Liebherr manufactures rail-road excavators and does so very successfully! The excavators, which can travel on both rail-ways and on the road, are built by Liebherr-Hydraulikbagger GmbH. Over 200 A 922 Rail and A 924 Rail models of rail-road excavators are manufactured here every year. That makes Liebherr the market leader in the specialist rail-road excavator sector. A specialist sector? Definitely, because the machines have several special features. The area of operation for rail-road excavators is the rail network, which is very busy in most countries. A great many companies compete to use the same tracks. The track network does not end at national borders and international train traffic must be maintained (inter-operability). In addition, there is a good deal of public interest in railway traffic as many rail networks are state-owned and are used to transport both passengers and (hazardous) goods. The fact that railway traffic is so important is demonstrated quite clearly by legislators issuing regulations for both people and machines. ECM (Entity in Charge of Maintenance) The ECM is the body responsible for the maintenance of a vehicle. Every machine must be assigned an ECM in the vehicle register so that the vehicle can be operated on the rail network.