Ahrens-Fox. The name alone conjures images of long, graceful fire engines, chrome gleaming in the light, water being pumped seemingly effortlessly. Often referred to as the “Rolls Royce” of fire engines, Ahrens-Fox apparatus was known for a high level of craftsmanship and impressive build quality. The other Ahrens-Fox calling card was the large pressure dome, or air chamber, placed in front of the engine. More on that in a moment…
Like many fire apparatus manufacturers in the early twentieth century, the Ahrens-Fox Fire Engine Company was the result of several business mergers, separations, and restructurings, with its earliest beginnings in the 1850s. Founded by John P. Ahrens and his brother-in-law Charles H. Fox in 1910, Ahrens-Fox quickly became recognized for their sound construction and reliability.
The shiny sphere in the front of many Ahrens-Foxes became a symbol of pride for many firefighters, before it became a beacon of a bygone era for many fire buffs. If you’ve ever inflated a bike tire or used a squirt gun, you know that a steady flow of air or water is impossible to maintain. This is due to the piston pump configuration of these types of pumps. By adding the pressure dome to the pump, a steady stream of water could be produced regardless of the speed of the engine. The air trapped inside the dome helped to equalize the pumping pressure between the pistons.
The Fox that resides here at the Fire Museum is a 1922 KJS-4, with a 750 gallon per minute piston pump, two ground ladders, and a history with the Baltimore City Fire Department. It has been restored to its 1939 appearance, complete with proper decoration (be sure to check out the details on the pump during your next visti). It still pumps flawlessly, and recently won Best in Show at the Pennsylvania National Fire Museum muster in June of 2015.