Philadelphia Rapid Transit Company in 1929 realized the pressing need for attractive, speedy new equipment to replace its functional yet cumbersome unattractive equipment then in use.

The PRT engineering department, in conjunction with the J. G. Brill Company engineers set about to develop such a car in January 1930. In March, the three-year-old Brill Peter Witt car 8528 was equipped with Brill 84-E trucks with four high-speed GE 298-H motors, track brakes, GE PCM foot control, forced air ventilation and Nichols-Lintern dash illuminator headlight. Extensive line tests were conducted with this car over most lines to evaluate the new equipment.

A close up of the Brill 84E truck was provided by William Powellson.

In late March, a satisfactory design was chosen with further study and modifications being made through October, the only basic difference from the design shown being the addition of swivel seats on the right side of the car in front of the center door.

Car 8528 was returned to its spartan 1926 condition in 1937, including return of its original Brill maximum-traction two-motor 39E-2 trucks, only to be modernized in 1940. Below is PRT 8528 in its original condition: