Locomotives - Hudson

The first 3/16" locomotive to be produced was the New York Central J-3a Hudson in 1939, the prototype of which had appeared in 1937 with considerable fanfare.  (Gilbert produced an HO J-3a in 1938, and it remained the only prewar HO locomotive.)  In the 1939 catalog, the O gauge Hudson is listed as 564, but the model is pictured as numbered 5405, which was the prototype number of the first J-3a.  However, all surviving examples of this locomotive appear to be numbered 5640, which was never an actual prototype number, but closer than 564.

Set 4022

Gear Drive

The first production models used a spur gear drive, taken over from the Chicago AF locomotives.  This seems to work well enough.  There were often quality-control problems with the diecast boilers and other diecast parts on these early locomotives, and sometimes the parts just seem to crumble into pieces.  But other examples are still in excellent condition. 

This model was produced with DRC (Directional Remote Control).  The Hudson was available as a kit.

#564 with gear drive.  Cab number is 5640.  Note RH machine screw in firebox for attaching frame.  Also, the turbo generator on the boiler immediately in front of the firebox is a separate casting, attached with a machine screw.

On left side, note the brush holders above the drivers.  

Note that this particular engine had parts of the cab roof broken off; it's been epoxied back together.

Spur gear mechanism for the 564

Worm Drive

Production later shifted to the worm-drive motor, the basic design of which remained unchanged for most S gauge steam locomotive production.  Starting in 1940, the Hudson with DRC was cataloged as 531, and the standard remote control version as 570.  These model numbers appeared on the cab.  The 531 was available as a kit.

The boiler is basically unchanged; the frame mounting changed to the system later used on the S gauge versions, and the turbo is now part of the casting.

The armature can barely be seen above the trailing truck.  The oil pan for the drive gear is held on with a screw.  The pickup contacts are an improved design.

Tender

Tender design remained unchanged.  In fact, the tender design was basically unchanged through the S gauge era, except for the trucks, of course.  As with most O gauge locomotives, the tender has no real function and is basically along for the ride.

S gauge compared to O gauge