Pennsylvania Railroad #643. Here's a view of Pennsylvania Railroad #643, a 1901-vintage, Class B4a Yard Switcher, as she coasts downgrade, approaching the entrance road to the Williams Grove Historical Steam Engine Association's show grounds, in Williams Grove, PA. Amazingly, this is the only surviving Pennsy steamer that is still capable of operation today. She's owned by the Williams Grove Historical Steam Engine Association, and operates on selected weekends during the summer on roughly a mile of track. She's seen here pulling the organization's excursion train, which typically consists of a couple of open tourist cars and a caboose.
Although built in 1901 by the Pennsy Shops in Altoona, this engine only spent about 16 years in service to the line before she was sold to a steel mill in Harrisburg in 1917. The PRR considered her obsolete by that date. Over the years, she received some modifications, so what you see today is not necessarily representative of the way she looked in PRR service. Her tender is larger and is of welded construction, and her original boiler, which featured a large, Belpaire-style firebox, has been replaced by a more conventional design, built by the H. K. Porter Company. Because the locomotive is not housed in climate-controlled facilities today, she operates without a boiler jacket, to minimize corrosion of the external surfaces of her boiler.
