<i>It's easy to get the impression that the FRA does indeed mandate a minimum weight given the discussions about the Acela being too heavy because of the Tier II standards.</i>
I doubt any other manufacturer would have done significantly better than BBD. In all aspects of Acela.
<i>Nevertheless, I personally see the existing standards as a roadblock to lighter trains whether they mandate minimum weights or not.</I>
Well, yeah. Tier II has a lot of just downright silly requirements which are poorly defined anyway.
<i>Modern signaling systems such as ACSES and ATC all but make crashes impossible. I'd rather have those things mandated, combined with a nationwide elimination of grade crossings (the single biggest reason for train wrecks by far) than worry about designing equipment for crash "surviveability".</i>
Equipment can be designed to work well in grade crossing accidents, yet still be fairly light - witness the TGV's history. Realistically, ATC/ACSES/PTC should be mandated for any/all passenger rail in the US, and the focuse shifted towards grade crossing performance and staying upright/inline durring a derailment - areas where US rail equipment generally does poorly.
<i> Although airlines are my least favorite way to travel (I won't fly at all for a variety of reasons) railcar engineers could take a cue from the airline industry. The focus there is nearly 100% on crash avoidance.</i>
It's not the engineers who need the clue, it's the FRA.
<i>Designing in crash surviveability is almost an afterthought.</i>
No, the FAA takes a realistic approach. By far the biggest danger in an airliner accident is smoke/fire. Decades of real life experience has seen plenty of accidents where fire and smoke made the difference.
<i>I'll grant that plane crashes are inherently less surviveable than train crashes, but to me worrying about making either 100% surviveable seems almost pointless.</i>
No accident is 100% surviveable, except the accident that never happens. thus, to get 100% surviveability - don't have accidents.
<i>The older equipment which didn't meet the new specs was in many crashes. I never remember huge numbers of fatalities. Even in the Chase, MD crash I was surprised that the death toll was so low given the speeds involved. The "non-compliant" equipment held up just fine.</i>
I keep asking for a listing of the deficiencies of the M-1 carbody, where they played a role in accidents, and what the FRA regulations would have done to fix them. Never get it from anyone. And I've asked people in the industry for this... Statistically, you are far safer on a 'tin can' M-1 with the LIRR's ASC system in place, than you are in any other railcar anywhere else in the US (except for MN). From a pure statistics standpoint, the effort that should be duplicated in the US is that of the lightweight, signle level, stainless steel railcar, running in a highly cab signnalled system with a strict rulebook and high crew standards.
<i>With better systems in place train wrecks can be literally a thing of the past. Witness the 40+-year run in Japan with no passenger fatalities on their high-speed lines, for example. Their trains probably could be made of paper given the safety systems which are in place. </i>
The Japanese view is extreme, but they are nonetheless very sucessful.
<i>A relaxing of the standards combined with some serious design work to meet the revised standards while minimizing weight would eliminate the disadvantage the US has right now.</i>
It's not a 'relaxing', more a simple issue of being realistic. IMHO, US passenger rail would be just fine with UIC standard equipment, decent track, and a decent ATC system. The costs would be significantly lower, the performance significantly higher.
The irony of the FRA's standards is they make rail so unattractive to most travelers - or just plain not available - that those people choose to drive, instead. And driving is far far far more dangerous.
<i>No reason we can't make a high-speed train with 80,000 pound coaches or an EMU with similar weights even without using carbon fiber.</i>
IMHO, a modernized version of the M-1 body with decent traction gear could have hit that number pretty easily.
<i> Speaking of the M2s, exactly how bad are they acceleration-wise?</i>
From my years of taking the NH line? Pretty horrid. When all cars are working, they're ok. But, realize that they don't have much HP per ton.
<i>Ditto for the M-7s you say run like "tar". I haven't ridden either, although I have seen M-7s pull out from the Flushing LIRR stop. They seem pretty good off the line anyway.</i>
They *were* decent when new, but the power issues meant cutting the HP back a few hundred. As they are now, they're no better than the M-1/3 cars. Slightly better out of a station, but at speed they're a joke. And they ride just as bad...
<i>Nasadowsk, would you expand on why the cars can't put out full horsepower?</i>
Ohm's law! You can only draw so many amps through a conductor before your voltage drop gets too high. This is why DC third rail died off for mainline electrification. Even with frequent substations, you STILL hit its limitations.
<i>My understanding was that the AC motors were more efficient than DC, and would put out more effective work for the same current input.</i>
Don't forget inversion losses
AC inverters aren't 100% efficient (or else they'd be really tiny), and the motors aren't eitherr (or else they'd be tiny too)
Nonetheless - you can't get something from nothing, and the limiting factor is the third rail. Drawing high current reliably isn't easy, and third rail resistance - and running rail resistance too - become big factors as current increases. This was recognized 100 years ago (more than), and is why high voltage AC systems developed despite huge technical problems.
