For levelling locks with a fall below 5.0 m, openings in the doors are usually used as levelling systems in Flanders. In 2008, WL started developing the programme vul_sluis.m (see project 00_077). As part of the drafting R&D research programme, a project proposal has been submitted for the further development of the programme vul_sluis. For this purpose, the following research steps are proposed: - Conducting an in-depth sensitivity analysis on the input parameters of the vul_sluis programme and certain variables used internally in the code. - Comparing the methodology for calculating translation waves in vul_sluis with other methods based on solving the momentum and continuity equation - Comparing the water level variations, flow rates and longitudinal forces calculated with vul_sluis with those calculated with other programmes, such as Delft3D, LOCKSIM and possibly LOCKFILL. - Carrying out an investigation of flow through an opening in a sluice gate, using the scale model for project 14_050.