Bow hatch
In the case of vehicles, a front flap is generally understood to be a pivotable or lockable cover on the front of the vehicle, which serves different purposes. On the one hand, it can serve as a protective cladding for units belonging to the vehicle, but also as a loading gate, such as on cargo planes or RoRo ships .
In rail vehicles , a pivotable or lockable cover of the coupling shaft is used on the front of the vehicle in order to avoid aerodynamically disadvantageous front parts or, as in trams, the risk of accidents due to a protruding coupling. Bow flaps are used in railways, especially in streamlined multiple units such as high-speed trains (e.g. ICE , TGV ) from various railway administrations.
Nose doors are normally closed and are only opened when the coupling has to be used, for example when two multiple units are running in double traction. If the control device of the front flaps is defective, the flaps are always operated with the flaps open in order not to impair the operational sequence - for example when reinforcing a multiple unit by another during a short stay at the station.
On road vehicles such as buses, which due to their different radiator position, do not have a front radiator grille in the actual sense, the term front panel is used more, even if this can be opened for maintenance purposes or for the emergency coupling. The term bow hatch is also used in connection with caravans; behind this are utilities such as propane cylinders and water tanks.
The terms bow or bow flap have their origin in seafaring, although here - due to the different and sometimes very complex constructions - other, different terms such as bow port, bow ramp , bow gate or bow visor are also used. The terms bow flap or bow ramp are used more on ships where the lock also serves as a loading ramp, e.g. B. in the hovercraft . In displacement ships, these bow gates consist of several components: on the one hand the bow visor as an external lock, a vehicle ramp behind it, which seals off the bow gate in a watertight manner, and an optional additional deep sea bulkhead .