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In-Box Review
HO scale
Genesis 4-8-2 Steam Locomotive
HO 4-8-2 MT-4 w/DCC & Sound, Unlettered
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by: Frederick Boucher [ JPTRR ]

Originally published on:
RailRoad Modeling

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Moving Mountains

Early 20th Century railroading is known as The Drag Era. Speed was not deemed as important as the ability to drag as much freight tonnage as possible. However, these slow freights got in the way of the fleet passenger trains. At the same time perishable freight was demanding faster freight train speeds. Freight locos like 2-8-0 Consolidations and 2-8-2 Mikados were not up to the task. The Mikado had potential if the driver size and steaming capacity could be increased. This was achieved and a four-wheel leading truck, such as used on fast passenger engines, was also added for stability at speed. Thus was born the mighty 4-8-2 Mountain type. In 1927, ultimately fitted with a Superpower four-wheel training truck, the type was afforded the ability for steam generating capacity for sustained high speed running with tonnage. Thus evolved the ultimate fast dual-service locomotive, the 4-8-4 Northern type.

The Chesapeake & Ohio Railroad is credited with the development and employment of the locomotive with the 4-8-2 wheel arrangement. They needed a more powerful locomotive to haul the ever-increasing weight of their passenger trains over the Allegheny Mountains. Thus the C&O named this new type of locomotive Mountain. [1] Mountains were a very successful class of fast dual-service locomotives. They were operated by 41 railroads in North America alone. The first of some 2,204 Mountains was C&O 316, built in 1911. The last one was built in 1948 for the Baltimore & Ohio R.R..

Southern Pacific / El Paso & Southwestern 4-8-2 Mountain
The first 28 "Mountains” on the Southern Pacific Lines were built by the American Locomotive Company and were delivered during 1923 and 1924. These locomotives were designated Class Mt-1 and assigned road numbers 4300 through 4327. They had 28" x 30" cylinders, 73" drivers, a 210 psi boiler pressure, a tractive effort of 57,510 lbs. and weighed 368,000 pounds. Later, in 1924 another six Mountains were delivered from ALCO. These six (road numbers 4385 through 4390) were designated Class Mt-2 and were similar to the Class Mt-1s, but had a 225 psi boiler pressure and a tractive effort of 61,620 pounds.[1]

The Sacramento General Shops of the Southern Pacific built 49 Mountains between 1925 and 1930. These were built in three batches: road numbers 4385 through 4345 designated Class Mt-3 in 1925 and 1926, road numbers 4346 through 4366 designated class Mt-4 built between 1926 and 1929 and road numbers 4367 through 4376 designated Class Mt-5 in 1929 and 1930. These locomotives were essentially copies of the Class Mt-1s. There are no surviving examples of the Southern Pacific Mountains. [1]
Southern Pacific Class Mt-4
No. 4346-4366
Built 1926-1929

• Valve Gear Walschaert
• Overall Wheelbase (engine & tender) 83.50'
• Engine Weight 368000 lbs.
• Tender Water Capacity 12000 gal.
• Tender Fuel Capacity (oil/coal) 4000 gal.
• Driver Diameter 73.5”
• Boiler Pressure 210 psi
• Cylinders 28" x 30"
• Tractive Effort 57120 lbs.
• Factor of Adhesion 4.31
• Firebox Area 355 sq. ft.
• Grate Area 75.70 sq. ft. [1]

While this model is of a Southern Pacific (also known as SP and Espee) prototype, it has classic lines that can fit right in for Mountains of many railroads.

HO 4-8-2 MT-4 with DCC & Sound, Unlettered

Now equipped with a SoundTraxx Tsunami Digital Sound Decoder, Athearn also produces MT-4s with partially shrouded skyline casings; some of those received the spectacular Daylight livery on the cab and tender for hauling Espee passenger trains.

Athearn pride shows in their packaging. Athearn Genesis models are packaged in a sturdy glossy blue box which is decorated with a gold embossed Genesis logo. The locomotive and Vanderbilt tender models are securely held in an open side, form-fitted wraparound cradle which provides a base, ends, and top; the cradle snap locks via a tab to an end. Within the cradle the models are protected from scuffing by foam blocks and sheets. The cradle is then ensconced inside a clear plastic sleeve, and a piece of Styrofoam supports the base of the cradle. The sleeves snugly set inside cutouts in a thick foam tray in the box. Finally, a thin foam sheet protects all of the above from the inside of the box lid. These models are superbly protected from shock and jostling.

Documentation includes a DCC quick-start guide, an Athearn advertisement, and a 10 page booklet about the model and the prototype. It features a detailed history of the type, an exploded-view parts diagram and parts list, a dramatic watercolor of a racing MT-4, and an MT-4 photo gallery. The DCC quick-start guide lists web sites for referencing further information.

The locomotive and tender are fully assembled. You must join them before they will operate; a plug from the tender fits into a receptacle under the cab apron and the two units are joined by snapping an engine mounted drawbar into the tender. The MT-4 continues the tried and true Athearn model engineering concept. You have an injection molded styrene body shell secured upon a die-cast underframe by tabs and screws. Mounted on the underframe between two metal weights is the dynamically balanced five pole skew wound motor with dual flywheels. This transmits power to the axles of each powered driver via the Genesis driveline and worm gears. The only drawback is that the drive can be seen in the open space between the running gear and the boiler. Power is transmitted from the track to the motor via spring-button pick-ups. These are small rods that touch the inside of the drivers. Though this method has been used for decades, some DCC users warn that these can melt should the model encounter a severe short circuit. All eight wheels pick up power. Two have traction tires.

Some previous steam locomotives by Athearn featured a single connecting rod for all of the drivers. Prototype steam loco manufacturers found this to be flaw, and it does not work well on model steam locos, either. The more drivers, the more binding can occur. Athearn manufactures the connecting rod for the MT-4 in three parts. Attached to the rods is a good representation of Walschaert valve gear. The metal drivers are blackened with nickel tires. Unfortunately, the pilot and trailing truck wheels are shiny, as are the tender wheels.

The top boiler shell is molded as a single piece. Most of the main details are plastic or light metal and separately applied. Few elements are molded on. Not all parts listed on the website are applied to all models. Only those parts applicable to the prototype are included with the finished model. The website states the model has see-through running boards when in fact, they are solid.

My inspection finds the model to be in conformance with NMRA Standards and Recommended Practices, with RP-25 wheels and couplers at the proper height. The model weight, combined with traction tires on some drivers, should give you some good model tractive effort.

Key Features

* Boiler backhead with full details and printed gauges
* Individually applied detail parts like piping, valves and generators
* Blackened metal wheels
* Factory installed DCC sound board and speaker mounted in the tender
* Decoder automatically senses the power supply (works with both DC and DCC systems)
* McHenry scale knuckle spring couplers installed
* Smoke unit ready with no soldering needed (not on this model)
* Minimum radius: 22" recommended

This sharp model features the type of detail that, until about a decade ago, was only found on brass imports.

On the Inspection Track: Details

First, the engine. This appears to be an early version of the MT-4. The headlight is certainly the early style. Sunbeam or visored Pyle headlights were added as MT-4s were modernized. Each headlight has a single micro bulb. These give an authentic amber glow.

Although some steam locomotives were massed produced on a production line, they were still handmade. And every shopping could result in changes unique to a locomotive. Two engines parked side-by-side could receive appliances of different manufacturers. If you want to model a specific loco, you’ll have to decide on the specific date range and find references for it.

We’ll start our walkaround at the front with what differentiates classes of steam locomotives from each other, the wheel configuration. A Mountain is a 4-8-2 per the Whyte notation (UIC classification 2′D1′). The leading (pilot) truck features basic detail including brake shoes. The wheels are shiny. Next are the eight 73-inch drivers. They are properly blackened except for the tires. Not a concern as some railroads accentuated these with white or silver paint. Brake hangers and sand pipes properly detail the spaces between the drivers, though no driver springs are represented. The trailing truck is plastic, sprung, and does a fair job of hiding those shiny metal wheels. The truck features casting data on both sides.

A fully detailed and animated Walschaerts valve gear sprouts from the rear of the detailed cylinder chest. Both plastic and metal parts make up the valve gear. It looks smooth when operating.

All of that is set in and upon a metal frame. The bottom third of the boiler is wonderfully detailed with the appliances of a steam locomotive. The engineer side sports a feedwater pipe, overflow, air brake reservoir tanks and valves, air brake cooling piping, and power reverse. The fireman side has the prominent compound air pump and Worthington BL feedwater heater, and the piping to feed them.

This MT-4 features a road pilot with individually applied steps and a McHenry knuckle coupler. A snow plow pilot is also available. Above and behind it is the stepped pilot deck (‘campground’ in hobo-speak) with metal tread decking. Train line and air brake hoses set atop this with their hoses dangling over the pilot. The coupler cut bar and handles cross over the pilot beam.

The smokebox front is sharply detailed with a variety of molded and applied accessories, such as the front-end-throttle cover. Unlike so many other model steam locos, this model did not have a gap between the smokebox front plate and the smokebox body. It shows in some photos as I picked at it to explore the ease of removal. The smokebox is painted in silver graphite. Wires to the headlight can just barely be seen due to the tight fit of the headlight to the front access hatch. Individually applied marker lamps and handrails adorn this area. However, the marker lamps are plastic and the lenses are painted; this detracts from the otherwise commendable detail of this model. It should not take much effort to drill them out and add marker jewels, or even replace them with brass markers. Atop the smokebox is a flared stack with nice thin walls. The number boards round out the engine’s face. On the sides of the smokebox are raised areas for builder plates and other data plates.

The boiler is a sharply molded plastic partial shell with the steam and sand domes molded on. The top is about two-thirds of the boiler with the bottom third part of the chassis. No flash, ejector marks, nor sink holes mar the shell. Nitpicky: a faint seam line runs along the top but you have to look for it. The boiler bottom third is a separate piece. Surface detail includes recessed lines for the boiler sheathing, molded raised detail for the boiler bands and fasteners, and various brackets, maintenance plugs and hatches. The top of the sand dome is separately applied, as is the stack. Fine wire handles adorn these. Including the previously mentioned parts I identified 47 individual parts applied to the boiler:
• Bell and hangar
• Whistle
• Pop-off valves
• Generator
• Steps
• Check valves
• Feedwater piping
• Railings and grabs

A separately applied cab brings up the rear of the superstructure. The cab is of a rakish “speed” style. A curved roof is attached to it. While the website states Cab hatches can be opened and closed, this model’s hatch is glued tight. Nor can I make either the engineer or fireman windows move, as advertised. That said, the cab does feature a folding metal deck between it and the tender, grab irons and handles, arm rests and sunshades, and a well detailed interior.

The interior features a molded backhead with basic detail such as firebox door, gauges, washout plugs, and fireman controls. Athearn advertises a Boiler backhead with full details.. . Honestly, the backhead looks bare. The steam and air gauges are prominent as they have printed faces. Smaller gauges do not have printed faces. The interior walls are painted a light green as was common in the era. Both the “hogger” and fireman have seats. Yet the highlight is what I did not see until I started taking photographs: great detail of the engineer’s controls! Individually added are a turret valve cluster, throttle, Johnson bar, and air brake stand. These are details rarely found outside of expensive brass models--impressive!

While no crew is provided, any aftermarket figures should easily fit through the spacious cab opening.

Second, the tender. Espee liked Vanderbilt tenders and fueled their locomotives with oil or coal, depending on what territory the locomotive operated across. This model represents an oil-fired loco, hence the lack of coal and the enclosed top. The top of the oil bunker features a wire dip stick and handles. The front of the bunker is relatively plain but does have a brake wheel. The close fit between the cab and the tender makes superdetailing this area moot. Aside from the rivet detail these tenders were fairly plain. Piping and tool boxes hang along the side. The water tank was fitted with railing and wooden planks to walk along. These have nice wood grain detail and are properly open to access the water hatches. The metal hatches do not open but have good detail. The tender has to-scale ladders, steps, and hand rails. This superstructure rides upon a heavy duty SP 12-wheel chassis. The chassis is well detailed with an air brake system featuring the triple valve, reservoir, brake hangings, and air lines. The rear of the tender sports the cut-lever, and air and train lines as found on the engine pilot. Supporting all of this is a pair of three axle trucks. The wheels are shiny. The trucks have good side detail.

To make this model move you plug the tender mounted wiring harness into a receptacle under the engine cab apron. Then you must snap the engine mounted drawbar onto a post under the oil bunker. This is tricky as the model’s wonderful fine detail is relatively delicate. Use finesse handling the units when attaching or separating them.

Paint and Finish

Athearn's decorated SP locomotives feature stars on the end of the driver axles, authentically depicting the prototype practice. I have read that Athearn did not paint these but used stickers that can be rubbed loose. The Espee models that I have examined have crisp, sharp opaque lettering on the tender and the cab sides.

This unlettered version has a smooth coat of basic black. It appears to be thick and slightly obscuring low detail on one side of the cab. The graphite paint of the firebox and smokebox is smooth and thin. The only blemished I have noticed are what appears to be glue marks on the end of the tender and cab roof.

Stop, Look, and Listen

Model railroaders have a saying, “No matter how many locomotives you have, if you only have one with sound, then you only have one locomotive!” When one of these models is activated, you’ll want to stop what you are doing to enjoy the show. Genesis models feature a factory installed SoundTraxx Tsunami dual-mode DC/DCC decoder with onboard sound. The system automatically senses whether you are powering it with a DC analog or DCC power source.

In DC analog, the model requires around 5 volts to “come to life” with sound, and 7.5 volts will start the unit in motion. The system is limited to 27 volts, damage will result above that; Tsunami is programed to protect itself at 21 volts by shutting down the motor and sound system. To further alert you of overload, the front and rear lights will flash.

The Configuration Variable (CV) is preset yet you can adjust it to suit your tastes.

DCC functions are impressive:
* Compatible with all NMRA standard DCC systems
* True 16-bit digital processor

First, the sound quality. The speaker is a one-inch type and mounted in the tender. The factory set volume and quality was pleasing to my ears. Not all modelers agree. However, the system is considered to be easy to adjust to suite your tastes.
Sounds available are:
• Exhaust chuff, which increases as the engine speed increases
• Whistle and bell
• Pumps
• Air releases
• Boiler blow-down
• Turbo generator
• Squeal of flange ‘music’
• Brake squeal
• Injectors
• Coupler crash and release
• Pop-off valves
• Engine crew ‘tapping around’

Most of these are triggered by you and some are random. Tsunami works with both DC and DCC. DC cannot trigger all functions but some are automated.

When power reaches the model the headlight comes on. It illuminates on a low setting until more power is applied. Lighting is directional -- the loco moves forward, the headlight illuminates; reverse and the tender light comes on. This model does not feature firebox flicker or cab lighting. You can trigger the number boards via a DCC function key.

Whether you do not like the factory settings or want to tweak them to your tastes, Athearn explains how to adjust the CV of a myriad of functions.

Mountain In Motion

While this is a great model for static display, how does she move? Steam loco models, on account of all of those rods and valve gearing, tend to be balkier than diesels. That said, straight out of the box, I ran this model back and forth across my track work of code 83 and 100 Atlas flex track and Atlas and Peco turnouts. She strides gracefully over the rails and frogs and through the guard and wing rails. The slowest I could move her is a scale 4 mph. Adjusting the CV may help the model creep along even slower. Almost any model will run smoother after a break-in period, and a bit of extra lubrication works wonders, too. The wheels clack across turnout gaps with satisfying sounds and motion. Fast or slow, forward or reverse, DCC or analog, I had no trouble that I can attribute to the model. There was one time the pilot derailed backing across the slip switch, and under DCC the engine stalled a few times when crossing it. Adding extra power feeds to the other end solved that annoyance. And while Athearn recommends a minimum radius of 22 inches, modelers have reported it will go around an 18 inch radius (though it doesn't like to!)


The Genesis MT-4 Mountain is an impressive model! The fidelity and amount of detailing, ease and smoothness of operation, molding, engineering, sound library and quality all make this an exceptional model. My main complaint is the backhead. While this is a prototype of the late-great Southern Pacific, it's classic lines can fit right in for many railroads. I find the SoundTraxx Tsunami system to sound better than some other sound-equipped models I have. As the saying goes, "If you have dozens of engines but only one sound-equipped locomotive, you only have one locomotive." And you can’t go wrong if that one locomotive is an Athearn Genesis. Highly recommended.

Please remember when contacting vendors and manufacturers, to tell them you saw this model here--on RailroadModeling.net!


[1] Southern Pacific / El Paso & Southwestern 4-8-2 "Mountain" Type Locomotives by Richard Duley (http://www.steamlocomotive.com/mountain/?page=sp), © 1999-2011 SteamLocomotive.com

Click here for additional images for this review.

Highs: A host of authentic and accurate detailing with individually applied parts. Smooth running at all but the slowest speed and high quality sound in both DC and DCC.
Lows: Shiny wheels on the pilot truck, trailing truck, and tender trucks. A few glue spots here and there, and a sparse backhead.
Verdict: Southern Pacific's MT-4 is well represented with this sharp model. Athearn has produced a plastic model with detail that rivals brass, runs very well, and sounds good.
Percentage Rating
  Scale: HO Scale
  Mfg. ID: ATHG97000
  Suggested Retail: $399.98
  Related Link: 4-8-2 MT-4 Series
  PUBLISHED: Mar 28, 2011
  NATIONALITY: United States

Our Thanks to Athearn!
This item was provided by them for the purpose of having it reviewed on this KitMaker Network site. If you would like your kit, book, or product reviewed, please contact us.

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About Frederick Boucher (JPTRR)

I'm a professional pilot with a degree in art. My first model was an AMT semi dump truck. Then Monogram's Lunar Lander right after the lunar landing. Next, Revell's 1/32 Bf-109G...cried havoc and released the dogs of modeling! My interests--if built before 1900, or after 1955, then I proba...

Copyright ©2021 text by Frederick Boucher [ JPTRR ]. Images also by copyright holder unless otherwise noted. Opinions expressed are those of the author(s) and not necessarily those of ModelGeek. All rights reserved.


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