Models and Kitbashes by NightOwlModeler: SPMW Flat Car 1956 January Roster Data Analysis

In this post I want to cover some research materials I've been working with for nearly 20 years, thanks to the SPHTS publishing the SPMW Jan 1, 1956 Roster in various SP Trainlines over the years. I've been slowly adding the data into a spreadsheet over the years, which makes it much easier to sort through by assignment, car class, original car number, etc.

Let's look at some of the data I've been able to crunch out from this research. Specifically, I want to look at the SPMW fleet of flatcars at the time, what assignments they had, and what the original classes of cars were that they came from. This should help us choose what classes of cars, and to some extent what assignments we should be building and lettering our models for.

Six SPMW Supply Cars with low sides and a single-deck Wheel Car in this cropped photo of SP Sacramento Shops photo from mid-1950s - Inad Akeb collection

Not only revenue flat cars were converted to MW service as flat cars, many boxcars and other 'house' cars were 'cut down' to make more flat cars. Some of these 'cut down' cars may have received stake pockets, but not necessarily in any "standardized" pattern or location.

I have put in comments in the data tables for groups of cars retired after 1950 when it starts heavily shifting the data, mostly the large numbers of 1954-55 retired cars in the 1956 roster. These newly retired cars probably replaced older classes of cars. However, without older rosters determining what those were is impossible.

SPMW 5323, F-50-12, retired 1959 at Carson City Museum, 2018 - Jason Hill photo

Some cars I know of were retired after 1956 have been noted, some F-50-10/12 class continued to be retired into SPMW into 1959-1960, which certainly would have been painted in the SPMW Light Gray scheme.

General Service "Ready Flats"

SPMW 810, F-50-7, Ready Flat kitbashed from Walthers-TM flatcar.

Ready Flats were basically the "General Service" flatcar used in MW service, available to be used in any service not requiring specialized modifications or mechanical standards. Thus this service received many of the older classes, which may be in somewhat compromised mechanical status.

Foreign        3 (0.9%) *(CEI 37048 1932, M&WRR 100 1936, MI&T 35207 1929)
A-40-1        1 (0.3%) *(ex-Auto boxcar, cut down to flatcar)
B-50-1        18 (5.3%)
B-50-2        55 (16.2%) *(Cut down to flatcars, look similar to F-50-1/2/3 class, possible stakepockets)
B-50-4        1 (0.3%)
B-50-5        4 (1.2%) *(2 unmarked assignment, SPMW 3018, SPMW 3021)

B-50-8 1 (0.3%)
CS-33 7 (2.1%) *(older SP boxcar class)

"Box" 81k, 84k, 86k        14 (4.1%) *("Old" SP boxcar classes, not listed in 1956 roster)
CS-19A (ex-stock car) 10 (2.95%)
S-40-2        1 (0.3%)
Stock        2 (0.6%) *(Class not shown in 1956 roster)

CS-35A 31 (9.1%)
F-40-6 3 (0.9%) *(SPMW 2749 modeled)

F-40-7        4 (1.2%)
F-50-1        17 (5.0%)
F-50-2        61 (18.0%) *(Spread between 1936 and 1943)

F-50-3 42 (12.4%) *(Spread between 1911 and 1943)

F-50-4 31 (9.1%) *(Spread between 1937 and 1955)

F-50-5 10 (2.95%) *(1949-1953)

F-50-7 2 (0.6%) *(SPMW 810 modeled)
F-50-8 1 (0.3%) * (1954)

F-50-9 7 (2.0%) * (4 after 1953, 3 before 1941)

F-50-10 1 (0.3%) * (10-1954)

F-50-12 1 (0.3%) * (12-1955)

"Flat" 78890        1 (0.3%)
"Gon" 54977        1 (0.3%)
ex-Transformer car        1 (0.3%)
DT                2 (0.6%) *(reassigned from wrecker outfits)

"All Steel" 2 (0.6%) *(would have to look up by original number)
Misc 3 (0.9%) * ("Ditcher-Flat" F-50-3, "Rail Loader" CS-35A, "Flat" CS-35A shown as Ready Flat classification)
Unassigned "Rdy Flat"339 SubTotal, (49.8% of all SPMW Flats)

Note the shift in the Ready Flats fleet towards older classes of car and converted ex-boxcars and stock cars.

SPMW 2186, an early retired F-50-9 from March 1941.

Interesting that I've already modeled three of the classes with less than 1% of the Ready Flat pool! SPMW 810 (F-50-7), SPMW 2186 (F-50-9 "early" group) and 2749 (F-40-6). Looks like if I want to do any more Ready Flats, which should be half of my SPMW flatcars modeled! I should focus on the 'decked' B-50-2 boxcars, F-50-2/3 flats and maybe an F-50-4 or an CS-35A class flat cars. Good data to crunch looking for modeling projects.

Shop "Ready Flats"

Shop Flats were used to move materials between the SP's main or larger shops. Often this included unmounted wheelsets, diesel prime movers, traction motors, drivers, etc. These cars may have specialized stakes/sideboards for keeping equipment secured.

Six SPMW Supply Cars with low sides and a single-deck Wheel Car in this cropped photo of SP Sacramento Shops photo from mid-1950s - Inad Akeb collection

I'm thinking about building one of the two cars in the string to the left of the wheel car. Maybe make a load of the unmounted wheel castings.

B-50-2        2 (4.3%) *(ex-boxcar)
B-50-4        1 (2.2%) *(ex-boxcar)
B-50-6        1 (2.2%) *(ex-boxcar)
CS-19A        2 (4.3%) *(ex-stockcar)
CS-33        2 (4.3%) *(ex-boxcar)
DT                1 (2.2%) *(reassigned from wrecker outfit)
EPSW Stock        1 (2.2%) *(ex-stockcar)

CS-35A        7 (15.2%)
F-40-6        3 (6.5%)
F-50-1        1 (2.2%)
F-50-2        6 (13.0%)
F-50-3        1 (2.2%)
F-50-4        1 (2.2%) * (1952)

F-50-5 6 (13.0%) * (1 1942, 1 in 1944, 2 in 1952, 2 in 1955)
F-50-8 3 (6.5%) * (All 1955)

F-50-9 4 (8.7%) * (All 1955)
Misc 1 (2.2%) * ("Flat", "Stock", "Tank")

Shop Flat Cars 46 SubTotal (6.8% of all SPMW Flats)

SPMW 2452 under construction with notes marked on weight cover. Oct 25, 2021

The Shop Flat cars certainly were fewer in number than the Supply cars and even the T&M cars, so I'll probably limit myself to just one of these cars. However, if modeling a section of SP mainline operations, then more of the Supply and Shop cars will naturally show up as they move between shops and across the SP system.

By the numbers I should probably go with an F-50-2 or CS-35A... however the car in the photo is certainly an F-50-4/5/8/9 class car... so I'm choosing SPMW 2452, one of the F-50-5s converted in 6-12-1944 from SP 41069, which certainly could be one of the cars in the photo at Sacramento!

T&M "Ready Flats"

Track & Maintenance flats were assigned to track crews, extra gangs, etc. These could be seen left out in the field supporting track crews.

SPMW 3605, F-50-5, a 1944 conversion to T&M service, shown here with removable tie load.

Sometimes these cars were used as idler flats or tenders for other SPMW equipment, such as pile drivers, such as SPMW 1782 (F-50-9 retired in 1954) photographed with pile driver SPMW 3460 on page 216 of Anthony Thompson's SP Freight Cars Vol3.

A-50-6        1 (1.2%) *(ex-auto-boxcar)
A-50-7        4 (4.8%) *(ex-auto-boxcar)
A-50-8        2 (4.4%) *(ex-boxcar)
B-50-4        1 (1.2%) *(ex-boxcar)
B-50-6        1 (1.2%) *(ex-boxcar)
CS-19A        1 (1.2%) *(ex-stockcar)
CS-33        1 (1.2%) *(ex-boxcar)
DT                3 (3.6%) *(reassigned from wrecker outfit)
B-50-14        1 (1.2%) *(ex-boxcar)

CS-35A        6 (7.2%)
F-50-1        1 (1.2%)
F-50-4        7 (8.3%)
F-50-5        20 (23.8%) * (1 before 1950, rest after 1950-54)

F-50-8 6 (7.1%) * (1954)

F-50-9 24 (25.6%) * (4 in 1954-55)

F-50-10 2 (4.4%) * (1954 & 1955)

T&M Misc 2 (4.4%) *(RI 42830 1931, (SP)MW 2485 wood 1924)

T&M Flats 84 SubTotal (12.3% of SPMW Flats)

These cars certainly moved around, I would think mostly from Division Shops out to the field when regular gangs or extra gangs were working on the division, then back to the stores department to reload with the next set of materials. Some could have been assigned to specific outfits for storing supplies and equipment on.

As of Oct 2021, I'm not sure exactly where the distinction was drawn between Ready Flats, T&M Flats, and Tool Cars in regard to storing regular outfit tools. There are not very many "Tool" assigned flatcars in the 1956 roster, so most outfits must have snagged Ready Flats or T&M Flats to serve their needs transporting things like speeders and such, which don't fit well in boxcars!

"Supply Car" Pool Flats

This is My Railroad - 1947 version screen shot of SPMW Supply Flatcars, - fair use.

These cars may have specialized stakes/sideboards for keeping all manners of material secured, including the kitchen sink. The car above appears to have multiple 30 and 55 gallon drums, kegs of spikes, switch points, switch frog, and all sorts of other materials loaded. Another car in this clip has about 1/3 of the end of the car loaded with a pile of tie plates. Notice that the car above has stakes extending above the sideboards, where as the SPMW 229's stakes (below) are cut down, nearly even with the sides, which is modeled more after the cars in the mid-1950s photo at Sacramento above.

SPMW 229, F-50-5, Supply Flat with 30" sideboards for materials. Oct 25,2021

I'll be working on a couple of supply loads for the 229 car, which will drop in on a false-floor painted and weathered to match the interior floor of the car's wood deck. Something to look forward to in future blog posts! I still need to add the capacity data decals to the SPMW 229 model in the photo above. Many Supply Cars seem to keep their load stenciling data, even after assigned to SPMW service, often keep the lettering change to a patch over the reporting marks and maybe stencil the new assignment.

At least in SPMW 1782's case (Assigned T&M), the tare date from the last revenue weighing was kept, which was two years before the retirement date, and even in SPMW service it still carried the "HEAVY BAD ORDER" stencil from when it was retired! I believe "Supply Cars" were cars in good mechanical condition, as they would be running as many miles as regular revenue cars, around the SP system.

F-50-2        13 (7.3%)
F-50-3        18 (10.1%)
F-50-4        25 (14.0%)
F-50-5        37 (20.7%)
F-50-7        1 (0.5%)
F-50-8        6 (0.5-3.4%) *(1 in 1953, 5 in 1954)
F-50-9        49 (27.5%)
F-50-10        10 (5.6%) *(all 1955)
F-50-12        26 (14.6%) * (all 1955)
F-50-5 "Track Mtr"        1 (0.5%) *(SPMW 1643 1953)
F-50-2 Supply "T&M" 1 (0.5%) *(SPMW 3362 1911)

Supply Pool - Flats 178 SubTotal (26.1% of SPMW Flats) *(41 converted after 1954, probably replacing older cars)

Specialized Wheel "Supply Cars"

SPMW operated a small pool of wheel cars. Most were designed for shipping standard 33" freight car wheels from the Sacramento Wheel Shops out to the various R.I.P. tracks and car shops around the system at many division points.

SPMW 3116, an F-50-12 converted 12-56, Wheel Car 1960 Taylor Yard - Cornell University collection Public domain - cropped

However, specialized single-deck wheel cars with inboard 'rails' and 'yokes' to secure the axles were used to move varying size wheels, including 36" passenger car wheels and 40" diesel wheelsets out to various shops that needed to do any replacement work on cars or engines. Notice the roller bearing wheelsets and the "Napoleon-hat" triple-bolster profile of the closer wheelset from a (1937-1941 built) Daylight-series car.

SPMW 847, F-50-9, 1951 single deck wheel car, kitbashed from OwlMtModels #2003 kit

Notice that SPMW 3116 did not rebuild the sub-deck blocks, where as the SPMW 847 has the stake pockets removed and new solid sub-deck timber blocks fashioned. I still need to make the yokes to secure the wheels on the 847.

F-50-2 DD Wheels        7 (23.3%)
F-50-3 DD Wheels        9 (30%)
F-50-9 DD Wheels        2 (6.6%)
DD Wheels        20 (66%) all wheel cars - Sub-group

F-50-2 Wheels 2 (6.6%) * (1943)
F-50-9 Wheels 2 (6.6%) * (1950)
F-50-12 Wheels 1 (3.3%) * (12-56)
Special Rail Wheel Cars 5 (16.6%) *(SPMW 847, F-50-9, still Wheel Car 1953, returned to pool by 1956)
Wheel Cars 30 cars Total Wheel Cars (4.4% of SPMW Flats)

Misc Assigned Supply Cars

"Trailer" F-50-2 1 (Not exactly sure what the roster means my 'trailer' flat, perhaps speeder cars?)
"Tunnel" F-50-4 2 (SPMW 593, 594 both 1951)
Ditcher Flat 1 (SPMW 959, F-50-8 Misc.Supply)

SPMW "Rdy Flats" 681 Grand Total (not shown are flats assigned to wrecker outfits)

In Closing

Hopefully the upcoming SPHTS book on SPMW will have photos of the Tunnel cars! Those will be interesting to see. I also want to see what the book will tell us about 'Ditcher Flats'... if that is in reference to cars that were used to haul ditching shovels, etc on them, or if they were converted to have Jordan Spreader type wings to do the ditching themselves. Given that in 1954 several F-50-11 (50ft) flatcars were converted to ditcher service, I believe the prior is more likely than the latter option.

Jason Hill

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