OK gantry crane bridge metal structure weight method

In the calculation of the steel  bridge gantry crane ,  you must determine the role of the bridge girders or trusses on the same loads that is half the weight of the bridge (without considering the weight of the end beam) related. When determining the weight of the bridge, it is usually use structure, since a similar weight and span bridge  gantry crane  drawings can also be used by weight or weight characteristics characteristics table graph.
OK gantry crane bridge metal structure weight method, this method can be calculated when the different structures of the bridge was adopted.
Everyone knows that the most favorable bridge steel bridge on weight in a certain ratio between the span under guaranteed. For example, from the weight of 15 tons of lattice bridge, when a span of 15 meters, the most advantageous height was 15/9.
However, for purposes of placement tray, normally give a smaller area at a height dimension limits, therefore, must provide a relatively high degree of disadvantage of the bridge. For example, for  hoist gantry crane  lifting capacity of 15 tons of lattice bridge, when a span of 15 meters, it is recommended to take 1:1.
Gantry crane bridge structure should not only respect the allowable stress intensity conditions are met, it should be allowable deflection areas to meet stiffness conditions.
After the bridge height requirements, gantry  jib crane  designers should take into account, according to the National Bureau of lifting gear inspection regulations applied load bridge deflection is determined under static force, and the calculated stress is determined at full load, in other words, taking into account all factors into account the dynamic loads and activities identified under constant load.