Are railroad cars or locomotives built with any camber in them, the way semi trailers are built?
Thanks to Chris / CopCarSS for my avatar.
No. The wheel is rigidly pressed onto the axle and has no deflection from perpendicular... unless something goes very wrong.
Editor Emeritus, This Week at Amtrak
Yes. Some locomotives, some cabooses, and most flat cars are/were built with camber. The primary issue it to control coupler height. Since truck bolsters are at a standard height, flexible cars or cars with some distance from the bolster to the coupler need to address this issue.
I was thinking more of camber in the frame.
D.Carleton No. The wheel is rigidly pressed onto the axle and has no deflection from perpendicular... unless something goes very wrong.
He means camber in the carbody, not camber in the suspension. And yes, there are some classes of cars that display it, although the heavy underframe required to meet FRA buff standards usually provides enough stiffness even in low-tare-weight freight cars to minimize visible camber even when the car is new and unloaded... as noted, there's also the need to keep coupler height constant between loaded and unloaded condition.
Many of the early Amfleet cars when delivered showed visible camber, as did (IIRC) the first generation of NJT push-pull cars in the early 1970s.
Old cars with truss rods might have displayed camber when unloaded if the rods were adjusted to eliminate any tendency toward swayback at full load.
Almost all the locomotives I've been around had a subtle camber to them. It's actually one of the things I look for when I'm buying or leasing and engine.
Euclid What do you call the reverse of camber such as the slight manufactured swayback you see in some tank cars and most truck side frames? I have thought about the intention behind the tank car swayback, but have never heard it discussed or technically explained. Perhaps it is only to aid in draining.
Thats a funnel flow car, its made to empty more completely.
Randy Stahl Almost all the locomotives I've been around had a subtle camber to them. It's actually one of the things I look for when I'm buying or leasing and engine.
David1005 Yes. Some locomotives, some cabooses, and most flat cars are/were built with camber. The primary issue it to control coupler height. Since truck bolsters are at a standard height, flexible cars or cars with some distance from the bolster to the coupler need to address this issue.
For locomotives, most of the camber of the bare frame as manufactured is then 'taken out' when the weight of the engine, generator, full fuel tank, etc. is added. However, some camber is usually left in to counteract the bowing effect of the pulling/ stretching through the couplers and draft gear and/ or from the tractive effort of the trucks, which are each mounted/ suspended about a foot below the 'center of gravity' (actually, the centroid of inertia) of the frame.
Camber was (is ?) most evident on the 89-ft. long TTX piggyback flat cars, if you can get the right view (telephoto down the side). They're so thin and long, and most of the weight could well be in the middle portion, that something had to be done.
Cars that are shorter and taller/ 'beefier' / stiffer have less of a need - contrast a center-beam flat with a bulkhead-end flat.
- Paul North.
EDITED around 4:00 PM to add:
For what happens when there's not enough camber, look closely at this photo (not mine) of some flats with heavy steel plate loads:
http://1.bp.blogspot.com/-68W01q6K-aY/U4T9kgRlimI/AAAAAAAAOoQ/SffhKC6r_g0/s1600/blog308drawbar3.jpg
and http://2.bp.blogspot.com/-fFV4sgNDn7o/U4T9lYwhpyI/AAAAAAAAOoY/5jzkhsWeqLs/s1600/blog308drawbar5.jpg
from: http://tracksidetreasure.blogspot.com/2014/05/how-to-hold-up-train.html
There's also several mentions of camber in the B and C decks of a tri-level flat car in this patent: http://www.google.com/patents/US20040016362
Paul_D_North_JrCars that are shorter and taller/ 'beefier' / stiffer have less of a need - contrast a center-beam flat with a bulkhead-end flat.
I would expect a center-beam flat to be a fairly stiff structure, so long as the beam is connected to the frame of the floor. At least what I remember from the solids class ###ty some years ago suggests that. (To this day, I'm sure the professor wonders if the two EEs in that section had gotten lost or something.)
ChuckCobleigh Paul_D_North_Jr Cars that are shorter and taller/ 'beefier' / stiffer have less of a need - contrast a center-beam flat with a bulkhead-end flat.
Paul_D_North_Jr Cars that are shorter and taller/ 'beefier' / stiffer have less of a need - contrast a center-beam flat with a bulkhead-end flat.
At CRRM in Golden, they have one wood frame narrow gage combine/caboose that is so swaybacked that the roundhouse staff has put a ratchet jack under the centerbeam just to keep it from collapsing until they decide how to save it.
Having just spent a week staring at standard plans and utility installation specs, you can add newly installed pipe at a shallow depth to things with camber for structural reasons.
mudchicken [snipped - PDN] . . . Having just spent a week staring at standard plans and utility installation specs, you can add newly installed pipe at a shallow depth to things with camber for structural reasons.
I'm still waiting to see a locomotive cab with a steering wheel.
Modeling the "Fargo Area Rapid Transit" in O scale 3 rail.
Murphy Siding Are railroad cars or locomotives built with any camber in them, the way semi trailers are built?
we would reject JTTX flatcars which were used for long
steel loads if they sagged in the middle. They had to
have a slight arch upwards in the middle.
Future Settlement of surface water runoff piping.
No matter how good a contractor thinks that his compactive effort is and dirt being dirt, it's gonna settle. That train over the top will be the most effective E-80 vibratory compactor ever known.
(Uncle Pete's industry track construction specs get into it pretty deep)
Boyd I'm still waiting to see a locomotive cab with a steering wheel.
mudchicken Boyd I'm still waiting to see a locomotive cab with a steering wheel. You just want the hogger to lose his mind.
You just want the hogger to lose his mind.
But how is he going to sweve without one?
Norm
Norm48327 mudchicken Boyd I'm still waiting to see a locomotive cab with a steering wheel. You just want the hogger to lose his mind. But how is he going to sweve without one?
Well, in the Polar Express movie, they steered the steam locomotive on the ice by pulling the reverser lever back and forth while working the throttle in or out.
I don't know what you'd use in a Dismal. Maybe play with the horn and ditch lights switches?
Semper Vaporo
Pkgs.
Paul_D_North_JrAs with many things, it's mainly a matter of having enough pieces in the right places, and then proportioning them to match the task at hand.
Flashbacks of zig-zag plots along the horizontal axis. Now feel a slight tug to see if I can find my old solids text and brush up a little bit. Or not.
I was going to post a picture of a steamer with a wheel reverser instead of a lever, but the pic I found was copyrighted...
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
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