motor car, all three compartments are used by passengers. Previously, there were on-board toilets in all parts of the unit, but due to several fires caused by neighbouring electric devices, as well as their compressor inlets originally being located next to the toilets (hence spreading the odours around, likely leading to the "kibel" [lit. crapper] nickname applied since at least the 1980s), the toilets in the motor cars were removed. Class EN57 is capable of multiple unit operation with two or three units, using Scharfenberg couplers to connect units together. Each unit can seat up to 212 passengers. Service in other countries Three units of class EN57 EMU were exported to SFR Yugoslavia in 1964, where they were classified 311-0 (for trailers) and 315-0 (for motor cars). Another eleven were subsequently rebuilt from class 315-1 with additional fourth trailers. These units later remained in service in Slovenia and Croatia as SŽ 311/315 and HŽ 6011 respectively, until they were respectively withdrawn from service in 2021 and 2009. As in the time of delivery Władysław Gomułka was the leader of the Polish United Workers' Party, those units were nicknamed after him. Rebuilds and refurbishments Exterior and interior (2006–2018) From 2006–2018, many extensive EN57 rebuilds were undertaken in which the driver's cab exteriors and headlights/taillights were replaced into new designs, extending their lifespans by 15–20 years. These rebuilt trains are typically nicknamed "turbokibel" (lit. "turbocrapper"). SPOT and EN57-20XX In 2006, ZNTK "Mińsk Mazowiecki", Pesa Bydgoszcz and Newag Nowy Sącz begin rebuilding 75 EN57 EMUs under the SPOT programme, financed by European Union funds. The appearance of the end walls, cab driver and interior was changed. The separate service compartments were removed by connecting them with entrance hallways. The modernised EMU was adapted to the needs of disabled people through the installation of elevators for wheelchairs and bigger toilets. EMUs after modernisation had also installed alarm and 16 cameras. The main spinning transformer was replaced by electronic transformer giving voltage 110 V DC, 230 V AC and 24 V DC. These trainsets were given the numbering range 2001–2075, which was later changed to 2004–2078. EN57KM In 2007 SKM Trójmiasto and Koleje Mazowieckie decided to apply the start pulse in some of their rebuilt EN57's: SKM Trójmiasto: EN57-768, EN57-1089, EN57-1094 & EN57-1116 Koleje Mazowieckie: EN57-1486, EN57-1566, EN57-1567 & EN57-1562 ZNTK "Mińsk Mazowiecki" works rebuilt these units. They too applied microprocessor controlled drive and electrodynamic