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Refurbishment of sluice gate rails — Gamka Dam, Beaufort West

Client: Department of Water Affairs and Forestry  Consulting Engineers: ROTEK

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.