Hoppers are a very common type of freight car and come in a variety of shapes, sizes and purposes. They can be open or covered. They can be made of steel or aluminum.

Open hoppers carry heavy bulk commodities which can be exposed to the weather. For unloading, the commodity will flow or pour through the hopper discharge chutes into underground pits.

Covered hoppers are designed to handle dry bulk commodities which require absolute protection against the weather. They have a permanent roof with hatches to facilitate loading. A hopper's interiors is shaped into bays (hoppers) with discharge doors which allow unloading from the bottom either by gravity, pneumatic (suction) or airslide functions. Airslide hoppers force air between the fabric lining and slope sheets of the car, loosening the product so that it flows easily through the outlets.

The ARR uses open hoppers to haul mainly coal, gravel and ballast while covered hoppers are mainly for cement, chemicals and grain. Here is an example of a hopper utilization plan.

Click here for the hopper roster.  Also check to see if they have any leased.

Randy Thompson also has a PDF chocked full of scans from the ex-BC Rail pressure hoppers.

As you know, I work on the "North-end" (Healy/Fairbanks). Although I have taken quite a few Hyundai (Seward) trains from Healy to Anchorage, I have never gone south of Anchorage with one. The only thing that comes to mind is "Yellow-Bands". The Seward Coal or "Hyundai" Trains and many of our gravel trains are made up largely of "TNM" series, 100 ton hoppers. If you don't know already, "TNM" series coal hoppers have one end painted yellow. This is because the knuckle on that end spins 360 degrees on a rounded drawbar. Down South (in your neck of the woods), many coal and gravel trains are unloaded 3 to 5 cars at a time by a section of track equipped with grabbers that physically holds the cars on a section of track and flips the TNM cars upside down while they are still attached to the train. This is a much quicker (and a more expensive) way to dump a train. We lease those hoppers for our coal and gravel operation but we don't have any "flipping" tracks up here, we simply use the doors in the bottom of them to dump them.

Anyway, TNM hoppers cannot be coupled with the yellow ends together because of the rounded drawbar. If you hooked them up with the yellow ends together, the knuckles could rotate to a horizontal position, causing the train to come apart in a curve. We try to keep all of the yellow bands facing one direction, either north or south to help keep this from happing when making trains. If they weren't, making up a train is aggravated because every time you came across yellow ends facing opposite directions, you have to either loop or wye the cars, or find a "non-TNM" series hopper to stick between them. If cars are ever looped or wyed during the unloading operation, then they would have to be looped or wyed again to get them in the same orientation for arrival in the Anchorage yard in case the train was to be broken up to build other gravel or coal trains.

Brett Brown
Alaska Railroad locomotive engineer
4/28/02

On 4/17/04 Jason Kuehn adds, "The Alaska Railroad leased a string of these - 60 cars I think - from RailTex back before RailTex was a shortline operating company and they were mostly into car leasing particularly for the aggregates business.

These are Ortner (now Trinity Industries) rapid discharge cars designed primarily for handling aggregates. They are the best car on the market for this type of commodity. The 60 degree slopes sheets provide for a fast clean unloading of commodities like sand and gravel without using a car shaker. Unfortunately the ARR the gravel season only lasts 4-5 months due to the weather.

These cars have a cubic capacity of only about 2,000 cubic feet (plus or minus 10%). So they only can handle 60-65 tons of coal when used in coal service in the winter as much of the ARR fleet started doing when the Seward coal move started. But they weigh nearly as much as a standard hopper so they are not very efficient cars for coal handling.

You will also notice the long platforms on the ends of the cars and the relatively short car body. This is a major pain for loading in motion like is done with the Usibelli tipple and the current gravel terminals in Anchorage. It is really easy to start the loading early or end late in trying to fill the car as full as possible and spilling material on the end platforms.

So these cars were not well suited to the evolving needs of the ARR for a flexible hopper car fleet. The ABI blue rapid discharge hoppers worked much better for handling coal in the winter and flood loading both coal and stone. I think the ARR had the TRAX cars on lease for three years in the mid-1980's and then returned them, opting for more conventional hopper cars. Being a specialized car designed specifically for stone they had a fairly high lease rate as well.

There are a couple of photos in the Nicholas Deely book of one of these cars in a freight train (probably handling coal) in the winter time.

On 11/16/04 Pat Durand adds, "Some years ago the Alaska Railroad leased a string of Ortner Three Bay Rapid Discharge hoppers. Here are two views showing both ends of the cars. Modelers note: Microtrains has just announced an N scale version Item #125010.

The Alaska Railroad has rostered a variety of hoppers over the years. On the 1931 Equipment Register 12A there is only reference to Coal Cars not hoppers. I believe these were Hart Convertible Gons dedicated to coal service.

On Equipment Register 12G of 1963 there were four different number series of Twin Hoppers. At the Museum of Alaska Transportation and Industry is Hopper 60432 which through the weathered paint shows original number 6043 in white. This car was dedicated to the Alaska Railroad Power Plant in Healy and thus made the short trip from the Suntrana Tipple to the ARR power plant along side the main line in the Healy Yard.

There were only five cars in the series 6041 - 6045 as of 1963 and they were rated at 100000 lbs or 50 ton. The car body is 30'8" long and 10'10" high with internal capacity of 1817 cu ft. Modelers note: Stewart Hobbies Fishbelly 55 ton 6 panel 2 Bay Hopper in HO is a dead ringer for 6043. Accurail also produces a very nice kit for the 2500 Series USRA Twin Hopper that matches this car.

Prepared by Pat Durand

• 5001 - 5030
• 5031 - 5040
• 6001 - 6010
• 6011 - 6030
• 6041 - 6045, 6046 - 6065
• 6066 - 6075, 6076 - 6084