In the long line of PRR 4-4-0 locomotives which were originally designated class P, the last 16 were built in the Juniata shops at Altoona in 1894. Compared to the previous ones, the drivers had been enlarged to 80 inches or 2,032 mm and the cylinders had been enlarged to 19 inches or 483 mm. With a smaller diameter stack, the exhaust beats were reported to be much sharper. The boiler still had a Belpaire firebox typical for the PRR.

In 1895, the different types of the former class P were designated D11 to D14 to distinguish them from each other. The 16 locomotives shown here were designated class D14a. When they were not needed anymore for express service at the beginning of the 20^th century, they got 68 inch (1,727 mm) drivers for use on branch line service. No. 88 shown in the picture was scrapped in 1917.