(Xinhua) -- China
Communications Construction Company (CCCC) has
drilled the longest railway tunnel in East Africa,
the company said Monday.
The tunnel is part
of phase 2A of the Standard Gauge Railway (SGR) that
runs from the Kenyan Capital city of Nairobi to
An Aijun, general manager of SGR project head
office at the CCCC, said that during the excavation,
the project team overcame the challenges of water
leaks, uneven pressure, shallow-depth excavation,
surrounding rocks, structural fault-line, and oil
"With a total length of 4.5 km, the Ngong tunnel
is currently the longest tunnel in East Africa and
the dominant work in SGR Phase 2A," An said during
celebrations to mark the breakthrough of the Ngong
The Phase 2A which extends for about 120 km is
set to be completed in 2019.
The 4.5 km Ngong tunnel has been designed as a
single-track railway tunnel with a clearance height
of nine meters and a width of seven meters.
CCCC engineers used the New Austrian Tunneling
Method (NATM) of drilling and blasting to build the
tunnel and it is the first time that such a method
has been used on such a large scale in Kenya.
The tunneling method is economical, efficient and
has strong adaptability for different geological and
The method is preferred because it controls
surface collapse effectively, and enhances the
working environment during construction.
An said the construction team addressed the
technical difficulty in designing and constructing
in the Great Rift Valley to ensure a safe
breakthrough of the tunnel and this means that the
SGR Phase 2A has entered a new stage, laying a solid
foundation for inauguration next year.
The general manager said that with quality as a
foundation and safety as a lifeline, they shall
maintain an all-round quality control system in the
source, process, methodology and management, and
enforce strict safety management at all procedures.
"We will continue to protect the environment,
implement local contents, and participate in social
welfare, bringing real benefits to the local
communities," he added.
"Together with all our Kenyan partners, and
building on what has been achieved at the FOCAC
(Forum on China-Africa Cooperation) Summit in
Beijing, we shall construct a time-honored railway
that will stand the test of time and operations,
achieving greater success in a new era between our
two nations," he added.