940 EQUIPMENT MAINTENANCE, REPAIR, AND CONSTRUCTION SERVICES - RAILROAD 94054 * Power Supply Installation, Electric 94055 * Power Supply Maintenance and Repair, Electric 94063 * Rail Grinding 94075 * Signal System Installation 94076 * Signal System Maintenance and Repair 94085 * Tower Construction 94086 * Tower Maintenance and Repair 94088 * Track Construction and Inspection 94089 * Track Maintenance and Repair 94092 * Weed/Brush Control Services