Loch Ness Hydro Tunnel Makes BreakthroughThe Glendoe hydroelectric scheme is the biggest ongoing civil engineering project in Scotland. Upon completion, it will provide enough electricity to power every home in a city the size of Glasgow. It will produce up to 100 MW of energy, enough to power 250,000 homes, when it becomes operational at the end of this year.Glendoe is the first major hydroelectric scheme in Scotland since Errochty in Perthshire opened more than 50 years ago. Plans for the hydroelectric scheme were given the go-ahead in July 2005 with the aim to make a significant contribution to meeting renewable energy targets. Scotland's target for the amount of electricity from green sources has been raised to 50% by 2020. Glendoe will make its own contribution towards achieving that target. With average annual rainfall in the area reaching about 2,000 mm, compared with under 700 mm in Edinburgh, Glendoe is ideally located to generate hydroelectric power. Almost two years after Tony Blair triggered a detonation in February 2006, 600 metres above Loch Ness in the Monadhliath mountains, to begin the creation of the 8 km headrace tunnel, the Glendoe hydro scheme reached a milestone on 7th January as a tunnel boring machine finished digging out this main underground tunnel. The 220 m-long machine, nicknamed "Eliza Jane" by local schoolchildren, broke through the ground near Loch Ness in the Highlands, marking the end of a major phase in the GBP140 million sustainable energy project by Scottish and Southern Energy (SSE). Visit www.scottish-southern.co.uk and view a video at www.stv.tv/The 5,030 mm-diameter hard rock TBM was shipped by Herrenknecht to Tyneside before being transported to the Monadhliath mountains, to the east of Fort Augustus in Inverness-shire, in 2006. It was taken in sections to the site and assembled before it began work in September of that year. Since then, it has bored the 8 km headrace tunnel to allow water collected in a new reservoir 608 metres from the loch to reach an underground power station near the loch's southeast corner, before being discharged into the loch itself. Visit www.herrenknecht.com and www.glendoe.co.ukThe GBP7 million TBM has climbed 608 metres into the hills from the power station to the reservoir intake. It has been chewing upwards into the hillside, cutting through about 1.8 metres of rock every hour. The machine travelled an average distance of 23 metres in a day. The tunnellers spent 10 hours each day working underground. Fifty tonnes of rock has been excavated every metre while 400,000 tonnes of rock will be taken out of the hillside during the operation. Work will continue to complete the dam, create the reservoir and progress on the 100 MW power station built by drill and blast. Concreting of the cavern walls is finished up to machine hall level. It is hoped it will be operational from the end of next year. The builder is the Hochtief Glendoe JV led by Hochtief. The contractor's designer is Pöyry while Jacobs Engineering is SSE's advisor. Marti Technik supplied a 1,555 m-long 800 mm-wide external conveyor belts for rock haulage, powered at 422 kW and with capacity for 400 tonnes/hour. Visit www.hochtief.de, www.poyry.com, www.jacobs.com and www.martitechnik.chThe Glendoe scheme involves: a dam, 35 m high and 905 m long, being built at the head of Glen Tarff, a 38 m-long x 32 m-high x 18 m-wide power station constructed in a cavern 250 metres below ground level, inside Borlum Hill. to feed the powerhouse, a reservoir more than 1.5 km long capable of holding eight million cubic metres of rainwater, collected from 155.4 square kilometres of surrounding hillside using a network of underground pipes, a 8.6 km-long 4.6 m-diameter aqueduct tunnel to collect water and take it to the reservoir, built from six drives, an 8 km-long 5 m-diameter headrace tunnel to channel water from the reservoir to the power station, a 1,250 m access tunnel, 7 m in diameter, leading to the power station cavern. The 608 m drop from the reservoir to the turbine is the highest of any hydro station in the UK, allowing it to generate more energy from every cubic metre of water than any other facility. The cavern will contain the turbine, which will be turned by the force of the water flowing through it, and the generator, which turns that force into electricity. The facility, which will be operated remotely from Perth, will be able to generate electricity at full capacity within just 30 seconds. Click uk/44. Read E-News Weekly 30/2006 & 20/2003. 04/08.