Official classification context
Industry overview This class comprises establishments primarily engaged in executing work related to track blocking devices, electrical signal machines, interlocking machines, switch-and-lock movement apparatus, level-crossing security devices, electrical signal line supports and other signal safety devices, fire alarms and other warning devices.
Major group context This Major group comprises establishments primarily engaged in direct contracts with the orderers for completing electric structures, telecommunication signal facilities, air -conditioning equipment, water supply -drainage with sanitary equipment, elevator systems, and other machinery and equipment, or the establishments engaged in comple ting similar work by self -construction (construction for the establishment itself) as well as those engaged in subcontracting installation work as a part of work for these machinery and equipment.