X31 Series Box Car Information for Modelers

Bowser X31A

In the middle of the depression in 1934, the Pennsylvania began a massive car building program in it’s Altoona, PA shops. The round roof design was adopted to achieve the maximum cubic foot capacity loading and still clear tunnel restrictions, and the X31 series became their new and distinctive standard box car. Two basic roofs were adopted - one flush to the sides and the other with a 2” setback at the top of the roof. Cars were both 40‘ in length and came with either single or double doors with 6' and 12’-1-1/2” or 14‘-6” openings respectivly. During one period between March and April 1936, many of these cars were contracted out between builders AC&F, BSC, GATC, GSC and PSC. In 1939 and through 1940, the PRR modied the roofs of 690, 40’ double-door cars with a distinctive extended roof to accommodate jeep shipments. These were designated as X31F and classifed XAR.

X31

• 250 cars ordered Oct 1932 (likely with KD brakes) (59862-60111)
• 500 cars ordered Jan 1934 (60222-60721)
• 500 cars originally to be X31A added to 1934 order (69500-69999)
• Late 1930s- early 1940s
  • 109 cars converted to class X31A
  • 690 cars converted to class X31F

X31A

• 2500 cars ordered Feb 1934 (delivered by August 1934) (67400-69499, 70000- 70399)
  • 500 cars equipped with double doors (69000-69499)
  • Remaining 2000 cars were built with single doors
• 4700 (single door) cars announced Dec 1935 (76400-81099)
  • First cars not built exclusively by PRR
    • 700 built by PRR
    • 1000 built by Pressed Steel Car Co.
    • 800 built by AC&F
    • 700 built by Pullman Standard
    • 600 built by Bethlehem Steel Co.
    • 400 built by General American
    • 250 built by Greenville
    • 250 built by Ralston
• 100 cars converted from X31 (double doors) (81100-81199)
• 9 cars converted from X31 (double doors) (120003-120011)
  
  
• November 1, 1935 - change from transverse to longitudinal reservoir
  • X31A numbers below 76777 should have a transverse reservoir.
  • X31A numbers over 77061 should have a longitudinal reservoir.

X31B

• 1190 cars announced Dec 1935 (61100- 62799)
  • Introduces a new “flush” roof eave.
  • No automobile loaders
• Circa 1959, many were converted to K11 stock cars

X31C

• 810 cars announced Dec 1935 (60800- 61099, 62800-63309)
  • Autoloader equipped
• Circa 1959, many were converted to K11 stock cars

X31D (X31 Rebuild)

• 6 cars converted from X31A briefly, circa 1937 (57703, 57704)
• 3 large roof hatches installed
• Assigned to Armstrong Cork Co., Lancaster, Pa. for top loading of linoleum, etc…
• Appear to have been converted back within about a year

X31F (X31 Rebuild)

• 690 cars converted from X31 circa 1940 (81200-81889)
• “Turtle roof” – roof height increased except end panels
• NOT Designed to haul “Jeeps” – predate the Jeep
• Autoloader equipped
• Some may have been converted from KD equipped cars

X31G

• 1 car converted from X31A, #77742, circa 1958
• Roof hatches installed
• Coal tar loading

Overview of Sub-Classes

Cars on the PRR roster (as listed in the Official Railway Equipment Register (ORER)):

X31A with Single DoorX31B with Double Doors

X31F with Turtle Roof