4. The design basis of THQ900t bridge girder launcher for tunnels

The product design is in accordance with relevant provisions of new national codes and standards, it mainly has:
● 《crane design specifications》（GB/T 3811）
● 《construction equipment research technical conditions for Beijing-Shanghai passenger special line》
● 《general purpose gantry cranes》(GB/T14406)
● 《steel structure design codes》（GB 50017）
● 《steel structure construction and acceptance specifications》（GB 50205）
● 《wire rope with important purpose》(GB 8918)
● 《electrical device installation project construction and acceptance specifications》 (GB50256)
● 《hydraulic system general technical specification》(GB 3766)
● 《railway engineering construction safety technical procedures(Book One)》（TB10401.1）
● 《bolts, boults and double-screw bolts with fasteners mechanical character》（GB 3098.1）

5. The video of THQ900t bridge girder launcher for tunnels

6. Main design requirements of THQ900t bridge girder launcher for tunnels

● Lifting steel wire rope safety factor: n≥6
● Boom stretch stress safety factor: n≥6
● Structural strength calculation safety factor: n≥1.5
● Institutions transmission parts safety factor: n≥1.5
● Factor of safety against overturning n≥1.5
● Electrical equipment and wiring insulation class should be in accordance with that insulation class of construction ministry and related electrical equipment, protection level should  reach: electrical machinery IP54, other electrical equipment IP65 or above.
● Crane utilization grade: U0
● Crane utilization condition: Q3
● Crane working level: A3
● Crane institutions working level: M4
● Bottom deflection of main girder: S/700