Sentence:  In addition the <WSD>catenary</WSD> itself is divided into 1-2 km sections (corresponding to mechanical sections or tension lengths) with motorized remotely controlled sectioning off-load isolators such that only one train is likely to be immobilized at any one time as a result of an incident associated with the <WSD>catenary</WSD> system. 
Meaning of the word marked with <WSD> tags:  A cable, the segments of which between supports take a catenary geometric shape, supporting in turn an overhead conductor that provides trains, trams or trolley buses with electricity, or the combination of the conductor, the cable, and supports. (Rail transportation)