PBL/Benchmark/Boo-Rim Precision (Korea) Brass DM&IR M-3 & M-4 2-8-8-4 Yellowstone

Introduced: 2004

These gorgeous and fine-running Benchmark steamers are quite scarce, with something like 25 (or less) of each road number having been produced. And at least as of this 2012 writing, they are even more difficult to find for anything less than full "retail" price (between $1000 and $1100). Each locomotive is packaged with a caboose (cabooses also available separately).

The mechanism design is very much reminescent of the SP cab-forwards Samhongsa made for Hallmark back in the 80's and 90's -

The chassis is all metal and fairly minimal (with the boiler shell providing most of the model's weight). The motor is a coreless Maxon (#118534). Right-rail pickup is provided by seven of the eight right-side drivers (with one set of drivers on the rear engine being equipped with traction tires). Left-rail pickup is provided by all of the left-side tender wheels (with current transferred from the tender to the locomotive via a pair of stiff wires on the drawbar). All the rest of the wheels are electrically neutral.

A pair of metal driveshafts linked with a plastic sleeve spins the worm for the rear engine. In turn, a long plastic driveshaft with ball-and-pin connectors connects to the metal driveshaft on the forward engine in order to spin its worm. The worm enclosures have leaf springs, allowing them a bit of up-and-down flexibility. One axle per engine is geared (with the other driver sets turned by the running gear). The forward engine is articulated (free to pivot) whereas the rear engine is fixed to the chassis (ala the prototype). Benchmark sternly advises that one should handle the locomotive with two hands at all times, as the ball-and-pin driveshaft that runs between the two engines is prone to popping out of its sockets if the forward engine is allowed to hang loose while picking up the model.

A non-directional headlight is mounted to the forward engine assembly. The wiring for said light runs forward from the motor, and includes plug/socket connectors (allowing one to completely separate the two engines). The tender is equipped with a directional backup light (a small wire with a pin/socket connection provides the tender with right-rail current from the locomotive). The pilot has a really tiny non-operational knuckle coupler (although it does pivot). The tender coupler is a chassis-mounted Micro-Trains. Wheels are low-profile, so no problems on Code-55 rails. Only the pilot wheels are blackened, so no pickup problems out of the box.

These are outstanding models in every way. Paint and detailing are first-rate and performance is beyond sublime. Mine runs smoothly and virtually soundlessly at all throttle levels. No wobbling, shimmying, buzzing, grinding or any of that other "cheap steam" nonsense. Throttle response is nimble and slow speed creep is amazing (mine can crawl along almost slower than the eye can detect). OK, the top-end speed seems a little excessive, but that's just nitpicking. Pulling power is exceptional, as mine can haul thirty freight cars with ease. I don't know what the absolute upper limit might be, but it's gotta be well over fifty cars. I didn't have any problems keeping all of the wheels on the rails. And with all those wheels collecting current, stalls and jitteriness are a non-issue as well. Mine doesn't seem to mind curves as narrow as 11"-radius, although it does looks pretty strange on curves that sharp. The articulation of the forward drivers seems much more pronounced in this model than other articulateds - with the front of the boiler swinging way out on even moderately sharp curves. I think this steamer will look best on 19"-radius curves and broader.

Overall this is one of the all-time great steamers of N scale (brass or otherwise), and well worth the current prices.

Here's what Benchmark has to say about them (most of the drooling hype removed) -

You're looking at a broadside of one of our Worthington feed water heater equipped M-3's (the feed water heater is the small, rectangular box just ahead of the smoke stack). The actual size of the loco and tender you see here is 9.5 inches.

Features -

- Scale-sized sanders and sander piping
- Triple step etchings throughout
- Accurately modeled cylinders and valve gear
- Accurately modeled ladders and hand railings
- "Wrapped" steam piping where required
- Sprung, working tender-to-cab vestibule

In collaboration with our builder, we had the motors for these models custom-wound so that their top speed is only 8,000 RPM - about half (or less) what most N-Scale motors rev to. The motors were wound to produce torque, which they do in abundance. These models are able to run smoothly at very slow speeds on straight DC power - no "pulse power" required.

Some other things to look for -

- The "front end throttle" with its bellcrank setup - These locomotives were so long that the enginehouse "hostlers" had to stay on their toes because expansion or contraction due to temperature could lengthen or shorten that throttle rod, causing a locomotive to creep during the night. Sometimes with disasterous results.

- The "pedestal truck" under that tender - These were oftentimes referred to as "centepede trucks" (for obvious reasons).

M-3 road numbers - 220, 221, 225, 228

M-4 road numbers - 231, 232, 234, 235

Visit the Benchmark Models website for instructions on how to remove the boiler shell (it's pretty simple).

Grade: A

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