DAM/Specific/TBT-DAM-009

Flood Gate and Penstock Installation

Dams, Reservoirs & Flood Defence › Specific › Flood Gate and Penstock Installation

Presenter		Project
Location		Date

Flood gates and penstocks are mechanical barriers installed in flood defence walls, channels, and pipelines.
They control water flow during normal operations and close to prevent flooding during storm events.
Installation involves heavy steel or aluminium components requiring crane lifts into confined concrete structures.
Working in channels, chambers, and culverts during installation creates confined space entry risks.
Residual water in channels creates drowning risk even when flows are diverted or reduced.
Gate guides, sills, and frames must be set to precise tolerances for the gate to seal correctly.
Grouting and fixing operations in wet environments require specialist materials and techniques.
Mechanical and electrical connections for powered gates must be installed by competent specialists.
Testing the gate under water pressure is essential before the installation is considered complete.
LOLER 1998 applies to all lifting operations; confined space regulations apply to chamber entry.

Drowning risk	Working in water channels and chambers during gate installation creates immediate drowning hazards for installation teams.
Heavy components	Gates and frames weigh from hundreds of kilograms to several tonnes, creating crush risks during handling and placement.
Flood protection	Incorrectly installed gates fail to seal during flood events, resulting in flooding of protected areas and communities.

Don't

Treat all work in channels and chambers as confined space entry with permits.
Wear personal flotation devices when working in or near water channels.
Prepare a lift plan for every gate, frame, and heavy component being installed.
Divert or reduce water flows before entering channels for installation work.
Set gate guides and sills to the tolerances specified in the installation drawing.
Use waterproof grout and fixings designed for submerged or wet conditions.
Test the gate under water pressure to confirm sealing before handover.
Position rescue equipment including throw lines at the channel work location.
Ensure mechanical and electrical gate connections are installed by competent persons.
Brief the installation team on the confined space and water rescue procedures.

DON'T enter water channels or chambers without a confined space entry permit.
DON'T work near water without wearing a personal flotation device at all times.
DON'T lift heavy gate components without an approved lift plan and rated accessories.
DON'T install gates in channels with uncontrolled water flows still running.
DON'T accept gate guides or sills that are outside the specified installation tolerances.
DON'T use standard grout products in permanently wet or submerged locations.
DON'T commission powered gates without electrical isolation and safe testing procedures.
DON'T leave rescue equipment in a store; position it at the water channel edge.
DON'T assume diverted flows will stay diverted; monitor upstream conditions continuously.
DON'T skip the water pressure test before handing over the completed installation.

See also: Flood Defence Construction Safety | Working Over Water

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