OKc1

Hannover 1602 (Hanomag 1825/1885) represents first variant of the Bauart Hannover. Factory photo, source: Lokomotiven der alten deutschen Staats- und Privatbahnen by H. Maey and E. Born, Transpress, 1983.

T4¹ Erfurt 6411 (Henschel 3048/1891) was sold in 1925 to Raw Meiningen and served there until 1934. Source: as above

Another picture of this engine, most probably taken on the same occasion. Photo by Werner Hubert (source: www.commons.wikimedia.org).

Former TKb100-10, erroneously designated TKc100-1, Henschel 3838/1893, rebuilt by Borsig in 1927. Railway Museum, Warsaw, July 23, 2002.

The same locomotive, photographed on September 19, 2010. Differences from the original T4¹ are evident.

Side drawing of the T4¹ Normalbauart. Source: Lokomotiv-Archiv Preußen Band 3 (see References).

Factory illustration of the KPEV Altona 1639 (Hanomag 1951/1888). This locomotive remained in Germany and was written off before 1925. Source: Die Lokomotive July 1921.

In 1906 Prussian state railways KPEV modified their locomotive designations system. In many cases this involved grouping of various types under one new class designation. This was the case with class T4, which included several types of tank locomotives with axle arrangements 1-2-0 or 0-2-1. With drivers slightly below 1600 mm, they were intended mainly for passenger traffic on commuter lines. These types included:

- T4 Bauart Elberfeld: 32 examples originally built for Bergisch-Märkische Eisenbahn by Hanomag, Henschel, MBG Karlsruhe and Esslingen between 1868 and 1881, impressed into KPEV after nationalization in 1882, plus 63 built for KPEV between 1884 and 1890, later re-designated T4², some designated T2 (0-2-1);

- T4 Bauart der Rheinischen Eisenbahn: fourteen examples built for Rheinische Eisenbahn by Wöhlert and Hanomag between 1873 and 1875, impressed into KPEV after nationalization in 1880, plus nine more from Hanomag and Vulcan, delivered between 1885 and 1889, some designated T2 (0-2-1);

- four variants known as Moabit-Typ (six from Borsig, 1882), Bauart Altona (ten from Union, 1888), Bauart Magdeburg (fourteen from Borsig and Henschel, 1884-1888) and Berliner Form (68 from Hanomag and Henschel, 1888-1893), differing in details and later developed into standardized T4¹ (1-2-0);

- T4 Bauart Hannover (also known as Bauart von Borries) built in two versions for Hannover and Bromberg regional managements, the latter with extended side water boxes (24 from Hartmann, Henschel and Hanomag, 1885-1890, 1-2-0)

- standardized (Normalbauart) class T4¹: 129 built for KPEV by Henschel, Hanomag and Schichau between 1890 and 1898 plus three for Königliche Militär-Eisenbahn from Borsig and Henschel between 1891 and 1892 (1-2-0);

- T4³ for Werrabahn: three examples from Schichau, 1898 (1-2-0).

All these variants had single-expansion steam engines and were fitted with Allan valve gear. Steam pressure of 10 bar was increased to 12 bar in later versions. With the appearance of more powerful types (T5¹, later T11 and T12) these locomotives were gradually shifted to local traffic on secondary lines. Many older examples were withdrawn in early 1900s, some were sold to various private railways. Although it was originally intended to keep a few dozen T4s in service, all were withdrawn from DRG before 1925 due to obsolescence, so no numbers were actually assigned. The sole exception was 69 6101 (class T4², Henschel 4084/1894), sold to a private railway in 1912. Taken over by DR in 1949, it was withdrawn two years later. One T4¹ (Henschel 3048/1891, formerly Erfurt 6411) was used by Raw Meiningen repair establishment after being withdrawn from DRG, but, although designated 70 7007, it was not the DRG property and is not included in their stock lists.

After WWI PKP acquired just two examples of these already obsolete locomotives, Bromberg 6401 and 6402 (Henschel 3985/1893 and 3986/1893). They were classed OKc1, but most probably only formally, as both were withdrawn before 1927. One was sold to Gosławice sugar plant that operated a standard-gauge line connecting their premises with the Konin railway station. Numbered 1 and nicknamed ‘Kusy’ (short), this locomotive was after 1945 classed TKc, in the PKP style. Withdrawn about 1963, it was later scrapped. This, however, was not the end of Polish T4s. The sole surviving example of this class is a T4¹ (Henschel 3838/1893), originally designated Breslau 1462, then Kattowitz 1462 and Kattowitz 6409. Sold to Stolper Kreisbahn in 1917 and re-numbered 31, it was rebuilt by Borsig in 1927 and fitted with new boiler with superheater, as well as modified cylinders and valve gear. In 1945 it was impressed into PKP. Although of Prussian origin, it came from a local railway and hence was designated TKb100-10 (despite its original appropriation it was considered a freight engine, but correct designation would have been TKc100-10). Sold in 1953 to an agricultural cooperative, it was re-designated TKc100-1649 (after factory number of the new boiler). In 1979 it was written off and transferred to the Railway Museum, Warsaw, where it can be seen on static display bearing erroneous PKP designation TKc100-1. Externally it hardly resembles an original T4¹.

Main technical data

No.	Parameter	Unit	Value
1.	Years of manufacture	-	1890 – 1898
2.	Total built / used in Poland	-	172 / 3^1)
3.	Tender class	-	-
4.	Axle arrangement	-	1-2-0
5.	Design maximum speed	km/h	75
6.	Cylinder bore	mm	2 x 420
7.	Piston stroke	mm	600
8.	Engine rating	kW/hp	380 / 500
9.	Tractive effort	kG
10.	Boiler pressure	MPa	1.22
11.	Grate dimensions	m x m	1.60 m^2
12.	Firebox heating surface	m^2	5.7
13.	Distance between tube plates	mm	3 600
14.	Number of flue tubes	-	181
15.	Heating surface of flue tubes	m^2	83.9
16.	Number of smoke tubes	-	-
17.	Heating surface of smoke tubes	m^2	-
18.	Evaporating surface, total	m^2	89.6
19.	Superheater heating surface	m^2	-
20.	Diameter of drivers	mm	1 580
21.	Diameter of idlers front/rear	mm	1 130 / -
22.	Total weight, empty	kg	33 600
23.	Total weight, working order	kg	43 200
24.	Weight on drivers, working order	kg	29 100
25.	Weight with tender, empty	kg	-
26.	Weight with tender, working order	kg	-
27.	Maximum axle load	T	14.6
28.	Axle base (with tender)	mm	4 200
29.	Overall length (with tender)	mm	9 840
30.	Brake type	-	Carpenter

Note: all data for T4¹ Normalbauart.

1) Including one rebuilt.

References and acknowledgments

- LP, TB vol. 2;

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

- Länderbahn-Dampflokomotiven by Lothar Spielhoff (Weltbild Verlag, 1994);

- Koleje żelazne Cukrowni Gosławice 1912-1992 (Railways of the Gosławice Sugar Plant 1912-1992) by Maciej Matuszewski (PKMK, 1993).