ET40 and EP40

ET40-55, photographed near Zduńska Wola Karsznice depot, June 13, 2003.

This ET40-46 was photographed near Toruń on June 18, 2003.

ET40-42 in Inowrocław, September 12, 2004

ET40-35 in Tczew on a sunny day: June 27, 2005.

ET40-43, photographed near Zduńska Wola Karsznice depot on April 5, 2006. Due perhaps to large dimensions, ET40s are favorite targets for graffiti ‘artists’...

...which is confirmed by the ET40-38, photographed at the same location on October 30, 2006.

ET40-45, photographed in Rybnik on October 20, 2006, also displays traces of graffiti activities.

Manufacturer’s plate on the ET40-45.

Another graffiti victim: ET40-21, photographed in Zduńska Wola Karsznice on December 14, 2006.

ET40-26, photographed at the same location on January 28, 2008.

This ET40-19 was photographed at a railway crossing near Kędzierzyn Koźle on June 15, 2008.

So-called Coal Trunk Line, built in the 1930s to connect Silesian coal mines with Gdynia, has always been a domain of heavy freight traffic – at least by European standards. The heaviest steam locomotives in the PKP service, American Ty246s and indigenous Ty51s, operated mainly there. Electrification of this line between 1964 and 1969 immediately brought about a demand for a heavy electric freighter, as the most powerful machine at hand, six-axle ET22, had the continuous rating of only 3000 kW and maximum tractive effort of about 42 tonnes. 1970s were the ‘golden age’ of coal production – and export – in Poland and very heavy drafts were common. It was thus decided to purchase a suitable twin-unit locomotive of about 4000 kW and orders were placed in Czechoslovakia and USSR. Czechoslovak machine was the first to enter service and hence was classed ET40.

ET40 was built by well-known Škoda works of Plzeň (factory designation 77E1) and, in principle, based on the successful and proved class E499.1 (later 141, factory designation 30E1), which also – in a slightly modified version – served with PKP as EU05. Apart from coupling two units, changes included different transmission and reduction ratio (84:27 instead of 84:37) and fitting additional cooling fans for startup resistors, necessary due to long and slow startups with heavy drafts. These fans are installed in a roof-mounted housing with louvers, very characteristic for this locomotive. With continuous rating of 4080 kW, ET40 could develop a tractive effort up to about 50 tonnes. Initially ET40, commonly nicknamed ‘Bombowiec’ (Bomber), proved unable to match EU05 as far as reliability was concerned; due to higher load, failures of traction engines and wheelsets were not uncommon. As each section could be operated independently and spares were sometimes in short supply, it was a typical practice to join two units originally belonging to different locomotives, without changing their service numbers.

Thirty ET40s were purchased between 1975 and 1976 and a second batch, numbering also thirty examples, followed in 1978 – these machines were distinguished by two current collectors at each section instead of one (factory designation 77E2). In addition to standard class designation and service numbers, individual units were identified by capital letters A or B (e.g. ET40-10-A and ET40-10-B); according to new standards, this letter is to be placed between class designation and service number, but few machines have been re-designated so far. All sixty locomotives were immediately put to service on the Coal Trunk Line and all were based at the Bydgoszcz depot. Between 2000 and 2002 six of them operated in the Lower Silesia, but this was just a short episode in their service. According to rosters available at www.lokomotywowniapkp.republika.pl, 46 examples are still in the PKP inventory, but not all of them are serviceable.

Experience with these first twin-unit locomotives in PKP service prompted an order for a similar machine based on license-built EU07, which later materialized as ET41.

In 1990, a peculiar attempt was made to convert ET40 into a fast locomotive for express trains, running at 160 km/h. This was in part due to problems with EP09 and twin variant of the very successful EU05 seemed a sound alternative. One example – ET40-41 – was modernized and appropriately re-designated EP40-41. Reduction gear with 77:44 ratio, as in EP05 (itself a modernization of EU05) was fitted, as well as new wheelsets, current collectors, speed-meters and many minor items of equipment. Similarly to other express locos in the PKP service (EP05 and EP08) this machine was painted orange and red, instead of typical green livery of freighters. EP40-01 was transferred to Warsaw and, until withdrawal in January 1992, logged over 150,000 km. Service experience was rather discouraging: many element and sub-assemblies suffered from vibrations, which resulted in frequent malfunctions. Further development could probably save the project, but the idea was abandoned and EP40 was re-converted into its original version.

Modernization of the ET40-04 was of different nature and consisted mainly in replacing several elements of electric and pneumatic systems and cabin equipment with new and modern ones, to improve safety, reliability and crew comfort. Overall characteristics and external appearance were not affected. Modernized ET40-04 was rolled out in February 2000, but no more examples have followed until today.

Although in Czechoslovakia class E499.1 was also developed into a freight version (E469.1 and subsequent modifications), the standard-gauge twin-unit 77E1 was not ordered by ČSD and was built for PKP only. However, a broad-gauge version for 1524 mm track was developed, classed E469.5 (later 125.8, factory designation 67E1). Twenty-two examples were delivered in 1976. According to the ČSD practice, individual units were numbered rather than entire locomotives, so service numbers ran up to 469.5044. These locomotives, re-classed 125.8, still remain in use with ŽSCS, a subsidiary of ŽSSK (apart from 469.5009 + 469.5010, withdrawn after a crash in 1984), hauling heavy trains transporting iron ore from Ukraine to steelworks at Hanisky pri Košiciach in eastern Slovakia. Due to drafts of even 4200 tonnes and slopes up to 17‰, double-heading is a normal practice and a third machine pushing is not uncommon – this must be an impressive sight!

Main technical data

No.	Parameter	Unit	Value
1.	Years of manufacture	-	1975 – 1978
2.	Total built / used in Poland	-	60^2) / 60
3.	Axle arrangement	-	Bo’Bo’ + Bo’Bo’
4.	Control	-	individual^1)
5.	Design maximum speed	km/h	100
6.	Traction motors (number X type)	-	8 X 7AL4846ZT
7.	Voltage	V	3000
8.	One-hour rating	kW/hp	4688 / 6376
9.	Continuous rating	kW/hp	4080 / 5549
10.	Electric current at one-hour rating	A	360
11.	Electric current at continuous rating	A	350
12.	Rotational speed at one-hour rating	rpm	900
13.	Rotational speed at continuous rating	rpm	920
14.	Engine suspension	-	Sécheron
15.	Reduction gear ratio	-	84:29:27
16.	Diameter of drivers	mm	1250
17.	Total weight	kg	164 000
18.	Axle load	T	20.5
19.	Axle base	mm	28 710
20.	Overall length	mm	34 420
21.	Maximum width	mm	2 950
22.	Brake type	-	Oerlikon

1) Multiplied in each section.

2) Additional 22 for 1524 mm track (ČSD class E469.5, later 125.8, factory type 67E1)

References and acknowledgments

Many interesting data were taken from www.cmbydgoszcz.kolej.szczecin.pl – this website is maintained by Paweł Telega. Concise information can be found in AL and AV. Interesting account of this class development is available (in Czech) at www.spz.logout.cz/vozidla.