The Pennsylvania Railroad Clearance Car

From the collection of H. Earl Snyder

The Pennsylvania Railroad, for many years, had operated a specially designed car for the purpose of accurately measuring the distance of objects such as bridges, tunnels, stations and rock cuts above or adjacent to the tracks.

 

The demand for increased speed to shorten travel time by both present-day industry and the business world and the ever increasing size of passenger and freight cars and commodities in open top cars, coupled with large motive power, has caused the railroad to provide more clearance for movement of equipment. This trend of larger equipment and larger commodities in open top cars has made the gathering of clearance information of growing importance.

 

The Pennsylvania had spent many millions of dollars to increase clearances for handling traffic. In the 1950's, the Panhandle Division Tunnel project between Pittsburgh, PA and Dennison, OH cost alone was over eight million dollars.

 

With the increased speed and more frequent train schedules, together with the vast increase in traffic experienced during World War II, it became necessary to develop a means of measuring clearances of structures along the railroad with greater speed and accuracy without interference to the regular now of traffic. This had not been possible with the clearance car that was operating prior the '50's. Therefore, it had become obsolete and was dismantled in mid -1950.

 

The Pennsylvania Railroad was able to accomplish the challenge of more accurate measurements with its new clearance car. The car was designed by the Mechanical Department and the Chief Engineer's Clearance Department and was built at the railroad's Altoona Works in Altoona, PA in 1950. The first test run was made over the Middle Division on November 1, 1950, measuring the Spruce Creek Tunnel (22 miles east of Altoona).

 

The car was a former inspection car and of the P-68 passenger type of that time. It is divided into five compartments. The head end (or front) is the template room where all the measuring instruments are located. This compartment also has an observation dome for inspection of overhead structures and tunnels. This is accessed from the template room and has a seat on each side of the dome.

 

There are 126 measuring instruments (called feelers). The template room is the location of the gauges that record the measurement of each feeler.

The feelers are divided into four groups:
(1) the oval template called the "Horse Shoe"
(2) the "Main" templates (one on each side of the car) called the "Main"
(3) the "Right Foot" template and
(4) the "Left foot" template

Article is continued on the Philadelphia Chapter Pages....