the fluid or was it from platform level?

 

[Eng274]

That sounds like a typical low coolant situation. Did the fitter have to go below the solebar to top up the fluid or was it from platform level?

I didn't hang around unfortunately :neutral: as soon as I arrived I sprinted to P3 to catch a train onward to Waverley.

 

[driver9000]

I didn't hang around unfortunately :neutral: as soon as I arrived I sprinted to P3 to catch a train onward to Waverley.

No to worry, was only curious really as it would have indicated the fault (oil fillers are below the solebar, coolant is bodyside).

 

[umontu]

In relation to the questions it felt like the clutch had engaged too quickly causing the engine to splutter.

 

[Cherry_Picker]

150s don't have a clutch though do they? As far as I am aware they use a hydraulic transmission.

http://en.wikipedia.org/wiki/Voith_Turbo-Transmissions

Read that, and the links on Torque Converter and Fluid Coupling.

 

[umontu]

150s don't have a clutch though do they? As far as I am aware they use a hydraulic transmission.

http://en.wikipedia.org/wiki/Voith_Turbo-Transmissions

Read that, and the links on Torque Converter and Fluid Coupling.

Just saying what it felt like compared to my experience with cars. I know little about mechanics, only what I learnt in High School, College, driving and through myself.

 

[PaulW]

150s don't have a clutch though do they? As far as I am aware they use a hydraulic transmission.

http://en.wikipedia.org/wiki/Voith_Turbo-Transmissions

Read that, and the links on Torque Converter and Fluid Coupling.

The above is a diagram of a gearbox in 175. Same principle as to what you'll find in most DHMUs. There isn't any mechanical contact between the engine and wheels. These change gear (aren't any conventional gears to change btw) by filling/draining the torque convertor/fluid coupling(s).

Say on a Sprinter, you set off. From about 0-40MPH, the torque converter (or first gear as it were) is full of oil. The torque converter is set at a high ratio to give out maximum torque (hence the name) to get you shifting from a standing start/crawl. At roughly 40MPH the oil in the torque converter drains and is filled into the fluid coupling (second in a sprinter/top gear), set at a more 'direct' ratio in order to hit higher speeds. Sometimes you can hear the engine race very slightly as the transition occurs.


That's my self-tought understanding of it, said in a very basic way! If you search the Voith Turbo website, you're bound to find more information about these gearboxes.

 

[driver9000]

PaulW's explanation of the way a Torque converter/Fluid transmission works is a good simple explanation of the way they work. They aren't supposed to 'race' the engine when changing between the two stages. When running they should normally change over about 45mph on a 14x/15x (65mph and 95mph on 3 stage models like a 180 has), but if you ease off to cruise at say, 30-35mph the transmission will change over to the fluid coupling and then change back when a higher power demand is made. On the whole they are a very reliable piece of equipment and give very little trouble except for being a little slow to reverse at times.

The problem Unmontu describes sounds to me (and I'm no mechanical expert) like the engine may have had a slight issue with the fuel injector.

 

[strange6]

PaulW's explanation of the way a Torque converter/Fluid transmission works is a good simple explanation of the way they work. They aren't supposed to 'race' the engine when changing between the two stages. When running they should normally change over about 45mph on a 14x/15x (65mph and 95mph on 3 stage models like a 180 has), but if you ease off to cruise at say, 30-35mph the transmission will change over to the fluid coupling and then change back when a higher power demand is made. On the whole they are a very reliable piece of equipment and give very little trouble except for being a little slow to reverse at times.

The problem Unmontu describes sounds to me (and I'm no mechanical expert) like the engine may have had a slight issue with the fuel injector.

I can remember the transmissions the 142's had in the early days - notoriously unreliable they were so I hear. They moved off at low revs and moved up through the gears, sounding like they had a conventional manual gearbox

http://www.youtube.com/watch?v=lTJF4a4etkw

You can hear a 142 with the old transmission being released at Wigan Wallgate sidings at 42 seconds in the above clip

 

[driver9000]

The original transmission fitted to the 142 was a 4 speed automatic Self Changing Gears affair coupled to a Leyland TL11 engine. It was really designed to be used by road vehicles and wasn't up to the demands put on it by rail vehicles. They were gradually changed for the Cummins L10/Voith T211r drive line in the late 1980s, early 1990s. The original gearboxes operated without interaction from the Driver, who operated the power handle normally while the gearbox changed gears according to the speed the train was running at. The only time a Driver would need to control the gears was climbing steep gradients when the 'Hold Gear' switch was operated to prevent the gearbox hunting between gears - 15x cabs also had this switch for working with 14x units when new.

 

[tinselworm]

I've been in a 150 at Yatton... The driver started braking quite hard for the station and the engine just cut out as he started braking, had to restart it as we were about to leave...

 

[strange6]

The original transmission fitted to the 142 was a 4 speed automatic Self Changing Gears affair coupled to a Leyland TL11 engine. It was really designed to be used by road vehicles and wasn't up to the demands put on it by rail vehicles. They were gradually changed for the Cummins L10/Voith T211r drive line in the late 1980s, early 1990s. The original gearboxes operated without interaction from the Driver, who operated the power handle normally while the gearbox changed gears according to the speed the train was running at. The only time a Driver would need to control the gears was climbing steep gradients when the 'Hold Gear' switch was operated to prevent the gearbox hunting between gears - 15x cabs also had this switch for working with 14x units when new.

Thanks for that. Have you ever had the 'pleasure' of driving such a unit?