New Alstom PL42AC

[Anonymous]

I have just read the article in August 2003 Trains about the new proposed locos for NJT and I wonder why they they would want to use an inverter rather than a seperately powered HEP system. With the proposed set-up if the diesel engine or alternator failed you would have no propulsion, lighting (mayby battery emergency only) air-conditioning/heating or other electrical power. A simular scenario happened to a train here in Queensland some time ago where all power was lost, the windows are double glazed and fixed and the train staff couldn't risk opening the doors because the passengers may have tried to leave the train. I am not sure how long they had to sit in their steel tube in the Queensland sun before they were rescued but I remember they were not happy. If there was seperate engines on the proposed loco's at least they would have either propulsion or air-conditioning/heating.

Darren

[Anonymous]

I have just read the article in August 2003 Trains about the new proposed locos for NJT and I wonder why they they would want to use an inverter rather than a seperately powered HEP system. With the proposed set-up if the diesel engine or alternator failed you would have no propulsion, lighting (mayby battery emergency only) air-conditioning/heating or other electrical power. A simular scenario happened to a train here in Queensland some time ago where all power was lost, the windows are double glazed and fixed and the train staff couldn't risk opening the doors because the passengers may have tried to leave the train. I am not sure how long they had to sit in their steel tube in the Queensland sun before they were rescued but I remember they were not happy. If there was seperate engines on the proposed loco's at least they would have either propulsion or air-conditioning/heating.

Darren

[Anonymous]

The article is incorrect, too.
Siemens had offered a higher powered dual engine locomotive (even at a lower price than Alstom), where HEP AND traction could still be maintained, if one diesel engine failed.
NJT rejected the proposal on grounds of reliability (wrong) and higher LCC (true).

[Anonymous]

The article is incorrect, too.
Siemens had offered a higher powered dual engine locomotive (even at a lower price than Alstom), where HEP AND traction could still be maintained, if one diesel engine failed.
NJT rejected the proposal on grounds of reliability (wrong) and higher LCC (true).

[Anonymous]

It's really not that easy to specifiy a commuter locomotive. Before a railroad is criticized, it's necessary to completely understand the situation.

The choice of an inverter or a separate diesel-generator set in a HEP-equipped commuter or passenger unit is influenced by the overall weight of the locomotive, the desired fuel capacity, the desired maintenance costs and intervals, and reliability considerations. Weight per axle is critical. A separate HEP generator set increases weight. FRA crash standards have added a considerable amount of steel to a locomotive, and most four-axle commuter locomotives are right at the upper end of allowable weight if they're to carry any amount of fuel. Using an inverter saves a considerable amount of weight, allowing a higher fuel capacity for a given axle loading, thus reducing fueling intervals. The alternative may be to permit and construct an additional fueling facility, which is neither easy nor inexpensive.

Diesel-driven HEP sets add maintenance and in most cases decrease reliability because of the addition of numerous moving parts and items that can fail, in comparison to an inverter. The trend is away from separate HEP sets toward inverters--just as in the 1980s, railroads departed from individual electric generating and air-conditioning units on each passenger car and toward a single locomotive-carried HEP system, in order to achieve lower maintenance costs and higher reliability. The more separate systems are employed, the greater the probability of one or more being in failure at any given time.

It takes detailed economic and engineering studies, which incorporate political considerations and funding projections, to determine the optimal solution, and there are rarely perfect solutions. Small shifts in assumptions made on the front end can have large influences on the outcome. It's easy to Monday-morning quarterback, but it takes complete access to all of the data, assumptions, and expertise that's available to the railroad to know if the decision was poorly made or not.

[Anonymous]

It's really not that easy to specifiy a commuter locomotive. Before a railroad is criticized, it's necessary to completely understand the situation.

The choice of an inverter or a separate diesel-generator set in a HEP-equipped commuter or passenger unit is influenced by the overall weight of the locomotive, the desired fuel capacity, the desired maintenance costs and intervals, and reliability considerations. Weight per axle is critical. A separate HEP generator set increases weight. FRA crash standards have added a considerable amount of steel to a locomotive, and most four-axle commuter locomotives are right at the upper end of allowable weight if they're to carry any amount of fuel. Using an inverter saves a considerable amount of weight, allowing a higher fuel capacity for a given axle loading, thus reducing fueling intervals. The alternative may be to permit and construct an additional fueling facility, which is neither easy nor inexpensive.

Diesel-driven HEP sets add maintenance and in most cases decrease reliability because of the addition of numerous moving parts and items that can fail, in comparison to an inverter. The trend is away from separate HEP sets toward inverters--just as in the 1980s, railroads departed from individual electric generating and air-conditioning units on each passenger car and toward a single locomotive-carried HEP system, in order to achieve lower maintenance costs and higher reliability. The more separate systems are employed, the greater the probability of one or more being in failure at any given time.

It takes detailed economic and engineering studies, which incorporate political considerations and funding projections, to determine the optimal solution, and there are rarely perfect solutions. Small shifts in assumptions made on the front end can have large influences on the outcome. It's easy to Monday-morning quarterback, but it takes complete access to all of the data, assumptions, and expertise that's available to the railroad to know if the decision was poorly made or not.

[zardoz]

When the CNW converted its F & E units for suburban service, they installed Cummins diesels for the Head End Power (HEP). These motors had many electrical problems, leaked oil (and sprayed it all over the inside of the engine compartment), were incredibly noisy, had to be operated from a panel right next to the engine (so ya always got covered in oil when putting the HEP on-line), and were in general very unreliable.

When Metra bought the F40PH units, they had the inverter system. This system was very reliable, with the only drawbacks were that the 645 would run at a constant run 8 speed (when the HEP was on-line), and the HEP took about 400hp away from the traction motors. But one could operate the entire system from the cab. And if the weather was extreme (hot / cold), and the train was to sit for a while (like during layovers), the HEP could be put on-line in 'standby' mode, which caused the 645 to run only at about run 4 speed.

Needless to say, for all of those reasons, as well as what was stated above by Mark, I would think the inverted system would be the way to go.

[zardoz]

When the CNW converted its F & E units for suburban service, they installed Cummins diesels for the Head End Power (HEP). These motors had many electrical problems, leaked oil (and sprayed it all over the inside of the engine compartment), were incredibly noisy, had to be operated from a panel right next to the engine (so ya always got covered in oil when putting the HEP on-line), and were in general very unreliable.

When Metra bought the F40PH units, they had the inverter system. This system was very reliable, with the only drawbacks were that the 645 would run at a constant run 8 speed (when the HEP was on-line), and the HEP took about 400hp away from the traction motors. But one could operate the entire system from the cab. And if the weather was extreme (hot / cold), and the train was to sit for a while (like during layovers), the HEP could be put on-line in 'standby' mode, which caused the 645 to run only at about run 4 speed.

Needless to say, for all of those reasons, as well as what was stated above by Mark, I would think the inverted system would be the way to go.