The reference for locomotives and railcars
Mecklenburg XXI
later T 4 and German Reichsbahn classes 9119 and 91640
Germany | 1907 | 56 produced
No. 714 from a series of 30 machines from 1907-1914
No. 714 from a series of 30 machines from 1907-1914
works photo Henschel

The class XXI was one of the few locomotives that were specially procured for the Grand Duchy of Mecklenburg Friedrich-Franz-Eisenbahn. It arose from the fact that a tank locomotive like the Prussian T 9 was needed for branch lines, but the axle load was too high. Therefore, as the developer of the T 9, Henschel was commissioned to build a similar locomotive with an axle load of only twelve tonnes. The resulting XXI shared the same 2-6-0T axle formula and similar visual appearance, but was lighter and had smaller supplies. From 1910 it was given the designation T 4.

Between 1907 and 1922, Henschel and Orenstein & Koppel delivered 50 engines in slightly different designs to Mecklenburg, which became the class 9119 at the Reichsbahn. In addition, there were six more in 1919 and 1920 for the light railways in the province of Saxony, which later became the class 9164. Depending on the year of construction and design, the locomotives had axle loads of between 11.8 and 14 tonnes with different amounts of coal and water. The driving wheels were either 1,150 or 1,200 mm in diameter and allowed a top speed of 45 or 50 km/h. Despite the lighter construction compared to the T 9, the indicated power could remain at the same level due to advances in technology.

The Reichsbahn took over all 50 Mecklenburg machines and later also those of the private railways after they had been nationalized. After the war only four locomotives came to the Bundesbahn, where they were retired by 1950. Two more were in Poland and were used there as TKi 100. The remaining 32 were all left in the East Zone. Half of them had to be handed over to the Soviet Union as reparations, where they were given the designation TT. The remaining half was used by the Reichsbahn together with the former private railway locomotives and retired by 1970.

Variant1908 variant1915 variant1916 variant
ManufacturerHenschel, O&K
Axle config2-6-0T (Mogul) 
Gauge4 ft 8 1/2 in (Standard gauge)
Dimensions and Weights
Length34 ft 0 7/16 in35 ft 5 3/16 in
Wheelbase18 ft 4 1/2 in
Empty weight78,661 lbs82,453 lbs92,594 lbs
Service weight99,737 lbs101,633 lbs114,640 lbs
Adhesive weight79,366 lbs79,587 lbs92,374 lbs
Axle load26,455 lbs26,544 lbs30,865 lbs
Water capacity1,347 us gal1,400 us gal
Fuel capacity3,307 lbs (coal)
Power sourcesteam
Estimated power469 hp (350 kW)503 hp (375 kW)
Optimal speed15 mph16 mph15 mph
Top speed28 mph31 mph28 mph
Starting effort19,436 lbf18,627 lbf21,378 lbf
Power Plant
Driver diameter45.3 in47.2 in45.3 in
Boiler pressure174 psi
Expansion typesimple
Cylinderstwo, 16 1/8 x 22 13/16 intwo, 16 15/16 x 22 13/16 in
Grate area17.2 sq ft20.5 sq ft
Firebox area79.8 sq ft90.4 sq ft
Tube heating area995.7 sq ft963.4 sq ft
Evaporative heating area1,075.4 sq ft1,049.5 sq ft
Total heating area1,075.4 sq ft1,049.5 sq ft
Calculated Values
steam locomotive
tank locomotive
secondary line
last changed: 04/2022

We use cookies to save the following settings:

  • selected navigation structure
  • selected language
  • preferred units
  • spelling of railway company names

If you refuse the use of cookies, the settings will only be retained for the current session and will be reset to the default values the next time you visit the site.

Display of units

Here you can set the desired unit system for the technical data.

  • Metric: Lengths in meters, weights in tonnes, and volumes in cubic meters
  • Imperial (UK): Lengths in feet/inches, weights in long tons and volumes in imperial gallons
  • Imperial (US): Lengths in feet/inches, weights in pounds, and volumes in US gallons
  • Individual: Depends on the country of origin of each locomotive
Operator names

Here you can set the display of railway company names.

  • Short: Abbreviation or short form of the name
  • Standard: commonly used name, partially translated to English
  • Complete: full name in local language