21: Stetson
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21:Drive Train
21: Backhead
21:Tender
21:Bob Baxter

North Pacific Coast No 21 - Thomas Stetson

This was the most innovative engine ever built by William (Bill) Thomas, the NPC master mechanic who was nationally known and holder of a number of patents.  This engine was constructed with parts from No 5, the Bodega.  The Bodega was a Baldwin 4-4-0 purchased by the NPC in 1875.  It was wrecked and scrapped around 1897.

Thomas used the running gear and frame from No 5 to build No 21.  But he added a new boiler and cab, installed in reverse order creating a locomotive that was unique and first of its kind in a number of important areas.  According to Harlan, Thomas received a patent on this locomotive design.  What is not clear is which of its many unique features were the subject of the patent application.  The Southern Pacific claimed that their adaptation of the cab forward design was not a patent infringement as all they did was take an existing locomotive and turned it around.  Neverless, this locomotive had a number of features that set it apart from any locomotive built before 1900.

  1. It was the first cab forward locomotive and as such lays claim to being the grandfather of the Southern Pacific's cab forward articulated locomotives.
  2. It used an oil burner for firing the boiler.  Some claim it was the first oil fired locomotive although others claim other railroads experimented with oil firing prior to 1901.  It was certainly the first locomotive designed from the ground up to be fired with oil.
  3. The boiler was a marine boiler, the first to be installed on a locomotive.  Jim McAdam, the line's master boilermaker constructed a marine water tube boiler, slanted toward the rear of the engine for good circulation.  Water was heated through sixty three inch tubes through a corrugated furnace inside the boiler shell.
  4. A steam tube mounted to the top of the engine replaced the steam dome on conventional engines.  The sand box was mounted beneath the boiler.
  5. The tender was a flat car with vertical tanks for oil and water.

No wonder No 21 was referred to as "The Freak" as it moved up and down the line.  One author says, "When the oil jets were opened, the fire boomed and roared like a blast furnace.  Flames flared from open seams in the fire box.  When No 21 passed at night, its fire lighted the countryside.  Windows in houses a half a mile distant shook and rattled when the locomotive rolled by."

The 3 following drawings are from George Harlan's "Those Amazing Cab Forwards" published in 1983.

This is a side view showing boiler detail. 

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This is a front and rear view.  Front view shows boiler piping.

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This is an exterior side view drawing.

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This is a front and rear exterior drawing.

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This series of photos, also from the Harlan book shows the boiler under construction.

This is the interior portion of the boiler containing burner and tubes.  The inner boiler is being slid into the outer boiler.

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This photo shows the exterior boiler jacket.  As the above photo shows the area between the interior and exterior portion contained water.

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This is a second construction photo.  A portion of the boiler shows inside the cab.

Note: This photo is reversed.  This is the fireman's side.

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The following is a fairly complete set of in service photos.

This photo was taken during the construction process.  The boiler is well back in the cab interior.

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This photo shows No 21 on her trial run with Bill Thomas at the throttle and Bill Wosser firing.  Note the headlight placement.

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This side in service photo is the best side shot of controls.

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This in service photo shows No 21 at Point Reyes.

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This photo shows No 21 in service on Christmas day in Occidental in 1901.  Note the unusual tender.

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This final shot shows No 21 crossing a trestle in San Anselmo in 1902.  Note that the headlight has been raised and large tube has been added to supply additional air to the oil burner firing the boiler.

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Alas, No 21 suffered from a lack of weight over the drive wheels causing it to be more prone to slippage than the other NPC 4-4-0s.  In addition, it was hard to find crew with the expertise to fire this unusual stem engine.  Crews were nervous because of the lack of protection in the event of an accident.  Apparently seats at the rear of the cab needed to be raised to allow the crew to exit to the running boards.

According to Harlan, she was not retired as a result of a fireman mistake as pointed out in a number of other publications.  Rather the burners were too close to the steam generating tubes, causing them to blister.  This was invisible to those servicing the engine.  She was doomed from the beginning.  But she was also the father of the Southern Pacific Cab Forwards.

bulletBackhead Detail - A vexing question given the unique boiler design for this engine.
bulletDrive Train - This is the part Bill Thomas kitbashed.
bulletTender Detail - How the water and oil supply system worked.

Inspiration & Other Models

I was inspired to begin compiling the prototype information by a post by Bob Baxter at the MLS Web site asking for help with backhead details on No 21.  I had always dreamed of building this engine, but I saw the project as being somewhat overwhelming.  But with a combination of the research compiled in this section and the inspiration of Bob Baxter and Chris Walas, I'm gaining the courage to take this on.  Here are some photos of models of No 21 built by friends at the MyLargeScale.com Web site.

bulletBob Baxter
 

(c) 2007 Iron Horse 1:29