- locks of large dimensions in plan and high heads with more complex
filling and emptying systems, designed to ensure uniform distribution
of water during the filling and emptying along the whole lock area;
- locks with combined direct and indirect filling.
11.8.2 Locks with direct filling
In the case of low- and medium-head locks (H12 m), of small to medium
dimensions in plan (B12–24 m, L190–230 m), the locks have the shape
of a prismatic trough with vertical walls and a solid bottom, constructed of
anchored steel sheet piles (Fig. 11.8(a)), suitably reinforced concrete
precast components, as an in situRC open frame (Fig. 11.8(b)), or con-
crete walls braced at the lock bottom.
Some older locks, and even some of the modern low-head locks, are
fitted with mitre gates with vertical sluices built directly into the gates
(Fig. 11.9(a)). On other low-head locks, particularly on the more recently
built or renovated ones, upstream gates rotating about a horizontal axis or
sliding gates are used (Fig. 11.10). These lock gates serve simultaneously as
the direct filling mechanism, which considerably reduces the costs of the
478 INLAND WATERWAYS
Fig. 11.8 Cross-section of locks
