Geared Steam Locomotive Works ©

Cylinders Trucks Saddle Tanks

Heisler Catalog

Drive Mechanism

The view above is of a two truck Heisler.   In the very center,  above the "1", is the cam part of the crank shaft. To this the piston rods from each steam cylinder are attached.   Above the "2s" are universal joints which allow the trucks to swivel to negotiate a curve and still receive power from the drive shaft.  The drive gear boxes noted above the "3s" are located on the wheel axles that are furthest from the center or middle of the locomotive.  A large bevel gear in the gear box on the axle received its power from a mating smaller beveled gear on the drive shaft.   As you can see, only one wheel axle per truck receives direct power from the drive shafts. This differs from the "all wheel sets" are geared design used on both the Climax and Shay.  This difference was promoted by the Heisler company as being an advantage over the Climax and Shay design because there was ...No friction loss due to needless gearing .   It was probably cheaper to manufacture as a result.   The nonpowered wheels did receive power from the powered (gear box) wheels via side rods on the outside of the wheels, noted just above and below the "4s".  This was a "push me", "pull me" ... or ... "drag me along" sort of method not present or even needed on the Climax or Shay.  

 

On the three truck Heislers, I do not have any information as to how the drive shaft when through the second truck to the third.  Likewise, I do not know if it was the rear most or the front wheel axle on the third truck.   If you have a reliable drawing, photo, or textual accounting, please share it so I can get my "ducks in a row" on this. 

 

Steam Cylinders

Heisler Catalog

The above is a  "cut-away" image of the Heisler's  two steam cylinders.  The cylinders were  positioned  one on either side of the boiler just in front of the crew cab.  They were arranged in a  V shape below the center of the boiler.    Similar to the Shay but unlike the Climax, the connecting rods attached directly to the crankshaft for a direct drive.  This  V cylinder arrangement contributed to the Heisler's construction symmetry and stability as was touted in their marketing literature.   This contrasted to the Shay's offset boiler arrangement and cylinders being on one side.  On a cylinder by cylinder arrangement, it is this author's opinion that the Heisler's cylinders and housings were larger than those ever used on the Shay and Climax.

 

Trucks

Heisler Catalog

The image at left above shows a single truck with one wheel on a block to demonstrate Heisler's patented truck. The Heisler sales promotion booklet touts this design as follows:

      A patented 3-way swivel --- perfectly flexible in its action, while rigid and sturdy in construction--- holds each wheel in contact with the roughest track. Every wheel is always gripping the rail, carrying its full share of the locomotive's weight, and delivering its full share of the hauling power.  

This flexibility was further promoted as  saving the buyer money by requiring  less expensive lighter rail, lighter trestles, and fewer rail ties because they could be spaced further apart.

The side rods described previously are clearly visible on the downward side of the wheels in the above image.  The wheels are spoked with counter balance weights placed on the upper side and opposite the side rods.  The two brake pads (one for each wheel)  are visible to the sharp eye, just above the  side rods and in contact with each wheel.

The image at right above is a top cut-away view of the Heisler trucks.   The bevel gear case and pinion drive shaft connector are clearly visible.  As mentioned previously, the image demonstrates the fact that only one wheelset and axle on the Heislers were geared, with the other of the same truck being ungeared.  This differs from the Shay and Climax which have both wheelsets of each truck geared.

Page  2  of Heisler Components

Page changed: March 10, 2020 01:58:43 PM