The Unimat 09-4x4/4S E³ universal tamping machine for tracks and turnouts uses the electrical energy from the overhead line not only for electrical traction during transfer travel. The vibration shafts of the tamping units are also powered electrically. When the units are raised in idle mode, the noise is reduced by more than 20 dBA. This is a massive noise reduction, compared to units with conventional drives. The noise created in idle mode is 62 dBA, which is equal to the noise level of a normal conversation in the office.1
During standard tamping work shifts, work site logistics can cause considerable idle times. The new drive technology allows for a significant reduction of the rotation speeds in idle mode when the unit is raised. Its speed is only increased during the actual operation – penetration and squeezing. When the rotation speed of the unit is reduced, the electrical energy is recovered.
During operation, the tamping machine’s drive car generates more than 13 dBA less noise than the drive car of a diesel-hydraulic machine.2 The all-electric E³ drive offers an ergonomically designed working environment, placing particular attention on staff protection.
Depending on the operating situation, a tamping machine travels not only during tamping work, but also during measuring, reversing for the next tamping cycle or transfer journeys. Thanks to the new technology, lineside residents are no longer exposed to the noise generated by hydrostatic drive pumps.
 Measured at 1 m transversally to the tamping unit
 Average value measured at a distance of 1 m to the drive car of the machine working past