A stable environment10 October 2008
Châtelot hydroelectric project, located on the River Doubs on the Franco-Swiss border, has been used to generate electricity since it was first commissioned in 1953.
In recent years, rockfalls from the gorge surrounding the project’s dam have become a problem. Electricité Neuchâteloise SA and Electricité de France, the owners of the dam, decided to contract mountain access and engineering specialists Acrobât Sàrl to assess the gorge walls and come up with a way to stabilise those areas that could compromise security of the dam.
Maintenance access to the dam is via a 1m gauge funicular railway, made during the dam’s construction and inclined at around 45 degrees, dropping some 350m in its length of around 1000m.
Acrobât Sàrl devised a solution that would anchor certain rocks using cable and steel netting and use sprayed concrete guniting over wider unstable areas. To power the necessary pneumatic drills and specialist concrete application equipment, compressed air at 10bar pressure was required.
To meet environmental concerns, there was an additional need for 100% oil-free air, while the compressor needed to be compact enough to fit on the carriage of the railway.
Atlas Copco Specialty Rental created a package that included a ZT 75/10 electric powered, oil-free compressor complete with a 3000 litre air receiver. Drawing its power from electricity generated by the dam, the compressor’s oil-free air delivery was suitable for all the air-powered tools being used at the rockface.
Acro-bât Sàrl started in April and completed the gorge stabilisation work in June this year. The company’s personnel carrying out this specialist work needed to be extremely fit, working from a harness for extended periods. Careful planning was needed to ensure exacting safety requirements were met, but logistics had to be spot on too. Failure of any item of equipment would have lead to costly delays.
‘This was an interesting rental project for us,’ says Jens Uebersax, sales representative of Atlas Copco Specialty Rental. ‘The customer needed a reliable, compact and clean running oil-free compressor with sufficient free air delivery and pressure to power the guniting equipment.
‘With its 3000 litre air receiver, the compact ZT-compressor which is certified by TÜV, as ‘oil-free’ under ISO 8573-1 CLASS 0 proved absolutely ideal for the job.’
For further information please contact: Kris Herremans, Communication and Rental Academy Manager. Email: [email protected] www.atlascopco.com/rental