Photo showing the air brake distributing valve and related piping ahead of the cab on the right side of a Heisler geared locomotive at Erie, Pennsylvania. Photograph by Schauble.

Photo taken from the rear of the firebox of a locomotive boiler for a Heisler geared locomotive at Erie, Pennsylvania. Photograph by Schauble.

Photo taken from the right side of a locomotive boiler for a Heisler geared locomotive at Erie, Pennsylvania. Photograph by Schauble.

Photo of the cab interior of a Heisler geared locomotive at Erie, Pennsylvania. Photograph by Schauble.

Photo of the cab interior of a Heisler geared locomotive showing the johnson bar and air brake valves at Erie, Pennsylvania. Photograph by Schauble.

Photo looking at the end of a Heisler geared locomotive center truck used on three truck locomotives with bolster in place and frame bolster sitting on top at Erie, Pennsylvania. Photograph by Schauble.

Photo looking down on a Heisler geared locomotive center truck used on three truck locomotives with gear covers and bolster removed at Erie, Pennsylvania. Photograph by Schauble.

Photo looking down on a Heisler geared locomotive center truck used on three truck locomotives with gear covers removed at Erie, Pennsylvania. Photograph by Schauble.

Photo looking down on a Heisler geared locomotive center truck used on three truck locomotives with gear covers and bolster removed at Erie, Pennsylvania. Photograph by Schauble.

Photo looking at the underside of a Heisler geared locomotive center truck used on three truck locomotives at Erie, Pennsylvania. Photograph by Schauble.