TKi2

The sole surviving 91 134 (Grafenstaden 4843/1898), photographed in Potsdam on May 17, 1993, by someone who wishes to be known as MPW57. Source: www.wikipedia.de.

Class 91^0-1 side drawing from TB vol.2 by M. Kratochvil.

An earlier picture of the 91 134 taken in 1988, when this engine was owned by Verkehrsmuseum Dresden. Source: www.commons.wikimedia.org.

TKi2-11 (ex Erfurt 7220, Borsig 4679/1899), ready to depart with a suburban train from Poznań to Puszczykowo, 1926. This engine later became TKi2-5Dz and its ultimate fate is unknown. Source: National Digital Archives (used by permission).

Class T9¹ freight tank engine of Prussian state railways KPEV, although built in fairly large numbers, was not entirely satisfactory. In particular its running qualities left something to be desired, due to the 0-3-1 axle arrangement. Thus Union Gießerei decided to develop the 1-3-0 variant, fitted with Adams leading axle. Boiler was shortened by 470 mm, but with the number of smoke tubes increased from 162 to 197 its heating surface was only marginally smaller. Steam engine of the earlier design was retained, but shifted to the rear, which improved weight distribution. Running qualities were, however, found only marginally better and maximum speed remained at 60 km/h. Substantial improvement was achieved only with T9³, which featured leading Krauss-Helmholtz pony truck. The latter engine, of which over 2000 examples were eventually built, was very successful and even ran with light passenger trains. Total output of class T9² was not particularly impressive, with 235 examples built between 1892 and 1901. The majority came from Union; from 1898 onwards orders were also placed with Borsig, Grafenstaden and Hanomag and from 1899 with Hohenzollern.

Initial DRG re-numbering plans included as many as 163 T9²s, but eventually only 112 were retained in service. They were classed 91^0-1 with numbers running up to 91 115, but last seven were in fact erroneously classed T9¹s. On the other hand, four T9²s were erroneously classed T9¹ and numbered 90 022, 90 023, 90 123 and 90 124. Several were sold to various private railways. Essen 7215 was sold to the Bremen harbor in 1922 and returned to DRG in 1930, becoming 91 116. Five engines originally assigned to the Saarbrücken depot were transferred to Saarbahnen in 1920 and in 1935 became DRG 91 117 through 121. Between 1928 and 1930 DRG sold six locomotives to the Braunschweigische Landes-Eisenbahn (BLE); when this railway was taken over by DRG on January 1, 1938, they were given new service numbers, 91 131 through 136. State railways got rid of their T9²s between 1926 and 1932, so only former Saarbahnen and BLE engines survived until WWII, as well as 91 060 and 91 088, both sold to private railways after 1925.

After WWI Polish railways took over 24 locomotives of this type. In 1926 they were classed TKi2 and given service numbers TKi2-1 through 18 and TKi2-1Dz through 4Dz (they were based in Gdańsk, hence Dz). Two examples were not given new numbers, so probably they were withdrawn before 1926. In the 1930s TKi2-5, -9 and -11 were transferred to Gdańsk and re-numbered TKi2-7Dz, -6Dz and -5Dz, respectively, to be withdrawn in 1938. Four engines were written off before 1936 and, following further withdrawals in 1937 and 1938, in September 1939 PKP had thirteen TKi2s still in use. Of these, TKi2-15 fell into Soviet hands and was later captured by Germans; this locomotive served with Ostbahn and was written off in August 1943. The remaining twelve examples (plus withdrawn TKi2-7) were taken over by DRG and numbered 91 137 through 149. After the war ten were returned, but one was erroneously classed TKi3. All were withdrawn between 1948 and 1953. Two were sold to industry; TKi2-9 (pre-war TKi2-13, Union 989/1898) was finally written off in April 1970.

Last two locomotives of this type in service with DR, 91 133 and 91 134, were withdrawn in August 1966. The latter (Grafenstaden 4843/1898, initially KPEV Saarbrücken 1858, then 91 048 and BLE 41) has been preserved and is currently owned by Mecklenburgische Eisenbahnfreunde society of Schwerin.

Main technical data

No.	Parameter	Unit	Value
1.	Years of manufacture	-	1892 – 1901
2.	Total built / used in Poland	-	235 / 24^1)
3.	Tender class	-	-
4.	Axle arrangement	-	1-3-0
5.	Design maximum speed	km/h	60
6.	Cylinder bore	mm	2 ´ 430
7.	Piston stroke	mm	630
8.	Engine rating	kW/hp	338 / 460
9.	Tractive effort	kG
10.	Boiler pressure	MPa	1.22
11.	Grate dimensions	m X m	1.58 m^2
12.	Firebox heating surface	m^2	7.9
13.	Distance between tube plates	mm	3930
14.	Number of flue tubes	-	197
15.	Heating surface of flue tubes	m^2	99.7
16.	Number of smoke tubes	-	-
17.	Heating surface of smoke tubes	m^2	-
18.	Evaporating surface, total	m^2	106.8
19.	Superheater heating surface	m^2	-
20.	Diameter of drivers	mm	1350
21.	Diameter of idlers front/rear	mm	1000 / -
22.	Total weight, empty	kg	41 000
23.	Total weight, working order	kg	54 000
24.	Weight on drivers, working order	kg	42 000
25.	Weight with tender, empty	kg	-
26.	Weight with tender, working order	kg	-
27.	Maximum axle load	T	14.0
28.	Axle base (with tender)	mm	6 600
29.	Overall length (with tender)	mm	11 650
30.	Brake type	-	Westinghouse

1) Including four (later seven) examples used in Gdańsk.

List of vehicles can be found here.

References and acknowledgments

- Ingo Hütter’s locomotive database (www.lokomotive.de),

- TB vol. 2, LHR, LP;

- Lokomotiv-Archiv Preußen Band 3 by Andreas Wagner (Bechtermünz Verlag, 1996).