Shipbuilding gantry crane [1] working-level A5, use grade U5, load status Q2, lift truck 0.4t, span 96m, 2 × 60t hook, when loaded with 0.2 ~ 5.5m / min (frequency conversion). Shipbuilding Gantry shipyard crane suitable for production facilities (dock, berth) in the shipbuilding operations, with a single crane, double crane lift points, three lift cranes, aerial flip hanging pieces and light load (≤50% load) rapid movements, low wind speed (≤ a variety of job functions 8m / s) fast run, etc., shipbuilding gantry crane hoisting a whole, the main beam lifting is the most critical aspect to 800t gantry crane, for example, the main beam total weight of 2680t, up and down the car and maintenance Hanging was 324t, 155t and 45t, shipbuilding gantry crane girder from the previously vertically trolley and maintenance Hoisting the main beam before the rise, according to the overall lifting weight with the vertical trolley placement main beam centroid position to prevent the shipbuilding gantry crane hoisting process the emphasis. Therefore, the total weight of the main beam reaches 3204t, a total weight of two tower cranes for 4000t, in the range of shipbuilding gantry crane safety safety factor of 1.25.