Those seeking a brief history of Marx toys and trains click below:

Louis Marx Toy and Train Brief

  MarX the Mercury

Blue Windup Whistling Mercury             Black Windup Mercury

Here is an example of a popular steam locomotive the MERCURY. Produced from 1938 until the early 50's, this loco pulled everything from freights to passengers. Formed of heavy sheet metal with a tear drop metal smokestack and 0-4-0 wheel arrangement, it was quite versatile. It bears the Mercury nameplate on the sides and Made in USA, NYC Lines on the pilot. Coming in traditional black, red, gray, and blue colors, it is still quite popular today as a windup or electric model. It is cataloged as number 635 (or 233). It is nearly 9 inches long and weighs 1.5 pounds.

Some of these Mercs have a special mechanical whistle that is quite unique! It is placed at the very front of the boiler underside. Better check if yours has one, it's really neat!

Pulling articulated passenger cars, it has a fixed coupler that is an integral part of the loco cab floor that would accept a coupler pin (talgo) that is formed through the roof/body of the cars.

Pulling copper passenger cars, the engine would have been black and have a brass/copper (actually yellow varnish) boiler front. !

As a freighter it would have a rotating riveted metal hook coupler. However it could pull six inch red passenger cars in this form also, and could have a chrome(nickel plate) pilot. I think this is my favorite, with lighted white and red litho base passenger cars!  

And speaking of Red Mercs, there is even a 6v battery pack power version of the Merc.

The only way that I know of that is was not used, was as an army train !

Marx Army Train Review