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F-50-Series flatcar kits (2000-Series) - HO Scale

OwlMtModels is proud to introduce our new F-50-Series Kits made in the U.S.A.!

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Correction to F-50-Series Instructions!

We have found a small mistake in the instructions which may cause some confusion and possibly even consternation with our modeling customers. Please take a moment to see the correction in the image below. (clicking on it will bring up an larger version)

Correction to Page 2 of F-50-series instructions
Note: The centersill notches were in the wrong slots in the deck. This image has the correct placement of the arrows at the left end of the deck. In the original instructions the arrows pointed outside of the molded centersill flanges, when the centersill pieces should be placed towards the centerline of the car of the same molded flanges in the deck.

We are also trying to place additional correction sheets in the instructions, but it is possible that you'll receive a kit which doesn't have one of these correction slips.

New Decals Arrived - March 2022!

The arrivial of the new decals has forced us to change the offerings of our 2002 and 2003 kits going forward. The improved decals have generated the need for us to reduce the square area of decals included in each kit. Thus, we have been forced to drop the "one decal set can make any prototype lettering scheme" set included in every car format. Now you, the customer, has the choice of which railroad and era range to choose from.

  • 1210-Jumbo Set (All RR's, All eras, enough for 3-cars) $14.95/3cars
  • 1210 SP (Rev-B, new March 2022) $4.95/ea
  • 1211 SPMW (Black, post-1958) $4.95/ea
  • 1212 Blackburn Patent Sugarbeet Rack - Decals Only $4.95/ea
  • 1213 F-50-Series Sideboard - Decals Only $4.95/ea
  • 1214 SPMW (White, pre-1958) $4.95/ea
  • 1215 Northwestern Pacific (NWP) $4.95/ea
  • 1216 Pacific Electric (PE) $4.95/ea
  • 1217 Texas Lines (T&NO, LW,GH&SA) $4.95/ea
  • Just a side note, the 1210-Jumbo set is available if you desire to choose from any road/era and letter up to three models. However, we only had about 60 sets of the "Jumbo" produced before we switched to the individual car sets (1210,1214-1217-series with separate "Era" data sheets). So with the extra expense to produce the 1210-Js, when the Jumbos are gone, they're gone.

    Ordering F-50-Series Models

    SP_43745_Sac-B1sml
    Kit 2002 finished as SP 43745, an ex-PE F-50-9 transferred to the SP along with 99 other cars in 1928.

    All kits contain all parts needed to complete the model for running on your HO railroad, including: Trucks, wheels, Kadee #156 couplers, screws, weight, decals, brass castings (stirrup steps, brake wheel, and roping staples) and wire to make the brake rods, grab irons (jig provided), and brake staff. Both AB & K-brakes are included and can be applied to the model to suit whatever era is desired. - Note: In this photo the Underframe plastic sprue is gray plastic, production kits will have this part in the same brown as the sides and detail sprues. The Deck will be in gray plastic as shown.

    New Ordering Menu for 2002

    Please use the prompted RR/Era drop-down choices above the PayPal checkout process to sellect decals to be included in your kit.

    Kit #2002 - F-50-5,-8,-9 w/T-section Trucks

    Correct for 1650 prototype cars, built 1916-1924. White decals options for SP, PE, NWP, T&NO, (GH&SA, LW) and SPMW. A number of these cars were assigned to SPMW service, at least 181 by 1956 in many assignments.

    Kit #2002 - $39.95 Use PayPal options to select upgraded decals (March 2022).

    Buy 2002 F-50-5/8/9 Kits Here for $39.95.

    Kit #2003 - F-50-10,-12 & Retrucked Cars w/U-setion Trucks

    Correct for 950 prototype cars, built 1927-1929 for SP, in three number series. Decal options provided for SP and SPMW. A number of NWP, PE, & T&NO cars of earlier classes (F-50-5/8/9) received U-section truck upgrades after around 1940, which make this kit ideal for modeling those cars as well. A number of these cars were assigned to SPMW service, at least 36 by 1956. Note: OMM 2005 has been retired, if you're looking for SPMW post-1958 black decals, use this button and select "SPMW - (Black-1958+)" in the decal options.

    Kit #2003 - $39.95 Use PayPal options to select upgraded decals (March 2022).

    Buy 2003 F-50-10/12 Kits Here for $39.95.

    Kit #2005 Post-1958 SPMW Gray with Black Lettering - with U-section Trucks

    Correct for F-50-10 & -12 class prototype cars repainted in SPMW light gray after 1958. Totaling at least 36 cars by 1956, many lasting into the 1970s.

    Kit #2005 RETIRED, March 2022. To get this version select Kit #2003, then choose "SPMW Black-1958+) in the decal options (New SKU is #2003-11.

    Decals Only

    OwlMtModels also offers separate decals for sale for your F-50-series kits.

  • 1210-Jumbo Set (All RR's, All eras, enough for 3-cars) $14.95/3cars
  • 1210 SP (Rev-B, new March 2022) $4.95/ea
  • 1211 SPMW (Black, post-1958) $4.95/ea
  • 1212 Blackburn Patent Sugarbeet Rack - Decals Only $4.95/ea
  • 1213 F-50-Series Sideboard - Decals Only $4.95/ea
  • 1214 SPMW (White, pre-1958) $4.95/ea
  • 1215 Northwestern Pacific (NWP) $4.95/ea
  • 1216 Pacific Electric (PE) $4.95/ea
  • 1217 Texas Lines (T&NO, LW,GH&SA) $4.95/ea
  • Choose from above list in the dropdown menus in Square store-front below.

    Buy Decals for F-50-series Kits Here.

    Buy Lumber Load for F-50-series Kits Here.

    Buy Blackburn Beet Rack & F-50-series Combo Kits Here.

    Prototype Design and Service History

    Southern Pacific's earliest flatcars can easily be traced back to the building of the transcontinental railroad in the 1860’s. These wooden cars evolved and grew larger until the first steel framed flatcars were developed in the early 1900’s. E.H. Harriman took over the Southern Pacific (SP) in 1901 and developed the “Common Standard” for structures, engines, and rolling stock for the five railroads he controlled at that time. SP and Union Pacific (UP) designs, along with their subsidiary roads, fell under this standardization plan of the “Associated Lines.” The first Common Standard flatcar was the CS-35-A of 1903. Other early designs included the F-50-1,-2 and -3’s, with the F-50-4 as the last true Harriman “Common Standard” flatcar design.

    After the Supreme Court break-up of the Harriman roads back into their individual identities in 1913, the CS numbering system continued, but the SP and UP settled on a simpler classification system of car type: “F” for flatcars, “50” for 50-ton nominal capacity cars, and then sequential numbering for that weight and car type. So F-50-1 would be the first class of 50-ton flatcars designed in this system. Designs after 1913 for UP and SP diverged, but retained the F-50-type series nomenclature for many years. The SP finally abandoned the naming system around 1965 when they stopped designing most of their own freight cars and bought “off the shelf” designs from other car builders.

    After the 1913 divestiture, SP’s design department improved the F-50-4 class with the F-50-5 in mid-1916. The initial design of the F-50-4’s, with the Bettendorf single I-beam underframe, was found to be inadequate for regular service. Under loads, the underframes failed regularly by fracturing along the section of the I-Beam that was cut and bent to create the “Fishbelly” profile between the trucks. The new production F-50-5 and later designs used a built-up double beam centersill underframe.

    F-50-5,8,9_Roster_Table1
    The last of 50 NWP F-50-5s, NWP 4499, built from Kit #2002 and lettered in a typical 1920s NWP scheme. The car shows last being reweighing in Willits in July 1921. In later years NWP's lettering changed to be more like SP's standard freight lettering to comply with AAR's later recommended reporting mark practices.

    F-50-6 & -7 designs were very different from the previous classes, but the F-50-8 and -9 designs went back to nearly identical designs to that of the F-50-5. Table 1 summarizes the F-50-5, -8 and -9 cars built during this era. The distinguishing feature of all these flatcars was the overhanging deck with wooden blocks and steel angle iron to support the overhang. This feature is often very identifiable in photos, even in 7/8 front views of trains. This OwlMtModels series of kits replicates this deck block feature, unlike any other HO-scale flatcar on the market today.

    Of about 7400 SP and subsidiary railroad flatcars built with this deck design, this OwlMtModels #2002 kit replicates the F-50-5,-8, and -9 designs of 1650 prototype flatcars; the “sister” #2003 kit replicates the later F-50-10 and -12 series of 950 cars (with U-section trucks), and our upcoming #2001 kit represents the 1500 prototype F-50-4 flatcars.

    F-50-5,8,9_Roster_Table1
    (Click Images for Full Size View)


    The SP 38892, an F-50-8 class car made with Kit #2002 was one of the last group of surviving cars from PE 3614-3763 group (150 cars) which were transferred to the SP in 1951. The PE's cars were absorbed into the SP numbering system in three groups starting in 1928 along with the two CP cars. The second group joined the SP ranks in 1940, and the last group in 1951. The cars in each of these groups were repainted as the car's next regular shopping and reweighing came due, which was every 48 months (4 years).

    The F-50-4, -5, -8, -9, -10 and -12 cars were the mainstay of the SP's fleet until after World War II, when the new F-70-series cars were built in large numbers. Many earlier cars were renumbered as they continued in service (Table 2). Over the years the F-50 cars were modified (either permanently or temporarily) for various special loads or services. Temporary mounting of racks allowed shipment of sugar beets, pulpwood, and wood chips, while more permanent modifications included rails for copper anode plates, log bunks, and many maintenance-of-way (MOW) variations for supplies, ditchers, ballast spreaders, and special deck cradles for moving car wheel sets between shops.

    Renumbering_of_F-50-5,8,9_Cars
    For additional information, see Southern Pacific Freight Cars Vol 3 Automobile Cars and Flat Cars by Anthony W. Thompson, Signature Press, 2004.


    Many other SP F-50-series flats were reassigned to maintenance-of-way (MOW) service, such as SPMW 1413, an F-50-5 converted for Supply service in October 1952. This model from Kit #2002 with supplied T-Section trucks, K-brakes, and white SPMW decals.

    Many of the F-50-series cars continued to be used in SP and T&NO's MOW rosters from 1958 until about 1980 with the change to light gray paint and black lettering. These later MOW cars can be modeled with our #2004 & 2005 kits which has black SPMW decals instead of the regular white set.


    SPMW 2054, an F-50-10 converted to MW service in Oct 1954, sports a worn post-1958 gray paint job with black lettering as it would have appeared in the late-1960s. This model was made from Kit #2005, with the black SPMW decals, AB-brakes installed and U-section trucks.

    Considering the F-50 series of cars lasted in various forms for 60-70 years, they truly have an impressive legacy.

    Relavent SPMW Roster Jan 1956 Jason Hill's blog for 1956 F-50-series roster of SPMW cars.

    New Design Features

    Narrow Draftgear

    One area where we're pushing the limits with the new F-50-series cars is in the draftgear and endsills. During our development phase of this project, we observed that the F-50-series models are much smaller than what we're used to seeing in the hobby with the bigger boxcars (even WWI era USRA cars). If we put a full 1/4" wide coupler slot in the end of the car for a standard HO NMRA-Kadee box and reproportioned the other details around it, then the endsills looked very over-scale compared to prototype photos. We decided to try something new in HO scale.


    SP 38909's end sill with 'near-scale' draftgear-shank opening and Kadee-156 coupler.

    In 2013, we converted several test boxcars to use this new narrow draftgear-shank opening design. We 3D printed our first pilot model and tested it extensively in-service at a large model railroad club layout. Various positions in the train were tested, including putting the pilot model directly in front of a helper shoving on 40 cars on a 2% grade! The 3d printed pilot model did amazingly well in these tests that were designed to purposefully find problems with the design concept of the car.

    We found that these cars performed very well and also worked down into tight 18" radius industrial spurs without any issue. The narrower coupler shank opening only became an issue when attempting delayed magnetic uncoupling on tight (18" Radius) curves. The Kadee-156 coupler heads and knuckles actually have enough freeplay (slack) in them that cars can stay coupled down to very tight radius (almost to the point of the corners of the two models touching).

    We felt that in most operating conditions for the cars these days, the narrower shank opening combined with the extra 'slop' in the mating areas of the Kadee Scale Head couplers will perform well. Modelers running into any issues from the narrow draftgear opening can easily create more movement by filing extra width into the sides of the striker opening section of the box and continue until the needed draft gear movement is achieved.

    Instruction Sample for Kit 2002

    Common Lettering Diagram

    For 1910-1950 for SP F-50-series flatcars. This PDF file has four common lettering plans for SP's F-50-4/5/8/9/10/12 class cars from 1910-1917, 1917-1928, 1928-1946, and 1946-1950+.

    F-50-series lettering diagram

    Common Lettering Plans F-50-series.

    Lettering Diagram 2018 Copyright OwlMtModels for private modeling use only.

    Weathering Tips, Techniques, & Addition Information

    F-50-5,8,9_Roster_Table1
    T&NO 22419, an F-50-5 built from Kit #2002, about 1950 after changing from LW to T&NO reporting marks. Click on link below for Additional Information on subsidary roads that purchased F-50-5,-8, & -9 classes.

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