While determining the hoist capacity required for the operation of gate i.e. either lifting or lowering of gate following forces are taken into consideration
-Weight of gate
-Frictional force between roller wheels & track plate or sliding seal & bearing plate
-Frictional force between rubber seal & seal plates
-Frictional force between roller pin & bushing
-Weight of ballast required to be added for the gate closing under self weight
-Down pull/ up thrust forces acting on the gate
Gate Embedment normally consists of following parts :
Track Girder assembly with track plate, Guide tee assembly, sill beam assembly, horizontal seal plate assembly, vertical seal assembly, Wall plate assembly, steel linings, anchorages, bye-pass pipes, air vent pipes, etc.
For upstream sealing gates,skin plate is provided on upstream of the gate frame and also seals are provided upstrems of the skin plate.This results in dry conditions in the hoist well on the downstream of gate and gate components such as horizontal girders; end vertical channels, rollers, etc are protected from submergence in water & resulting corrosive effect. Also as the hoist well is dry, hoist platform can be lowered to a suitable lower level. Service gates (Sluice gates) have normally upstream sealing.
In Down stream sealing gates,skin plate is provided on the down stream side of the gate frame and also seals are provided on the downstreams of the skin plate.This results in wet conditions in the hoist well on the downstream of gate and gate components such as horizontal girders; end vertical channels, rollers, etc are submerged in water. On account of submergence, such gates are used only when required for short durations and hence not affected by corrosive action of water. Emergency gates (Sluice gates) have normally downstream sealing.