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Awash Bridge two weeks ago stretched by 20mm when a
transformer four times heavier than its carrying
capacity crossed it. The 213tns transformer with the
capability to generate 540MW of electricity was
intended for the Gilgel Gibe II Hydro Power Project
that is being undertaken by the Italian construction
firm Salini Custruttori SpA.
With a trailer specifically geared to transport the
shipment, the transformer on January 28, 2008,
passed over the 110m long, 40-year-old bridge that
has a maximum carrying capacity of 50tns a week
after it set out from Port of Djibouti.
“The transformer is crucial for the country’s
development and the bridge lies on the main route
for the country’s goods,” a senior government
official told Fortune. “Though it was a
difficult choice, we had to find a way to proceed.”
Both the transformer and the truck trailer were
manufactured by Spanish CYMI-SOCOIN. The design of
the 22-axle trailer was undertaken by Negussie
Tebeje (Engineer.), a 63-year-old retired professor
from the Technology Faculty of Addis Abeba
University (AAU).
“The 20mm stretch will have no impact on the current
and future life of the bridge,” Negussie told
Fortune.
According to a civil engineer, if the numbers of
axels are increased when the load of a cargo on a
truck trailer is high the bridge could handle the
weight as the load would be distributed evenly.
“It is because of the many axles of the trailer the
bridge handled four times its recommended capacity,”
said the engineer.
Negussie for over a year has been studying ways to
transport the transformer on the bridge.
The vigilance came following the threat posed by the
Tunnel Boring Machines (TBM) that crossed Abay
Bridge, the country’s largest bridge (145m) that
stretches over the Nile River, in July 2006 after
they were stranded for over three weeks. The
machines were brought for the Beles Hydropower
project underway in the Amhara Regional State.
Of the four trucks blocked at the gate of the bridge
at the time, two trucks carrying 62tns and 64tns
were allowed to cross the bridge that only is dubbed
to carry 40tns following a recommendation by
Negussie after a 10-day study on the bridge. The
other two trucks that collectively had carried over
100tns of shipments were forced to reach their
destinations through different route via Wollega in
a bid to protect the 57-year-old bridge.
Salini, which hired Negussie to study the passage on
Abay Bridge, has been working with the veteran since
then.
Salini has been constructing Gilgel Gibe II as an
extension to Giglel Gibe I with a project cost of
400 million Br. Prior to the latest passage two
equipments weighing 107tns have crossed Awash
Bridge.
For this project, two transformers weighing 213tns
each are needed including the one that crossed
recently. The transformer crossed on the bridge at a
snail pace of five kilometres per hour. The other
transformer is expected to arrive soon.
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