How long after starting can you drive a diesel?

[arabianights]

Generally speaking, when you start up a DMU or diesel locomotive can you drive it immediately, or do you have to wait for it to get up to operating temperature? Or maybe there are operating restrictions for a while? How long?

Differences between traction (which I am anticipating - my hunch is that you can drive a modern DMU instantly but say a Deltic with an engine the size of a house you might have to wait an hour or two, just guessing tho') would be of interest too.

 

[physics34]

Modern DMU drive it immediately, locos or first gen DMMUs, i dont know.

 

[cjmillsnun]

I doubt it would be an hour or two. Maybe 10 minutes at the most. Ship engines are normally good to go almost immediately after startup.

 

[furnessvale]

I doubt it would be an hour or two. Maybe 10 minutes at the most. Ship engines are normally good to go almost immediately after startup.

More a case of waiting for air pressure etc build up.

 

[Cherry_Picker]

Depends how cold it is outside. Trying to start something up on a freezing January morning after it has been sitting dead overnight is quite different to starting something up in the middle of a balmy April afternoon.

 

[dk1]

With DMUs it's just reliant on air pressure. Class 15x units tend to have compressor speed up which hurries things along when flat at a witches... The class 170s allocated to Anglia where never fitted with this facility & can cause delay if not to the train in good time if the engine has not been left running & off for more than an hour or so.

 

[Murph]

I doubt it would be an hour or two. Maybe 10 minutes at the most. Ship engines are normally good to go almost immediately after startup.

That rather depends on the individual ship, and how much time has been spent preparing to start the engines. There's also cases such as most of the old EE diesels, where the governor will not hold a steady throttle until the oil has heated up. In the case of some ships, you can't even consider starting the main engine(s) until the auxiliaries have been running for quite a long time to melt the bulk fuel oil (but I've never heard of railways using the heavy oil fractions).

If you search through MAIB reports, you can find plenty of cases of ships coming to grief while at anchor due to the length of time required to go from full propulsion shutdown to all engines available (even with the master screaming for immediate power and to hell with any damage it does to the engines).

It's not going to be an hour or two, but 15-30 minutes is quite possible from cold shutdown to fully available on ships. Even on small craft, it's quite customary to start the engine well before departure and let it warm up at idle while you go about the craft preparing everything else.

 

[HMS Ark Royal]

That rather depends on the individual ship, and how much time has been spent preparing to start the engines. There's also cases such as most of the old EE diesels, where the governor will not hold a steady throttle until the oil has heated up. In the case of some ships, you can't even consider starting the main engine(s) until the auxiliaries have been running for quite a long time to melt the bulk fuel oil (but I've never heard of railways using the heavy oil fractions).

If you search through MAIB reports, you can find plenty of cases of ships coming to grief while at anchor due to the length of time required to go from full propulsion shutdown to all engines available (even with the master screaming for immediate power and to hell with any damage it does to the engines).

It's not going to be an hour or two, but 15-30 minutes is quite possible from cold shutdown to fully available on ships. Even on small craft, it's quite customary to start the engine well before departure and let it warm up at idle while you go about the craft preparing everything else.

Indeed, although the two superferries that work out of Hull can answer bells for flank speed inside five minutes from a cold shutdown

 

[E50019]

for a first generation DMU, probably about 10 mins after starting the engines, its only air pressure you are waiting for. Once you have 70 psi your ok to go.

Depending on the number of engines (and therefore compressors) this time could vary a little, and by which time your vacuum chamber is at the required level as well.

 

[physics34]

for a first generation DMU, probably about 10 mins after starting the engines, its only air pressure you are waiting for. Once you have 70 psi your ok to go.

Depending on the number of engines (and therefore compressors) this time could vary a little, and by which time your vacuum chamber is at the required level as well.

similar to 171s. about 5-8 mins waiting for it to "pump up", depending of course on how much air pressure its lost and how long its been off.

 

[cin88]

I've known engines to cold start and be good to go almost straight away, although we're talking cold starts on the one properly hot day of the year.

If the loco has a pre heater then that'll be on for a while before the engine is started, then usually there's some waiting for various things to get themselves ready to go once the engine is up and running.

 

[Spagnoletti]

I can only speak from experience on preserved locos. Before starting there's between 5 and 15 minutes of preparation and brief exam for obvious defects, after getting the engine running it will take a few minutes to get the air system up to working pressure. Once there you can start brake tests, ensuring you can take power from both ends and stuff like that. It can easily be 30 minutes from starting prep to having a loco ready for duty. I dare say all this is much quicker on modern kit.

 

[A-driver]

If all you are waiting for it the air pressure then it's no different, if not quicker, than an electric unit after start up.

Cutting in an electric unit from dead can mean waiting up to 15mins for the aux compressor to build enough air to put the pan up alone. Once the pan is up you can be another 10mins waiting for the air pressure to build enough for the brakes to release.

 

[No Fault Found]

MTU engined class 43's have a pre-heater and the engine cannot be started below 40c for this reason. There is an override to get you out of trouble but this is logged by MTU any time it's used and can affect the warranty.

 

[driver_m]

A 221 voyager will need at least 15 minutes from dead to get sufficient air in it to get everything running or working correctly. A 220 at a guess will be a bit quicker with less equipment to be powered ie tilt.

 

[arabianights]

Cheers lads

 

[SpacePhoenix]

https://www.youtube.com/watch?v=5cs_ibmc1uw

That's a Voyager 220 being started up, no idea how much time has been snipped out.

With modern locos/units does it make much difference if the loco/unit is being start from cold or has been running earlier in the day?

 

[GB]

https://www.youtube.com/watch?v=5cs_ibmc1uw

That's a Voyager 220 being started up, no idea how much time has been snipped out.

With modern locos/units does it make much difference if the loco/unit is being start from cold or has been running earlier in the day?

With a 66, from a dead cold start (ie left shutdown over night), you can technically be on the move within a few minutes once the man res has built up, but normally power restricted to notch 3 untill things have warmed up. Not a problem light engine but if you have a load on you won't be going anywhere fast.

If the loco was used and then shut down in the morning and you come to start it in the afternoon its usually fine.

Allocated 20 minutes on a full prep anyway.

 

[cjmillsnun]

That rather depends on the individual ship, and how much time has been spent preparing to start the engines. There's also cases such as most of the old EE diesels, where the governor will not hold a steady throttle until the oil has heated up. In the case of some ships, you can't even consider starting the main engine(s) until the auxiliaries have been running for quite a long time to melt the bulk fuel oil (but I've never heard of railways using the heavy oil fractions).

If you search through MAIB reports, you can find plenty of cases of ships coming to grief while at anchor due to the length of time required to go from full propulsion shutdown to all engines available (even with the master screaming for immediate power and to hell with any damage it does to the engines).

It's not going to be an hour or two, but 15-30 minutes is quite possible from cold shutdown to fully available on ships. Even on small craft, it's quite customary to start the engine well before departure and let it warm up at idle while you go about the craft preparing everything else.

I did say AFTER startup!, and whilst that may be the routine modern engines do not appreciate excessive idling. It causes bore wash.