Refurbishment of sluice gate rails — Gamka Dam, Beaufort West
Department of Water Affairs and Forestry Consulting Engineers:
Scope of Work
- Removal and replacement of sluice gate rails.
- 30 meters of vertical rails of approximately 150kg each. Water depth 0 to 18 meters.
- Visibility 0.03meters with use of artificial lighting.
- Bolts being corroded and with limited visibility, existing rails had to be removed using Brocco Cutting and hoisted to top of tower for disposal.
- New Holes could not be drilled with rails insitu, hence accurate marking and drilling was required with the allowable hole tolerance of 3mm.
- Custom drilling equipment was required to drill a primary M20 hole through 40mm of steel, followed by an M18 core hole, 120mm into reinforced concrete.
- Rails were fastened using M16, A4 Hilti Hit500RE chemical anchors.
- Rails needed to be carefully manouvered to avoid damage to the 1.5mm of anti corrosive paint spec.
Refurbishment of the 3.5 ton tidal pool valve, Monwabisi Tidal Pool
Client: City of Cape Town Consulting Engineer: Entech
Scope of Work
- Removal for refurbishment of the 3.5 ton tidal pool valve.
- Depth: shallow diving in the tidal zone.
- Involved excavation in loose gravel to expose and remove the bolts, while in the impact zone, further the construction of a temporary access road was necessary to enable the lifting of the valve.
- After 8 months, when replacement valves were ready, further excavation was required.
- The original valve was replaced with 3 smaller valves, which require ongoing maintenance.