The ground lifting machine for coal seam gas coring drill is required to be speedy and powerful.

In this article,the author introduces some installation technologies of integral steel box girders,such as applying simple equipment to draw across the bridge piers with a winch,and using lifting device to dropped girders into place,which is applicable in practice to installation of structure in large size.

The offshore drilling platform jacking gear is divided into two parts——the electric driving and the hydraulic actuation.

Analyses of reasons for the collision of marine lifter with its protection covers and their solutions;