The six designs
- Straightforward
- Reliable parallel systems (14 valves)
- Simple construction
- Sensitive to negative head
- Silting up of valves and compartments
- Underwater maintenance
- Barrier can be closed even in extreme floodcurrent
- Simple construction system with proven hydraulic and offshore techniques
- Opened doors vulnerable to collision
- Silting up of gate chambers
- Gate chambers cannot be pumped dry (for maintenance)
- Interference from shipping during construction (sill construction with railtrack on top of it)
- Gate has to plough through sediment deposits
- 24 independent valves (risk of failure small)
- Takes up minimum amount of space
- Valves, caissons and bottom protection under-dimensioned
- Foundation techniques (as for tunnelling) applicable?
- Maintenance awkward
- Silting up of valves
- Gates well protected when open
- Gates easily accessible in drained door-chambers (for inspection and maintenance)
- Simple construction system within field of experience
- Interference from shipping during construction
- Over-dimensioned
- Most expensive solution
- Insensitive to silting up
- No moving parts below water (reliability and ease of maintenance)
- Less easily controlled closing-process
- Loads uncertain (has direct bearing on control of closing-process)
Floating sector, gate BMK
- Doors well protected when open
- Ease of inspection and maintenance in drainable gate chambers
- Well balanced design
- Entire load borne by single point (hinge)