What is the difference between a Center flow covered hopper and a plain covered hopper?
Guy
Modeling CNR in the 50's
A center flow hopper has a single central line of outlets at the bottom of the car. When they were first introduced, pretty much all other covered hoppers had them in TWO lines of outlets at the bottom. This was because there was a center sill through the middle of the car, and the outlets thus had to be on either side. The center flow doesn't have a center sill--it uses the car body instead.
ACF introduced them in the early '60's, I believe. And they called them "Center-Flo" and/or "Center Flow". ACF also used a roundish car body. Other manufacturers decided they liked the idea, but most or all of them used a car shaped like "regular" covered hoppers: flat sides with vertical ribs.
So, the "regular" ones may or may not be Center flow, depending on your feelings and/or your capitalization. ACF perhaps has something to say about it, also.
Here's a photo of one of the early ACF cars. Notice that they were quite a bit more rounded than the later cars:
Ed
Thank you for the detailed info.
As mentioned above, the ACF Center Flow cars have no center sill. ACF had extensive plate steel rolling experience(tank cars) and were able to tool up for this type of construction. ACF built scads of 4600 & 4650 cubic foot Center Flows for grain service.
The other major builder of grain hoppers was Pullman-Standard. They employed sheel steel with channel ribs to provide strength to the sides, and a steel center sill. Early cement hoppers designs(like the PS-2) had discharge hatches on either side of the center sill. Starting with the PS-2 4427CD(4427 cubic ft capacity, Center Discharge) a large discharge hatch was employed, but still with the center sill running through the discharge outlet path.
The ACF Center Flows are now getting pretty old and have been replaced by newer designs. Also, service bulletins warning about 'pull apart' issues when the cars have been in fertilizer service have been published. I am not sure if the ACF style cars are even built anymore. The PS car design was sold to Trinity, and the current Trinity(5161 cubic feet) design has rounded sides like the old Center Flows, but appears to be a center sill design(and built in Mexico).
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
I was assuming that the P-S cars didn't have center sills. But, looking at the various design elements, it's obvious they have to--there's no way transfer forces from the couplers up into the car sides.
I'm lucky enough to have a copy of Edward Kaminski's "American Car & Foundry 1899-1999". On page 263, there's a photo of the first Center Flow (spelled that way on the car side) car. It was SHPX 60000, and was a 3950 cuft car. And was built in June of 1961.
The GN car in the photo was a 3960 cuft car.
jrbernierThe PS car design was sold to Trinity
Actually Pullman-Standard's entire operation went to Trinity around 1980.
Although similar clones of the Pullman-Standard 4750cft hopper were also built by several other builders including Trinity, Ingalls Shipbuilding, Berwick and Richmond Tank Car. Plus other cars built from P-S kits/components by North American, US Railway Equipment/Evans etc. Maybe one or two other obscure builders.
Also, technically *every* covered hopper ever built by Pullman-Standard was a PS-2. It's not a particular design or model. Similarly every P-S built boxcar is a PS-1, not just the 1940s-50s 40' and 50' smooth side cars that modelers typically mean when they use the 'PS-1' term.
Chris van der Heide
My Algoma Central Railway Modeling Blog
jrbernier Starting with the PS-2 4427CD(4427 cubic ft capacity, Center Discharge) a large discharge hatch was employed, but still with the center sill running through the discharge outlet path.
The 4427 got a lot of publicity among model railroaders, but the "center discharge" design started with earlier cars. Pullman built a few cars with a single, center discharge arrangement as early as the mid-1950s (UP rostered a few), although I don't think they were marketed as "PS-2CD" at the time.
Union Pacific took delivery of the PS 3572 cars starting in 1962 http://www.rr-fallenflags.org/up/up19724k.jpg . These still looked like bigger versions of older Pullman designs, but with the new outlet design. At about the same time, PS introduced a 4000 cu ft car that looks much like a smaller 4427. I know the PS 4000 was marketed as a PS-2CD, and I'm pretty sure the original stenciling on UP's 3572s featured that lettering as well. The 4427 came later, in 1964.
This article has some good information on the 1960s transition period in covered hopper design http://trainlife.com/articles/830/car-spotters-guide-no-18-pullman-4427-covered-hoppers .
Rob Spangler
7j43k I was assuming that the P-S cars didn't have center sills. But, looking at the various design elements, it's obvious they have to--there's no way transfer forces from the couplers up into the car sides. Ed
Pullman Standard did have one class of Covered Hoppers without Center Sills. The PS4785's. They had reinforced ends and the forces were channeled along the sides of the car for strength. Major users of this car were the NYC, PC, MILW, and SP/SSW. Rail Yard Models made a resin kit for this car.
Rick J
Rule 1: This is my railroad.
Rule 2: I make the rules.
Rule 3: Illuminating discussion of prototype history, equipment and operating practices is always welcome, but in the event of visitor-perceived anacronisms, detail descrepancies or operating errors, consult RULE 1!
wp8thsub This article has some good information on the 1960s transition period in covered hopper design http://trainlife.com/articles/830/car-spotters-guide-no-18-pullman-4427-covered-hoppers .
That UP covered hopper is a beefy and interesting car. Would be great HO model!
Is trainlife fixed? In recent months, all the magazine articles came up with red x's although I haven't tried for some time. When I follow the link you gave, all the boxes are blank. Although it's not a good test at work because some photo hosts are blocked.
Rio Grande. The Action Road - Focus 1977-1983
riogrande5761Is trainlife fixed?
Not that I'm aware of. Article photos don't show up for me either.
jrbernier The ACF Center Flows are now getting pretty old and have been replaced by newer designs. Also, service bulletins warning about 'pull apart' issues when the cars have been in fertilizer service have been published. I am not sure if the ACF style cars are even built anymore.
The ACF Center Flows are now getting pretty old and have been replaced by newer designs. Also, service bulletins warning about 'pull apart' issues when the cars have been in fertilizer service have been published. I am not sure if the ACF style cars are even built anymore.
Once some of the ACF patents expired I believe Trinity did build some cars that looked very much like Center Flows.
American Railcar Industries continued ACF's rail car production for a number of years. Whether ARI is making genuine Center Flows now I do not know, but they did for several years.
Dave Nelson
wp8thsub riogrande5761 Is trainlife fixed? Not that I'm aware of. Article photos don't show up for me either.
riogrande5761 Is trainlife fixed?
Works for me:
Go to site.
Click on "magazines"
Click on drop-down "publication title"
Click on drop-down "publication year"
Click on "view full content" for desired month.
I'm a-lookin' at it right now. On the other screen.
7j43kWorks for me: ...I'm a-lookin' at it right now.
Navigating to the above article as you described (starting on page 41 of the February, 1994 Railmodel Journal), just gives me text (and I have to click on "show page text" to see that) - no photos. I've tried on two separate machines using Chrome and IE, and have nothing blocking images. The issue displays properly only through page 19.
Yeah, I see.
I checked another issue, and it went only to page 20.
Definitely disappointing. Unless you're wanting something on page 12.
7j43kI checked another issue, and it went only to page 20. Definitely disappointing.
Dang, I was hoping you had a solution.