It’s all about the Three

The Sierra #3 is labelled in three primary locations; on the front of the boiler, painted on the side, and two cast metal threes, mounted to the side of the sand dome.  In preparing the sand dome for sandblasting, one of the threes was damaged, necessitating casting of a new three.  Volunteer Leonard Jones took on this project, preparing the three for casting, and working with a foundry near Stockton to cast the replacement.  Since most of the work and expense is in the preparation, a few spares were cast as well. 
The current number three, removed from the Sand Dome.
A current number three, from the sand dome.
The foundry worker prepares the pattern board.

The foundry worker prepares the mold by cutting in the riser passages.

Filling the molds with the molten brass.

Filling the molds with the molten brass.

The filled molds, showing the holes or "gates" where the molds are filled.

The filled molds, showing the holes or "risers" where the molds are filled.

The "shake out".  The finished product, still connected to the gates and risers, is separated from the rammed bentonite mold material.

The "shake out". The finished product, still connected to the gates and risers, is separated from the rammed bentonite mold material.

The final threes, with gates and risers still attached, await final cleaning.

The final threes, with gates and risers still attached, await final cleaning.

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