* Expensive in first cost, so only viable where the traffic is heavy enough to generate enough revenue.
* Locomotives and power cars of multiple-unit trains only have to carry traction motors and electrical control gear.
* Better pollution control, as the power is generated remotely from where it is actually used - either from its own power station, or taken from many sources, such as the National Grid in the UK,
* Locomotives and trains can be arranged to be regenerative - electric motors generate electricity when coasting, which can be fed back to the power supply, or used to assist in braking.
Diesel
* Best solution for less-heavily used railways, where electrification is not a viable alternative.
* The vast majority of diesel locomotives and multiple-units are diesel electric, so apart from having the have similar traction motors and electrical equipment to 'straight' electrics, they also need heavy diesel engines and generators/alternators, plus fuel tanks, radiators and water supplies. The result is that - size-for-size and weight-for-weight - diesel-electric traction units are generally half as powerful as electric, and less efficient, as they have to drag around a lot of dead weight.
* Straight Diesel-mechanical drive can only realistically be used for power outputs up to about 300hp, and Diesel-hydraulic transmissions up to around 600hp.
* More pollution - both atmospheric and noise.
To comment on one of the other answers, most modern electrification systems are indeed powered by overhead catenary, typically at 25,000 volts a.c. This is because a.c. current can be transmitted more efficiently over long distances without significant 'voltage drop', meaning that the track-side sub-stations can be further apart. However, most of the south of the UK is electrified on the old third "live rail" at 750 volts d.c. The system grew so rapidly after 1923 that it would be totally un-economic to convert it. I used to work on the line between London and the South-west, driving electric trains at speeds of up to 100mph. These are the fastest electric multiple-unit trains in the world to use the "third rail"
limitations with Electrical railway is that it needs electric supply of minimum 25000 volts or even much more, and in many area, electric cables are not available along with the track.
Diesel engines are much powerful and generally preferred on long routes where heavy electric lines are not available. drawback is that they create pollution.
Answers & Comments
Electric:
* Expensive in first cost, so only viable where the traffic is heavy enough to generate enough revenue.
* Locomotives and power cars of multiple-unit trains only have to carry traction motors and electrical control gear.
* Better pollution control, as the power is generated remotely from where it is actually used - either from its own power station, or taken from many sources, such as the National Grid in the UK,
* Locomotives and trains can be arranged to be regenerative - electric motors generate electricity when coasting, which can be fed back to the power supply, or used to assist in braking.
Diesel
* Best solution for less-heavily used railways, where electrification is not a viable alternative.
* The vast majority of diesel locomotives and multiple-units are diesel electric, so apart from having the have similar traction motors and electrical equipment to 'straight' electrics, they also need heavy diesel engines and generators/alternators, plus fuel tanks, radiators and water supplies. The result is that - size-for-size and weight-for-weight - diesel-electric traction units are generally half as powerful as electric, and less efficient, as they have to drag around a lot of dead weight.
* Straight Diesel-mechanical drive can only realistically be used for power outputs up to about 300hp, and Diesel-hydraulic transmissions up to around 600hp.
* More pollution - both atmospheric and noise.
To comment on one of the other answers, most modern electrification systems are indeed powered by overhead catenary, typically at 25,000 volts a.c. This is because a.c. current can be transmitted more efficiently over long distances without significant 'voltage drop', meaning that the track-side sub-stations can be further apart. However, most of the south of the UK is electrified on the old third "live rail" at 750 volts d.c. The system grew so rapidly after 1923 that it would be totally un-economic to convert it. I used to work on the line between London and the South-west, driving electric trains at speeds of up to 100mph. These are the fastest electric multiple-unit trains in the world to use the "third rail"
Both have Advantages and Disadvantages,But the True Fact is Modern Diesel Locomotives are Diesel-Electric...!!!
www.irfca.org/articles/diesel-vs-electric.ppt
I assume you want the advantages and disadvantages of each.
ELECTRIC:
ADVANTAGES;
- More powerful Locomotives (up to 13000HP currently, diesel is about 6000hp)
- Trains weigh less so are less punishing on the tracks
-Better acceleration
-cheaper to maintain trains
-can regenerate areas (people see them as modern)
DISADVANTAGES:
-Expensive to start up
-Dangerous
- Trains can only go where the wires are.
- limits the size of trains.
Someone else can do Diesels.
Electrical engines are clean powerful.
limitations with Electrical railway is that it needs electric supply of minimum 25000 volts or even much more, and in many area, electric cables are not available along with the track.
Diesel engines are much powerful and generally preferred on long routes where heavy electric lines are not available. drawback is that they create pollution.
One has exhaust smoke the other has sparks.