|SD45 w/o DB
The mechanism employed in these models is very typical of 1980's Samhongsa design -
The chassis is all-metal and fairly flimsy (with most of the actual heft being provided by the brass shell and fuel tank). The motor is an open-sided / straight-wound 5-poler (made by Hanasam) that screws to a vertical bracket on the chassis. Four wheels on each truck provide pickup (via wheeltop wipers). Current is transferred from the trucks to the motor via wires (two per truck).The plastic driveshafts consist of three individual pieces connected by U-joints. All six axles are geared and all gearing is brass. There are no traction tires. The shell lacks window glazing and couplers (although mounting points for MT-style coupler boxes are provided). There is no lighting. Ala carte snowplows are included in the box (to be installed by the modeler). As per usual, Samhongsa also includes a little baggy of handy dandy spare parts (screws, springs, etc).
Performance is generally pretty solid. However, as is often the case with this standard Samhongsa design, they do generate quite a bit of noise (barbershop razor syndrome). As delivered, the pickup scheme is adequate enough (no problems with stalls or stuttering). That said, I do have my concerns about the long-term viability of those wheelwipers (frankly, they're a pain in the ass to keep clean and adjusted). Pulling power is strong, with mine able to haul around forty assorted 40-foot freight cars on level track. The minimum radius for curves is right around 11" (the trucks will derail on 9.75" curves or sharper). Overall, these are great looking models that perform adequately.
Part of the noise problem with these models is due to the relatively flimsy motor mount (which allows for a fair amount of vibration). I was able to quiet mine down significantly by applying small pieces of foam insulation tape to the back and underside of the motor.
The "B" units are pretty hard to find, with perhaps as few as 50 having been made. Also note that these "black box" models differ significantly from the "silver box" six-axle EMD diesels released by Hallmark/Samhongsa in 1989 (the 1989 models having a radically different Kato-esque mechanism).
To remove the shell, unscrew the two screws in front of the rear truck and the two screws on either side of the forward truck. The shell should lift right off at that point.
(Thanks a million for the loaner, Jason)