Locomotives

Why are all the high speed lines electrically powered?   That seems to be true worldwide, but what prevents GE or EMD from changing the gearing of a conventional diesel-electric and selling it for the 150 mph & up service?  There is sort of a hidden assumption here that a line to run it on already exists, but let's ignore that for a moment.

Diesel fuel vs electricity costs might be one answer; but the cost of catenary seems to prevent the Class I's from converting their freight lines, so that can't be the whole story.   

 Not enough horsepower and too much weight. Take the standard German passenger electric the Class 101, it is rated at about 8800 hp. and weighs just 92 tons, and these are only good for max of 140 mph. The French and Germans feel if you want true high speed (186 mph or above), you have to keep axle loadings below 17 tonnes (18.7 tons US). Otherwise track maintenance costs become uneconomic.

Short time horsepower rating may also be a factor. A 3000 hp diesel is limited to 3000 hp. A 3000 hp electric may reach 4000 hp or higher for a short time when starting.

The diesel loco is very heavy set. It also can't be called a special name like "power car."

 A power car is a locomotive that is actually part of the train, such as the M10000 or something like that.  Or the Zephyrs I believe.

Lyon_Wonder:

I believe some high speed locos in France are powered by gas turbines rather than diesel or pure electric.

No gas turbine locomotives in France, they had trainsets like Amtrak's RTG sets. Otherwise electric or diesel.

trainfan1221:

 A power car is a locomotive that is actually part of the train, such as the M10000 or something like that.  Or the Zephyrs I believe.

The GM&N Rebel was not articulated, but used a power car.

The first IC Green Diamond was articulated, with power car:

The first UP City trains (through 1941), and the first CB&Q Zephyrs (through the Silver Streak Zephyr) had what seemed to have been called "power units." All of these trainsets were articulated. But, I doubt you would have been executed had you called the power unit a "power car."

Johnny

High-speed rail in the US does not necessarily mean electric, and the Federal Railroad Aministration actually does research the possibility in a project known as "High-Speed Non-Electric Locomotive Technology". It's mentioned in their 5-year plan: http://www.fra.dot.gov/downloads/Research/rdv0202.pdf

I encourage you to explore the documents and presentations on the DOT's web site to find out more. I cannot find the big document that describes the project in detail. It appears to have been moved (it had been under "Research and Development" section): http://www.fra.dot.gov/us/content/199

The project stalled and of course there is the Bombardier JetTrain prototype sitting in weeds somewhere (looks alot like an Acela but a turbine where the transformer would be).

I believe the Bombardier JetTrain is the fruition of the FRA project.

 The problem is that what the FRA is spending is a pittance compared to what the Europeans are spending. Even if the new Administration ups the funding we are many years behind them. Better to not reinvent the wheel and instead take advantage of their expertise in HSR. Any non-electric system has to carry the weight of the fuel along with it which is a big disadvantage. Weight is the enemy of HSR.

nedthomas:

Short time horsepower rating may also be a factor. A 3000 hp diesel is limited to 3000 hp. A 3000 hp electric may reach 4000 hp or higher for a short time when starting.

One solution may be using dual mode locomotives in and out of stations. We do not know how well the new NJ Transit dual mode locos will work and how heavy they will be. If  -- ? -- the locomotives can take 8000HP under CAT and 4000 otherwise then if stations had CAT installed the full 8000 could be used to accelerate out  to some speed and then the diesel take over. Anyone have acceleration curve ratings per 1000 tons (or other value)?? 

Deggesty:

trainfan1221:

 A power car is a locomotive that is actually part of the train, such as the M10000 or something like that.  Or the Zephyrs I believe.

The GM&N Rebel was not articulated, but used a power car.

The first IC Green Diamond was articulated, with power car:

The first UP City trains (through 1941), and the first CB&Q Zephyrs (through the Silver Streak Zephyr) had what seemed to have been called "power units." All of these trainsets were articulated. But, I doubt you would have been executed had you called the power unit a "power car."

Johnny

I don't think that there is any production diesel capable of over 150mph anywhere in the world.  The official world speed record for a production diesel is only 148mph (set by a British Rail HST, which only do 125mph in regular service).  The Spanish Talgo XXI prototype has since reached 159mph and a Russian TEP80 prototype is claimed to have managed 168mph.

The HST and Talgo XXI are relatively lightweight trainsets of the kind which would not meet FRA specifications, but the TEP80 was a conventional locomotive.  I don’t know what it weighed, but even with B+B-B+B wheel arrangements its axle loading combined with the speed must have been extraordinarily tough on the track.

The British HST sets are due to be replaced in a few years, and the contract for their replacement has just been awarded to Hitachi (so much for buying British L).  However, there is an ongoing debate about whether building new diesels represents value for money.  It has been argued that it would be cheaper to electrify the remaining inter-city lines than to pay for the development of high-speed diesel technology for which there is no demand elsewhere in the world to share the cost.  Obviously, the track mileage requiring electrification would be fairly small when compared to the U.S. situation.

It is time for our engineering minded posters to take out their power charts and figure out how much HP is needed to maintain a certain speed on say a 1% grade per 1000 ton train for various speeds and then addapt that to an amfleet trains. ie can 4000HP pull 7 cars at 80 mph, 5 at 110, 3 at 125 or what is the actual figures? Then we can better argue about the high speed diesels and their value. I seem to remember that the NE corridor NH - BOS always had two F40s pulling the 6 car trains befor the electrification was completed.