Greenly’s Hudson

Jim Mullner

March 2022

Drawing Corrections

Eccentric Rod Length

Error noted on drawing AH8 - eccentric rod is 11-1/8 inches long not 10-1/8 inches long. I spent about 3 hours chasing it down today. I would hate to build this without first modeling it entirely in CAD. I had to scale the print to find the error.

Rod Interference

Found another fairly obvious interference issue. The reversing shaft interferes with the coupling rods (see drawing AH14).

I had just completed an animation of the Baker valve gear when I noticed it. The Baker valve gear was a quality job except for the eccentric rod and drop arm.

Smokebox Door

This is not an error, per se, but worth noting. Greenly's drawing number AH20 is a bit sparse, but it looks like there are two working dogs, and those are at 3 o'clock and 9 o'clock. The other dogs are just lining up against the edge of the door and do not actually clamp it down. Perhaps the intent was to make it less tedious to open the smokebox door. British prototypes use a single rotating locking mechanism on the center of the smokebox door, so it appears this was Greenly's solution to simplify access while retaining the look and feel of the American prototype.

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  Detail of the Smokebox Door of Henry Greenly's 4-6-4 Hudson drawing AH20.

Gallery

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  An American 4-8-4 Northern in 7-1/4 inch gauge built from Henry Greenly's Hudson/Northern plans.

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  Exploded view of the cylinder. This can be done using the eDrawings viewer from the parasolid file.

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  Assembly of slide valve cylinder for Greenly's American 4-6-4/4-8-4 locomotive in 1.5 inch scale. From "Model Steam Locomotives" by Henry Greenly, Oct 1962 edition.