Within the moder­ni­sa­tion, only the frame, bogies with trac­tion motors and fuel tanks have been left from the old loco, all of which undergo a com­plete over­haul. Based on the new design docu­men­ta­tion, the vehicle body shape has been com­ple­tely chan­ged. In moder­ni­sed locos, a new power-generating unit has been used. The pre­vio­usly used a8C22 motor has been repla­ced with American-made C27, a 12-cylinder, high-pressure die­sel engine manu­fac­tu­red by CATERPILLAR of 708 kW (962KM) power con­nec­ted by fle­xi­ble coupling with a syn­chro­nous gene­ra­tor set (main and auxi­liary gene­ra­tor). Micro­pro­ces­sor con­trol­ler and loco dia­gno­stic sys­tems have been instal­led. The power-generating unit has been fit­ted with a modern radia­tor and turbo-charge air cooler and a brand new intake and exhaust sys­tem. These solu­tions have signi­fi­can­tly redu­ced fuel and oil con­sump­tion and impro­ved the loco’s reliability.

Locos are fit­ted with a modern bra­king sys­tem using an inte­gra­ted pneu­ma­tic board, screw com­pres­sor and spring-actuated par­king brake. Auxi­liary dri­ves (trac­tion motor fan drive and com­pres­sor drive) are pro­vi­ded by asyn­chro­nous motors powe­red by the auxi­lia­try gene­ra­tor  via inverters.

The trac­tion engi­nes are powe­red  by a trac­tion gene­ra­tor via a set of diode rectifiers.

A brand new driver’s cab has been desi­gned with two ergo­no­mic con­trol panels for the dri­ver, ame­ni­ties, pano­ra­mic wind­screen (thanks to lowe­ring the machine room ceiling), air-conditioning and effi­cient heating as well as com­for­ta­ble, adju­sta­ble seats on tracks fixed to side walls, which makes it possi­ble to hide them com­ple­tely under the con­trol panel. The cab is set on the loco frame with metal-rubber absor­bers which muf­fle vibrations.

The loco’s modern body shape meets the con­tem­po­rary requ­ire­ments in design, ergo­no­mics and safety and the pano­ra­mic win­dows instal­led in the driver’s cab have signi­fi­can­tly impro­ved track visi­bi­lity. Locos are adju­sted to be ope­ra­ted by one per­son and they may be equ­ip­ped with the radio con­trol system.