The MMU, dubbed the Next Generation Maintenance Machine (GMAC) by JR East, is a two-car train consisting of a work vehicle and a material carrier. The work vehicle has no floor, allowing staff direct access to the track from inside the vehicle to undertake inspection and maintenance.
Staff were previously required to walk along the track to conduct inspections, and would often have to carry equipment to the site up. The MMU provides a safe environment, along with lighting and power, while a seat has been mounted within the vehicle above the track to improve access. Maintenance tasks such as rail replacement can also be completed within the vehicle.
A platform on the roof of the train allows inspection of high level assets including tunnels and overhead electrification.
The material carrier holds heavy materials and tools, which can be delivered to the work vehicle via an inter-connecting gantry crane. There is an additional underfloor storage area where six 10m-long rails can be transported.
Additional features include moveable sidewalls that can increase the working area to 4.4m, a tail lift to assist loading and a sprinkler system for weed spraying.
JR East expects to use the MMU as its main maintenance vehicle. This will assist the railway in reducing the required manpower in response to a shrinking workforce, while also improving safety and reducing costs.