This series of tower cranes, ranging from QTZ31.5 to QTZ315 has a horizontal jib frame, a jib-trolley radius-changing mechanism and a hydraulic self-raising mechanism. It is original in design, reliable in operation and satisfactory in shape. Equipped with all necessary safety devices, these cranes show a good speed-control capacity, satisfactory operating stability and high work efficiency. They can be widely used for the construction of high-rise hotels, residential buildings, high-rise industrial buildings, large-span factory buildings and tower-like buildings like tall chimneys.

feature&advantage
1. suitable for all kinds of construction project and can work under all kinds of work condition.
2. It has high working speed, good speed-adjusting performance, steady operation and high efficiency.
3. The crane has complete set of safety devices, which can guarantee the safe and high efficienct operation of the equipment.
4. Three-speed motor and mono-speed ratio decelerator are applied in the lifting struction, which enables heavy load low speed and light load high speed.
5. Planet gear decelerator is applied in the circumgyrating structure, together with moment-limiting hydraulic coupler, which can relize high load capacity, steady starting and reliable operation.

. This Machine is used for erecting concrete box girders for high speed (250km,350km) passenger railway lines.
2. This machine is suitable for equal span girders or different span girders which can be 20m, 24m and 32m .
3. The rear part has two supports. One of the supports is "C" shape column with rotary and foldable technology. The “C” shape column technology saved the traverse space during traveling and which enables to travel through tunnels with the girder transfer vehicle.

Safety features:

1. Overload protection: If the material is over the capacity, the crane will give a sharp warning for protection itself.

2. Emergency brake: If the operation staff encounter some emergency situation, we could start the emergency brake system to protection the related treasure.

3. Control Method: Room control or remote control to avoid any injure to the operation staff

4. Main lifting motor: with thermal protection and currency protection.