MTH Electric Trains HO Erie Triplex

One of the more unusual prototypes to grace North American rails is now available to HO modelers. The 2-8-8-8-2 Triplex is the second HO scale offering from MTH Electric Trains. An accurate replica of the prototype, the model operates with realistic sound in DC, Digital Command Control (DCC), and MTH’s own Digital Command System (DCS).

The prototype. Built by Baldwin Locomotive Works for the Erie RR in 1914, the 2-8-8-8-2 was an attempt to put the power of three helper locomotives into the hands of one engine crew. The locomotive had three engines, two under the boiler and one under the tender, to maximize tractive effort. The locomotive was a Mallet type that had a set of high-pressure cylinders in the center that exhausted steam to low-pressure cylinders on the front and rear engines.

Although it produced 160,000 pounds of tractive effort, the Triplex was expensive to maintain and its boiler was notoriously hard to fire. Used primarily in helper service on Susquehanna Hill and occasionally on drag freights, the Erie P-1 class locomotives usually ran at speeds under 20 mph.

In 1916, the Erie ordered two more Triplexes and the Virginian Ry. ordered a 2-8-8-8-4 Triplex. After only four years, the Virginian rebuilt its Triplex into three locomotives. All the Erie Triplexes were retired by 1927.

The MTH model matches the dimensions of the Erie Triplex in the 1919 Simmons-Boardman Locomotive Dictionary and Cyclopedia.

Details and paint. The MTH Triplex is constructed primarily of die-cast metal, and the quality of the casting is excellent, with sharply defined rivet seams and other molded-in detail. Other separately applied parts, such as piping, steam and sand domes, and positionable cab roof vents, are plastic. The detailed cab includes painted fireman and engineer figures, window glazing, and an apron with safety tread.

The coal load in the tender is separately applied, but some chunks measure one HO scale foot across.

Paint coverage on the model is smooth. The boiler on our sample is painted in a glossy, gray-blue color to depict Russian iron. The lettering and cab numbers match prototype photos. The superheater patent plates and Baldwin builder’s plates are legible under magnification.

Drivetrain. Housed in the boiler, the model’s flywheel-equipped can motor powers the third driver set of the front and middle engines. The non-powered drivers of the rear engine under the tender roll freely.

Without any traction tires, our sample pulled the equivalent of 67 HO freight cars on straight and level track. Replacing the rear drivers of the middle engine with the included traction-tire-equipped set increased the drawbar pull to the equivalent of 150 cars.

The model can negotiate curves as tight as 22″, since both engines under the locomotive boiler are articulated. On the prototype, only the front engine under the boiler was articulated. The MTH Triplex looks much better rounding broader curves.

When handling the model, you should support the front of the engine from underneath. The steam pipe on the front engine of our sample had slipped out of its slot under the boiler, causing the rear drivers of the front engine to lift off the rails. This has been reported by others who received the model. The problem was easily fixed by using a jeweler’s screwdriver to push the pipe back into the slot.

DC and DCC performance. In DC the model’s sounds, lights, and smoke came on at 6.5 volts. The headlight automatically dims when the locomotive is still or moving backward. As the Triplex moves the fan-driven smoke unit puffs, syn- chronized to the exhaust sounds.

At 7.5 volts the model crept along at 2.5 scale mph and at 12 volts reached 20 scale mph, which is within the prototype’s speed range.

The model is designed to operate on up to 24 volts, which is above the 16-volt maximum for HO DC power packs as specified in National Model Railroad Association Recommended Practice RP-9. Using an LGB power pack I tested the model from 16 to 24 volts, where it reached its top speed of 70 scale mph.

For DCC operation, the Triplex supports 128 speed steps. I tested the model with a Model Rectifier Corp. Prodigy Advance system that supplies 16.4 volts to the track. Slow speed performance was impressive in DCC, as the Triplex started moving in speed step 1 at 1 scale mph. Again the model reached a top speed of 70 mph, but speed control is noticeably more precise at slower speeds.

The model’s 28-function DCC decoder lets you control effects such as the bell and whistle and turn the lights and smoke on or off. The instruction sheet lists only 10 programmable configuration variables, limiting the user’s ability to fine-tune the model with DCC.

DCS mode. I also tested the model using an MTH DCS Commander (available separately for $149.95 or with a 100-watt power supply for $229.95). The unit is easy to install and provides access to all the model’s functions. The Commander allows you to toggle instantly between multiple DCS locomotives. You can also adjust the volume levels of individual sound effects.

The Triplex ran well using DCS. The thumbwheel throttle increased or decreased the speed in accurate 1 scale mph increments displayed on the LCD screen.

The DCS Commander can be connected to a DC power pack or DCC system but will only control DCS-equipped locomotives. To use the Commander to run DCS-equipped models and conventional or DCC-equipped models in the same block, you have to toggle between DCS mode and conventional or DCC (called Pass-through) mode. You can’t run a DCS-equipped locomotive in DCS mode simultaneously with a conventional or DCC-equipped locomotive in the same electrical block.

Great sound. In all three modes the sounds of the MTH Triplex are impressive. The whistle is one of the most realistic that I’ve heard in HO scale, and you can vary its pitch and duration with the DCS Commander’s thumbwheel. I especially enjoyed the ability to easily shift between labored and light chuffs in DCC and DCS modes.

The sound effects include multi- part dialogue between the engineer and fireman and a fun train wreck scenario. A master volume control knob and smoke unit on/off switch are under the tender’s coal load.

Standout sounds and details makes the MTH Triplex a fine depiction of a unique prototype.

HO Erie Triplex
Price: $499.95

Manufacturer
MTH Electric Trains
7020 Columbia Gateway Drive
Columbia, MD 21046-1532
www.mth-railking.com

Description: Die-cast metal and plastic sound-equipped ready-to-run locomotive

Paint schemes: Erie (Russian iron) nos. 5014, 5015, 5016; Erie Black) nos. 5014, 5015, 5016; Virginian no. 700

HO Triplex features
Automatically switches between DC, Digital Command Control (DCC), or MTH Digital Control System (DCS)
Constant-voltage headlight
Die-cast metal construction
Drawbar pull: 4.8 ounces
Engine and tender weight:
2 pounds 2 ounces
Front and rear scale-size magnetic knuckle couplers (mounted at correct height)
Five-pole skew-wound motor with flywheel
Illuminated marker lights and cab interior
Minimum radius: 22″
MTH Proto-Sound 3.0 operates in DC, DCC, or DCS
NMRA RP-25 contour metal wheels (in gauge)
Operating fan-driven smoke unit
Sprung drive wheels
24-wheel electrical pickup
User-installed traction-tire- equipped (or plain) drivers