Grain hoppers and coal car ends are not ribbed/rippled and neither are the ends of locomotives, auto carriers, or semi truck trailors for that matter.
The ribbing appears to take up twice the steel, so apparently there is a good reason for it.
For the smartee that is going to say because ribing makes it stronger, then why are the ends ribbed and not the sides? Why isn’t it this way for other cars or semi tractor trailors?
Gabe
Ribbing add structural rigidity to an otherwise flat surface. The ends of the cars are the structural cornerstones of the box car.
You’ll find ribs on box cars and gondolas because they can conceivably be loaded in such a way that the lading can shift from end to end with slack action or impacts. Bulk cars (coal, covered hoppers, etc.) don’t need that because the lading fills the car to a given height and is not subject to these forces to the same degree. Automobiles on the racks are tied down (besides, those are doors, not really car ends), and bulkhead flat cars have strengthening members in the bulkheads, and don’t need the additional reinforcement.
It doesn’t take much to shift a load–we see them all the time, even before they’ve been humped!
Think of corrugated cardboard – which is basically layer upon layer of stiff, evenly rippled manila-colored paper.
Or a good old-fashioned truss bridge, although the mechanics work in a slightly different way.
So older box cars with bowed out ends are the result of a shifted load. What causes the roofs of some box cars to have a “raised” look in some parts? I gather it’s from an over-enthusiastic forklift jockey ?
For her pleasure of course…
Natch. [:D]
Gabe:
Certain semi trailers are corrugated. Most today are smooth panels, but certain ones are corrugated, primarily refer units.
ed
Why are boxcar ends rippled? Why, so I could get my engineering education.
My understanding is that Walter P Murphy became wealthy from a patent on the corrugated-style boxcar ends (increases strength according to explanations of above posts), and a lot of that money was contributed to the Northwestern University engineering college (called McCormick but formerly Tech Institute). If you search on Northwestern web sites, there is a Walter P Murphy this and a Walter P Murphy that, but I guess who Walter P Murphy was has kind of been forgetten somewhat.
Boxcars do not look right with flat ends. Has anyone ever seen the Nevada Northern boxcars (I wonder what happened to them) or the ARMN 110000 series reefers?
I worked in the brick industry for 18 years and the last 10 years loading boxcars with cubes of brick. It was customary to start by loading wooden gates into each end to act as a buffer and a way to hold the top tier as we double stacked the brick cubes. After setting four cubes of wrapped brick on a padded floor of either sawdust or discarded cardboard, we would back up a few inches while leaving the forks inside the cubes and ramming at speed to pack the brick cubes with the front of the truck. This may explain why the ends of these cars are shoved out, but our fork trucks were small in size and did not have the power to pu***he ends out.
Fork trucks are dangerous as I have seen many cars come into our yard with pushed out ends and dented roofs. Even some had the doors ripped off the track with broken appliances where we wired the door shut after loading. Some doors had to be pulled closed by hooking a chain to the back of the fork truck while your buddy used his truck front to hellp close the door.
Ramming the cubes was a head jarring thing.
Eric, it would be interesting to see what’s under the smooth ends of those reefers–besides insulation. Plenty of room for corrugations of some sort, I’d bet!
I never did find out why those NN 200-series box cars were built with ends like that. They were relettered MISS in 1985. I lost track of them after that, but they aren’t on the Mississippian Railway roster any more.
Dan!