I see more center-beams every year, and about half the time they’re rolling empty, as I would expect. So what are the main advantages of using center-beams instead of ordinary flatcars?
If I send a flatcar loaded with lumber to Pittsburgh, I can reload that flatcar with steel or machinery, or anything that can fit into a container, thereby minimizing empty nonrevenue generating miles. A center-beam, on the other hand, can only be loaded with lumber or must be run empty to its next lumber reload. And the flatcar isn’t as tippy as a center-beam either.
Also - the center beam provides structural strength while reducing tare weight. Less weight equals more load capacity and/or less weight to pull, hence less fuel wasted hauling iron.
Oh man, I see these things loaded with stainless steel round ingots, pipe, sheetrock, lots of stuff besides lumber, very creative use on the return trips.
Freight cars of all sorts have become more specialized, so it’s not that common to get a loaded backhaul. Although as Ed points out, some rather creative uses for a backhaul do occur.
It always seemed to me that the inconvenience to the customer of having to load and unload from both sides would overrule the structural benefits of lighter weight with more rigidity from having the center-beam.
You have to unload both sides of the car anyway, so there’s not much inconvenience to unload some from this side, some from that side.
To a certain extent, you’d want to load and unload something like lumber from both sides of a flat car as well. If one side is empty, the car takes on an angle, and makes it more difficult to get the forklift forks in.
To add a little to what Murphy Siding said below**:**
"…To a certain extent, you’d want to load and unload something like lumber from both sides of a flat car as well. If one side is empty, the car takes on an angle, and makes it more difficult to get the forklift forks in.…"
When one of these center beams is unloaded from one side only; the other side is particularly hard to unload, particularly, when the car flops over on its loaded side in the middle of you lumber yard’s unloading area. [:'(]
Unloading rough lumber from a boxcar in the Summer sun is no picnic either. Sort of like setting up your bar-b-que pit in a sauna. Especially, when you have to start the unload while crawlin’ in, to lay on your back while passing one board at a time out the door.
I’d guess that the load vs. empty mileage ratio is not much better for standard flat cars vs. center beams. Those things get looked at during both the design and purchase stage. Given the size of the center beam fleet, it would appear that both the railroads and lumber people like the car.
My summer job out of high school was at a sash and door plant. Everything moved in and out in box cars. I never had the pleasure, but unloading the two by douglas fir had to be the most fun. The boards came in whatever width came off the log, often three or more feet.
These responses haven’t brought up the reason why the center beam runs faster than bulkhead flat cars. It is the reason for their existence.
Versus flat-cars without bulk-heads: on flat cars, slack action could slide the load off the car. Build a big heavy but strong bulkhead to hold in the load, unintended consequence ensue.
As the wheels anywhere… strike a flange the stuff above, the empty bulkhead gets a shot of energy aiming the bulkhead toward the tracks’ field side. The bulkhead after being stopped rebounds, twisting the car and inspiring the car’s other truck to hit the flange, impart to its bulkhead similar movement, One end of the bulkhead flat , then both ends, and then all in the train yuo’re meeting on double-track wildly dnace skip and don’t hop, I hoped when I met Emptys Eugene trains on rhe Cal-P going to the NWP that terrifed .I didn’t know that realizing that connecting, quite-rigidly, the bulkheads with a center beam would resrict the repetitive oscillating.motion.
What car’s, beside bulkhead flats, don’ have their highest portions at their extremes not connected rigidly there?
That flexibility of the bulkheads versus the strength of center-beam cars allows a 15 mph speed difference…40 mph vs.55 mph when you’re out there. …for mtys. Loaded, each are rigidly end-to-end connected by the mass of the loaded stuff.
A lightly loaded center-beam’s likelyhood of oscillation is minimal. tho’ a lightly loaded bulkhead flat is high: it’s the bulkheads mass versus the longitudinal strength…
In my comment about loading and unloading, I was thinking in terms of working from a loading dock where the forklift or whatever would ride onto the flatcar, but I realize now that the work would likely be performed from the ground at the lumber mill or lumber yard. It makes more sense now.