High altitude air: Special demands on one of Vietnam's hydro electric schemes

Acontractor cutting a tunnel as part of a hydroelectric project is using a recently commissioned Atlas Copco XAS 186 portable compressor on a site 2000 m above sea level in the Vietnamese Central Highlands. The XAS 186, delivered to the site at the beginning of June last year, is supplying power for the drills and other equipment used to cut 4 km into the rock of the hillside to form the 2.3 m diameter main outlet water tunnel for the dam that is being built further upstream.

Electricity Vietnam (EVN), the state-owned agency that provides Vietnam's electricity supplies via a national grid, has designed the 150 MW Krong Kmar Hydroelectric Power Plant, which is now nearing completion. The project is being built in the Chu Yang Sin National Park in the Krong Bong district of Dak Lak province, in the Central Highlands.

Dak Lak is centred on a plateau some 600 m above sea level, but the surrounding hills, the many rivers and the abundant rainfall make the terrain ideal for the building of dams and reservoirs that in turn will help to fulfil Vietnam's urgent need for power supplies.

The contractor building the tunnel for the project is Song Da 10.1 Joint Stock Co, a division within construction and engineering conglomerate Song Da Corporation, an enterprise that comes under the direction of the Ministry of Construction. Song Da 10.1, the division that specializes in tunnel works, purchased the XAS 186 from Atlas Copco Vietnam Co Ltd, which supplied the machine from its Ho Chi Minh City office.