Class CC1s (Locobase 12008)

Data from Rob Schoenberg's http://prr.railfan.net/diagrams/PRRdiagrams.html?diag=CC1s_62046.gif&sel=ste&sz=sm&fr=(visited 2 January 2011).

This was the earlier prototype Mallet pusher that inspired the Pennsy to buy the 10 larger and more powerful CC2s locomotives described in Locobase 1425. Like all Pennsy engines of the time, the CC1s had a Belpaire firebox All of them served the Lines West (of Pittsburgh) portion of the system as drag-freighters and pushers.

Class CC2s (Locobase 9498)

Data from "Mallet Articulated Locomotive for Pennsylvania Lines West," Railway and Locomotive Engineering, August 1919, pp. 235. See also DeGolyer, Vol 59, pp. 311+. Baldwin produced them as singles over a 5-month period from April to September 1919 works numbers were 51716, 51867, 51904, 51938, 51973, 51994, 52054, 52227, 52291, 52372). Except for one 3-engine batch, road numbers were typically non-consecutive: 7250, 7332, 7335, 7649, 7693, 9357-9359, 8158, 8183.

These were enormous compound articulateds that were significantly more powerful than the single CC1s experimental engine procured in 1912 (Locobase 12008). Intended for pusher and hump yard service, the CC2s class was designed to work on grades up to 5% and on curves with radii up to 18 deg. So small were the drivers that the leading LP cylinders showed a perceptible rake (1 in 35) to ensure that they'd clear the rail as the front engine traversed in curves. All 4 cylinders were supplied by 14" (356 mm) piston valves. Firebox heating surface area included 76 sq ft (7.05 sq m) in the combustion chamber and 42 sq ft (3.9 sq m) in the arch tubes.

Although deprived of the Belpaire firebox usually found on the Pennsy, the giant switchers nevertheless proved quite satisfactory and remained in service until the late 1940s. The first was sold for scrap in October 1947, the last in April 1949.