Introduced: 1968 (by Atlas)
This, the first industrial switcher ever offered in N scale, is not a bad running little locomotive (relatively speaking). That speaks volumes, given the generally sad state of most of the locos released by Mehano. Yes, it's pretty smooth and pretty quiet. However, you just can't get around the fact that it's simply too light and has too small of a pickup footprint to be run reliably - IE, it runs OK at full throttle, but that's about it. Couple all that with the sloppy paint and primitive shell detailing and you have a model that simply doesn't belong in an operational fleet.
The shell is held to the chassis with two plastic tabs, and basically lifts right off with a little bit of pressure.
Atlas dumped this locomotive fairly quickly, and instead went with a Roco-made WDT circa 1972. The shells between the two models are virtually identical (although they do have their subtle differences). The mechanisms, on the other hand, are quiet different. It's easy to tell the two versions apart - the Mehanos don't say anything on the bottom of the chassis, whereas the Roco units are stamped "Atlas - Made in Austria". Unfortunately, the Rocos aren't really much of an upgrade - performing pretty much the same as these Mehanos.
Post-Atlas, these Mehano locos were imported for a few years by Model Power (who had a propensity for scooping up low-end models otherwise dumped by their higher profile brethren). I'm not entirely sure when they met their ultimate demise, but I seriously doubt they lived to see the 1990's. As far as I know, this model remained essentially unchanged throughout its entire production run - no upgrades, no improvements, no nothing.