Steam & Excursion > What's missing from this boiler?

The Billy Jones Wildcat Railroad #2 (Los Gatos, California) was originally built in 1906 for the 18" gauge Venice Minuature Railway. The designer, John Coit, wanted modern locomotives for his three engines, #1 a 2-6-2 built in 1905, the #2 also a 2-6-2, and a smaller 2-6-0 built in 1903. His designs featured a unique component in boiler construction for that era. (Both the #1 and the remains the 2-6-0 are under private ownership).

When the BJWRR re-boilered the #2 over 10 years ago, they requested the new boiler, built by John Greeco of Bay City Boilers, to follow the original Coit design. The original 1906 boiler was placed as an exhibit in front of the BJWRR roundhouse.

The images are of the original boiler and of the operating #2.

What makes this locomotive boiler design unique? Are there other existing locomotives with the same design?



Edited 1 time(s). Last edit at 08/19/17 19:53 by KMiddlebrook.

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That construction almost looks like a water tube boiler, need an end view.

Out

I see no staybolts and no firebox. Looks like the combustion takes place inside a direct heating surface consisting of a relatively large cylinder surrounded by a larger cylindrical boiler shell containing the water/steam space. Probably fired by a gas or oil burner in the center of the direct heating surface.

Scott Griggs
Louisville, KY

sgriggs Wrote:
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> I see no staybolts and no firebox. Looks like the
> combustion takes place inside a direct heating
> surface consisting of a relatively large cylinder
> surrounded by a larger cylindrical boiler shell
> containing the water/steam space. Probably fired
> by a gas or oil burner in the center of the direct
> heating surface.
>
> Scott Griggs
> Louisville, KY


You are correct. It is a Vanderbilt firebox design of basically a cylindrical firebox supported inside the cylindrical boiler shell by plates. The result...no stay bolts. Around 1900, mainline railroads explored methods of reducing locomotive maintenance costs by eliminating, in this case, stay bolts. Unfortunately, this came at the expense of losing firebox heating surface and steaming capacity.

The Vanderbilt design worked fine for the Venice Minature Railway where the boilers were somewhat large for the scale.

In a 1909 article, Coit talked about occasionally taking a cold boiler to full 175# operating pressure in 45 minutes! For the kids reading this at home...that is NOT a good practice.



Edited 2 time(s). Last edit at 08/20/17 11:38 by KMiddlebrook.

Um, if it works, then nothing is missing.