ngotwalt wrote:Those 20 heritage diners are down to about nine, because of structural defects. These cars are real warhorses, at least one was built seventy years ago for service on the California Zephyr, these cars are simply at the end of their useful lives. Amtrak has been running them hard for 46 years, and they already had twenty or so years of service before that. I believe they are each fairly unique cars too, meaning there are cars from Northern Pacific, Burlington, New York Central, etc and each road built cars to their own specifications, so each car needs unique parts, which Beech Grove has to often custom manufacture. No, stick a fork in the old diners because they are done. Hopefully a few will end up in Museums. Especially ex CBQ CZ diner, it's one of only two left.
Cheers,
Nick
Bingo.
A note on what is known as "design life". When designing a passenger car, a frame isn't designed just to hold 50 tons of steel between two trucks. Because the structure rolls, rocks, bumps, freezes, etc... the 50 tons of steel acts dynamically. Think of it like bending a paper clip. The paper clip isn't just designed to hold 20 pages together. It's designed to hold 20 pages together while they are inserted and removed from a briefcase repeatedly, papers added and removed, stacked on top of other pages... thus a design life. If Staples assumes a design life of 90 days for a paper clip, they can figure out how to beef it up to survive the very dynamic life of a paper clip for 90 days. After that, it breaks. It's cheaper to replace than fix.
The same is true with railcars. The builder assumes (or is told by a railroad) perhaps a 30 year design life is required. They then calculate the stresses based on the average mileage rolled per year x30, the average couplings per year x30, the average loadings and unloadings per year x30 (more useful with freight cars as passenger weight is sorta negligible). They then figure out how to prepare a frame that won't crack or give out until 30+ years. It might last to 32, or 38, or maybe 40. But 50 or 75 is 2-3x design life, they just don't design for that. So it goes beyond repaint, rust repair, renovate interior. At some point, the fundamental bones of the train car are kaput.
A final note on excursions cars: they run perhaps 2x/week during a few seasons. Even if they run daily, the trains are usually slow moving, they aren't shunted hard, there is no hard use. That's why 1920's-vintage cars still run on dinner trains.
There is a word for this: "duty cycle". It measures how hard something is used given a constant capacity. A 74-passenger excursion car has a light duty cycle as it rolls 2x/week, 3-5 months/year. A commuter car has a medium duty cycle as it probably rolls 4x/day in AM, sits daytime downtown, 4x/day in PM, then sleeps nighttime in the burbs. An Amtrak car has a high duty cycle as it goes Chicago-LA for 3-4 days, sits a few hours, then goes back. It rolls all day every day. All of them hold similar passenger counts, but the wheels roll more, the couplings happen more often, the toilets flush more, the HVAC cranks far more CFM...
Makes sense?
The new Acela: It's not Aveliable.
