Was the switch to lightweight cars strictly an economy measure or where they actually an improvement in comfort and ride over the older heavyweight cars?
Additionally, did all heavyweights ride on six wheel trucks and lightweights on four? Or is their more to it than that? What were the pros and cons of four vs six wheel trucks?
I’ve done some general background reading on this but I know there is a lot to this topic so appreciate everyone’s insight. Thank you.
“Heavyweight” and “lightweight” have no official definitions. PRR P70 coaches were heavyweights, but they had 4-wheel trucks, as did lots of other heavyweight coaches. “Lightweight” is almost a synonym for “built with smooth sides and roof”; some “lightweight” cars had 6-wheel trucks.
The American Flyer coaches were an in-between.
I’m guessing a heavyweight Pullman rode at least as well as a lightweight sleeper, but I was never in one. Maybe the heavyweight was quieter?
Just as a note: plenty of ‘lightweight’ cars rode on six-wheel trucks, both when articulated and needing three axles’ worth of load-bearing and when the full weight of the car required it (the ‘poster child’ perhaps being the Superdomes).
These six-axle trucks could involve just as modern a high-speed OSH design as any contemporary 4-wheel truck and shouldn’t be thought of as a rewarmed ‘legacy’ truck design from the Great Steel Fleet era.
You will find a surprising number of these things in pictures once you know to look for them…
The only times I rode in heavy weight Pullmans they were on not so fast trains (L&N’s train from Cinicinnati to Montgomery that used the old main line above Decatur, Alabama, and the Pullman Lake Pearl on at least two steam excursions out of Birmingham). They seemed , as I recall, to ride well. I did spend some nights on heavy weight coaches, which did not disturb me by the ride quality. I do not like sleeping in seats that do not recline–but the last night I slept in such a coach (from Atlanta to Charlotte), I had the seat right by the men’s washroom, and could stretch out on it, and I slept all night.
An interesting subject, which ought to get and perhaps has gotten more interest than I’ve seen, is the modification of heavyweight trucks for higher ‘streamliner era’ speeds. This is distinct from converting them to newer trucks (as in some private cars, and office cars like PRR 120)
There are examples of this in some railroad museums, where you see six-wheel frames of what may be considerable antiquity now fitted with roller bearings, better bolster damping and compliance, modern primary springing, multiple Spicer drives, etc. I believe there were manufacturers in the '40s specializing in these conversions.
Illinois Central had some heavyweights with six-wheel trucks modified for higher speeds. They were used on some second tier trains and student specials for holidays.
The difference between heavyweight and lightweight appears to be in the roof.
Just what was a “clerestory roof” and was this for better natural ventilation? Why did they do away with it in the lightweight passenger car? Because of air conditioning?
The Amfleet cars appear to have a lower roof line than “lightweight”, and the Canadian LRC cars yet an even lower roof line. The Santa Fe Hi-levels, it seems, had a pretty low roof when you consider that the passenger rode on an elevated deck. What changes did they make to allow a lower roof apart from making the passengers stoop when they walked along the aisle?
A fuller discussion of the clerestory roof
High speed 6 axle trucks were also used on the AT&SF Hi-level dining cars as well as the UP boiler cars. IIRC, the UP did rebuild many of their heavyweight cars for streamliner service - a couple examples are a streamlined heavyweight coach and lounge car at OERM. Think the ttrucks had been modified to use roller bearings.
My understanding was that heavyweights had floors made of poured concrete so they rode better. Not sure if improved suspension systems could make that unnecessary.
A trip on the Grand Canyon Rwy got me thinking about this issue. I was observing all the different types of cars. I’m aware from reading their history articles that their cars are sourced from many different places so what is currently high or low end to them doesn’t necessarily correlate to what was high or low end back when they were all new.
Personally, I think this was a convention (like using stagecoach styling in early passenger cars) which came to denote ‘real-railroad’ vestibule cars. Where you see it in narrow-gauge, interurbans, etc. I think it’s likelier to be an establishment of ‘visual legitimacy’ more than ventilation or light; it certainly doesn’t add to strength or decrease cost and it’s more difficult to keep maintained than an arch.
Note that there was little perceived difficulty in ‘rounding off’ the heavyweight roofs with air-conditioning ducts and suchlike in later years, by which time a matched set of highly-varnished palace cars was no longer a competitive aesthetic necessity…
Succinctly, because in lightweight construction the carlines and purlins are structural. While the arch roof may be less stressed in something like a Pullman-Standard ‘fake Budd car’ than in early UP Streamliner practice following the general Stout Railplane practice, it is still significant. A clerestory roof without ‘tie bars’ as in some Renaissance churches does not offer this strength…
Amfleet uses the ‘tubular train’ construction of 1956 as later refined and applied to the Metroliners, and this is something that essentially treats the carbody above the windows as part of the roof. You could approximate a clerestory with windows in this construction if you wanted a sort of Skytop effect, but there is little perceived point in this, especially given the complex changes in formed components and jigs that wou
This is part of the reason they were ‘heavyweights’ – aside from the ballasting and suspension preload this produced a certain amount of ‘inertial stabilization’ of short-period track forces communicated up through the trucks. Perhaps the finest flower of this were the ‘late’ PRR P70s that had something like 2" of concrete (that might have had steel-mill slag in the aggregate) in the deck, and the refined high-speed trucks. It is difficult to describe how beautifully and quietky these things rode on indifferent PC track in the early-‘70s NEC (much of which was still jointed rail in no more than 128’ sticks then). On the other hand when you arrived at 30th St. on a typical clocker the sheer amount of stinky blue brake smoke would attest to the extra weight…
It can, and it does, and in fact in many modern trains probably including any true TGV the use of inertial ballasting would be a waste. Lightweight cars often featured a kind of ‘poured floor’ underlayment for noise and shock blanketing; if you look at some of the contemporary car builder advertising you can see this was very much like a ‘cement deck’, just with lighter materials.
The basic issue with good riding in lightweight cars is the difference between loaded and empty; an associated concern is the change in ride height accompanying this where the train uses ‘Continental’ platforms. The usual-suspects approach to this is to use those big airbag springs in the bolster secondary suspension, airing them up or down to get level at the doors. This adds much of the cost of a full-active suspension even if reservoir air can be safely tapped to run the ride-height system.
If you use negative-cant-deficiency systems,
The Santa Fe Hi-levels, it seems, had a pretty low roof when you consider that the passenger rode on an elevated deck. What changes did they make to allow a lower roof apart from making the passengers stoop when they walked along the aisle?
Observed when riding the Starlight that the floors were about 4 " lower on the Sante Fe lounges than Superliners. Always felt it was a tripping hazard going from lounge to SL but also somewhat the other was. Plus had to duck when going from SL to lounge. Another problem noted that the lounge only had one hand hold when going between cars. Not as safe as could be.
Cannot imagine trucks would need anything but adjusted for one weight. If we were to take every passenger, luggage , and potable water as 250 pounds per passenger and overload of 80 passengers that is only 20 thousand pounds difference. Tune trucks at 10k above empty weight and ride would not be that different ? Now if Amtrak changed weight of seats maybe ? ?
Yes, I remember that difference in height. It took me by surprise the first time I moved from a Superliner car into the former Santa Fe car. I do not remember seeing anything about that difference in all that I had read about using the Santa Fe cars on the Seattle-Los Angeles train. Thereafter, I remembered. I always enjoyed riding in those pre-Amtrak cars.
Yes, the Superliners are taller, with maybe the higher upper deck to have a more usable lower deck. I think Plate C is 15’6" and the Superliners exceed that and are at an even 16’?
As to building a Hi-level car with a lower floor and taller ceiling, I read that one rationale of the Hi-level is to have the passengers ride higher to be able to see more out the windows. This is part of why people like SUV automobiles over sedans – to ride up higher and see out more.
I rode the Amtrak Southwest Limited from Chicago out to Pasadena, CA once in the mid 1970s when coach class was Hi-level and the sleepers were conventional “lightweight” cars. This was the combined El Capitan (coach) and Super Chief (all sleeper) that Santa Fe sued to prevent Amtrak calling it the Super Chief (is it now called the Southwest Chief?). In the 40-hour 2-overnight trip in a coach seat, a deep recline leg-rest seat, but still a squirm-inducing coach seat, I remember encountering the other “train sets” covering daily service on this route. I noted some odd Hi-levels that had slightly angled instead of straight sides and wondered about them.
I later learned that “sprinkled” among the multiple train sets (consists) were the prototype Hi-levels built in the Santa Fe shops before they gave the main order to, was it, Budd? I read that these had the seats up on a step relative to the aisle way to give more elevated Hi-level goodness. The theory was giving coach passengers assigned seats that were like riding in a dome car.
Part of the dome car experience is the glass dome where you can look out the sides on the passing scenery whereas in a regular coach seat, your view through a narrower window is more limited, expecially from an aisle seat. The other part of the dome car is that it is meant to give some approximation of the view out the front of a ride in the locomotive cab, which is really something you can offer only with
I’d always heard the purpose of the Hi-Level cars was predominantly to raise passengers above track and ‘truck’ noise, with the view advantages real, but secondary. It would not have been rocket science to give them ‘overhead’ windows (as in some cars that ran in the East with essentially glass roofs over the lounge area – I don’t recall if these were cleared to run under catenary or not). If you thought HVAC was tough in Hi-Levels where ATSF often ran – imagine the tons of further cooling needed with the added non-low-E glass, and the added duct and return systems to distribute the air.
I had thought that use of individual gensets on ‘electrified’ cars was fairly widespread even in the '30s. As an alternative to a couple of Spicer generators and a whopping bank of batteries it could be attractive. I’d like to be able to say to google ‘Waukesha Enginator’ (one of the more famous period devices) but you’ll immediately come upon misinformation puled on stupidity that confuses ‘Enginator’ as a term meaning what we now call ‘Genset’ with Waukesha’s production of gas engined skid-mounted equipment. See also the Ice Engine for air conditioning compressor operation with fans, duct motors, etc. supplied from axle generation if needed…
You might have to go to RyPN to locate correct information on generators for individual cars and their ‘best’ fuel source and controls. In the meantime here is some potentially-illuminating light reading (I’ll stop with the puns now):
http://www.erixrailcar.com/techpubs/Waukesha_Ice_Engine_E_and_Engine_Generator_C.pdf
An amusing detail is that at least one company has actually made up a replica Enginator shell meant to be installed around a modern, smaller genset to give a historical look to the installation!
The stated purpose of the AT&SF high level cars was to minimize weight per seat. By having the entrance/exit and restrooms on the lower level, the whole 80’ or so of upper floor space could be given to seating space. The ride may have been better as the inverted pendulum effect would have softened lateral shocks.
The “El Capitan” was close to maxing out in length with conventional coaches and Hi-Levels were an imaginative way to increase capacity of individual cars. As a comparison, conventional coaches seated 48 to 52 while the Hi-Levels seated 68 or 72 per car.
The two 1954 pre-production Hi-Level coaches were 15’4" tall, the 1956 and 1964 production coaches 15’ 6" tall (same as a Budd Dome) and the Superliners are 16’2". The key dimension for Hi-Level floors is headroom in the lower level bathrooms, lounges and kitchens. There were several variations is “step-down” end stairways to match single level equipment, with some cars having front-end steps, some rear-end, and some no step-down. “Front” meant towards the end of the car when the stairway is on the left. A fair number of cars from the 1964 order were fitted to have convertible step-downs, but it’s not clear how many were actually converted.
Santa Fe assigned H-Levels to the El Capitan and later the San Francisco Chief. Amtrak regularly assigned Hi-Levels to the Super Chief/El Capitan (Southwest Limited), The Chief, the Texas Chief(Lone Star) and the Sunset Limited. Later the cars were mixed in with Superliners, usually as step-down cars in mixed consists. The last all-Hi-Level trains were the Heartland Flyers which eventually received Superliner coaches.