The locomotive 111Ed has a modern drive with 2 traction converters cooled with liquid and 4 inverters (one for each traction motor). It is equipped with regenerative and resistant electrodynamic brakes. Transferring the tractive force from bogies to a body is conducted by means of inclined traction links.

The locomotive is equipped with two equivalent air-conditioned control cabins located on both ends. Each cabin is entered through two external doors, whereas the machinery compartment is entered through an anti-panic internal door. The panel was designed in the cooperation of drivers and instructors. Systems of the on-board and service diagnostics allow for the analysis of all parameters which are important from the perspective of safety. High reliability of the locomotive is ensured by the online diagnostics system. The locomotive is equipped with a highly efficient anti-lock braking system through intelligent control of each axle. This allows to overcome elevations which so far were unreachable for four axle locomotives.

The body of the locomotive is made of steel with increased resistance. The side plating and removable roofs are made of light alloys. The structure of the locomotive meets the strength requirements consistent with the standard EN 12663 and the standard EN 15227 concerning collisions (four collision scenarios). Used deformable components are made as removable and easy to be replaced if damaged. The safety of operation is ensured by appropriately designed crumple zones.

The Marathon system used in locomotives is an alternative to an electric drive. The unit driven by a modern diesel motor allows the locomotive to move on stretches deprived of a contact line. This additional drive, which is used and appreciated by carriers, is mainly intended for shunting works – it allows to drive a train with the mass of 3200 t on an elevation reaching even 7 per mille. It is also helpful in emergency situations (instant loss of voltage in a network), which was already proven repeatedly as it always led a train to its destination.

The name of the locomotive “Marathon” is not accidental – the maximum range of the locomotive at full capacity allows for problem-free operation of all sidings and movement of a train formation on stretches deprived of traction voltage at minimum range of 42km.