July TRAINS item on electrification - the "FL9" solution?

[MichaelSol]

DC electrification went out around 1900 and hasn't come back so nothing has been developed to do so. 

It is probably safe to say that 99% of DC electrification has been installed since 1900; 1900-1956. A 1999 European railway electrification conference showed several papers presented on improvements in DC railway electrification. Research is continuing in this type of system; indeed, at that conference there were nearly as many papers on various aspects and developments in DC design as AC related papers.

The idea of a dual-source locomotive makes little sense. EMD pitched a specific design to the Milwaukee Road in 1972, converting SD40 locomotives to alternative 3kV DC by the addition of a pantograph and related control equipment. Naturally, it cost more than either the straight Diesel or the straight Electric. This meant, when being used in the Diesel mode, it cost more per horsepower than a comparable Diesel-electric. When used in the electric mode, it cost more per horsepower than a comparable straight Electric. On 600-800 miles runs, there just wasn't a cost savings compared to simply switching motive power.

Too, combining a subsystem with a 92% availbility (the Electric) with a subsystem with 84% availability (the Diesel-electric), the resulting availability of the dual-mode machine was 76%, requiring more such machines to haul the targeted tonnage.

Too, the concept undercut a key advantage of a straight electric locomotive -- the one-third cost of maintenance and the 30-40 year economic service life. Each dual mode locomotive gave up all of the mechanical and service life advantages of the straight electric -- key reasons for electrifying in the first place.

Finally, every time one was used in its diesel-electric mode, crucial electric horsepower was unavailable under the wire -- and that was what the fleet investment was for in the first place, and also the limiting factor. It was a poor use of electric horsepower if the whole idea was to get the maximum utilization of system horsepower out of the high cost overhead instead of the high cost Diesel-electric.

Again, the railroad had to look at a significantly larger and more expensive overall fleet to meet its needs, at a significantly higher cost per unit, in order to ensure maximization of the use of the catenary, if there was any likelihood at all that a portion of the fleet would be out "somewhere" burning up diesel fuel. And the numbers worked the wrong way there as well: for every diesel horsepower being used in the diesel-electric mode, the company gave up 2 electric horsepower. It made no sense to ever do that.

They cost more, they were in the shop more, and the railroad would have needed more of them.

It truly was a lose-lose proposition.

 

[beaulieu]

It's not so much weight as complexity and space, for high-power AC hybrid. The standard Siemens Eurosprinter is a 4-axle 8500hp AC electric with 3-phase drive with a weight of 84-85 metric tonnes (about 93 US tons). With a DC overhead you run into the need for heavier cabling and heavier support structure, more substations, etc. The equivilent of two SD70s would require 4000 Amps at 1500V DC which is about the limit for Amperage. With 3000 V. DC you could operate 4 SD70s. But its not uncommon to find that many on one train, so only one train could be in each cantenary section drawing full power. On busy mainlines, which is where you would electrify, that would be difficult. 6000V DC has been done, but it gets too complicated inside the locomotive for any kind of hybrid. Prices for a straight electric should be competitive with current Diesel-Electrics when produced in similar volumes.

Regarding existing US hybrids, both the EMD FL9 and GE P32ACDM have significant limitations on 3rd rail power. Amtrak has instructions to train crews to switch from 3rd rail power to diesel as soon as they are out of the tunnel, unless the diesel won't start, in which case they must notify the Dispatcher immediately, and then permission to run on electric will be given to run on 3rd rail to Croton-Harmon, where help can be obtained. 

[ndbprr]

Electrics aren't small or cheap for a reason.  There is a lot of heavy duty electrical equipment under those hoods to convert AC to DC.  the reason for AC is it's much easier to send long distances and much more practical to do so.  DC electrification went out around 1900 and hasn't come back so nothing has been developed to do so.  With a DC system on a third rail already in place it was "fairly" easy to make them dual power but nobody is going to install a new DC system on tracks where there is possibility of trespassers turning themselves into carbon due to the liability and the operating costs. It would also be virtually impossible to fit a diesel and an AC electric system in a carbody.  Don't forget a major factor in the cost of electricity is it takes the most BTUs to produce work.  You still have to burn something to make heat to make steam to turn generators and then distribute that over wires to where the work is to be done.  Every step has energy losses. Plus you have all the energy costs of smelting  all that copper and steel in the first place and then hanging it.  The answer may still be the steam engine using high sulfur coal with scrubbers on board.  With modern materials and polution devices it may just be the most practical solution some day.

[CSSHEGEWISCH]

At the risk of being tarred and feathered, I am going to suggest that the FL9 was overrated and undermaintained.  It was proposed as a way of replacing both aging diesels (DL-109's) and aging electrics in one fell swoop.  NH was quite short of operating electrics at the time the FL9's were ordered and the original plan was to operate them in the electric zone in peak periods only to take some of the load off the power plant.  Remember, they were not equipped to run off of the AC catenary.  The dual-power provision was only to allow them to run into GCT, and as the years progressed and proper maintenance lagged, some of them were running into GCT on diesel power.

The FL9 was offered to both PRR and NYC, but neither road purchased them.  Both roads continued to change power at the end of the electric zones.

Currently, both Amtrak and Metro North operate dual-power locomotives but it would be useful to know how much time they actually operate off the third rail.  I would suspect that they cut over to conventional diesel-electric operation as soon as they reach open air, even within the electric zone.  Additionally, Amtrak's dual-powers don't operate west of Albany on the Lake Shore Limited, so a change of power is still involved.

[DMUinCT]

The "FL9" was as Diesel locomotive with DC traction motors that EMD rigged to pick up voltage from the 660 DC outside Third Rail in the New York area, as well as its own diesel driven generator. Full of bugs when first put into operation, the system has lasted 50 years. It's still is a good way to go.

To pick up power from 25,000 AC volt overhead wire you start with a LARGE transformer. (this takes up a large part of an electric locomotive carbody) and when down to the 600 volt range rectified to DC.  (even if AC "VVVF" control is used)   This would be one BIG and HEAVY locomotive. (diesel and transformer)

Todays remaining overhead wire systems were installed by the New Haven before World War I, by the U.S. Government on the Pennsylvania in the 1930s as a "make work project", and the last leg to Boston by Amtrak (a U.S. Government agent).  To add more wire or third rail, could a Local or State government justify to the voters such a large cost? I think not.  The FL9 approach is the one that would be "cost effective".

The private for profit railroads seem happy to buy new, state of the art, locomotives from GE or EMD.  Run them for 20 years and then sell them to Regional Railroads for another 15 years of service.

[oltmannd]

Montreal and NJT have a request for proposal out on just such a beast.  I were a frt RR, I'd certainly have my eye open watching this develop.  I'd also be pushing the legislative end to get fuel tax money made available for strining catenary, selling the environmental benefit and offering up improved passenger service as a public benefit.

[Tulyar15]

I would not have thought it would be too difficult to make a diesel loco into a hybrid. It's been done in Britain, so if we can do it within the constraints of the British loading gauge, it ought to be a peice of cake in America. At the present time Virgin are rumoured to be considering converting their diesel electric Voyager trains into hybrid Electro-diesels by adding a pantograph and a rectified to the centre car; this would then feed in to the power bus cable that runs along the train. At present these trains spend a lot of their time running on a electrified lines; this conversion would enable them to draw power from the overhead and thus save diesel fuel.

[erikem]

From the standpoint of the electrical system, an AC locomotive would be the easiest to convert as it already has a (more or less) constant voltage internal power bus. This is pretty much how the hybrid GE locomotive works - the battery is effectively placed in parallel with the rectified output of the traction alternator - for a modern 'FL-9' replace the battery with the appropriate current collection device (pantograph or 3rd rail shoe) and voltage conversion circuitry (if needed).

Making this all fit mechanically would be a different story. It would probably work best with a relatively small prime mover to allow room for the electrical gear (and pantographs).

Converting a DC locomotive would be more of a challenge as the Lemp system does a pretty good job of providing a constant power output from the generator/alternator over a wide range of loads (though things got to be pretty hairy with the GP35). Modern power electronics can provide similar functionality, but it is no longer a case of simply putting the external power in parallel with the output of the traction alternator. 

[Anonymous]

On page 10 of the July issue of TRAINS there's a brief news item regarding the possibility of reviving plans for electrification due to the high cost of diesel fuel.  The consensus conclusion of the author seems to be that mainline electrification is still too expensive even with today's fuel prices due to the upfront costs of stringing catenary and buying whole fleets of electric locomotives.

Taking a cue from the "Milwaukee Road Innovations" thread, I would like to return to the idea put forth a while back regarding the concept of converting some of the current fleet of diesel-electrics into dual power locomotives in the vein of the old FL9 concept.  We all know that diesel electrics draw their current from on board generators turned by compression-ignition engines.  How hard would it be to add-on the necessary components to today's modern diesels that would allow the traction motors to draw current straight from overhead wires?

The point is, this dual power mode method would allow for electrification sections to be limited to the most energy intensive portions of a line, aka mountain grades.  That would certainly be a lot cheaper than electrifying whole subdivisions and buying whole redundant fleets of eletric-only locomotives, not to mention eliminating locomotive changeovers between electrified and non-electrified portions of the mainlines.

Any takers?