Lots of factory and steel mill structures were also built with a clerestory for ventilation reasons.
Lithonia Operator Even if the clerestory windows were shut, it was still a place for hot air to rise to. My guess is that seated passengers' heads might be 10 degrees cooler than the air up in the clerestory.
Even if the clerestory windows were shut, it was still a place for hot air to rise to. My guess is that seated passengers' heads might be 10 degrees cooler than the air up in the clerestory.
Exactly, it was the right design at the right time. Made obsolete by conditioned air.
Sheldon
ATLANTIC CENTRALWeakness? I don't see where or why that would be an issue?
My recollection is thet they were talking about clerastory roofs over wood sided cars at that point.
I like the ventilation idea. Great for natural convection when sitting still. Get forced flow from the venturi effect when in motion.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
The celestory roof wasn't just for train cars:
https://www.conceptcarz.com/vehicle/z11537/alco-model-six.aspx
I've seen this one myself, its impressive. I had a Moto-Meter (the radiator cap thermometer) insert for an Alco car which I donated to the Crawford museum that has this car in their collection.
Erik_Mag ATLANTIC CENTRAL Weakness? I don't see where or why that would be an issue? A continuous arch roof is stronger than a clerestory roof of the same weight. The stiffness in heavyweight cars was primarily provided by the center sill and frame, with the carbody above floor level providing little more than protection from the elements. The sides and roof of leightweight cars provided much of the overall strength and stiffness, with the center sill focused on draft and buff loads.
ATLANTIC CENTRAL Weakness? I don't see where or why that would be an issue?
Weakness? I don't see where or why that would be an issue?
A continuous arch roof is stronger than a clerestory roof of the same weight. The stiffness in heavyweight cars was primarily provided by the center sill and frame, with the carbody above floor level providing little more than protection from the elements. The sides and roof of leightweight cars provided much of the overall strength and stiffness, with the center sill focused on draft and buff loads.
Agreed, but as long as the floor was built the old way, there was no incentive to build the roof differently. Although there were a fair percentage of arch roof heavy weight cars, mostly coaches, baggage and RPO cars.
Clerestory roofs were not purposely or neglectfully inferior, it was just a design evolution.
Not sure when the last heavyweight cars were built, but by the mid 30's most new passenger equipment was of a streamlined carbody appearance regardless of exact construction method.
So effectively, cleresstory roofs and the ventilation features were a "pre air conditioning" feature (first air conditioned rail car, 1930, B&O diner Martha Washington).
The desire for art deco streamlining and A/C eliminated the clerestory roof from new railcar construction pretty quickly, but that did not remove thousands of cars from service. Many of which lasted into the 60's, and are still with us today on tourist lines and in museums.
Gramp Did heavyweight cars ride more smoothly? I recall that people would try to not be seated over the trucks.
Did heavyweight cars ride more smoothly? I recall that people would try to not be seated over the trucks.
Compared to the first lightweight streamliners, yes, heavyweight cars road much better.
It took a while for designers to get smoother riding lightweight designs perfected. And some of those early streamliners were only a little "lighter" than the heavyweight cars.
In 1935 the B&O bought two streamlined train sets from American Car and Foundry. One for the Alton's Abraham Lincoln and the other for the Royal Blue. They were not happy with the ride, by 1937 the Royal Blue set was sent to the Alton to supplement the Abraham Lincoln/Ann Rutledge service.
Rather than buy any more new lightweight streamlined equipment, the B&O rebuilt their heavyweight cars into streamliners, but underneath they remained traditional heavyweight cars.
While some more modern cars were purchased later, the B&O did fully embrace modern passenger cars until the C&O took control in the 60's.
Many heavyweight cars were rebuilt and upgraded but retained their core construction and remained in service until the decline of passenger trains.
MidlandMike Excerpts from a book on Google Books rgarding passenger car archetecture says that the clerestory roof just be came an excepted standard, despite its weakness compaired to an arch roof. Harriman arched roofs just had vent risers on the roof. Eventually some clerestory roofs got partially rounded off by the addition of air condition ducts.
Excerpts from a book on Google Books rgarding passenger car archetecture says that the clerestory roof just be came an excepted standard, despite its weakness compaired to an arch roof. Harriman arched roofs just had vent risers on the roof. Eventually some clerestory roofs got partially rounded off by the addition of air condition ducts.
They are referring to later steel cars without clerestory windows, just vents.
After the indroduction of A/C in the 30's the inside of the clerestory was often converted to ductwork space and additional ducts were added to the lower roof exterior, rounding off all or part of the roof.
Pullman was by far the largest car builder and the steel cars of the first part of the 20th century were built from standard parts. Yes, Pullman and others were reluctant to change the design until streamlined cars became the norm.
Heavy weight cars of this era had steel framed floors filled with concrete like an office building to prevent cars from telescoping and limit roll overs in crashes.
Then you got these:
Heat rises, the design provided natural air flow out the vent windows that aided in improved comfort.
The glass vent windows in the earliest cars also provide improved aisle lighting in daylight.
Headroom was not really an issue, the lower roof over the seats was more than tall enough. But, going back to my opening comment, just like taller ceilings in older homes, the extra headroom provides a place to pull the warmest air away from the people, including those walking in the aisle.
Designers and Architects understood convection cooling pretty well back then.
MidlandMikeI presume you are talking about clerestory roofs. They originally had little window/vents on the short vertical side that could be opened for ventilation.
I have no doubt that you are correct. I also wonder if it was for additional headroom in the aisle?
I presume you are talking about clerestory roofs. They originally had little window/vents on the short vertical side that could be opened for ventilation.
See subject line for question
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