41 241 with two tenders

The BR 41 was one of the standard (Einheits) locomotives on which the axle loading could be adjusted to either 18 or 20 tons. Initially, the BR 41 was to have been built as a 1’D to succeed the Prussian G 8² (BR 56^20-29). In order to design and build the necessary boiler that would generate sufficient power to achieve the required 56 mph (90 km/h) top speed and, more specifically, exceed the performance of the BR 56, it was decided to proceed with a two-cylinder 1’D1’ proposed by Schwartzkopff. Two engines, 41 001 and 41 002, were delivered in 1936 and were turned over to LVA Grunewald (Berlin) for technical evaluation. Bw Schneidemühl evaluated the engine’s performance.

Series production started with 41 003 which incorporated some modifications growing out of the evaluations of the two prototypes. These mods included air inlet doors on the ash boxes, wider ash tray rings, Karl-Schulz Schieber in place of Regelschieber with edge valves, a wider cab, Hängeisen in place of a Kuhnsche Schleife. The prototypes’ 2’2’T32 tenders were replaced with 2’2’T34. The BR 41 used the same boilers as the BR 03. The steel was St 47K and boiler pressure was 20 bar (290 psi).

During the 1936 to 1941 period 366 BR 41s were constructed. Almost all German locomotive builders took part. Additional orders were canceled as a result of the war. The BR 41 was a very successful design that only excelled in fast freight service but also saw passenger service in mountainous regions of Germany. After war’s end in 1945, 220 BR 41s were in the DB region and 142 in the DR.

After the war the DB and the DR had to reduce the boiler pressure to 16 bar (232 psi) because of the tendency of the St 47K steel to lose its strength over time. From 1957 to 1961, the DB installed 103 of the BR 41s with new, welded boilers fitted with new fireboxes. The new boilers were capable of maintaining considerable higher performance. These new boilers were also used on the BR 03¹⁰. Of the 103 machines, 40 were outfitted for oil firing. Bw Braunschweig did the boilers and Henschel took care of the oil firing work.

The oil-fired locomotives reached superheating temperatures of 480 C (896 F) which led to some "coking" (carbonizing) of the lubricants in the cylinders. As a result the superheating temperature was lowered to 440 C (824 F). Power output of these engines was about 100 hp higher than the coal-fired BR 41s.

When the DB instituted the new numbering system, the coal-fired BR 41s became BR 041 and oil-fired ones became BR 042s. The BR 041s were phased out by 1971 and the 042s lasted until 1977.

Even though the DR reduced the BR 41’s boiler pressure from 20 bars to 16 bars, the degradation of the St 47K steel was only slowed by this but not stopped. Like the DB machines, the DR eventually retrofitted 21 of their engines with welded boilers. Of this number, 20 used Knorr grating preheaters and one, 41 288, used a mixing preheater. An additional five engines with the old boilers received mixing preheaters. Starting in 1961, 80 locomotives were upgraded at Raw Zwickau and Karl Marx-Stadt with new welded boilers and fireboxes. Like the DB, the DR considered the BR 41 one of its most versatile locomotives but by the beginning of the 1980s, the end of its service life was in sight.

Specifications

Values in italics are for BR 41s equipped with new boilers.

Sources:

"Das grosse Typenbuch deutscher Lokomotiven," Weisbrod, Bäzold, Obermayer, Transpress 1992, ISBN 3 334 70751-5.

"Die Dampflokomotiven der Baureihe 041," Märklin Magazin, 1/78, page 28.