SP Train Master Project

jwaldo Nov 6, 2023

  1. jwaldo

    jwaldo TrainBoard Member

    With my GP20s completed and everything else on hold for want of parts, I'm ready to tackle the Fairbanks-Morse H-24-66 Train Master I picked up earlier in the year. Unlike the GP20s, the Atlas TM is already quite close to the version Southern Pacific had, with relatively few weird SP-specific details missing. Looking at prototype pictures, the main things the Atlas model needs are:

    • A snowplow on the front pilot
    • Large front numberboards and spare number boxes
    • Steam generator vents on the top of the short hood

    After that it's just the usual superdetailing suspects (grab irons, cut levers, sunshades, etc.) So this should be a relatively straightforward project (famous last words!)

    I started tonight with the pilots, removing the molded-on details and adding some missing parts. We've come a long way from the days of wide-open pilots and truck-mounted couplers, but the area around the coupler is still pretty barren on a lot of N-scale locos, this TM included. Both ends got shimmed for 905 Z scale couplers, and had some of the missing draft gear hardware scratchbuilt. The rear pilot will keep its steps, but on the front I removed the pilot steps and most of their supporting hardware to recreate the open space visible between the pilot face and snowplow on the prototype:


    I left the supports at the bottom so the snowplow will have something to attach to. And speaking of the snowplow, it's a custom assembly rather than a standard off-the-shelf plow, so I'll have to scratchbuild that too:


    I started by trimming some pieces of 0.010" styrene sheet until they were about the right size and shape. I've tacked them to a piece of 0.005" brass, and once that dries I'll trace the outlines onto the brass to make the final pieces. The prototype plow is made in three pieces (left, right, and middle), and mine will be too. That should slightly simplify the shapes I have to make.

    While I wait for the snowplow experiment to dry I've filled in the holes for the original single-chime horns, and marked off approximately where the new 5-chime horn and other roof details will go:

  2. brokemoto

    brokemoto TrainBoard Member

    When FM first delivered them to Texas, they actually had stacks for the steam generator vents. By the time that they got to California, many of them had lost the stacks. By the "bloody nose" era, only two or three of them still had the stacks.
  3. jwaldo

    jwaldo TrainBoard Member

    Good to know! Rooftop references are always hard to find. By the era I'm modeling (mid-70s, not long before they retire) the TMs all seem to have been converted to the flat vents.

    Gluing the templates onto the brass with Micro Kristal Klear worked better than I expected. I was able to cut the plows out with no trouble. Adding the notches for the end steps, on the other hand, involved lots of careful filing and muttering of words I can't post here. But the plow turned out pretty well, if I do say so myself:


    I'll set them aside and finish the rest of the pilot before gluing them on permanently.
  4. jwaldo

    jwaldo TrainBoard Member


    Added some grab irons, cut levers and pilot handrails. Ignore the glue blob smack in the middle of the pilot face, I only remembered to sand that down after I took the photo. I also added jacking pads to the sill, then promptly knocked one right back off while aligning the cut levers. But at least the ones that are visible in this picture turned out nice :whistle:

    I thought I'd tackle the cab sunshades next, but I am out of sunshades and so is every vendor I've checked. Someone tell Atlas/BLMA to hurry up and etch a fresh batch already!
  5. Hoghead2

    Hoghead2 TrainBoard Member


    Is that the Third and Townsend Depot , S.F.? I only know the Caltrain depot on Fourth and King streets.
  6. jwaldo

    jwaldo TrainBoard Member

    According to the Wikipedia page I found the image on (I forgot to cite my sources. For shame!), that is Third and Townsend. Anyone know what kind of passenger cars those are right behind the TM? The ones at the back are bi-level commute cars, but that's where my passenger car knowledge ends.

    Meanwhile, the ends (and for that matter the entire sill) is ready for paint:


    Assembling everything before paint isn't my preferred order of operations, but these parts are challenging enough to mount that I don't want to try and do it after everything's painted. Luckily everything except the hoses will all be the same color. This is my first time using Miniatures By Eric trainline hoses. The detail isn't quite as nice as the old BLMA ones, but hose itself is thinner, and the fact that it's brass instead of plastic means I can bend the hose into a more natural shape and not have to worry about snapping it off.

    Meanwhile, I'm marking out where the steam generator hardware will go. Good roof shots of the TM are hard to come by, so I'm also taking measurements off of a model that already has the hardware in question:


    Yeah, I'm copying Athearn's homework. A new low :whistle:

    Lastly, does anyone know where to find the correct Nathan 5-chime horn nowadays? Miniatures By Eric doesn't have one that matches. BLMA used to, but it doesn't look like it's been re-run since the Atlas acquisition.
  7. SP-Wolf

    SP-Wolf TrainBoard Supporter

    308GTSi, jwaldo and BNSF FAN like this.
  8. jwaldo

    jwaldo TrainBoard Member

    Well darn. I knew the bi-level cars are pretty much nonexistent anymore (does WoT ever re-issue ANYTHING? I also just missed out on their H-12-44 shell), but I was hoping someone had the Harriman cars readily available.

    And for the horn I guess either I wait for Atlas to re-release the BLMA horns, or I wait for Atlas to re-stock shell parts for a loco with a plastic 5-chime horn. Maybe they'll be nice enough to do one or the other along with my cab sunshades :confused:
    BNSF FAN likes this.
  9. brokemoto

    brokemoto TrainBoard Member

    Those are Harriman "subs" (suburban cars) SP used them mostly on the Peninsula commutes They were the principal commuter cars until the bi-levels began to arrive in the early to mid 1950s.

    Until early to mid-1957, you could see bi-levels behind steam, as the Peninsula was the last holdout of steam on the SP.

    I rode SP Peninsula commutes from the mid-1960s to the early 1970s, when I left California. At the time, the weekday power was mostly the FMs. There were some torpedo boat GP-9s, the occasional PA (until SP retired them) and an former SSW FP-7. That FP-7 was on its last leg even in the late 1960s but it held on at least until the very early 1970s. On the weekend,s the FMs went to work the freights from Carquinez Straits to Sparks, Nevada. On the weekend, the Peninsula Commutes got the SD-7s/-9s, torpedo boat GP-9s, GP-9s equipped for passenger service and with dBs(!). the occasional PA. The Lark, Coast Daylight and Coast Mail usually had E-units until the first and last were discontinued. The Del-Monte usually had a pair of torpedo boat GP-9s. It had Harriman subs and bi-Levels added to the consist between SF and San Jose. It was usually three or four cars between San Jose and Monterey but with both the GP-9s. The usual cars were smooth sides in silver with the red stripe: one or two coaches, a baggage car and a club car.
  10. jwaldo

    jwaldo TrainBoard Member

    @brokemoto This is awesome information, thanks! The TMs were long gone before I ever got to see the SP in action, it's cool to have a first-hand account.

    Today I started on the steam generator vents. Step one was to figure out where everything goes. I marked the centerline of the shell as a reference point, measured the Athearn reference, then marked a dimple in the shell at one of the corners of each of the vents.

    With one corner marked off, I got out the scale ruler and laid out a rectangle of etching guide tape. This stuff is similar to the thick plastic tape used to make embossed labels, but it’s clear and slightly more flexible, so it sticks to the curved roof. And as it turns out it's also very, very hard to photograph :LOL:



    Once the guide tape was in place (and reinforced with some Scotch tape), I carefully inscribed the outline using a tiny hobby chisel. ~10 passes is enough to engrave a solid line that will mark where I need to file to:


    With the tape off, you can see that the lines aren’t quite perfect. Some are a little wide, and in one spot I overshot the corner. If I was making a door outline or something else where the line itself was the finished product this would be grounds for starting over! But since there's still a lot of cutting and filling left to do, this will be fine.

    Next, I drilled out as much of the vent openings as I could with a pin vise and small drill bit, punched out the center piece, and squared up the openings with a hobby knife and a jeweler’s file:


    Now that the holes are opened up, I can add mesh. But that's turning out to be a whole 'nother post worth of work!

    Incidentallt, this picture also shows an unrelated aspect of the TM I am excited about. Despite the model weighing a million scale pounds, there's still a lot of empty space inside the hood. I’m pretty sure I can fit a speaker in that cavernous nose space with room to spare!
    John Raid, JMaurer1, SP-Wolf and 6 others like this.
  11. bremner

    bremner Staff Member

    this is going to be great when done. the FM's have always been a favorite of mine, and they were the only diesel that could accelerate like a booster equipped 4-8-4
    JMaurer1, SP-Wolf, 308GTSi and 3 others like this.
  12. nscalestation

    nscalestation TrainBoard Supporter

    I have been on the SF peninsula since 1979 and recall those Harriman cars being used on weekends right up to the time of the establishment of CalTrain. After that some of them went to the Grand Canyon Railway in Williams, AZ. The SP bi-levels from the 1950's also remained in service until CalTrain which was around 1983.
  13. jwaldo

    jwaldo TrainBoard Member

    First, I cemented some thin styrene strips inside the edges of the vents to provide a lip for the mesh to sit on. For the mesh itself, my original idea was to use the same Edouard photo-etch mesh I used for my 70-Tonner walkway:


    But as soon as I test fit a piece I realized that plan was no good. Even by Fairbanks Morse’s chunky standards this particular mesh is much too coarse for the job. I scoured my Useful Things Drawer and found a metal coffee filter. The good news is it is VERY fine mesh that looks about right for N scale. The bad news is, because it’s a woven mesh instead of a solid photo-etched piece it is MUCH harder to shape small pieces without having them unravel at the edges. I accumulated a large pile of mangled scraps before figuring out that the best way to get clean cuts is to cover both sides with tape and cut the tape-and-mesh sandwich with scissors.

    Once I had two un-mangled mesh squares of about the right size I laid them into place. Then I applied a little Tamiya Extra Thin Cement around the edges of the holes and very, VERY carefully pressed the mesh down flush with the rooftop. The cement softened the plastic enough to mold the mesh into the shell, making for a very flush joint after some clean-up sanding:


    The vents on the prototype have some very fine raised strips around them, which I may or may not attempt to recreate. But for now I'll go back to brainstorming how to make the front numberboards and waiting for the cab sunshades I ordered to arrive.
  14. country joe

    country joe TrainBoard Member

    That is some fiddly/fine work! You did a great job, R.J.
    DeaconKC and BNSF FAN like this.
  15. jwaldo

    jwaldo TrainBoard Member

    Thanks Joe! This is definitely not the sort of work I want to do right after a cup of coffee!

    My cab details arrived just in time for Turkey Day, along with a little something else I threw into the order: an ESU speaker.

    With even the thinnest provided soundbox option, the speaker is much too tall to fit in the loco without massively modifying the frame. Without the soundbox, the speaker fits with a mm or 2 to spare:



    My experience with installing speakers is limited to non-train items, but in my experience having a soundbox/resonating chamber makes a very big improvement in the quality of the sound. I suppose I could build an even thinner soundbox, or even incorporate one directly into the shell. Any sound gurus have some helpful advice?

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