|
The headquarters of Salini
Costruttori in Addis Abeba was deserted on
Friday, February 12, 2010. The eerie quiet of the
corridors and responses by office assistants that
their bosses were in continuous meetings, or that
they were “away at sites” were subtle indications of
a crisis. Apparently, the Gilgel Gibe II Power
Plant, which was inaugurated recently, the
construction firm’s and the Ethiopian Electric Power
Corporation’s (EEPCo’s) pride and glory, had
suffered a tunnel blockage due to a cave-in.
It all started on January 21, 2010 when there
occurred what experts called an unusual drop in
water pressure – an essential parameter for power
generation. Water entry into the tunnel was thus
blocked by officials on the 24th of the same month
to salvage the plant from further damage, and make
the tunnel accessible to inspectors. This,
naturally, meant halting the power production of the
plant.
“The plant was producing over 200MW (about half of
its rated production capacity, which is 420MW),”
Miheret Debebe, CEO of EEPCo, said.
A team of six people were the first to enter the
tunnel that comprising of members from the
contractor, consultants and project owner EEPCo.
They were able to identify the problem as being one
of a 15 metre length of the 26km tunnel ceiling
lining having caved in at 8.98km from the water
outlet, a location with 1,300 metres of overburden
from the peak of the mountain that lay above it.
Boulders had blocked the passage of water.
The plant has been providing power to the national
grid for the past four months, and that was the
reason behind the consistent power the country had
been enjoying after having spent a rainy season with
prolonged power outages that had affected life and
industry throughout the country.
The causes of the cave-in were not clear.
“These kinds of mishaps are expected in light of
the magnitude of the project,” Semegnew Bekele
(Eng), project manager for the Gilgel Gibe II
Project, told Fortune.
The one-year delay in completing the project was
mainly due to the increasing geophysical challenges
of making a tunnel through a mountain, according to
a 2008 statement by Miheret.
Salini too associated the problem with the tunnel
passing through what they called “heterogeneous and
complex geological formations” in a statement they
issued on their website.
Semegnew thinks the new phenomenon has nothing to do
with what happened in the construction phase and
that the current failure is not as troublesome as
the past.
“We are working vigorously to solve the problem, and
it is a resolvable one,” he said.
Although the incurred cost is yet to be
determined, officials have steered clear of laying
out the details of who is responsible for covering
them.
The settlement is going to be carried out
according to the contract the two are already bound
by, said the Salini project manager and EEPCo CEO.
“We have a defective liability period stated in
the contract agreement,” Alemayehu Tegenu, minister
of Mines and Energy, said.
The issue of cost is not currently on the agenda
according to Eugene Zopis, Salini project manager.
“The first task is consolidating the area above
the tunnel,” he said, “followed by the work of
replacing the tunnel lining.”
Meanwhile, the Salini employees, whose offices
were abandoned, together with a team from the mother
company in Italy, were in high-level meetings with
the EEPCo administration and the EEPCo board of
directors that is chaired by Girma Birru, minister
of Trade and Industry.
Although officials at Salini and EEPCo were
reluctant to put a date on the time the maintenance
is going to take, insiders estimate the time at
three months. Time was on the side of the
maintenance procedure, as it does not involve
transporting machinery to the site, Alemayehu
mentioned in a statement he made to the press.
“They are already on the site and have not been
moved since the inauguration,” he said.
EEPCo’s priorities lie elsewhere, however. The
corporation is making preparations to take what the
CEO called energy crisis management steps.
“These include speeding up the completion of the
Tana Beles Hydroelectric Power Project which was
scheduled for April,” according to Alemayehu, “and
deploying diesel generation stations.”
Miheret also called on all electric users to try
and conserve what little power they can.
The power giant is more focused on the mitigation
of the supply of power. Since the exclusion of the
Gilgel Gibe II power from the national grid, the
supply of power at peak hours of the day is
straining to meet the demand. But there is no
connection between the power outages that are
recently being reported around town and the
situation at Gilgel Gibe II, Miheret said.
The Gilgel Gibe II Project was believed to have
increased the power production of the country by
38pc. The project, which was awarded to Salini
without a tender, cost a staggering 608 million
dollars, 52pc of which was financed by the European
Investment Bank (EIB) and the Government of Italy,
while the rest came from the Ethiopian Government.
Consultants from Austria, Switzerland, South
Africa, the United States and Italy were involved in
the process. The need for different consultants was
part of the delay, according to Abdul Hakim
Mohammed, process executive officer for Generation
Construction at EEPCo, and was necessitated by the
repeated slides that occurred during the tunnelling.
The project was launched on June 11, 2004, and
completed on October 31, 2009. It involved 4,000
workers, of which 150 were foreign nationals,
Abdulhakim said.
Gilgel Gibe II operates on water that flows from
Gilgel Gibe I, inaugurated in 2004.
The tunnel, ompleted in June 2009, was excavated
using two boring machines. The water then passes
through 500 metres of metal pipe (penstock) down to
the four turbines, each responsible for generating
105MW. The water then goes on to join the Omo River.
|
Gilgel Gibe II tunnel collapse causes electricity
strain