This series is originally based on the license of the Swedish company ASEA. It was produced in order to be used as a universal locomotive, for both passenger and freight traffic. There was a need to have a powerful electric locomotive to pull freight. At that time, this was mainly on the mainline tracks, which were electrified, and prepared for 160 km/h. Originally, it had diode voltage selector. A later, modernised series, the 3xx subseries, include thyristor voltage selector, and an on-board computer. Later 3xx series have an onboard look-behind-camera for video surveillance of the sides and also new livery.
Depending on subseries, 1xx, 2xx or 3xx, some members of this class can drive with maximum speed,,, or , depending on the gearing. The most common gearings are for intended for freight and passenger trains, and intended for passenger services, with locos for being rare and locos for all converted for. The models with higher maximum speed got less tractive power and are used for passenger or light freight trains only, whereas the models with lower maximum speed got high tractive power and are thus able to pull heavy freight trains as well.
Liveries
Original livery of Yugoslav Railways was red and blue with white stripe and "Jugoslovenske železnice" inscription on it. Serbian Railways class 441 today have red and greyish-dark blue livery. Locomotives of Republika Srpska have similar livery as the original Yugoslav, but with faded colours and a white stripe between blue and red. In Croatia, there are three basic liveries. The standard one is the red with white stripe. There is also a very rare livery, in colours similar to Croatian flag. The third, newest livery is the HŽ official livery. The Romanian Railways' original livery was in grey with a red or blue stripe, some examples even with the Romanian tricolor flag used instead of the blue or red stripe, but after 2000, the traditional white-red livery has been applied. A reversed variation of it appeared on the 3 Class 46 locomotives modernized in Croatia, whilst for the rest Class 46 members, the livery is similar to the ones applied on the Class 47 locomotives.
Export
Starting with 1972, between Yugoslavia and Romania a convention was concluded for reciprocal delivery for locomotives. It also involved the Romanian companies Electroputere Craiova and UCM Reşiţa. Thus the Romanian party delivered to Yugoslavia a number of 103 Co’Co locomotives of the 461 JŽ series and sub-assemblies for 130 Bo’Bo locomotives of the 441 JŽ series, delivered to Romania and registered with CFR under the number 040-EC between 1973 and 1984. The Yugoslavian locomotives derived directly from the already renowned prototype ASEA RB1 improved in the mechanical construction under the RC1 series pattern. A number of locomotives have been modernised to Class 46, initially 3 units by Končar Group, and later by PROMAT and Softronic Craiova. Class 46 is also a number used by Class 43/44 locomotives that were reclassified after being renumbered into UIC system, though with no modernisation what so ever. The Class 44 is the same as Class 43, but modified for higher speeds. Since the dissolution of SFRY, this locomotive is also exported. Some pieces are in North Macedonia, and some were leased to Turkish Railways. Now, most of the former Republics which have been formed after the dissolving of Yugoslavia have some of these locomotives, inherited from the former JŽ. These units have different designations, but very similar characteristics.
