GG1s Power Car : why no pantograph on the power car?

Hi

A special power car was needed for the GG1 to used it with Amfleet Cars.
These power cars were equipped with a diesel motor/generator set to provide head end power for the passenger cars.

My question, why did they use a genset?
Why they didn't installed a pantograph on top of the roof and installed a transformator in the power car.

Were these power car only used on the electrify part of the NEC?
And when the GG1 was uncoupled and a diesel engine was coupled to the train for example, the power car stay together with the GG1 at the station, right?
The HEP for the train was now provide by the diesel engines and the power car wasn`t needed.

Next idea: The GG1 was multiple unit able, right, so if there were a MU-connection between GG1 and Power Car the engineer could for example raised/lower the pantograph or switch the main switch from the transformator. Useful when the train crosses a connection point between two substations.]

Some Pics:
http://www.hebners.net/amtrak/amtGG1900/amt906a.jpg
http://www.hebners.net/amtrak/amtE9B/amt686.jpg


Hope my grammar isn't too bad.

Greets Andre

The generator car may be needed because the GG1 cannot produce enough juice. If I remember correctly the Amfleet Cars use a different level of electricity than the GG1s.
http://www.railpictures.net/viewphoto.php?id=9840
http://www.rrpicturearchives.net/showPi ... ?id=267925

The GG1 dont provide electrical HEP at all, it had a steam boiler that provide steam to heat the cars. The newer Amfleets use a electrial heating, which the GG1 cant support.

My question was, why did they use a diesel engine to produce the electricty when serveral feet above the roof a wire is span, that have the capability to provide it in a easier way.

I think a diesel engine needs more maintance than a pantograph and transformer.
Also the engine consume fuel, which have to refuel in regular intervals, whats a gas station required.

Greets

Hi,

It must be borne in mind that the GG-1 was from the steam era and as such was equipped to produce steam for heating the cars. Air conditioning was part of the individual car's electrical system with a power take off and generator on an axle of the car.

To have the "power car" equipped with a pantograph would require a transformer of some size and considerable insulation to handle the 11000 volts at 25 cycles, Hz. Transformers weigh quite a bit, especially when they are required to handle lots of Amperes of juice for ten to twenty cars. There probably are instances where a double headed GG-1 set required more than one Pover Car to provide HEP for the long train.

I remember when the ICE train toured the USA and had two Genesis diesels powering the train. The train also had power cars for all the amenities the ICE train had.

The simple thing is that the powercar required a rotory generator to generate 480 volt 3 phase, and to transform the 25hz to 60 hz.

So a pantograph was useless without transformer and at least a huge motor generator set to transform the single phase 11 000 volt 25hz into 480 volt 60 hz.
Inverters were not functional till about 20 years later and so only option was to use a diesel generator .

pennsy wrote:Hi,
To have the "power car" equipped with a pantograph would require a transformer of some size and considerable insulation to handle the 11000 volts at 25 cycles, Hz. Transformers weigh quite a bit, especially when they are required to handle lots of Amperes of juice for ten to twenty cars. There probably are instances where a double headed GG-1 set required more than one Pover Car to provide HEP for the long train.

Lets say every car needs 90kW / 120 hp (source) with maximum 20 cars that's are 1800kW / 2400hp
A transformer with 11kW 25Hz and 2000kW = 2MW isn't small *) , right, but i think a genset that provide 2400hp is much heavier & voluminous.
In this weight class i think they use ex-B-Units (see 2nd pic from U-Haul)

*) the transformator of the GG-1 had 3660kW, i dont its size or weight ,
but dont forget transformers for traktion motors (differnt tapping for differnt voltage) are very differnt from transformers that have a constant ratio.
'traktion current transformers' are much bigger than a 'constant ratio transformer' in the same 'weight class'

I think technical and electrical it was possible to use the overhead wire feeded power cars, but i dont know, why they weren't used.

DutchRailnut wrote:The simple thing is that the powercar required a rotory generator to generate 480 volt 3 phase, and to transform the 25hz to 60 hz.

So a pantograph was useless without transformer and at least a huge motor generator set to transform the single phase 11 000 volt 25hz into 480 volt 60 hz.
Inverters were not functional till about 20 years later and so only option was to use a diesel generator .

*DOING*

Right! I tought much to complicated, the HEP is 3 phase! (In Germay we use a single phase current to heat and lighten the cars, and i assume it for american cars too...)

Thx Railnut

When the HEP equipped Amfleet cars first came on the scene, some of the
diesels used to pull them were not equipped with HEP either and the same
power cars could also operate behind steam generator or even freight
diesels as well as GG-1's.
There was much more flexibility in their use by being diesel operated.
Noel Weaver

I think that 480VAC 3ph is used is because it is an industry standard
in the US and Canada. This makes it easier to apply off the shelf
components to RR equipment (i.e. lighting, motors) rather than come
up with a different distribution system (single phase or different
voltages etc.)

The key here is 3 phase, 480 VAC, 60 hz You cannot change 25 hz to 60 hz through transformer action, and single phase to 3 phase is very expensive. The new (post GG1) utilize electronic synthesized 3 phase. The voltage waveform looks like a stair step compaired to a rotation generator linear waveform.

The HEP version of the E60, the E60CH, had a motor generator in the same space as the steam generator found in the E60CP. A GG-1 could have been retrofitted in the same manor. However, it was the intention from the start to replace the G's with HEP equipped motors. An existing coach fitted with an 'off the shelf' generator set was a quick and easy (cheap) stop-gap measure until the AEM-7's arrived.

While an MG set (actually a motor-alternator) could have been built to built to convert 11k, 25 cycle single phase to 480/3/60, it would have been expensive. You would have needed a transformer to step the 11k down to something that a motor could have used, unless you wanted to use an 11K motor. And the motor would have had to have been a custom item, to run at a speed that would allow use of a conventional commercial alternator to provide the 60 cycles. Plus you would have needed some extra switchgear, fuses, lightening arrestors and controls for the motor.

Using a Cat. or Cummins to spin a commercial Kato or Marathon alternator (using the names of common manufacturers for this type of equipment-) was a fast and dirty solution. I can easily imagine that the units used were just about off the shelf, skid mounted, and with little or no real engineering (or customization) involved. I've seen some tourist lines and dinner trains operated with a commercial unit stuck in a boxcar, and running with the doors open for cooling and exhaust. Simple-

Flexibility was mentioned by Mr. Weaver. Think about a Florida train. The wire only extended to Washington, and the G motor had to be cut off the train and replaced with a diesel. If the HEP had come from the overhead, the generator car would have been replaced as well. Using a diesel genset, the HEP car could stay with the train.

As mentioned above, the HEP power cars could be, and were, used with other locos as well. Here's a picture of a Hudson Line train pulled by a FL9 and using one of the power cars.

http://www.thebluecomet.com/amt488Garrison.jpg

The power cars I pulled with Amfleet trains were outfitted with a skid mounted two stroke Detroit diesel either a 600 hp V-12 or 850 hp V-16. Typical noisy, oil leaker Detroit but it got the job done on the cheap and I cant really recall ever having HEP problems with a power car equipped train.