Danske Statsbaner 4-4-2 Locomotives in Denmark

Class P (Locobase 590)

These were designed by Otto Busse (Director-in-Chief of the Mechanical Department of the DSR). See Railroad Gazette 14 December 1906 (533-536) and "Four-Cylinder Compound Atlantic Type Locomotive for the Danish State Rys," The Locomotive Magazine, Vol 13 (13 August 1907), pp. 140-141 for full description. Hollingsworth (1982) gives different dimensions.

Gregersen's Danske Damploko gives the following details about builders and dates:

Road Numbers Date Builder Works numbers

P 901-P 905 1907-1908 Hanomag 4771-4775

P 906-P 916 1908 Hanomag 5012-5019, 5167-5169

P 917-P 919 1909 Hanomag 5405-5407

P 920-P 933 1910 Schwartzkopff 4383-4392, 4456-4460

Roger Hennessey (nsc.chelt@talk21.com), in a July 2000 email, says the following about this class: "Known by Danish railwaymen as 'The Big P's' - another name for your list. The date you give (1907) represents the first batch; 5 were delivered in that year (all were from German builders). Others followed: 11 in 1908; 3 in 1909; and 10 in 1914. They were virtually identical and (if my reading of the Danish data is in order) they were four-cyl compounds with 78.1" driving wheels."

The LM report notes that after Busse drew up the plans for this class, he visited the United States and was exposed to Baldwin's Vauclain compound design. The lessons he drew included the adoption of a single slide valve to feed both the HP and LP cylinders on a side. He also switched to the bar frame. The inside-mounted Walschaert gear limited cut off to a maximum of 82%

They were later superheated; see Locobase 4024.

Class P (II) - superheat (Locobase 4024)

Data from William Bay, Danmarks Damplokomotiver (1977). Class information from []. .

20 of the P-class Atlantics (Locobase 4023) were superheated. This makeover disposed of the inefficient Knorr superheater with which most were initially fitted and replaced it with the Schmidt firetube design:

1911 912

1913 901, 904, 906-907

1914 903, 917, 920, 927

1916 908, 910, 919, 923, 924, 926, 928, 932-933

1917 930, 931

The class continued to be the predominant traction power for express passenger service well into the 1950s. Seven were rebuilt during World War Two and redesignated Pr; see Locobase .