The 55-ton (40.0 metric ton)  lifting capacity National NBT50-128 Boom Truck is part of the National Crane Series NBT50 and is equipped with a 31.7 ft - 128 ft (9, 7 m - 39, 0 m)  five-section telescopic boom and comes with an optional  26 ft (7, 9 m) fixed offsettable jib or a 26 ft - 45 ft (7, 9 m - 13, 7 m) two-section offsettable extension, providing a maximum tip height of 179 ft (54, 6 m). 

Crane Features

• The 3rd wrap and last level indicators will alert operators when the last of the wire rope is being
used and the cable follower will keep constant tension on the rope reducing the potential for bundling.
• Speedy-reeve boom tip and sheave blocks simplify rigging changes by decreasing the time needed to change line reeving.
• Easy Glide boom wear pads reduce the conditions that cause boom chatter and vibration. The net result is a smoother crane operation.
• Pressure compensated, load sensing hydraulic system
- PTO mounted axial piston pump
- Superstructure mounted reservoir with integral suction valve/filter, return filter, sight gauge, and
temperature gauge
- Oil cooler with 406 mm (16 in) fan and temperature sensor
- Pressure transducers are integral to the lift cylinder holding valve.
• LMI system features a 178 mm (7 in) graphical, color display. Real-time crane information is displayed with numerous operator features such as soft metric load chart conversion, hydraulic filter change reminders, and an electronic hour meter. LMI system also displays key truck diagnostics such as fuel level, coolant temperature, and DPF status.
• The display console allows each crane control function to be set independently to reduce speed
(100%, 75%, 50%, and 30%).
• Dual-axis controls are optional for superior operator control, along with standard air conditioning, a diesel heater, and ergonomic seats.