ScaleTrains.com's line of C39-8 models was released under their high end "Rivet Counter" label. They are available either DCC-Ready or equipped with a factory-installed ESU LokSound DCC-Sound decoder and speaker. Each model has its own unique paint and detailing package (based on the prototype in question). As pictured below, the level of fine detailing on these models is pretty much off the charts -
Internally, these models are quite similar to STC's 2018 line of GEVo diesels. The chassis consists of a metal base with a metal bracket screwed to the top (holding the motor and drivetrain in place). The motor is an open-sided 5-poler with skew-winding. Each motorshaft is equipped with a flywheel (although they are somewhat ineffective, as these locos start and stop on a dime without the aid of a decoder). Plastic driveshafts seat inside of the flywheels and connect to notched cups on the truck towers. Short metal shafts connect the cups to the brass worm gears mounted inside the truck towers.
The main PC board is screwed to the top bracket and receives current from the trucks by way of four wires. A pair of separately wired LED boards (for the headlight, backup light and numberboards) are mounted to the front and rear of the top bracket. Models equipped with ditchlights have an additional LED board mounted to the front of the chassis (my Conrail unit is not so equipped). The headlight and backup light are directional, whereas the numberboard lighting is not. The lighting is white and very bright. Additional wires run from the main PC board to the motor and (for DCC-Sound models) to a speaker mounted inside the fuel tank. The decoder interface on the DCC-Ready main board is "Next 18" (aka NEM662). For the sound-equipped models, a small piece of white foam insulation sitting between the decoder and the chassis helps to keep the decoder from popping loose when putting the shell on.
All six axles are geared and all gearing (apart from the worms) is plastic. The wheels are blackened and low-profile (no problems on Atlas Code-55 track). There are no traction tires. STC "E Type" automatic couplers are mounted to the chassis. Note that said couplers do not come with any sort of metal trip pin, so I guess magnetic uncoupling is not an option. Personally, I've never been real impressed with STC's couplers (they don't auto couple very well). For those interested in trying something else, I'm told that Atlas Accumate couplers are a good replacement option (they reportedly drop right into the stock Scaletrains draft box).
The plastic fuel tank is screwed to the bottom of the chassis. Holes are not provided for the speaker that comes with the DCC-Sound models (not really needed since the speaker is installed such that sound projects upward rather than downward).
All 12 wheels provide pickup by way of axle-end wipers (the axle ends seat inside of holes in said wipers). Wires soldered to the axle wipers transfer current to the main PC board. As pictured, the trucks are a rather complex assembly and removing them would likely be a rather daunting proposition. An extension on the top of the plastic truck tower assembly holds the trucks inside the chassis, and so I guess you would basically have to completely disassemble the truck towers and disconnect the driveshafts in order to get the trucks off.
Shell removal is very simple - just unscrew and remove the couplers. At that point, the shell should readily slide up and off. Note that the various shell components (hood, cab, sidesill, etc) appear to be glued together. So, if you're a repainter.... well, good luck with all that.
These are very nice runners - smooth, whisper quiet, excellent slow-speed creep and a realistic top-end speed. Mine ran well right out of the box, so pre-emptive wheels cleaning doesn't appear to be required. Mine can creep through insulated frog turnouts at very slow speeds, so pickup is flawless. Pulling power is decent (albeit unspectacular) with mine able to haul around 27 assorted 50' freight cars through curves on level track (any more than that and the wheels are slipping). The minimum radius for curves seems to be right around 11" (despite STC's claims to the contrary, mine would consistently derail on 9.75"-radius curves). The sound on the DCC-equipped models is robust and nicely rendered.
One minor annoyance I have with the ESU decoder is the whole protracted "start up" sequence the locomotive goes through when moving from a dead stop (basically the locomotive sits there making various noises for 4-5 seconds before it starts moving). All very prototypical I'm sure, but not something I really want to have to deal with (particularly when MU'ing an STC loco with some other brand of loco that just wants to go). Setting CV124 to 16 eliminates this behavior. Also, the default behavior is for sound to be off when you first put the locomotive on the rails (with F8 then turning it on). If you want the reverse of that (sound comes on when you put the loco on the rails and turns off with F8), set CV31=16, CV32=2, and CV419=32.
For the DCC-Sound models, some CV tweaking may be necessary in order to achieve optimum performance. Out of the box, mine exhibited a very slight stutter at slow speeds (IE, it couldn't maintain a consistant speed). So, the first thing I did was to perform a CV54 "BEMF auto tune" (set CV54 to 0 and then hit F1). Unfortunately, this didn't really change anything. So, the next thing I tried was to lower the value of CV56 (default setting is 255) to reduce the amount of BEMF influence over the speed. And, lo, this smoothed things right out. Another option to adjust BEMF would be to increase the value of CV52 from its default setting of 15. Between those three CVs, it should be possible to address any BEMF-related glitches that might arise. And FWIW, this does not appear to be a common problem with these models, so evidently I just got "lucky" with mine. Overall they are terrific looking models that run extremely well.
Introduced in 1984, the C39-8 maintained the clean contours of the long hood and rounded cab roof of the Dash-7 series but featured larger, angular radiator "wings" at the rear of the carbody, an angular low short hood, and a boxy dynamic brake and clean air compartment at the front of the long hood, which jutted above the cab roofline. Even though Conrail and Norfolk Southern were the only two railroads to purchase C39-8 locomotives from GE, both railroads routinely operated C39-8s as run-through power on CSX, Union Pacific, and Southern Pacific. In fact, SP leased Conrail C39-8s in the early 1990s. The only two C39-8 locomotives in operation today are owned by the Pennsylvania Northeastern Railroad.
- Fully assembled
- Up to six road numbers per model, detailed per prototype and era
- Directional LED headlights
- Printed and LED lit number boards
- Phase Ib, II, and III carbodies with correct panels and grilles per variant
- Standard (2-vent) or high-capacity (3-vent) dynamic brakes per prototype
- Early (6-panel) or late (4-panel) radiator exhaust grilles
- Wheel handbrakes
- GSC truck sideframes
- GE "nub" tread plate on walkways
- Highly-detailed 4,400 gallon fuel tank with fuel fillers and gauges
- Air reservoirs with separate plumbing
- Accurately profiled frame with separately applied plumbing and cabling
- Cab interior
- Factory-applied wire grab irons, snowplow, spare knuckles, trainline hoses, 3-hose MU clusters, MU cables, uncoupling levers, windshield wipers, mirrors, air reservoirs, underframe bell, brake wheel, and more.
- Body mounted ScaleTrains.com plastic semi-scale E Type knuckle coupler
- All-wheel drive and electrical pick-up
- Dual flywheels
- Motor with 5-pole skew wound armature
- Printing and lettering legible under magnification
- Operates on Code 55 and 80 rail
- Packaging safely stores model
- Minimum Radius: 9.75", Recommended Radius: 11"
DCC Features -
- ESU-LokSound Next18 Select Micro DCC and sound decoder with "Full Throttle"
- "Sugar cube" type speaker
- Accurate GEVO-12 prime mover and auxiliary sounds, horn, bell, and more
- Operates on both DC and DCC layouts
Grade: A (although some CV tuning may be required)