CMStPnP seems to be parochial as well as xenophobic, at least about China, as noted by three other members. Rail systems outside his immediate purview, whether domestic or overseas are denigrated without ever being able to comment with specifics on the speed ride comfort etc.
I am beginning to question his experience with Metra as a frequent commuter in the unspecified past. He stated that the gallery cars are drafty. I have long thought the design is poorly lit and sometimes noisy, but I never thought the cars were drafty. But donāt takey word, other members are regular riders.
Most people would say they disagree and leave it at that. Instead we are back to personal again. The whole fishing expedition on what I do or where I have been I usually never respond to because when I have in the past you forget it or bend itā¦thinking that might be age on your part. Itās not relevant to a Forum discussion of opinions though. Credibility is based on what you post not what you state in your posts as far as who you know or where you have been. That is how social media works, everywhere. You might not like it but I didnāt make those rules.
One issue with very high speed rail is dealing with air-resistance as is rho times V squared, the air is much denser near sea level than at 40,000ā. This was something that was mentioned in the 1960ās by an exec at United Aircraft and reported by Trains. Muskās hyperloop was supposed to operate in a partial vacuum for just this reason.
China has a much higher population density than the US and has fewer resources of hydrocarbon fuels, hence their emphasis on HSR and EVās. France was also hydrocarbon poor, and thus engaged in massive electrification programs after WW2 followed by various flavors of HSR.
My āpersonalā comments relate to your devaluing the observations by members which are more empirically grounded than the second-hand data you derived from reading uncited blogs or Wiki. You dodge and weave to avoid answering and instead attack those members who have first-hand experiences.
That is the problem here. But go ahead. I would like to see specifics as to what I have forgotten as you now claim is a function of my age [there are LAWS against engaging in ageist practices or insults].
But Iām āoldā and tired of your silly gamesā¦
The issue with drag in high-speed rail is why the exaggerated nose streamlining is provided ā but much of it is for tunnel and cut entry, and facing train meets. The use of high-voltage from OHLE, as opposed to cost-effective packageable gas turbines as in the TurboTrain, TGV-100, APT-E, etc makes both very rapid acceleration and over 22,000hp per train easily accommodated; you may remember that the 150mph testing of T-1 to T-4 Metroliner prototypes easily got to over 150mph with a practically flat nose and no real downforce.
Quartering wind force has little amplification from forward motion. The problem there is increased turbulence, which is little improved by āstreamliningā once the vortices and waves are established. That remains significant for many conventional and intermodal consists with a great many effective āflat facesā or worse, but less for a modern TGV consist ā even one with two exaggerated crocodile noses meeting in the middle of a train.
My recollection was that the GE powered Metroliners were good for 160mph and the Westinghouse Metroliners were good for 165mph. Acceleration was 1.1mph/sec up to 100mph.
The comment about air drag is in comparison to airliners, where a DC-7 could cruise at 350mph on 8,000 to 10,000hp. Similar thing with cars where one would be doing well to get 200mph with 700hp, where an Aerostar 700 could do over 300mph. Both planes get their speed from flying at relatively high altitude (though no where near U-2 or SR-71 levels) with lower density. Heck, on the 2012 trip to Durango, I noticed our getting car about 1 more mpg at 6,000ā than at sea level.
For the Cal HSR, Iām wondering if short haul electric airliners are operational before the LA to SF service starts. OTOH, a 110mph train from SD to LA would be faster than a plane.
Lipetz pointed out by 1937 that aerodynamic drag on a railroad consist substantially varied as the square, not the cube, of the speed, and on a comparatively small frontal area (an often-unconnected reason for Mallardās reaching 125mph). The Metroliner curved sides were stated to be a means of lowering quartering and lateral resistance, but very few current HSR trains have much tumblehome.
The motors were supposed to be good for 160mph, but the ārevisedā trucks certainly werenāt in practiceā¦
I donāt really understand why regional feeders like Zunum or Lilium arenāt already a āthingā feeding true HSR lines. Level 4 automation is much easier in that service than for much slower road vehicles.
With aero drag scaling with square of speed, power to overcome aero drag scales with the cube of speed. This is assuming that Coefficient of drag doesnāt vary with speed - which should be the case at less than Mach 0.5. Doing a CFD model of a train would be a bit more difficult than an airplane - modeling the airflow between the bottom of the train and the track looks like quite a challenge.
I would be surprised if the Metroliner trucks worked out on the first or second try. It took Nystrom a number of years to get what was then high speed trucks to work well.
The Metroliner trucks were supposed to be low-unsprung-mass āPioneer IIIā style, like beefed-up versions of the original Silverliner trucks. On the contemporary PRR and then PC tracks that would likely haveā¦ erā¦ been a very bad idea. So they designed those GSC 90 drop-equalizer trucks with weird hard lateral accommodation and high unsprung mass ā using brute and somewhat track-wrecking force to get traction motors on every car. I think some work needed to be done on the soft secondary suspension, including isolators in the radius and track rods that would keep the car body from wobbling on the air bellows springs ā the early Amfleet cars were very, very lame in that respect (and the transferred oscillation would often make parts of the interior plastics giggle like schoolgirls).
Nystrom was a dead end, and he himself mentioned that in his description in the late Thirties ā he noted that a āpassiveā truck optimized for 80+mph rode hard at 40 or below. Very great use of low mass, āsilentblocā-style isolators, and probably air secondary suspension with no inherent spring resonance would be needed to get something more generalā¦