The first two E3 machines are the Unimat 09-4X4/4S E3 tamper and the HTW 100 E3 hybrid tower wagon for overhead catenary maintenance.

Electric power offers several benefits. The machines are much quieter - during tamping noise is only generated when the tamping tines hit the ballast. Electric traction motors are smaller than traditional hydraulic units. Plasser says less maintenance is required and operating costs are lower.

The new machine has a tamping assistance system which recommends the optimal tamping process for track or switches. Laser and video units at the front of the machine produce a virtual image of the track which is combined with data on how the track should be maintained, which is stored on the onboard computer.

This will make it possible to achieve slightly higher tamping speeds and eliminate the lifting operator. However, Plasser says it is too early to fully automate the process. The machine is currently being tested and has successfully tamped two switches in Austria.

The tamper is also equipped with Plasser’s new onboard spare parts ordering system.

The hybrid tower wagon is fitted with batteries which provide sufficient power for two six-hour shifts. A special cooling system developed by Kreisel, Austria, maintains batteries at a constant temperature which prolongs their life.

The unit drives to and from work sites at up to 100km/h, enabling the batteries to be charged. It is also possible to regenerate power during braking. When the machine is working it only uses electric power which means it can operate with low noise levels in urban areas and without emissions in tunnels.

Both machines have a new design of air-conditioned cab and work station which has noise and vibration damping, as well as lighting which can be adjusted for day or night working.