Why cant we have duel mode or locomotive pulled light rail cars?

[Brooklyn Trolley Dodger]

    Your regional planning agency wants to extend the light rail system or subway line down a existing railroad track about 5 miles. But the cost of cat is very high....So why not have a locomtive meet the cars and shuttle them down the line? Or use lightrail cars that run on electricty in the city and biodiesal in the suburbs like a hybrid bus?

[edblysard]

What was it that the Scarecrow in the Wizard of Oz always said, "If I only had a ..."

[Brooklyn Trolley Dodger]

brain?

[tree68]

    Or use lightrail cars that run on electricty in the city and biodiesal in the suburbs like a hybrid bus?

http://en.wikipedia.org/wiki/EMD_FL9

Imagine that!

[Anonymous]

    Your regional planning agency wants to extend the light rail system or subway line down a existing railroad track about 5 miles. But the cost of cat is very high....So why not have a locomtive meet the cars and shuttle them down the line? Or use lightrail cars that run on electricty in the city and biodiesal in the suburbs like a hybrid bus?

There might be merit in this, but it would depend on the balance of many, many factorrs.  In a very general sense, multipurpose machines usually must suffer a compromise in the performance of each purpose to pay for the ability to serve more than one purpose.  A Swiss Army Knife is the classic example of this inherent compromise.  It performs multiple functions, but does not perform them as well as they would each be performed by a dedicated tool.

[ajmiller]

I'd like to see a duel mode rail car. We could stage reinactments of the Aaron Burr - Alexander Hamilton feud on it, or shippers vs. carriers, or Dennis Weaver vs. fuel truck, or something.

[PBenham]

    Your regional planning agency wants to extend the light rail system or subway line down a existing railroad track about 5 miles. But the cost of cat is very high....So why not have a locomtive meet the cars and shuttle them down the line? Or use lightrail cars that run on electricty in the city and biodiesal in the suburbs like a hybrid bus?

There might be merit in this, but it would depend on the balance of many, many factorrs.  In a very general sense, multipurpose machines usually must suffer a compromise in the performance of each purpose to pay for the ability to serve more than one purpose.  A Swiss Army Knife is the classic example of this inherent compromise.  It performs multiple functions, but does not perform them as well as they would each be performed by a dedicated tool.

[Murphy Siding]

I'd like to see a duel mode rail car. We could stage reinactments of the Aaron Burr - Alexander Hamilton feud on it, or shippers vs. carriers, or Dennis Weaver vs. fuel truck, or something.

  Or perhaps Brooklyn Trolley Dodger vs. all his previous personalities.

[cordon]

I don't think catenary is all that expensive, compared to the benefits of lower-pollution power.  There may be other issues with sharing tracks, however.  The cost of trying to do that safely may be too high.  In Dallas/Ft. Worth BNSF depends on Trinity Rail Express tracks to get to Ft. Worth from Irving.  There are many instances of interference where the BNSF trains get held up for three to five hours. 

[txhighballer]

   The main problem is crash standards. Light rail equipment cannot meet FRA crash standards, so the two do not mix.

[stmtrolleyguy]

I understand that using a seperate locomotive wouldn't work, and that light rail standards are different then railroad standards, but if we can build gen-set locomotives, why not gen-set light rail cars?  You'd loose some passenger capacity with space for a generator, but that way you could have a core light rail line, run on electricity, in the larger cities, but once you reach outlying areas, you could switch over to deisel (or some other fuel.)

 This idea could work quite well (assuming you could get a small, but powerfull enough generator.)  Cities usually can get the capitol for larger projects (with catenary and clean electric power.)  Suburbs, however, would just have to pay for the tracks upfront, while the railcars switch to the deisel engines while in the suburbs.  As funding becomes availible, the catenary can be extended farther and farther out from the city.

 I don't think anyone in the US has tried the idea of combined power yet, but if you look, separately the technologies have both thrived.  Many cities are putting in light rail, with electric power, but the NJ River Line went with deisel railcars instead, because they probably can't string wire over the freight line (clearance issues.)  I don't know if the idea is technically feasable now, but I wouldn't be so quick to dismiss or laugh at the idea.  It's got potential, especially as eletric motors get stronger and use less power (requiring a smaller generator.)

[beaulieu]

I understand that using a seperate locomotive wouldn't work, and that light rail standards are different then railroad standards, but if we can build gen-set locomotives, why not gen-set light rail cars?  You'd loose some passenger capacity with space for a generator, but that way you could have a core light rail line, run on electricity, in the larger cities, but once you reach outlying areas, you could switch over to deisel (or some other fuel.)

 This idea could work quite well (assuming you could get a small, but powerfull enough generator.)  Cities usually can get the capitol for larger projects (with catenary and clean electric power.)  Suburbs, however, would just have to pay for the tracks upfront, while the railcars switch to the deisel engines while in the suburbs.  As funding becomes availible, the catenary can be extended farther and farther out from the city.

 I don't think anyone in the US has tried the idea of combined power yet, but if you look, separately the technologies have both thrived.  Many cities are putting in light rail, with electric power, but the NJ River Line went with deisel railcars instead, because they probably can't string wire over the freight line (clearance issues.)  I don't know if the idea is technically feasable now, but I wouldn't be so quick to dismiss or laugh at the idea.  It's got potential, especially as eletric motors get stronger and use less power (requiring a smaller generator.)

Such a thing exists, the big problem here is collision standards if you are going to share track space with freight. The French are now operating MU-cars running on diesel or Cantenery, in this case 1.5kV which means they don't need transformers. 

[cpbloom]

    Or use lightrail cars that run on electricty in the city and biodiesal in the suburbs like a hybrid bus?

http://en.wikipedia.org/wiki/EMD_FL9

Imagine that!

 

[daveklepper]

First of all, what you propose is technologically possible.   Locomotive-hauled light rail cars would be wasteful.   You need a train of several cars to make locomotive haulage economically sensible.   But the dual-mode light rail cars exist, are off-the-shelf from the top-quality Swiss railcar builder Stadler, who has a website, and are in use on about two German transit systems, or possibly one Swiss and one German.  The Stadler railcars now operating on New Jersey Transit's River Line can easily be upgraded to also take power from third rail or trolley wire and were designed with that possibility in mind.

The German system uses light rail diesel on non-electrified railroad tracks in the suburbs, but runs into town over the tram system and enters the tram subway for the downtown entrance. and electric operation was essential in the subway.

In another German town, however, standard gauge diesel light rail cars operate on the surface into the town center, with dual-gauge three-rail track on the appropriate route of the town system, which is meter-gauge.   I believe this line, definitely a light rail line, has been extended across the border in the Czeckoslovakia, with the rebuilding of a bridge with rail tracks.

In Boston, the Silver Line route direct without change from South Station to Logan Airport (competing with the Blue Line third-rail rapid transit requiring two changes, Red Line-Blue Line-bus), uses dual mode trolleybuseses that leave South Station in a trolleybus subway and switch to diesel and then run though the new Callahan Tunnel to East Boston and the airport.  Easy as pie to apply the technology to light rail.

Explore the website www.lrta.org and you will get the specific facts on all of this.

[Brooklyn Trolley Dodger]

  The problem here is that FRA rules say "Thou shalt not mix streetcars and light rail on freight track"

    That means that because Light Rail Cars being of Europeon design because they are not built like tanks as in the Budd Car (RDC) can not run on freight tracks even if the Light Rail Cars move during the day and the freight is switching at night. The FRA can grant a exception but I only know of two places in the US where this happenes.  The Baltimore Light Rail and the NJ Transit Line Phili Camden-Trenton Line.

[daveklepper]

The exception has become almost routine.  Newark subway (outer half mile), Salt Lake City TRAX, and San Diego (was, may not be currently in freight operation).

 

Again, if the town streetcar system doesn't use subways, there is no reason why diesel operation cannot be extended over the electric streetcar tracks, with no more pollution or noise than the best diesel buses.    Dual-mode is better and is available.

[wallyworld]

 

 

 

This concept would have been considered at the cutting edge of technology had it been posted well over one hundred years ago as a number of experimental and \ or routine alternatives to overhead power were in full bloom. Steam Dummys were the nickname applied to locomotion applied by steam in a carbody that some lines used as motive power. As can be imagined, then as now, the cinders and smoke pouring out on a busy metropolitan street was not exactly seen as an advantage. So, the arose the Soda Motor, which used a witches brew of the aformentioned chemical as a work around for the avoidance of producing smoke. Some lines actually used battery powered cars, particularly on the South side of Chicago. I was always surprised that no one had utilised Fireless Cookers..but then again, all of this has been relegated to the backwater of history.    

[CSSHEGEWISCH]

Fireless cookers aren't as light as one might think, consider that they were used in conventional railroad service in potentially hazardous environments.  They would also have range restrictions similar to battery cars or soda motors and would require a good source of steam for the initial charge.

FRA restrictions regarding light rail and conventional railroading on the same track are for safety reasons and do make sense.  Most dual-use lines require minimal freight service anyway so the curfews are less of a restriction than imagined.

[wjstix]

The Chicago-Milwaukee Electroliner could run on streetcar/elevated train trackage, but also go very fast on it's own RR mainline.

However, cities have generally not been very receptive to having "heavy" railroading on light rail line. Many of the old streetcar systems had statutory requirements that they be built to wider or narrower than standard gauge, to ensure only their equipment would run on them, and that they wouldn't start running freight cars down the street.  

[CSSHEGEWISCH]

Most light rail operations have enough tight curves to preclude the operation of conventional rail equipment.  Illinois Terminal built its various freight belts and bypasses (except at Bloomington/Normal) to get around this restriction.  Also note that the Electroliners were designed with the restrictions of Milwaukee street running and the L in mind.  South Shore was the exception on overly tight curves, the builders bought the lots where curves were necessary so the track could be built to steam road standards.