WELDING solutions from Leister Technologies including combinations of its Triac, Comet, Twinny T and Fusion continue to secure prominent projects in the region, with the ongoing STEP (Strategic Tunnel Enhancement Programme) tunnel scheme in Abu Dhabi. UAE, being among the latest in the Swiss company’s projects portfolio.

Other landmark developments in the region where these welding solutions were used this year include the Louvre Museum Abu Dhabi and freshwater tanks at Lusail City in Qatar.

These projects follow the successful completion of the world’s second longest city road tunnel in Iran, which is designed to cut traffic bottlenecks in the Tehran metropolis.

The Niayesh city road tunnel used 245,000 sq m of sealing sheets and layers that were sealed with Leister’s tools in the final lining of the operation – a task which took six months to complete. The 10,252-m Niayesh city road tunnel is the second-longest of its kind after China’s Baotashan city road tunnel at 10,480 m.

Well aware that high-performance insulation and waterproofing were critical to the success of the tunnel, the Municipality of Tehran under the guidance of its team of consulting engineers partnered with market leaders in the development, production and application of geosynthetics and solution providers to geotechnical engineering problems.

Leister Technologies was singled out as the leading provider of welding solutions for this project to ensure complete prevention of water leakage into the tunnel.

Leading contractor in industrial and development projects The Material Manufacturing Company selected Leister machines – which are recognised for their performance, reliability and the quality of the welding seam – as the main source of welding solutions based on its 10-plus years of civil engineering experience.

For the lining, single-layer PVC membrane at 2-mm thickness and with a surface area of 195,000 sq m and 2-mm-thick high density polyethylene (HDPE) lining measuring 50,000 sq m were used.

Niayesh tunnel ... world’s second longest city road tunnel.

Leister products that were employed on this massive project included 33 units of the Triac S, five units of the Twinny T – four for civil engineering and one for tunnel construction works – 10 units of the Comet with 70 mm Wedge, and one unit of the Fusion 3.

The Twinny T, operating at a temperature of 560 deg C, achieved a speed of 2 to 2.5 m per minute on the tunnel works and 2.3 to 2.5 m per minute on other civil engineering works. The Comet with 70 mm Wedge was used at 430 deg C, welding at 2 to 2.5 m per minute.

The Leister tools were supplied by Thermoplast Manufacturing Company, Leister’s exclusive distributor in Iran. Thermoplast Manufacturing, which enjoys years of partnership with the Material Manufacturing Company and other contractors, provides quick service support and is well staffed to respond to the daily requests and offer solutions with regard to precision welding.

The construction of the two-way Niayesh tunnel began in March 2010 and was completed in February of this year. The tunnel starts at Niayesh Highway and the beginning of Kordestan Highway and ends in Sadr Highway.