This is the Potential of Power Functions

For those of you out there still holding on to 9v worried that the new Power Functions Train System will never be as good as 9v used to be, this is your wake up call. Not only can Power Functions be just as good as 9v, with a little work and some creativity it can be even better. My club PennLUG has been embracing Power Functions full tilt and what we have been able to do with the new system may suprise you. So here are three examples of the potential Power Functions can have.


Amtrak AEM-7  by Nate Brill "Shuppiluliumas"

Fellow PennLUG member Nate Brill brings us this beautiful model of Amtrak's AEM-7 and it is a speedster. Here is Nate's description of this wonderful model.

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Since I joined PennLUG and started doing shows, I've been interested in building full train sets, rather than just locomotives, and I wanted them to run well. When you've got a big crowd at an event you can't be chasing down derailments every five minutes, and you can't have your equipment needing repairs when you're trying to run for 10 hours straight. My first big success in this area was my New York Central 20th Century Limited. I've mostly modeled older equipment up to now, but I live in a major city, so I interact with operating trains pretty frequently, and I do have an interest in modern equipment. I wasn't exactly sure what I wanted to do, though, until I watched an Amtrak AEM-7 pulling a set of Amfleet cars through the station in Trenton, NJ:

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I've seen trains like this a hundred times before but, for whatever reason, this time I was inspired. So, a little history.

Amtrak inherited a whole bunch of equipment from its predecessors, both rolling stock and power, and only introduced new equipment as needed: it wasn't really a fresh start when they were formed. In the northeastern United States, where the main lines were electrified, Amtrak was still using Pennsy's famous GG1s into the 80s. They hoped to get an adequate replacement in the form of GE's E60. the E60 was not originally designed for passenger service, though, and they were not able to safely achieve the 100+ mph speed Amtrak was hoping for. They were mostly retired after a short service life. The GG1s were only finally replaced by the AEM-7, based on a Swedish design, in the late '70s and early '80s. The AEM-7s were smaller, lighter and faster than their predecessors and proved ideal for Amtrak's needs. They are still used in the U.S. Northeast to this day for regular regional service. Much like the AEM-7s, Amtrak's iconic Amfleet coaches were intended to finally replace much of Amtrak's inherited equipment. Their round shape and relatively low profile made them ideal for service through the narrow tunnels and low clearances in the Northeast.

For my model, I began with the prototype Amfleet coach, utilizing the new 2x4 curve slope with bottom tubes for the round shape. I felt getting the shape right was more important than the silver color or corrugated texture of the coaches. Silver obviously would have been very expensive, and I couldn't conceive of a way to do the corrugated sides that would even get close to the right shape. From diaphragm to diaphragm, my Amfleet coach is 64 studs long, a similar length to my 20th Century Limited Pullman coaches (both were 85 feet long in reality). I only have one coach built now, but I plan to build three more when I get around to getting the parts. I didn't plan on building the AEM-7 right away, but I was inspired by a new PF powered truck design of Cale's, used in his new B&O Mikado. The truck design allows for gearing up a PF motor with a 20:12 step up in the truck itself. I thought that combining this with some more gearing up outside of the trucks could create a lot of speed. I mocked up the power system fairly quickly as seen here:

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I have 2 PF XL motors with 36 tooth gears attached to them. These are fixed to the body of the locomotive, and geared up to 12 tooth gears, which transfer power to the trucks. Within the trucks, Cale's design steps up the speed even further. I am very pleased with the performance of this engine. It is most certainly fast, and should have no difficulty pulling the 4 Amfleet coaches I have planned for it. (I tested it on some of my other long coaches.) I'm excited by these results, because it gives me hope that a design like this with two steps up can be used in a more complicated power train, such as might be in a steam locomotive.

AEM-7 Flickr Gallery

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Baltimore & Ohio USRA Light Mikado #4500 by Cale Leiphart

I normally don't like to blog my own MOCs but in the interest of showing off what can be done with Power Functions I'll make an exception.

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During World War I, the federal government took control of the nation's railroads and formed the United States Railroad Administration (USRA) to efficiently mobilize troops and supplies. The USRA oversaw the mass production of standardized locomotives and operations of all privately owned railroads. Consisting of representatives from ALCO, Baldwin Locomotive Works, and Lima Locomotive Works, the USRA Locomotive Committee designed over 1,800 locomotives using the best of current technology. USRA control ended on March 1, 1920 but its durable locomotives continued to have a lasting influence on the railroad industry.

The USRA Light Mikado was one of the standard steam locomotives designed under the control of the United States Railroad Administration. This was the standard light freight locomotive of the USRA types, and was of 2-8-2 wheel arrangement in the Whyte notation. A total of 625 light Mikados were built under the auspices of the USRA, with a further 641 copies built after the end of the USRA's control. The first, for the Baltimore and Ohio Railroad, was completed in July 1918 and given #4500. The locomotives were considered well designed and modern, and were popular and successful. Large numbers remained in service until replaced by diesel locomotives.
With later copies, over 50 railroads used the type.

Constructed in just 20 days by Baldwin Locomotive Works, the B&O No. 4500 was the first USRA locomotive produced under federal management. The No. 4500 was equipped with the latest technology of its time, including a superheater and stoker. The weight of the versatile locomotive was considered "light" by most standards, yet it was quite powerful.

In the later years of its life, the No. 4500 operated on the B&O's Ohio, Newark, St. Louis, and Ohio River divisions. In 1957, the No. 4500 was renumbered as No. 300 to make room on the B&O roster for four-digit diesel locomotives. That same year, the No. 300 retired from service, and was sent to the Baltimore & Ohio Railroad Museum. There it was restored to its original number. In 1990, the No. 4500 became a National Historic Mechanical Engineering Landmark.

#4500 at the B&O RR Museum

While building this engine my main goals were to make this a sturdy design able to be handled roughly with out falling apart, and to have a 100% reliable Power Functions drive with a good balance of pulling power and speed. All while maintaining a high standard of detail. I think I've done pretty well in acheiving those goals and this engine has quickly become one of my favorites.

I originaly built this engine with a single Power Functions Medium motor and a 1:1 gear ratio in the front tender truck for power. The goal was to have a good medium speed freight engine capable of pulling at least 6 of my 8 wide cars. The Medium motor had the power to pull a string of cars but was really at it's uper limit and as a result speed suffered. So it was back to the drawing board. I upgraded to an XL motor and to gain back some of the speed I wanted I built a new front tender truck with a 20 tooth gear to a 12 tooth gear creating a ratio of 1.667:1. This  gave me the boost in speed I was looking for and the XL motor still has plenty of power left to pull a good sized train.

PF Drive

As Nate and I have been experimenting with different gear trains for our trains we've learned that the XL motor will always be a better power choice over the medium motor if you can fit it into your MOC. The XL has ample power and even when geared up for more speed it will still handle heavy loads well.

Flickr Gallery for #4500

Nate Brill was kind enough to take some videos of #4500 at a recent PennLUG display for me.

Mikado Video 01

Mikado Video 02

This is the first time I've built an engine as it appeared fresh off the erecting shop floor. All my previous steam engines have been depicted as they appeared later in their careers. Here is #4500 as it looked in a USRA publicity photo following it's completion.

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Reading G2-sa Pacific by Josh Sanders

Just in case you think that all that drive train complexity from Nate and my self is a bit much and want some thing a little more simple here is what PennLUG's Josh Sanders has don with two standard Power Functions Train Motors.

Reading Pacific

Needing stronger power for increasingly heavy trains, the Reading developed its G series Pacifics by expanding the very successful P 7 Atlantic design. The G2 locomotives # 175 to 179 were built by Baldwin in 1926, and a version of this design was supplied to the CNJ as well. These engines differed only in small details from the earlier G1 class Pacifics in use on the Reading. They were fitted with the large Wootten firebox common to most Reading engines. These engines were carefully designed so they could run as fast as the Reading's Atlantics. They are in my opinion some of the nicest looking engines owned by the Reading.

Josh chose a simple drive train for this engine. He has two standard Power Functions train motors under the tender for power with the battery box I.R. receiver in the tender body.

Here is video of Josh's Reading Pacific running at Steamtown with a string of passenger cars.

You can see this engine has plenty of power to pull 5 not so light weight passenger cars. Earlier this year at BrickFair Josh was pulling 7 of his big Reading passenger cars and it could have pulled more but the motors started loosing traction with added cars. Josh has since added some weight to the tender to help the slipping problem. The new Power Functions train motors have proven to be surprisingly good.

Reading #179


About the Author


Cale Leiphart lives in York Pennsylvania and is a veteran LEGO steam builder and founding member of the Pennsylvania LEGO Users Group. His main interest is modeling steam era railroads in the North Eastern US, in particular those local to his home town of York. Outside of LEGO and trains he enjoys video games, old cars, and collecting farm toys.


  1. jedspurg
    Jeramy Spurgeon September 25, 2011 at 1:47PM

    Excellent post!

  2. RailBlox
    Colin Redner September 25, 2011 at 4:25PM

    Im liking both of th wonderful models.

  3. talltim
    Tim David September 25, 2011 at 9:19PM

    Couldn't agree more with Jeramy. I was going to blog these yesterday, but wasn;t set up. However now I'm glad, because you have done it far better than I could have

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