REPORT continued Photos:
REPORT continued Photos: Axpo AG Muttsee reservoir, 2474 m Limmernsee Ochsenstäfeli, 1880 m Kalktrittli upper terminus, 1860 m Central cavern, 1700 m Tierfehd, 811 m 1 2 3 4 Access shaft 1 with funicular Access shaft 2 Access shaft 3 Naturally lit shaft 1 2 3 Reservoir pressure shaft Surge tank Pressure shaft Lake pressure shaft 4 1 Construction cableway 1 2 Construction cableway 2 Every diesel engine is equipped with a particulate filter and state-of-the-art exhaust gas treatment system. EXTREME LOGISTICAL CHALLENGES The logistical challenges at the construction sites are considerable. The experienced construction firm Marti AG is general contractor for the ARGE power plant at Limmern. At the Tierfehd base installation site, bundled equipment, machinery, vehicles and construction materials must be sent up the mountain at just the right time. A team of over 70 logistics and transport specialists Highest environmental standards consistently applied works 24 hours a day to keep things running smoothly. Computer-aided logistics planning starts when an order is placed and often involves “just in time” delivery. MOVING THROUGH THE TUNNEL SYSTEM The Kalktrittli upper terminus is right at the entrance of a branching system of tunnel shafts. From here, “taxis” (3.5-t minibuses) carry the workers through kilometers of tunnels and shafts to work at the various construction sites or to Construction cable railway 2. Inside the mountain is a never-ending hustle and bustle, with trucks, cars and construction equipment traversing roads covered in netting to suppress dust. A sophisticated ventilation system with airlocks at regular intervals keeps the air fresh at all times. Naturally all diesel engines on the project, whether stationery or mobile, are fitted with particulate filters and the requisite exhaust gas treatment systems. In general, it’s fair to say that Linthal 2015 is proceeding according to the highest environmental protection standards. For example, rapidly biodegradable lubricants are used wherever technically possible, such as MOTOREX OEKOSYNT HFDU 46 fire resistant hydraulic oil in the tunnel boring machine and elsewhere. THE IMPOSING CENTRAL CAVERN The tunnel boring machine is a highly complex piece of equipment. The walk-through machine is continually manned by up to seven workers. The central cavern is the heart of the facility. At an imposing 150 meters long, 30 meters wide and 53 meters high, it has the dimensions of a cathedral. This is where the four pump turbines will be situated, at the end of two pressure shafts over 1000 meters long with an extremely steep 90% gradient. In the immediate vicinity is the somewhat smaller (130 × 20 × 25 m) transformer 12
Some 240,000 cubic meters of rock are being blasted out of the machine and transformer caverns alone, and transported by conveyer belt for further processing. The Muttsee is being expanded as a reservoir. Soon it will be able to hold an astonishing 25 million cubic meters of water. cavern. This is where the future command center of the power plant in the mountain will be housed. Construction of the caverns generates some 800 cubic meters of excavated rock a day. A total of 240,000 cubic meters of rock is being broken up and transported by conveyer belt to the Ochsenstäfeli gravel plant for further processing. This is also where the Limmernsee dam and Construction cableway 2 are located. THE MUTTSEE AT THE TOP Construction cableway 2 leads to the upper terminus at the Muttsee, 2446 meters above sea level. A new kilometer-long dam is being built to enlarge this natural reservoir, increasing its current nine million cubic meter storage capacity to 25 million. The dam is being built out of material excavated while carving out the caverns. The Muttsee’s expanded capacity will be necessary for the pumped storage plant to operate efficiently. The Muttsee is the highest reservoir in Europe. 80-YEAR PAYBACK PERIOD At a total cost of CHF 2.1 billion, it is no exaggeration to call Switzerland’s biggest pumped storage plant a construction feat of the century. Once the facility is online in 2015, it will be capable of delivering peak power oncall and repeatedly whenever needed – an enormous benefit. The new plant in Linthal has an efficiency level of roughly 80%. In the future, the new pumped storage capacity will enable it to contribute significantly to security of supply in Switzerland and beyond. At night, when energy demand is low, water will be pumped uphill from the Limmernsee to the Muttsee until the “battery” is fully charged once again. • MOTOREX PRODUCTS PUSHED TO THE LIMIT A wide range of MOTOREX products are used at the Linth-Limmern construction sites – motor oils, gear oils, hydraulic fluids, etc. Safety and environmental protection are given special attention. For example, the hydraulic fluids used here are flame-resistant (a key safety aspect in tunnel construction) as well as biodegradable (a key environmental aspect). Since MOTOREX never sacrifices performance to deliver these features, the products are ideal for use under difficult high-alpine conditions. Various depots have been set up near the construction sites to prevent any supply bottlenecks, even during a night-time emergency. motorex Magazine I DECEMBER 2011 13
