are hermetically sealed and act as floats. The motion of the tilting gate is
governed by a hydraulic motor, mounted at the bottom of the upper gate
recess in a protective casing with sliding cover.
For direct filling of locks 12 m wide, with an initial water depth of
3.5–4 m, an incremental inflow below the gate at the beginning of its filling
of dQ/dt0.2 m^3 s^2 is permissible without the forces in the mooring ropes
of the handled ships exceeding their permissible values. The rate of rise of
the water level varies within the limits of 0.8 and 1.2 m min^1.
Directly filled locks may be emptied by means of short culverts or
directly below the downstream lifting gates, or even through openings in
the gates, closed with sluice, butterfly or flap valves.
Another type of a direct filling system suitable for low heads uses
two sector gates turning along vertical axes, with the flow passage formed
by their gradually increasing opening; the gates turn slowly through the
initial stages of lock filling and increase their opening speed as the water
level difference decreases. For larger heads a filling system utilizing a leaf
gate, as shown in Fig. 11.12, can be used. The filling system is designed to
prevent air entrainment in the filling passage below the gate, thus con-
tributing to a calmer filling.
480 INLAND WATERWAYS
Fig. 11.11 Rotating gate of Cˇábelka type (after Cˇábelka and Gabriel,
1985)
