This driveway leading up from Twin Arch Road to a junkyard marks the
location of B&O Plane 1, the first inclined plane encountered on the
Basically, each of Mt. Airy's four inclined planes occupied a relatively
steep area of terrain. In 1830, when the B&O planned this right of way,
no one accurately knew the gripping ability of a steam locomotive's metal
wheels upon metal rails. At that time, there were but a handful of
primitive steam locomotives to be found anywhere, and B&O didn't have
an operating one to test.
As a result, B&O chief engineer Jonathan Knight's estimate of how
steep a grade future locomotives could climb was little more than
an educated guess, and that guess turned out to be quite conservative.
Consequently Plane 1 hardly looks formidable by today's standards.
Is this surely the location of Plane 1? The even grading, the angle,
the unusual road surface, the cut, the proximity of commercial
property (the junkyard) in an otherwise residential area all say a
railroad had been here. The curve, however, is a puzzle. It is
likely the planes were straight, or nearly straight, runs, so the
I surmise the curve was added later, perhaps to facilitate room
for a nearby house.
The aerial photo linked below is centered on the driveway, which
at the time of the photo, shows little curvature. The base of Plane 1
was located east of the driveway's intersection with Twin Arch Road
(the large road running NNW to SSE) near the sharp loop in the river.