The aim and purpose of the WG 173 report is to determine technological guidelines for design, fabrication, construction, operation and maintenance of both rolling gates and movable bridges. Currently, rolling gates are a nearly unanimous choice in navigation locks with chambers wider than about 40 m. Rolling gates are ideal for applications that require handling a differential head from both upstream and downstream directions. For this reason, rolling gates are commonly used for locks subject to tidal changes and storm surges such as sea locks. Rolling gates utilizing the wheelbarrow design are the largest in world. In a wheelbarrow gate, one carriage is placed under and one at the top level of the gate on the operating machinery side. In the classical support system, there are two undercarriage assemblies arranged near the gate ends and both carriages are under the gate. The disadvantages of the wheel barrow type gate are advantages of a classically supported gate with two under carriages and vice-versa. Rolling gates are generally designed as buoyant to help reduce operating loads and support the gate load. Buoyancy tanks also allow the gate to be raised off the carriages by flotation to allow maintenance. Many components of the rolling gate are subjected to fatigue and wear in particular the carriages and rail tracks. A typical operating speed of a rolling gate is 0.3 meters per second but this can vary depending on the size of the gate. A rolling gate carries hydraulic lateral loads not only in the closed position, but also when moving or when in recess. These loads include loads by residual water heads at the end of filling and emptying, loads by wind waves, loads by currents and tidal forces in an open chamber, and loads by currents as result of salt and fresh water exchange. The skin plate of a rolling gate is sized to serve as the effective flange of the main supporting structural framing and as the plate that retains the water pressure acting upon the panels.