Woodford again thank you for the time and patience that you put into these posts in educating us all about the limitations and challenges surrounding reducing journey times especially with the N sets hauled by N class locos. Three aspects you and the gang might find of interest. The first is your observation about how remarkable given the relatively low tractive effort of N class locos as to how they are able to maintain the existing timetable with a relatively heavy train (450 tonnes). Your experience mirrors mine in the very early days of RFR when I had opportunities to ride in the cab of several N class hauled services on the Geelong and Bendigo Lines. The driver commented that his train was definitely accelerating more quickly and subsequently needed a lower throttle setting to maintain track speed and he put this down to reduced rolling resistance with higher quality track and probably a very good wheel/rail interface. Another point I can confirm made by kuldalai is that the NE standard gauge track standard was set up to enable V/Line locomotive hauled trains to operate at 130km/hr in regard to track standard and signal sighting etc, so that option remains open if a more powerful unit was to be used. The next point is CountryLink did submit a proposal for the XPT to be cleared for 160km/hr operation between the various interlockings/crossover locations on the basis that the number of intermediate stops (3) would permit them more sustained higher speed running and hence the potential to get some benefit. (The also proposed a speed restriction regime similar to what is done in NSW to address level crossings).
Going forward I think serious consideration should be given to developing a 2 tiered service when V/Line increases frequency to introducing a faster express with intermediate stops At Seymour, Euroa, Benalla, Wang and Wodonga for say 2 round trips per day and the current stopping pattern with Springhurst removed at 2 round trips per day plus reinstatement of the V/Line-XPT codeshare arrangement for V/Line passengers to access the XPT.
I don't know on the basis of a limited stop-express and a 3,000HP unit running at up to 130km/hr if that brings any meaningful journey time improvement but often perception can be stronger than reality!!!! Thanks again for your interesting posts
A number of points............
First thank you for your kind remarks, I have always taken great care to try and provide good clear information, because in the final analysis the only thing the matters in trying to bring about a better world is the. best possible understanding of the problems.
I myself have no direct experience with the loco's although I have driven both a steamer and a diesel hydralic loco. The analysis provided is mathematical in nature based on the well known "Davis" equations, although in this case the parameters have been adjusted to reflect the real performance of the VLocity 's and the N loco and N cars sets. I having done detailed timings of both of these and reverse enginneered these timing figures to produce the correct parrameters fro the equations. The better performance of the loco's you mentioned is probably the result of the much smoother track, the undulations of the older track require energy to over come and the only source of this is the loco it self, Note:These undulations take far more energy than you would think.
This side of it is beyond mathematics, as it requires a massively detailed model of the track and at least the suspension of the loco and one would require a render farm for the commputations.
My main source of information on the regauging project came from a Seymour driver (since retired) that I had a length conversation with before I joined Railpage (ie well before the project got under way). He was as it turned out almost completely accurate. One thing he did say that was the ARTC was NOT interested at all in any speeds above 115kph and Victoria (VLine) had to fight hard for 130kph. Even then from my own observations the original signal install was for 115kph to NSW standards, Victoria was VERY pissed off over this and well an truly dug in there heels until ARTC came up with the correct goods.
AS far as I am concerned every one can completely forget about 160kph running, the line simply NOT being straight enough (the Creighton hills and the Glenrowan pass at least for example) to allow extensive 160kph running even IF someone could talk ARTC into such running.
From my work I believe for any kind of 130kph service one would need at LEAST 5000bhp on a 6 car train, for really effective 160kph running on lines like there are in Australia one would require 8000 to 10000 bhp. To be able to climb hills and accelarte above 130kph requires massive amounts of power.