Iron ore travelled on the PRR from the inception of the steel industry. Until the 1940's, when the import of ore made any significant impact, the majority of the ore came from the Misabe range of Minnesota and was shipped via boat on the Great Lakes to eastern ports.
Until the arrival of cars specifically designed for the weight of iron ore -- the G38's and G39's circa 1960 -- almost any class of hopper came into use. H21a's were the most prevalent on the system, followed by GLa's.
Since iron ore was significantly heavier than coal, these hoppers could only manage one "scoop" of ore placed directly over each truck. This is why photos of ore in hopper cars make the cars look like they are largely empty. Filling the car or loading the center of longer cars would cause the car to buckle under the load! (An overhead view of an iron ore-loaded H21a appears on page 70 of Pennsy Steam Years, Volume I.)
Ken McCorry wrote "The H-21 class was the biggest on the PRR until the H-39 came along in 1960. Since the import ore business started in Phila in 1954 my educated guess would be H-21'a , GLa, H-31, H-35. The PRR knew the H-21 fleet was close to the end of it's economic life in the early 50's. They built or purchased the H-35 in 1956 as a possible replacement for the H-21 fleet. The H-36 and H-37 class were also built as a possible replacement. While most railroads would build a few cars for a test the PRR did it in a big way buying 1000-1500 of some of the pre H-39 classes. By the end of the 50's the 70 ton car was the norm and the H-39 became the replacement for the H-21. The ore business also showed the weakness of hopper doors keeping ore inside the car so thats one of the reasons the G-38's were built. When pellets became the norm the steam lance holes in the 38's would leak a steady stream of pellets along the right of way. The G-38 also cubed out with pellets before it weighed out therefore the G-39 class.
Ben Hom adds "Ken's guess is an excellent one, though the numbers of Class H31 (704 cars in 1953) and H35 (zero cars in 1954 - 2000 cars built in 1956) cars are far, far fewer than the other two classes (H21a 32,258, GLa 25,610 in 1955). Film shot by Clarence Weaver of the Shamokin Branch ore train in 1951-1952 show a predominance of Class H21a and GLa hoppers with a few foreign road hoppers appearing here and there (NYC, B&O, C&O). In fact, eastern roads that had ore traffic chose to use hoppers instead of purpose built ore cars until the 1960s, when they purchased specialized ore cars. In fact, the Bessemer and Lake Erie rated their offset triple hoppers (modeled accurately by the Ulrich offset triple in HO) at 90 tons, equipping their cars with heavy duty trucks with outside clasp brakes and using them in both coal and ore service. "
Dave Hopson notes "The Sept. 1962 of issue Trains magazine has a great article on PRR's ore traffic. It's required reading for the PRR fan."
According to the May 1954 issue of The Pennsy, "Iron ore complements coal as a big producer of freight tonnage and revenues for the PRR. Coal is the chief commodity carried in hoppers to the ports on the Great Lakes and te Atlantic where the Railroad has huge handling facilities for both commodities. There the same cars are loaded with ore on return trips to steel mills in New York, Pennsylvania, New Jersey, Maryland, West Virginia, Ohio, Indiana and Illinois. Iron ore furnished 21,740,507 tons of traffic -- 10.5% of total freight tonnage -- or 4.33% of total freight revenue."
The video, The Ore Train, from Penn Valley Pictures, is the defacto reference for domestic ore train traffic. It follows an ore train from the docks on Lake Erie to Northumberland -- a one locomotive, level route -- and then on to Mt. Carmel for handoff to the Lehigh Valley railroad. This last leg is a 27-mile jaunt up a steep grade. The ore trains typically had two I1 class locomotives at head and two more I1 class locomotives pushing.
I noted in the video two distinct colors of loads -- a washed out grey vs. red. Ken McCorry comments "I just got done watching the Ore Train video twice and while watching was talking with a good friend Jim Kerner who is an expert on the Bethlehem, Pa., plant of Bethlehem Steel. The cars filled with what looks like a light gray stone are probably dolomite limestone. This was lighter than ore but heavier than coal. The cars are too full to be carrying iron ore. The gons filled to a heap and the full hoppers are probably bituminous coal as are the hoppers at the back of some of the trains. The power plant at the Betlehem plant burned bituminous which the Lehigh Valley and Reading could not supply. According to Jim, most came from the PRR from the Bethlehem Steel mines north of Cresson on the Cambria & Indiana. You'll notice some of the hoppers in the trains were C&I cars. Some of the boxcars in the train are probably interchange with the LV but also could contain foundry sand which the Bethlehem plant used in large quantities. It had to be transported in a closed container to prevent contamination. Boxcars were the types used before covered hoppers became the norm. While some of the S-390 ore trains were unit trains of all ore-filled hoppers some were also mixed freights with other materials bound for the Bethlehem plant. Hard to get exact answers 50 some years after the fact but these are pretty good educated type answers."
According to the June 1954 issue of The Pennsy, "The Pennsylvania, which serves America's largest steel centers, has been keenly alert to the constant increases in iron ore imports: 2.5 million tons in 1940; 11 million in 1953; 20 million expected in 1955."
"The reson for this development is the gradual depletion of the high-grade ores in the Mesaabi range of Minnesota, simultaneous with the great explosion in steel production. There is plenty of Mesabi ore, but much of it is of lower grades that would take more work and cost more money to process. Furthermore, America's steel companies don't want to exhaust the Mesabi range completely; they want a domestic reserve in case of international emergency."
"Ore fields now being developed in Brazil are believed to be the largest in the world. In Venezuela, fields leased by American companies have at least one billion 300 million tons of high-grade ore. American interests have a proven 400 million tons in Labrador, and believe there is at least 600 million tons more. Other sources under development are in Liberia, on the west coast of Africa; Cuba, chile, and the Middle East. In addition, Norway and Sweden have long been suppliers of ore from American ships."
As a result, the PRR began construction of an 850 foot ore unloading pier in Philadelphia in 1951. It opened on March 19, 1954. It "can work two ships at a time, unloading 2,800 tons -- about 43 car loads -- per hour."
"The pier's location, close to the PRR's Greenwich coal dumping pier, contributes to ideal operation. Previously, coal cars, after delivering their loads to Greenwich Yard, returned to the mines empty. Now on the return trip they'll carry payloads of ore to steel mills, which are mostly located near coal mine territory."
The September 1954 issue of The Pennsy has an article on the dedication ceremony for the new ore pier. Though 31 ships had already used the pier, the S.S. Hawaiian docked for the festivities with a load of ore from Quebec-Labrador. "...by the next day its 20,000 ton cargo had been distributed into 299 hopper cars bound in four solid trains for mills in Youngstown, Ohio, and weirton and East Steubenville, West Virginia."
Bob Zoeller writes "Further to the cars that carried the ore, there is a photo on page 41 of the Horseshoe Curve booklet put out by Bob Reid (Pennsy Journal) of two J's pulling a Westbound "ore" train up the curve in "July, 1954", with two J's pushing, per the legend. The reason I put the date in parentheses is that while the second and fourth cars in the train appear to be H21 or H25 (hard to tell from photo), the first and third cars look suspiciously like H35 triple hoppers (again hard to tell from photos). Since latter were ordered in November 1955, according to John Teichmoeller's book, this photo may be later."
The April 1957 issue of Trains magazine has a graph showing all traffic on The Mountain (between SLOPE and Conpitt Junction) at midnight on September 2, 1956. The following ore trains are shown:
- GH Ore, westbound on track 4, approaching SG, led by 6155 and 6456 (both J1's), 56 loads, 0 empties, 5,400 tons
- WBJ Ore, westbound on track 4, approaching C, led by 9618A, 9620B, and 9622B (all FA-2's), 80 loads, 1 empty, 8,000 tons
- Ore Extra, westbound on track 3, approaching UN, led by 8809 and 8810 (both H16-44's), 36 loads, 1 empty, 3,700 tons, 5817 pushing (DR 12-8-30 "Centipede")
- GH Ore Extra, westbound on track 3, approaching MG, led by 9490A (CF16A "C Liner"), 9476B (B ERIE), 9453B (CF16B "C Liner"), and 9473A (A ERIE), 55 loads, 0 empties, 5,500 tons, 5814 pushing (DR 12-8-30 "Centipede")
Al Buchan writes "The smaller two pocket (AAR HM) hoppers were used in this service also. I have photos of 10-06 blt class GLA hoppers in new Plain Keystone scheme paint ca. 04-59 stenciled -
P.R.R. PHLA. PA
FOR ORE LOADING
Dave Hopson writes "I have a photo of two M1s leaving Enola with a ore drag in 1954. The hoppers are the "GLa" class. It's a "looking down" shot from the Iron Bridge. One bucket full over each truck. Also seen photos of mid-1950s PRR ore trains with Duluth, Missabe & Iron Range ore cars. I'm not sure if PRR was using Bessemer & Lake Erie cars in the mid 1950s. But they did use them for ore service."
Bob Netzloff writes "There are two chemical species which are 'iron ore', hematite which is red ('hema-' comes from the Greek word for 'blood') and magnetite which is 'dark gray with a metallic lustre' (and is magnetic, hence the name). I'm sure the 'metallic lustre' part applies to the pure compound, not necessarily to magnetite ores as found in nature. So yes, there could easily be ores which were gray in color. If I recall correctly, taconite is a rock which contains magnetite crystals scattered within a hard rock matrix. The processing grinds the rock to a powder, uses magnets to pull the magnetite particles out of the dust. That is combined with powdered limestone, moistened, rolled into pellets, the pellets sintered. The limestone apparently helps bind the pellets and reduces the quantity of limestone needed in the furnace burden. Maybe pellets make additional limestone unnecessary. Don't know, but it would save some handling in the stock yard if so. You say 'Hey Bob. You say the pellets are magnetite, and you say that magnetite is gray. But the pellets I see are dark red.' I say that if you take a few pellets home and whack them with a hammer, the broken surfaces will be gray with specks of metallic lustre. The red is just on the outer surface. Iron, when oxidized, will combine with oxygen to form FeO, ferrous oxide. But that can easily oxidize to Fe2O3, ferric oxide. The latter is the compound in hematite. Magnetite is a sort of betwixt and between compound. Think of Fe3O4 as FeO.Fe2O3, that is, one molecule of ferrous oxide combined with one of ferric oxide. Allow it to oxidize (you can't really stop it from oxidizing, not on this planet) and you end up with 2 hematite molecules for each magnetite you started with. Hence the red color of the pellets, but only on the surface, as oxygen doesn't penetrate into the pellets. And it just occurred to me: Maybe some early benefication method, rather than pelletizing, sintered the magnetite from taconite into clinker. Maybe that's what you saw in the cars."
Norm Bell writes "Having spent the bulk of my career in the steel industry since 1968 I do have some personal contact with iron ore and Taconite pellets. I have also visited Taconite mines and benefication plants. All the raw iron ore I ever saw used in steel mills was light orange red and very similar in color to Floquil rust. The problem with iron ore even when it was available to use directly is the amount of slag it generates. There was also no attempt to crush it or in any way keep the size of the ore the same. Lone Star Steel in NE Texas was built in WW2 by the government due to the iron bearing rock in that area and the need for steel. It didn't come online until the war was over but even into the 80's they basically shoveled the raw ore into the furnace and drained the slag off three times before tapping the furnace and that is the most extreme example I have ever run in to. Today's steel making requires a very consistent feed and mix of raw materials due to quality requirements. The iron ore source today is Hamatite because it can be magnetically separated after crushing to a fine powder. It has a dark maroon gray color and is about 80% iron. After crushing it is rolled into balls and out through a short rotary kiln to put a skin ion the pellets before being roasted at 1800 d. F. on a belt furnace to thoroughly harden the pellets. In the 80's great effort was undertaken to add the limestone into the pellets at the pellet plant to get greater contact with the iron in the blast furnace. To the best of my knowledge this was unsuccesful because the limestone changed the pellets from acidic to basic and none of the high temperature alloys required can handle a basic environment at temperture. Pellets are surprisingly heavy. 2 or 3 weigh about a pound in my estimation and are about 3/4" accross each. There isn't a furnace in the world today that can compete for high quality applications like strip appliance and car steel without using pellets because of quality and metalurgical reasons. USS Fairless used to get it's ore from Venezuela and is at the limit for ocean going ships on the Delaware River. It was cheaper to bring the ore from South America than to bring it from Minnesota at that time (at least that was what I was told there). The bottom line is that all ores are not equal and the weight is a direct function of the iron content. The ore used in NE Texas is quite light and pellets are the heaviest. To change the topic a tad, coke is so light it will float on water most of the time."
Bob Zoeller writes "The switch to hematite as the primary type of ore came in the Korean war due to the demand drying up other natural ores. The source I found said that pelletizing came into play in the 60's and 70's. I worked for a big player in pelletizing plants, Allis-Chalmers, though I did not work in that group, and in addition to the Iron Range, they did a lot near the Artic Circle in Sweden, so imports from that area could certainly be pellets."
Jamie Bothwell, who claims geologic training, concurs with Bob Netzloff's statement "So if I had to say, I'd say that hematite is probably more common that magnetite everywhere."
As for modeling ore loads, Bob Netzlof writes "I'd make them some shade of red oxide, because everybody knows that iron ore is red. The shade of red could be as dark as what Grumbacher calls Mars Violet, as bright as Venetian Red or Indian Red. I would make all the ore in one train the same shade of red. As I understand it, the ore suppliers took pains to blend ore at or near the mine(s) so that it had a constant iron content throughout a shipment and perhaps even over multiple shipments. (By shipment, I meant a boatload, which I think would be several trainloads.) While variety is often nice, the steel mill's furnace superintendent would become unhappy were he to receive 20 cars of this analysis, 15 cars of that, 19 cars of something else, and so on."
For HO modelers, both Dave Hopson and Ken McCorry recommend Woodland Scenics ore, which is available in two grades.
The wonderful cast of the "PRR-talk" list, with special thanks to Ben Hom, Dave Hopson, Ken McCorry, Bob Zoeller.
The Pennsy, various issues, as noted.
The Ore Train (video), Penn Valley Pictures.
Trains magazine, various issues, as noted.