How much more efficient are modern diesel locomotives compared to their first generation counterparts?
Vastly, with the advantages of EFI and more broadly FADEC being examples.
On the other hand ‘progress is not always forward’ most particularly with respect to pollution control, where fuel efficiency in particular can take remarkable hits and maintenance cost can metastasize.
As I have noted, it would not be difficult to make diesel prime movers much more thermodynamically efficient with better regulatory common sense combined with adoption of larger-mass-flow SCR.
I’d wonder if some improvement could come from turbo-compounding, with the turbine(s) driving an alternator(s). The electronics associated with the alternator would impose the optimal load on the turbine, with the electric power put on the same bus as the main alternator. The induction compressors would also derive power from the bus, allowing for faster spool up.
I believe F1 is using similar tactics with their turbocharged hybrid gas engines, which have ‘motor generators’ that are driven by heat (MGU-H) and kenitic (MGU-K) energy. The total package of 1.6L engine displacement is reported to put out over 1000 HP from both ICE and Electrical outputs.
Last month on my way to our 15th Cotton Belt Regional Railroad Symposium I encountered four southbound Union Pacific trains between Brinkley and Pine Bluff. Three were parked on the mainline with their crews staring at red blocks. The fourth was walking its train over the Arkansas River Bridge and into Pine Bluff Yard. It doesn’t matter how a locomotive is built if it is standing still. Later at the Arkansas Railroad Museum a retired SSW/SP/UP hoghead told me that as long as the trains are parked it was considered running time and not dwell time.
Ed in Kentucky
I’ll guess 20-25%.
Al Krug’s table is available on the Wayback Machine – it says an F7 or SW1500 burned 93 gallons per hour in Run 8.
https://web.archive.org/web/20100529204212/http://www.alkrug.vcn.com/home.html
I don’t know UP rules concerning stopped trains on the Main Line.
On CSX when I was working, trains were to be advised if they were going to be stopped for 30 minutes or more. Crews were to shut down all engines except for the lead engine for fuel conservation. Crews were to be given adequate notice of when they were going to be moving again so they could get the shut down engines running and on line again - nominally about 10 minutes per unit (note - with 21st Century AC road locomotives - on CSX it was rare to have more than 3 units on line account head end horsepower restrictions.) CSX didn’t begin to utilize DPU’s until after I retired, so I am not aware of how they are handling them.
Sitting in sidings or being held out of terminals is considered line of road delay, not terminal dwell. When it comes to operating statistics there is always a ‘game’ being played between terminal management and line of road management, the game started once it was understood there were terminals and line of road.
That’s exactly what I’d see when I was doing some lunch-hour or slow-day railfanning at a favorite spot near the Richmond Amtrak station. (Old RF&P, now CSX)
Typically a diesel lash-up of three or four units stopped and waiting, the lead unit running but the trailing ones shut down. It was pretty interesting to catch the start-ups too.
For context, the C44-9 burns 210 Gal/Hr so in a one-dimentional view, not an improvement.
If you look at the HP per Gal/Hr, it tells a better story. From the low of an E-8 at 12 HP/Gal/Hr to the C44-9 (about the newest locomotive with data on Al’s page) at 20.9 HP/Gal/Hr a definite improvement over the years.
The only real measure that the carriers look at it ton miles/gallon. In territories where 1st Gen locomotives were rated at 1000 tons, today’s locomotives are rated North of 5000 tons per unit.
It would be interesting to see the overall fuel usage and efficiency figures on the variable horsepower Cv40-9i’s (NR class) introduced by National Rail in Australia.
It appears that most of the recent work in Australia/New Zealand follows the theory that ‘managed’ trains best operate at sustained speed, directed via a ‘smart’ system like LEADER or TO – that implies reasonably fast acceleration subject to pollution control, then modulation of power as needed to control speed.
What this does NOT do is control the engine governors in a consist to achieve the equivalent of restricted notch or excitation. Instead it acts to keep some locomotives in the consist at high notch while near-idling the rest (see SmartConsist or Smart HPT) which is not what the three-stage derating system on the NDs apparently does.
What makes newer locomotives more efficient, by far, are AC traction motors and computerized wheelslip technology.
I would say from my experience at EMD it was continuous improvement in engine BSFC starting at about 0.4 lb/BHP-Hour for the roots blown 567 to close to 0.31 for a turbocharged 710, coupled with an ongoing pursuit of reducing parasitic accessory load of cooling fans and traction motor and generator blowers via multi-speed motors and lately variable speed drives. Larger radiators with more tubes and separate aftercooling allowed reduced fan HP and more efficient engine operation.
Probably valuable to add that the SFC improvements would have been far more dramatic if pollution control were not also a concern. One of the great advances was proportional EFI capable of multiple/pilot injection; another was eliminating the mechanical drag of the positive-displacement Roots blower at high engine rpm.
I think 20-25% isa on the low side. I’ll have to do some digging.
Close to 50% from 1965 to 2015 according to Michael Iden’s presentation to Railtech: http://railtec.illinois.edu/wp/wp-content/uploads/pdf-archive/9.1.pdf
1965 corresponds very well with the start of mass deliveries of EMD’s 645-powered 2nd generation locomotives.
Better watch out, though: Iden also includes a discussion of platooning (with favor) and considered the Arrowedge to be innovative out-of-the-box thinking (I consider it more out-of-their-minds thinking as things turned out…)
What is highly interesting is the virtual collapse of gallon-per-ton-mile consumption in the relevant graph (note the interesting little pip centered circa 1985) which really ought to be redrawn at much larger vertical scale with a commented timeline… hmmm, that might be the basis for a good Trains article.
Absent is a discussion of advances (and shortfalls!) in actual engine technology and pollution-control equipment. While that might induce MEGO syndrome in conference attendees just as it does in forum posts, it would have been interesting to touch on.
As would the relative worthlessness of ‘notch restriction’ in actually conserving gal/ton-mile, or the actual big saving from running those PSR monstrains… interesting things have happened since ~2015.
That says nothing about the efficiency of the locomotive – just the “efficiency” of the average train, based on ton-miles. The locomotive’s SFC hasn’t decreased by 50%.