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of gantries and the transfer house sections to the top of Silo 20,
which include lifts in excess of 40 t, and commissioning at the live
power station. The project scope is large and complex, with the
main focus being a very tight deadline.
It is an interesting project in that the entire Silo 20 was not
demolished. Rather the base and bottom half from the hopper up
were incorporated into the new structure. Another engineering
design challenge has been to ensure that the plant, which was built
originally over 20 years ago, complies with all the latest regulations
and requirements, without changing any fundamentals such as
the layout. A significant challenge is that the coal feed to the fully
functioning power station cannot be interrupted at all, which is
why Eskom has phased the project, with a bypass conveyor as an
interim solution.
Silo 20 is 65 m high, which presents a challenge in terms of
heavy lifts due to the windy conditions at this time of year, as well
as significant safety risks to all individuals working at heights to
perform these difficult installations.
Another major challenge in terms of the sliding in particular is
that the concrete mix has to be precise, an area where Hatch’s site
engineers paid particular attention to.
Project information
• Company entering: Hatch
• Client: Eskom
• Project start date: May 2015
• Project end date: December 2016
• Main contractor: Rula/Stefanutti
Stocks Consortium
MAJUBA POWER STATION
SILO 20 RECOVERY PROJECT
In November 2014, an incident occurred at Majuba, during which
the wall of Silo 20 fractured, leading to the collapse of the upper
section of the silo. The conveyor transfer house and the coal
conveyor gantry sections that were supported by Silo 20 also
collapsed, resulting in damage to the head end of the overland
conveyors, take up structures and the tail ends of the over-silo
link conveyors.
The configuration of the coal plant relies on the distribution
of coal to the desired silo from the Transfer House located on
top of Silo 20. Due to the structural failure of Silo 20 and the
associated conveying infrastructure, no coal supply to any of
the silos was possible.
Hatch won a competitive tender to provide engineering services
for the permanent solution, consisting of a detailed civil and
structural design for the plant, as well as a basic design, for all
associated interfacing plant, including Bulk Material Handling
(BMH), Electrical, Control and Instrumentation (C&I) and Low
Pressure Services (LPS).
The scope of the permanent solution project includes Silo 20
reinstatement, strengthening of Silos 10 and 30 and all supporting
systems. During the design phase, the urgent timeframe resulted
in Hatch having to shave several weeks off the engineering
design schedule. To date the project has been a success.
Challenges going forward include conveyor construction, lifting
Majuba is a six-unit, coal-fired power station that
produces a total of 4 107 MW of electricity.
It comprises three dry-cooled units producing
657 MW each, and three wet-cooled units
producing 712 MW each. Construction started in
1983, with the first unit connected to the national
grid in 1996. The last unit was connected in 2001.