Compressed air locomotives, use air compressed to between 900 and 1000 PSI to provide the energy to move the wheels of locomotives. The locomotives required a separate charging station capable of delivering the compressed air from a compressor. This example has sat at the Andrew A. Merrilees Company on Old Weston Rd, for many years.

H. K. Porter Company, Inc. (“Porter”) was originally organized in 1866 as Smith & Porter. In 1878 the name was changed to H. K. Porter & Company and in 1899 to H. K. Porter Company. Porter’s early business was primarily in the manufacture and repair of locomotives. In 1926 Porter claimed to be the largest manufacturer of locomotives in the United States.

Note in the upper right hand corner of the above images that the wheels have a rather thick section shaped like a fan, these are part of the wheel balancing design.

The above model is very close in design to the loco sat at Andrew A. Merrilees in the Junction. However the cab design is different, pictured above is a side  door design, while the loco in the Junction has a rear door.

It is the opinion of some local PRN rail staff the large upside down bell jar looking item on top is a pressure release valve, not really sure.