Back now a couple years ago an article was posted in American OO Today that included how to convert the HO A.H.M. Alco switcher to OO. Last week my only purchase at the train show was another of these vintage models, a model worth taking a bit more of a look at.

The short version is this model approaches OO scale in most dimensions and is also simple to convert to operation in American OO. This image is reproduced from the A.H.M. 1979 catalog. The full page with this image may be found on the HOSeeker website here, and the index page for the catalog is here. In the catalog it states that the “Alco 1000 Yard Switcher” is

An unaging switcher which is still being used today. A.H.M.’s model includes features such as operating headlight, gear drive, RP-25 wheelsets, and operating couplers at both ends.

The model itself is of an Alco model S-2 switcher, in particular according to the Model Railroader Cyclopedia, Vol. 2, Diesel Locomotives of a model produced 1943-44 with horizontal shutter slats on the radiator. It was their best selling model of switcher with 1502 units produced between 1940 and 1950.

Unfortunately for A.H.M. and for Model Power who later sold the same model, the scale drawings in the Model Railroader Cyclopedia tell the story of a model that is overscale for HO. For example the body should be 41′-6″ over the end sills and this model is 151 mm long which puts it at 37′-9″ in OO and over 43′ in HO. That does not really tell the story though as also the walkways are too narrow all the way around and the body itself is quite close to OO in length. The trucks have a wheelbase that is correct for OO as well with OO sideframes. The only dimensions that appear to be correct for HO are the width of the model and wheelset diameter. From the side it is certainly very close to OO and the hood is as well in width. The cab roof however has a “rounder” profile than the prototype, this being due to the model being essentially OO height but HO width.

As I noted in the earlier article it is a pretty simple model to convert to OO operation as really all you need to do is widen the wheels out on the existing axles, split the sideframe casting in the middle so that it can be remounted wide enough to fit, and remove the HO couplers and work out body mounting at the correct height for Kadee couplers. And it looks good with OO models.

This has been produced with at least two drives over the years. The old standard one is in the back in the photo, with a motor that is built into the truck with a vertical shaft. The later version  has a can motor mounted horizontally. I suspect that the back version is on the A.H.M. version of this model and the front on Model Power version of this model, but the changeover could have happened before or after the change of maker. Either version can be converted to OO. Of the two the later drive is the better setup, but the gearing is a bit high, the pulling power a bit low, and only two axles are picking up power.

The second type of drive can be rebuilt fairly easily with Athearn drive parts, and while it makes it a more advanced conversion, that would be my preferred plan for OO operation of this model. The gearing is better and also you gain eight week pickup. Run them in multiple for more pulling power. For a more advanced project you could also work out an RS-1 from the body parts; this is a project I would also like to tackle someday.

The A.H.M./Model Power Alco 1000 is an option for the OO operator who is an Alco fan and should be noted clearly as a model that can be rebuilt for operation in American OO.