Construction World December 2018

Specialist Contractors or Suppliers

DEMOLITION OF BOILER UNIT 3 AT DUVHA POWER STATION

WINNER

D emolition engineering commenced in January 2017 and access to the 96 m high suspended boiler, towering higher than the Statue of Liberty, was gained during April 2017. Final site clean-up and demobilisation was completed by mid-June 2018, with successful demolition of over 11 000 tonnes of steel carried out in less than 13 months. Preventing damage to the main support structure of the boiler house and its internal substructures was crucial, as their reuse was required for the rebuild. With Unit 3 being surrounded on all sides by operating power plant equipment, it was vital that demolition and removal activities were implemented without affecting normal 24/7 operation of the other 5 Units at the power station. This high-risk project involving the removal of critically compromised structures was carried out on 2 x 12 hour shifts per day with the labour force peaking at 145. Various innovative demolition methods were devised, including: complex rigging with purpose-built winches, extended-length chain-blocks and mobile cranes; extensive rope-access activities; and controlled cut-and-drop techniques where the boiler walls served as a drop chute. This very successful project logged 330 373 hours without a Lost-Time-Injury.  Unit 3 boiler at electricity utility Eskom’s 3 600 MW Duvha Power Station in Mpumalanga South Africa experienced an over-pressurisation event, resulting in irreparable damage to the boiler structure and associated equipment. The contract for demolition of the coal-fired boiler and ancillary equipment was awarded to Jet Demolition with the key requirements being safe, controlled and rapid removal of the damaged 600 MW boiler to facilitate later replacement.

PROJECT INFORMATION

• Company entering: Jet Demolition • Client: Eskom • Start date: 4 April 2017 • End date: 22 June 2018 • Main Contractor: Jet Demolition

• Project Manager: Eskom • Consulting Engineer: DRA

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