Articles - Atlas RS-1
01/01/2003
The American Locomotive Company ("Alco") started building the RS-1 road switcher in 1940 and continued to build them into 1957. This was the longest production run of any single design in diesel engine history. The RS-1 had a 6-cylinder 539 motor in it, rated at 1,000hp, with a top speed of 60mph. It was produced with four wheel trucks and some six wheel trucks. The six wheel trucks were used on lighter rail where the weight had to be more distributed. The RS-1 was followed by the RS-2 (1,500hp) and the RS-3 (1,600hp), although they were produced simultaneously by Alco. These engines could be used for yard switching, road service, or passenger trains. They were outfitted by the manufacturer for one of those tasks. PRR RS-1 #5906 was the Pennsylvania Railroad's first diesel road switcher, which was bought in 1948. It was used to replace a steam engine in the Baltimore, MD commuter service. During the Summer of 1950, the PRR bought 22 more RS-1s. Two more units were bought each year of 1951 and 1952. The PRR ran the engines with the long hood forward. All but one made it through to the Penn Central merger of 1968. In the PRR these were classified as "AS10am", except for the first one, which was a "AS10s". The first four characters stood for Alco, Switcher, 1000 horsepower.

The Atlas RS-1 is a very nice-looking, accurate, and good running engine.
Atlas RS-1

Disassembly

Atlas used to make a small book called "The Atlas Parts Catalog". It provides very good instructions for how to remove the body shell from the frame. This article was written before I started taking digital photos, so it is just a textual description. After popping out the handrails from the cab, remove the cab which is held with latches to the rest of the shell. Once the cab has been removed, you will see two small tabs on either side of the body shell. Grab these with a small pair of pliers and gently pull on the them to spread the shell out a little. This will disengage the tabs on the frame from the shell. The running board can now be moved out of the way. Note that it, too, has some tabs that may get caught in the frame. Again, gently spread the running boards out and away from the frame. There are two screws that hold the two frame halves together. Note that there is a insulating bushing between the frames. The nut that the screw goes into can easily fall out of the frame, so keep an eye on that. Remove the fuel tank shell, if you haven't done that already. Once the frame halves have been separated, the motor, flywheels, and worm gears can easily be removed. The two trucks will also fall out. The photo below is of the stock model with the original Rapido couplers. Atlas later produced another run of these engines, where they started using Micro-Trains compatible couplers.

Coupler Conversion

See my other article on this model about how to disassemble the model to get to the trucks. At first disassembling the trucks may seem like a daunting task with all those gears in there. It is actually quite simple, and not that difficult to re-assemble.
Atlas RS-1
Look at the truck on the side that doesn't have the coupler installation. You will clearly see the metal frame of the truck under the lip of the plastic body. Use a small screwdriver and wedge it in between the two parts. To make it easier on yourself, start with the frame half that doesn't have the gears.
Atlas RS-1
The frame half will almost pop loose. Carefully remove it.
Atlas RS-1
The frame half removed.
Atlas RS-1
Do the same with the other metal frame half.
Atlas RS-1
The gears can fall off, so keep an eye on them. All the gears go on in one direction, so don't worry if they do fall off. The next photo shows the disassembled parts of a truck.
Atlas RS-1
I cut off the large Rapido couplers by cutting the truck frame off a the point indicated by the knife in the next photo.
Atlas RS-1
To re-assemble the trucks, just go backwards. Make sure that the wheel wipers are in between the wheels and the metal frame half. The metal parts should snap into place. It takes a bit of patience, but it should go fairly smoothly. This is what the truck looks like after the Rapido coupler part has been removed and the truck re-assembled. This then allows for the space needed to install a Micro-Trains N- or Z-scale couplers, which are mounted on the body.
Atlas RS-1