Phosphate Hoppers - Seaboard vs. ACL

Beginning in 1935, Pullman Standard was contracted to construct a 100 car order of the newly designed P9 class hopper. As shown below, the P9 is a 70 ton covered hopper of reduced height (AAR circular D.V.1150, Exhibit N), rated at 1912 cubic feet and largely considered the catalyst of all modern phosphate hoppers. Seaboard again returned the following year, 1936, for a second order of 100 cars eventually amassing the largest fleet of the such cars. Atlantic Coast Line while following the lead of it’s rival competitor, turned to Bethlehem Steel for a 100 car order in 1938.

Seaboard 58850 was part of a 300 car order constructed in 1950 by Pullman Standard. Sporting Gypsum expanded metal grid running board, Miner powered handbrake and 33 inch one wear steel wrought steel wheels this car is representative of the later built hoppers. Differences among the fleet were minimal when considering the earliest of orders, however, as production and materials advanced welded designs became the standard.

Seaboard’s 70 Ton P9 covered hoppers circa 1935-1962:

Car Number:     Qty:     Builder/Lot:      Built:              Cuft:            Hgt:            Lgth:

58000-58099       100       P-S 5503            2/1935            1912            10’10”            36’6”

58100-58199       100       P-S 5525            7/1936            1912            10’10”            36’6”

58200-58399       200       P-S 5852            6/1947            1912            10’10”            36’6”

58400-58574       175       P-S 5890            12/1947          1912            10’10”            36’6”

58575-58674       100       P-S 5935            1949               1912            10’10”            36’6”

58675-58974       300       P-S 5968            9/1950            1912            10’10”            36’6”

58975-59174       200       P-S 5975            1950               1912            10’10”            36’6”

59175-59274       100       P-S 5987            4/1951            1912            10’10”            36’6”

59275-59474       200       BSC 219            12/1955          1912            10’10”            36’6”

59475-59624       150       ACF 5900          4/1962            1970            10’09”            37’6”

(Notes: P-S, Pullman Standard / BSC, Bethlehem / ACF, American Car and Foundry)

Beginning in 1960, Seaboard moved towards a modern paint scheme resulting in the selection of a gray car body over that of the oxide red as delivered by Pullman Standard. Roman lettering remained, however, as demonstrated above, stenciled road names and numbers became commonplace. The scheme above is a later paint scheme based on the location of the reporting marks to the B end of the car. The early hoppers featured the road name and number over and under scored within the center of the car body.

Noted changes in the Bethlehem Steel Company order included a straight profile side sill, sheet steel roping staples, the inclusion of vibration pads, gussets and a thin side sill directly below the bottom most rivets located along the car body. 

The sill variation began in 1951 with the delivery of SAL series 59175-59274; this design variation continued through the BSC order delivered in 1955 lasting for only two orders. It should be noted the sill slope was revised again in 1962 to resemble that of the early Pullman Standard deliveries, however, by this time cubic capacity, and the car design dimensions were enlarged. 

Seaboard’s fleet of early cars continued in varying service, ranging from sand service, fish meal service, and dedicated phosphate service until the FRA mandated 50 year rule was imposed thus bringing an end to the P9 era.

On July 1st, 1967, Seaboard Air Line and Atlantic Coast Line merged to form Seaboard Coast Line Railroad. The merger streamlined operations, but also eliminated duplicate trackage. A large component of the merger was the Bone Valley region of Florida. As a part of the elimination of duplicate trackage and operations, SCL sought to increase phosphate operations through a new phosphate unloading facility located in Tampa. The terminal was named Rockport Terminal and would increase the tonnage of export phosphate dramatically. The new facility allowed for complete trains to be rotary unloaded and would ultimately replace Port Boca Grande operations.

Beginning in 1969, two years after the Seaboard Coast Line merger, the cars were sent to Bethlehem Steel for heavy repairs and rebuilding. When the cars emerged from Bethlehem, the class was equipped with a full panel rooftop hatch constructed by Stanray. The full length hatch measured 27’7 5/8” in length and included the original 8 smaller roof top hatches which were retained in their original location. The flip top hatch included a hinged type action which allowed the car to be rotated vertically allowing the lading to fall into awaiting pits while in a rotary type dumper. The hinged section commonly called the flip top design marked one of the final design changes to the class.

The following roster denotes the new SCL car numbers, previous car number series, the build date, and the rebuilt date. The rebuild series was not completely inclusive of the series as examples of non-rebuilt cars exist, so one should assume that all cars were rebuilt in kind into "flip tops". The rebuilt series were given the new car classification US12 to follow ACL practice which utilized, "U" to denote phosphate hoppers.

SCL #:                         Previous #:                 Built:        Previous Class:   Rebuilt:           

858000-858199            58000-58199               1935            P9/SAL             1969 (198 cars)

858200-858674            58200-58399               1947            P9/SAL             1969 (466 cars)

                                     58400-58574             1947-48         P9/SAL             1969

                                     58575-58674               1949            P9/SAL             1969

858675-858916            58675-58916               1950            P9/SAL             1969 (200 cars)*

858917-858974            58917-58974               1950            P9/SAL             1969 (200 cars)

858975-859174            58975-59174               1950            P9/SAL             1969 (100 cars)

859175-859274            59175-59274               1951            P9/SAL             1969 (100 cars)

859275-859474            59275-59474               1955            P9/SAL             1969 (200 cars)

859475-859624            59475-59624               1962            P9/SAL             1969 (150 cars)

Note: (*) class renumbered 200000-200199. Not all cars rebuilt to flip top design. Classed by SCL as US12 to provide uniformity to car classification system.

It can be inferred that Seaboard’s 1934 plans took the dry rock industry by storm, however, rival ACL chose to implement the wait and see approach. Beginning in 1938, ACL turned to Greenville with nearly identical plans for such a car. Differing only in choice of trucks, and applicable hardware (brake wheel, running boards, etc…) the U7 is a near clone of the Pullman Standard product. 

ACL quickly augmented their fleet of U5 and U6 hoppers with the likes the of the new U7 quickly realizing the need for a larger, modern hopper. The U7 class, like the P9, featured riveted construction, a unit cast bolster, and the trademark saw tooth design which proved unusually successful. 

ACL’s newest class of U7s, 100 cars in total, became the only class of dry rock hoppers to feature outside bracing. While it was not an as delivered feature, ACL shop forces added the braces to strengthen the 3/16” sides due to corrosion and stresses from loading.

Atlantic Coast Line U-7 covered hoppers:

Car Number:            Qty:           Builder/Lot:         Built:        Cuft:            Hgt:            Lgth:

9200-9299                  100              BSC 85009         1937-38      1970            10’09”          37’6”

9300-9399                  100              BSC 14               12/1940      1970            10’09”          37’6”

9400-9499                  100              BSC 28               12/1941      1970            10’09”          37’6”

9500-9599                  100             ACF 3326            12/1948      1970            10’09”          37’6”

The U7 class totaled 400 cars in total with orders being placed in 1937, 1940, 1941 and 1948. Slightly larger in length and cubic footage while a decrease in overall height, the U7 is nearly identical in many terms when compared to that of the P9. Initially delivered in ACL Indian red or Mulberry red, the U7 class saw differing paint schemes varying from unpainted aluminum or gray Other items of note are Motor wheel journal box lids, Barber S2A stabilized trucks with 2 ½ inch spring travel, Wine door locks and fixtures.

The U7s featured three distinct paint schemes - Indian Red, unpainted Aluminum or gray. The shops of Lakeland, Florida are noted to be one of the major shop points within the Bone Valley region. Capable of heavy or minor repairs, rebuilding cars en mass and equipped with painting facilities, Lakeland or LAKD was a hub of activity during the 1950s. Both SAL and ACL also maintained extensive facilities within Tampa (TPA) and Uceta, Florida. 

                       SCL (nee-ACL) U7/8/10/12 class rebuilds (subclasses included):

SCL #:                   Previous #:            Built:       Previous Class:       Rebuilt:

739200-739499       9200-9299            1938               U7                          N/A (342 cars)*

                                 9300-9399           1940               U7                          N/A

                                 9400-9499           1941               U7                          N/A

739500-739599       9500-9599            1948               U7                          N/A

739600-739999       9600-9999            1951               U8                          1969 (400 cars)

610000-610199       10000-10199        1957               U10                        1969 (200 cars)*

610200-610499       10200-10499        1962               U12                        1969 (300 cars)*            

Note: (*) Class U7 conveyed in part to SCL. No cars rebuilt to flip top design. Classed by SCL as U7, U8, U10, or U12 to provide uniformity to car classification system. Some cars rebuilt with circular hatches in place of square type hatches. A majority of the U7 class were rebuilt into open ballast hoppers used in company service. 

The U7 class were the first cars to be retired of ACL’s fleet due to their service type and longevity. In all, 1450 cars were rebuilt to flip top conversions through 1969, making the P9 type hopper one of the greatest assets to the domestic phosphate industry.