In the early 1960s ACF introduced their roundish cylindrical hoppers, which differed greatly from ribbed sided hoppers of the era. These cars appear to have been made in 3-bay and 6-bay variations. These cylindrical hoppers were superceded on ACF’s production line by the Centerflow in 1964, a revolutionary design that influenced later covered hopper types. In the late 60s or early 70s Canada came out with 4-bay covered hoppers that appear to be derived from ACF’s pre-Centerflow cylindricals, used by CN, CP and various Canadian shippers. Why did the builder in Canada base their deigns off the older cylindrical and not ACF’s newer Centerflow? Perhaps ACF didn’t allow it because they believed their centerflow design was unique and threatened legal action against other builders copying it, or maybe Canada liked the cylindrical design better? And of course Canada roads appeared to prefer Canadian-built rolling stock.
If I remember correctly, ACF Industries had a patent on the Center-flow design. Unfortunately, I cannot find anything for ACF before 1971 and nothing at all for American Car and Foundry at the US PTO’s website. Trains had an article about Center-flows in the February 2000 issue, that may have some relevant information in it.
By the way, it seems like the article said that ACF’s cylindrical hoppers were the original Center-flow hoppers.
There’s a book on the history of the Center Flow covered hopper by Eric A. Neubauer that answers a lot of the questions. The second edition is on CD ROM. Eric is amazingly thorough (and my name’s in it as one of his resources).
The prototype Canadian cars made their appearance before ACF came up with its “tear-drop” Center Flow design, which gives more cubic capacity in a given length. Now just about everybody builds covered hoppers with smooth, curving sides; I don’t know if any ribbed-side cars have been built in the last five years or more.
In the 2000 Trains article it mentions that the ACF Center Flow name and design started with the Cylindrical Hoppers built in 1963.
Has anybody seen builder photos of the ACF Center Flow Cylindrical Hoppers in the Detroit & Toldeo ShoreLine scheme when they were new?
Canadian National and Canadian Pacific had Canadian built 1960’s cylindrical type hoppers that were closer to teardrop shaped compared to the 1970’s and 1980’s era cars that were truly Cylindrical. I wonder who built them.
A ‘box’ shaped hopper of the same length should hold more product. The problem is that most of the original PS covered hoppers had the steel center sill running through the bottom of the hopper. This resulted in pairs of dischage chutes on either side of the center sill, and restricted the flow of product when emptying the car. PS later offered a modified design(the suffix CD for Center Discharge).
The ACF design has large side members to carry the load and the discharge chutes have no center sill to restrict the flow of material. Also, there is less area for material to ‘collect’ and have to be cleaned out. Trinity Industries currently has purchassed the designs of several former rail car manufacturers and builds a variaty of different size convered hoppers. Most of these are based on the ACF Centerflow design.
When Trinity Industries was offering both ribbed-side and curved-side (not cylindrical, by any means) covered hoppers, it was the curved-side version (5161 cubic feet) that had more capacity with identical dimensions. The ribbed-side car (5127 cubic feet) had the small disadvantage of needing the ribs on the outside of the sides, which gave the curved-side car a couple of inches of extra width to work with.
I haven’t seen a ribbed-side covered hopper car built in this century.
I think that if you look closely you will see that most hoppers nowadays will have these curved sides on them, It adds capacity, w/o sacrificing length. Some aren’t as drastic of a bulge, or “curve” as the Canadian designs.
I always like to see the “Canadian” cars that are in the Rainbow scheme.
The Canadian Government bought a huge number of cylindrical hoppers. They were made at the Trenton Works in Nova Scotia, I think. Maybe elsewhere, too. They were ‘assigned’ to the CP and CN, but I don’t have any idea on the percentage to each. The Government of Alberta, and Saskatchewan, had a bunch, too. I heard that they have been recently sold to the railroads involved. The BNSF has been buying a large number from Trinity Industries, made in Texas and Mexico. 110-car unit-trains of these cars are common and the farmers still whine about the cost of shipping their grain (from their 6-month winter homes in Arizona, of course). Guess I gotta ‘Google’ some stuff!
I appreciate all the info on this thread everyone. I’ve been looking around for info on the history of this particular car type to see if it would fit into my era.
Does anyone else know specifically when the famous Canadian grain hoppers started coming out in their colorful schemes? I’m also curious about other Canadian roads that may have rostered cylindrical hoppers. Does anyone know if the Pacific Great Eastern/British Columbia Railway ever had any?
Also… does anyone know if there are any really good reference pages around online that detail different types and models of freight cars and what eras they were built in?
I believe all of the Canadian Wheat Board hoppers were built during the 1970s by Marine Industries and Hawker Siddeley. The Alberta and Saskatchewan hoppers, as well as the potash hoppers for PCS and Canpotex, came later from National Steel Car.
I’m not sure if these 2 sites are as detailed as you might want in terms of dimensions, etc., but they do have lots of photos and might be a good starting point, in addition to the one that Dale posted.
RR Picture Archives.Net - Rolling Stock Category: Covered Hopper - Index Page, at:
They were built from the late 1970s into the early 1980s. The 1970s cars were the brown Canadian Wheat Board cars. The bright red Canada scheme was introduced around 1981. The Alberta and Saskatchewan cars were also built in the early 1980s.
These cars were built by NSC, Hawker-Siddeley and Marine Industries.
Check this site for detailed roster information on Canadian freight cars including the government grain cars and other privately operated fleets:
