I haven’t seen any modern Cylindrical hoppers from US roadnames. Why is this? I know several US roads had them in the 60s-70s but why didn’t they catch on?
Possibly because a rectangular car of the same dimensions carries more due to a larger volume.
My first thought is that there is a difference in the core product being hauled, but I don’t know the numbers on that and it may not be a factor.
My second though is that the lesser capacity may be by design, so better to deal with lightly laid track.
Fabrication cost(and the machinery to ‘roll’ the panels that make the ‘tube’ come into play. In the US, ACF started with a round ‘Center Flow’ design, but quickly went to a ‘tear drop’ design. The round car body does add strength, but at the cost of heavier gauge meta(and additional ‘tare’ weight). ACF’s design was a balance of materials cost.
Pullman -Standard designs like the PS-2 4740CD(the Athearn model) went the ‘box’ route using lighter gauge steel, but the need for a multitude of vertical ribs to ‘stiffen’ the car body. As labor costs increase, the cost of manufacturing increases. The current Trinity 5161 covered hopper is the ‘hot’ covered hopper design - sort of ‘tear drop’ but with rather flat sides.
One of the advantages of a rounded roof design vs the flat or shallow pitch roof is that as product is loaded via the trough hatches on the roof, it naturally ‘flows’ to fill in the upper side areas. The flat roof designs did not allow the hopper to be filled to the full cubic capacity. P-S did change their design with the PS-2 4750CD covered hopper. It had a shallow arched roof, with a ‘cupola’ under the loading troughs, allowing a better ‘fill’ of the car.
As you mentioned, the Canadian designed/built cars did appear a a few railroads in the US, but I suspect the purchase cost was too high. Back in the 70’s, Canadian railroads would have paid a premium with the import duties on US built covered hoppers. I am not sure where ‘Free Trade’ currently is, but I suspect it is still cheaper to buy Canadian when there is car builder still in Canada.
Jim
Most of the hoppers you refer to were made by Hawker Siddeley, (former Avro Avaition) a Canadian company that made several types of railcars including the Go Transit Bi Level car.
Avro made several different types of aircraft, and turbine jet engines under contract for GE.
If I remember correctly, Hawker Siddeley was liquidated in the late 70s early 80s.
The hoppers were made in Canada exclusively for the Canadian Wheat Board.
Its not so much that they were succesful as that they were what the wheat board ordered.
A similar shaped hopper, somewhat teardrop shaped was built by AFC if I remember correctly, in an attempt to do away with the wasted space in the upper corners, but the concept never caught on.
Carl Shaver will have more detailed info.
In the early 1960s, there were three companies making cylindrical covered hoppers: American Car and Foundry (ACF) in the U.S., and National Steel Car and Hawker-Siddeley in Canada. Marine Industries made similar cars, too, but I believe those had curved sides and a flatter roof.
By the mid-1960s, ACF had come up with its hi-cube (tear-drop) design for its Center Flow cars (the earlier ones were also referred to as Center Flow cars by ACF), which could haul more volume in the same length. I don’t believe ACF had any Canadian licensees, so their patented design was all that was available in the U.S. for curved-side cars. Canada was stuck with cylindrical cars as the most advantageous when it came to fitting the most volume into a gicven length.
Apparently the Center Flow patents expired sometime in the 1980s, because that’s when companies like Thrall in the U.S. and NSC in Canada came up with designs that looked a lot like Center Flow cars. Trenton Works (successor to Hawker-Siddeley’s freight car production) had one that looked a lot like a Center Flow…so much that I referred to it as a tinplate version…something Lionel would come up with if it were designing a Center Flow for the toy-train market. Trinity Industries came up with a curved-side car, too, in several designs that were far enough removed to be distinctive.
Trenton Works was taken over by the Greenbrier companies, and eventually shut down due to labor problems (apparently). Greenbrier has since come up with its own curved-side design that looks a lot like Trinity’s. National Steel Car still makes curved-side covered hoppers, but the cylindricals are largely a thing of the past. ACF’s
That pretty much hits the nail on the head. And there was politics involved over and above the Canadian Wheat Board being a government entity. If Hawker-Siddeley had been located anywhere else in Canada, it is unlikely they would have ever been given the order. It was mostly a make work project for coal miners who were unemployed after the domestic coal market had collapsed in the 1960’s.
It should also be noted that it seemed like the cars were successful because there were just over 13,000 of them built. As I understand it, this was the largest group of one type of car owned by a single owner since the PRR stopped owning boxcars.
Bruce
There were also Canadian cylindrical iron ore cars.
All three Canadian builders were given a good slice of the work. The government liked to spread the wealth around if you will. To build these cars Hawker Siddeley used the former Eastern Car Company plant in Trenton NS (later Lavalin, later Trenton Works) but they also built a batch at their passenger car plant in Thunder Bay Ontario. I have seen hoppers so marked. This plant, now owned by Bombardier, still makes passenger and transit cars. In the past they made aircraft as mentioned but they also built army trucks, CanCar truck trailers and CanCar or Tree Farmer log skidders.
By about 1982 there was a glut and demand for rail cars slowed to a trickle and for Marine Industries these government hoppers were the only cars produced by them after that time. A number of these contracts kept them going until 1986 when they closed. In addition to freight cars they built and repaired ships, hence their name.
NSC built a small batch of these cars in 1994, long after the last group which dated from 1985-1986.
To see a complete roster of these cars as built, go here…
http://www.nakina.net/private/cnwx.html
Chris “BIGDoer”
Chris and Connie: Off the beaten path.
Hiking - Adventure - History - Exploration
And one of those companies made some custom articulated hoppers with 3 trucks. I have only seen 1 or 2 pictures of them.
To add a little, and answer this question. In the late 1950 and 1960’s I had a number of acquaintances who worked for the Frisco at Memphis, The big new (then) Tennessee Yard at Capleville,Tn. was under construction. The Aluminum Cylindrical Hoppers were starting to show up on trains in that area. Also they were gaining a troublesome reputation for spontaneous derailing.(?)
Back then there was a lot of 'stick rail used on many routes. The length of the rail, coupled with the joints; created along with the length of the Hopper Cars, a combined motion within the train (apparently empty or loaded?) to create within the train a sort of harmonic vibration. The cars would rock from side to side, and at a speed between 30mph and 40 mph (?) they would literally roll to the side and rock right off their trucks.
Needless to say holding trains with a large number of these types of cars in their consists down to such a low speed created a lot of issues on the railroads.
I think that the resolution came with a chane in the length of the cars along with a reconfiguration of the construction used in them. Additionally, the increased use of CWR also helped to improve the riding qualities of all the rolling stock…
Possibly, I am mistaken on this, but that was the story I recall was related to the Cylindrical Hopper Cars back then. Maybe Carl or Houston Ed or one of the
Sam,
I remember reading the same thing about the covered hopper cars, with truck centers close to 39’ apart there was a huge augment to the rocking motion. The work-around was to limit train speed to 10 MPH on track that was otherwise good for 40 MPH.
- Erik
The ACF Center Flows did not arrive until the early 60’s, and they were steel construction. The problem with ‘rock & roll’ was due to stick rail track joints at 39’. The wheel base of these new longer cars was around 40’. With low rail joints, the rock & roll would be really bad between 13 & 17 mph(IIRC) and we were required to accelerate though that range to reduce the problem. Even with CWR, there sometimes was .memory’ in the roadbed and there would be sags every 39’. Undercutting the roadbed & new ballast tamping usually got rid of the memory.
Some of the older Center Flows have ‘pulled apart’ in past years as corrosion and fractured welds have taken their toll.
Jim