Water, Sewage & Effluent September October 2018 | Page 18

appointed a specialist asbestos
subcontractor, Drizit Environmental.
Kleynhans elaborates: “We only had
two areas that were tied into an existing
800mm asbestos cement pipeline, at
the Eerste River crossing and at the
Macassar pump station, and only had
small sections of asbestos that required
removal. At the start was about a
10-metre section and at the end, about a
50-metre section. The new outfall sewer
followed a different alignment to the
existing outfall sewer, effectively on the
northern side of the existing sewer.”
Project info
Client City of Cape Town,
Water and Sanitation
Engineer Aurecon South Africa
(Cape Town)
Main
contractor Afriline Civils
Main
Rocla, Infraset,
suppliers, Concrete
Cape Town Units, Akwasol, and
Lafarge ready-mix
concrete.
Project management
“The depth of the excavations required that they be battered,
and staff had to work within a ‘drag box’ at invert level to create
a safe working environment for our staff.”
John Reed, contracts manager for Afriline Civils
pump station was replaced with a new
sewer line, consisting of HDPE-lined
concrete pipes with internal diameters
of 900mm and 1  200mm, respectively.
The pipes were manufactured by
Infraset (900mm) and Rocla produced
the 1 200mm pipes and supplied within
40 weeks.
While removal of asbestos can be a
hazardous process, the length of pipe
removed was not of a significant length.
Nevertheless, the necessary permits
and approvals were obtained, and
main contractor on the project, Afriline,
Client Keith Olsen
Engineer Stephan Kleynhans
Contractor Johan Marais
(contracts director)
John Reed
(contracts manager)
Chester Adams
and Dino Cupido
(construction
managers)
Arno Grobbelaar
(safety manager)
Christopher Reed
(general foreman)
Angelo Fortuin (senior
surveyor)
Duran Young
(concrete foreman)
Pipe specifications
“A total of 1 508 pipes were laid,
comprising 2 500mm in length,” says
Reed, adding that the logistics of
transporting the pipes to site was
undertaken with Afriline’s own crane
truck, a 22m-long Mercedes 3335
Axor truck and trailer.
•
•
•
•
DN  1200 diameter pipeline construction, along with existing pipelines that need to be
connected to the new system.
16
Water Sewage & Effluent September/October 2018
DN 1470mm – concrete
jacking pipes – HDPE-lined
270° – CH3583 to CH3669 –
for Macassar Road crossing
by pipe jacking method —
supplied by Concrete Units
— jacked by Wepex.
DN 1200mm 100D – concrete
pipes – HDPE-lined – CH1200
to CH3770 — supplied by
Rocla — manufactured and
supplied in 35 weeks.
DN 900mm 75D and 125D –
concrete pipes – HDPE-lined
– CH0 to CH1200 — supplied
by Infraset.
DN 2600 and DN 1800
precast concrete manhole
rings for 48 chambers —
supplied by Rocla.