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Rivarossi & the Indiana Harbor Belt U4a

While browsing the internet a while ago I happened upon a discussion about Rivarossi’s O-Scale 2 rail steam locomotive kits, namely their Indiana Harbor Belt 0-8-0 (class U4a). This is a BIG locomotive for an 0-8-0; it is beefier than most Mikados, and is often credited with being one of the largest steam switchers ever built. Three were built by Alco in 1927, equipped with a tender booster, Elesco feedwater heater, and most uniquely, a third cylinder directly under the boiler (more on that later). Rivarossi sure knew how to pick a unique obscure model.

IHB 0-8-0.jpg

Photo Credit:

Switcher 0-8-0.jpg

Photo Credit:

The New Haven Y-4

Sitting across Alco’s erecting floor from the U4a’s were the New Haven’s Y-4a class 0-8-0’s. After purchasing several standard USRA 0-8-0’s (classes Y-2 & Y-3), the New Haven decided it needed a switcher with a bit more muscle. In 1924 they purchased ten 3-cylinder switchers, class Y-4, and went back for another six in 1927 (the Y-4a’s mentioned above). The New Haven used these engines primarily in the hump yards on the system: Cedar Hill and Hartford (Ct), Maybrook (NY), Providence (RI), and Worcester (MA). However, as evidenced by a few photos in the wonderful book New Haven Power, these engines did occasionally hustle long trains on the mainline. I can’t imagine what a ride at speed would be like in a yard switcher.
The other cool thing about the Y-4 class engines were their delivery with modern road tenders. The idea was to order the new engines with large tenders, transfer those new tenders to larger locomotives already in service, and then cut the old (smaller) tenders into clear-vision tenders for the switchers. This wasn’t all done at once, resulting in several Y-4 engines running their first year or two with tenders as long, if not longer, than the engine itself.
The U4a and Y-4a, both being 1927 Alco products of similar concepts, bear a strong resemblance. Some details of the earlier Y-4 class, such as throttle position, were changed on the Y-4a, making that subclass more similar to the U4a. I thought this resemblance strong enough to create a credible Y-4a from the Rivarossi model.

Builders Photo Y-4 3605.jpg

Y-4 3605, with as built tender destined for a Road Locomotive.

Y-4-a 3613 is at Cedar Hill in May 1938.jpg

Y-4a 3613 with modified clear-vision tender. Note the change in throttle position from the Y-4.

Photo Credit for the two above photos, and for more photos of New Haven steam power:
Edward Ozog

Modifying the Details

The first thing that had to be done was to eliminate the Elesco feedwater heater and its associated piping. The bell was relocated from the boiler front to the top of the smokebox, just ahead of the stack. The box-like structure behind the stack was built up with some styrene shapes (I don’t actually know what this device is; I would appreciate it if someone could enlighten me). One of the handrails was flattened to eliminate a loop where the handrail dodged a feedwater pipe. All of the extra holes in the boiler left by the elimination of details were filled with styrene rods and sanded flush. The smokebox then got a quick dip of graphite gray, while the firebox was painted silver.

Side View 1.JPG

Side View 2.JPG

Front View 1.JPG

3rd Rail Operation

Luckily, Rivarossi used oversized flanges in their O-scale 2 rail models. Not nearly as large as in 3-rail, but just large enough to comfortably use on tubular track. The motor leads and outer rail pickups from the drivers were wired to the female half of a plug I installed in the locomotives cab. Diving into my parts bin, I picked out an old lionel tender and drilled out the truck rivets. A set of Williams by Bachmann 3-axle tender trucks (importantly, with third rail pickups) were attached in their place. An E-unit from a gutted MTH 2-6-0 was wired in, with 3rd rail and outer rail pickups on the tender, and the motor leads and another outer rail pickup going to the male half of the plug. The drawbar on the Williams trucks line up well enough to use the small drawbar mounting screw already on the bottom of the Rivarossi model.

Cab View & Plug.JPG

Tender Quarter View.JPG

Tender Underside.JPG

It is here I’d like to note that the model does run well on tubular track, including 0-36 Fastrack, and can pull quite a bit despite the size of the motor (6+ postwar freight cars at 16 Volts). When I have access to my home layout I will really be putting it through trials.

Future Work

Piping and other details may be added to the boiler to more closely match the Y-4a’s. I am happy with the look I have there now, so this part of the project will be much farther down the line. I am looking for a nice boiler front to replace the current one; because of the Elesco feedwater heater, the U4a’s have a much smaller smokebox door than the Y-4’s. The most urgent project is to construct a proper tender. Using the current Williams trucks, I am planning on constructing one of the as-delivered road tenders out of basswood. As part of this construction I plan on replacing the E-unit with a ERR Mini Cruise Commander (already on hand) and replacing the plug with a much smaller one.

3 – Cylinder Engines

Remember in the first paragraph when I said I would get back to the third cylinder?
Third cylinders were an effective way to increase the efficiency and power of a locomotive. While used much more extensively in Great Britain, in the US they could be found on a handful of railroads, including the New York Central/Indiana Harbor Belt, New Haven, Delaware & Hudson, Southern Pacific, and Union Pacific.
The cylinder was mounted at an angle below the locomotives smokebox; most commonly, it would be attached to a crank on the second axle. This means that instead of the two outer cylinders being quartered (the main rod being attached to the drivers 90o off from each other), all three cylinders were 60o off from each other. This resulted in more even power transfer to the rails; instead of 4 power strokes per revolution of the drivers, there were now six. A of minimum of two cylinders were also expanding or compressing at any given moment, while the third was at top dead center (or whatever the steam equivalent terminology is).
The third cylinder was governed most commonly by Gresley valve gear, designed by Sir Nigel Gresley of the LNER in Great Britian. In short, it used the position of the pistons in the outer two cylinders (which could be governed by a typical valve gear, like Walschaerts) to derive the position of the third pistion. This motion was translated through a series of levers, which can be seen attached to the front of the outer cylinders of locomotives so equipped.

Valve Gear Front.JPG

Front view of pilot, showing the third cylinder, Gresley Valve Gear protruding from the outer cylinders, and levers running under the smokebox.

Valve Gear Side 1.JPG

Valve Gear Side 2.JPG

Side views of valve gear; the gear for the third cylinder can be seen as the angled bar above and behind the front driver, behind the air pump.

Side Valve Gear.JPG

The valve gear on the outer cylinders are standard Walschaerts.

If you made it this far, thanks for reading.

8,520 Posts
I will be interested how this works out. I should be able to pull a lot more than six cars. It was a great loco, very unique. Thank you for this post.

0 Posts
You have presented this extremely well. Lot's of work on your part.
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