Class P 3 2 (Locobase 6339)

Data from Reder (1974, pl 228). Christian Lindecke data from [] (14 Nov 2004) shows a slightly smaller HP cylinder (420 mm/16.54"). See also W Nolte, "30 Jahren Verbundlokomotiven bei den preussich-hessischen Staatsbahnene. II", Die Lokomotive, Vol 7, No 8 (August 1910), pp. 171.

Von Borries dealt with stress on the lead axle by moving the cylinders (one HP on the left, one LP on the right) back to a point between the carrying axle and the first set of drivers. This forced the KPEV to use an outside Walschaert valve gear instead of its traditionally preferred inside Allan link motion.

The fireside diameter of each tube was 41 mm, which yields a heating surface area of 103.2 sq m (1,111 sq ft).

Class S1 (Locobase 1218)

Data from Christian Lindecke (latter website [] last accessed 6 May 2018); and a table of Prussian locomotive classes. Additional data from Harry Clifton Reagan, Locomotives: Simple, Compound, and Electric (5th Edition) (J.Wiley & sons, 1907) and W Nolte, "30 Jahren Verbundlokomotiven bei den preussich-hessischen Staatsbahnene. II", Die Lokomotive, Vol 7, No 8 (August 1910), pp. 169.

This compound variant was a sidetrack of the earlier S1 prototype. The outside diameter of each tube was 50 mm (1.97"). Placing the cylinders behind the lead truck and just ahead of the first driving axle encouraged a smooth ride and compounding reduced coal consumption by 15%. But, Wikipedia notes, the engines had some maintenance issues because of the compound layout

After these 14 locomotives, the KPEV settled on a simple-expansion variant and built over 200 of them. Even so, the class remained in service until the 'teens and twenties.

Class S1 compound - Henschel (Locobase 10331)

Data from "German Locomotive Works," The Locomotive Magazine, Vol VIII (30 May 1903), p. 374.

Although also designated S1, this sextet of Hannover-built von Borries-compound locomotives didn't have the relatively tall drivers on which rolled the Henschel engines described in Locobase 1218. They also didn't enjoy as long a career, being withdrawn in 1913.