Work on designing new family of Polish locomotives, able to pull trains with speeds higher than 125 km/h, started in the 1970s. Of those plans only one was finally realised, which resulted in construction of EP09 locomotives. In the beginning of the 1980s the CMK line (rail trunk line) was suited for passenger transport. Before that time it had been used exclusively for freight transport. At first EU05 and EP05 locomotives were used to service this line, but Polish railways needed faster locomotives, reaching 160 km/h. The machine was designed in Ośrodek Badawczo-Rozwojowy Pojazdów Szynowych (Rolling Stock Research and Development Centre) in Poznań. The prototype was ready in 1986, built in Pafawag in Wrocław. The machine was intended to be built with western parts, but severe financial restrictions caused many modern solutions to be abandoned. Co-operation with USSR gave little effect as well. Additionally, after the collapse of Eastern Bloc Poland was forced to use old EP07 solutions in later series of EP09.
It is impossible to find two identical locomotives of this class, as the design changed after each machine was completed. The First EP09 locomotive was presented in 1986, the next one in 1987. On May 29, 1988, according to the new timetable, those two locomotives started regular service. In 2005 EP09's livery was revised and unveiled. The locomotives are being repainted in during scheduled servicing. All the locomotives produced, except for EP09-035(which was involved in the Szczekociny rail crash) are still fully operational, and are deployed in the locomotive depots in Kraków and Warsaw. 12 units work in Kraków Prokocim depot, the rest are assigned to Warsaw. Besides running on the CMK line, those locomotives can be spotted on Warsaw-Poznań-Szczecin, Warsaw-Poznań-Wrocław, Warsaw-Lublin and Warsaw-Kielce lines. EP09 series proved itself to be highly defective, e.g. in 1996 PKP was forced to replace 10 traction motors and 24 bogies. In the same time serious breakdowns of compressors were noted. In the end of 2000 EP09 were temporally sent to Gdańsk. This was done in order to accustom engineers with this type of locomotive before rising top speed on Warsaw-Gdańsk line.
EP09-47 (left) and EP09-30 locomotives in Warsaw. Note the difference between front parts of locomotives (EP09-47 has additional air-intake mounted due to air-conditioning system installed) and between the types of pantographs.
EP09 is a Bo-Bo electric locomotive working in 3000 V DC electric system. The box is placed on two bogies. Each bogie has two, separately propelled axles. Crew compartments are located on either side of the box. There are battery box and air tanks mounted between bogies. Traction motors and transmissions are locked inside bogies. Behind each crew compartment the machine compartment is located. High voltage compartment is situated in the middle of the machine. EP09 is the first Polish locomotive to have electro-dynamic brakes. This enables braking the locomotive using the motors configured to work as generators. It is worth noting, that this device works only with speed below 140 km/h, due to first planned top speed of the locomotive. Other modifications to EP09 machine were e.g. ergonomic dashboard and windscreens equipped with internal heating.
Since locomotive number 38 the system of suspending locomotive on bogies was changed into Flexicoil and single pantographs (DSA200, Stemmann production) were mounted instead of the previously used double ones. Another important change during the production process is installing air conditioning system (since locomotive number 40). At present PKP works on bringing all machines into the same standard as the last two locomotives (046 and 047) brought into service in January 1998.