Hallmark/Samhongsa (Korea) Brass USRA 4-6-2 Pacific


Introduced: 1992

Hallmark's USRA 4-6-2 is a very nice looking model. And although "as delivered" it has a couple of problems, it does have the potential for being a fine runner (more on that in a moment).

The chassis is all metal, although it's also fairly minimalistic (with the shell providing most of the actual heft). The motor is an open-sided / straight-wound 5-poler. Right-rail pickup is provided by the three right-side drivers. Left-rail pickup is provided by the four left-side tender wheels. Current is transferred from the tender to the locomotive via a stiff wire on the drawbar. All the rest of the wheels are electrically neutral. Only the center pair of drivers is geared (with the remaining drivers being turned solely by the cranks). All of the driver axles are seated inside of spring-mounted bearing blocks.

The pilot truck also has a spring (providing downward pressure). The pilot coupler is a dummy (IE, non-operational) knuckle. There is no coupler on the tender (although a pocket and a screw are provided, so adding a Micro-Trains coupler looks to be a simple operation). The shell includes cab interior detailing. The wheels are low-profile, so no problems on Code-55 track. The drawbar has two holes - one for extreme close-coupling. There are no traction tires.

This locomotive actually has a directional headlight. Unfortunately, said light is clearly visible through the smokestack (ick). Sadly, there isn't a pin/socket connector on the wiring running from the chassis to the headlight, so completely removing the shell from the chassis would require that said lighting wires be desoldered first.

The actual locomotive mechanism is a good one. And running "wheels-up" on my workbench (with current applied directly to the motor contacts), it's just as smooth and as quiet as can be. However, there are a few issues that need to be addressed before this locomotive can be considered "operations worthy".

First of all, that "stiff wire" current transfer scheme on the drawbar is not reliable. The wire is affixed to the drawbar fairly loosely, resulting in a lot free play. As a consequence, current conductivity is all over the map. Yes, if you get lucky and wind up with a solid connection when you hook the tender to the drawbar, this steamer will glide around the rails beautifully - smooth, quiet, great throttle response, no pickup problems, etc. Unfortunately, it's all the luck of the draw, and you're just as likely to get an iffy connection (and with the resultant stalls and stuttering one normally associates with bad pickup).

One simple solution to the problem is to apply a glob of solder to the wire where it connects to the drawbar - basically fixing it more firmly in place. I have a Hallmark/Sam 2-8-2 where the previous owner had made this modification and the resulting improvement in performance is night and day. A more ambitious fix would be to replace (or augment) the drawbar wire with an actual insulated mini-wire (running from the tender to the motor). Unfortunately, running wires between tender and loco is never pretty. Still, it would definitely provide bulletproof electrical conductivity.

Another problem with this model is its pilot truck - specifically, the spring Samhongsa decided to stick on the screw that holds said truck in place. Yes, downward pressure on a pilot truck is generally a good idea, as it helps to keep the wheels from derailing. Unfortunately, there are a number of problems with the actual implementation here, and the end result is that the downward pressure is not applied evenly to the truck assembly. As a consequence, one end of the truck winds up getting pushed down more than the other, thus causing one set of wheels to lift right off the rails (basically defeating the desired "keep the wheels on the rails" purpose of the spring).

The quick fix here would be to simply remove the spring entirely (that's what I did on mine, and all of its pilot truck problems magically went away). However, if you want to keep the spring, there are other more ambitious fixes. First off, the truck screw on these models tends to be bent (try standing it up on your workbench - chances are it will look like the Leaning Tower of Pisa). Straightening out said screw by twisting/bending it with a pair of tweezers will go a long way towards solving the derailing issues. Also, check to see that the washer is installed correctly. It's supposed to be on top of the truck, sandwiched between the truck and the spring. However, I'm told that at least some of these have it installed on the underside of the truck (where it does no good at all). Lastly, the equalizing springs on the driver bearing blocks are overly robust, causing the nose of the engine to ride a bit high (and thus removing downward pressure from the pilot truck). Clipping a single coil off each of these springs will take care of this problem.

Another issue with these models is pulling power (or lack thereof). Without any traction tires to grip the rails, they can't pull more than about 10 freight cars on level track. Is that enough for a Pacific? I dunno, I guess that would be up to the individual modeler to decide. In any case, installing some sort of after-market traction tire (or Bullfrog Snot) would certainly help in that regard.

Lastly, these models are pretty much useless on narrow (9.75") radius curves. When faced with curves that sharp, the drivers will derail every time.

So overall, these are models that (with a few minor modifications) have the potential to be a good runners. Unfortunately, "as delivered" they're not so great.

To remove the locomotive shell, unscrew the two small screws on the back (cab) end. Next, unscrew the screw holding the pilot truck to the shell. The shell should lift up and off at that point. Be careful not to yoink the lighting wires.

Grade: C (as delivered)


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