The Mumbai Metropolitan Region Development Authority (MMRDA) has deployed one of the tallest straddle carrier cranes to be used in India to launch girders on the 14.5-km-long Metro 6 line connecting Lokhandwala to Kanjurmarg. The 29.5-metre tall straddle carrier — a freight-carrying vehicle that carries its load underneath by 'straddling' it, rather than carrying it on top like a conventional truck — will help to launch girders for the Metro line that at certain points will traverse 38 metres over the ground, which is equivalent to a 12-storey building. The equipment will put the girders on the tall piers and help in the construction of a viaduct on which the Metro will run. Two straddle carriers have been bought at cost of Rs 7.5 crore each by the contractor J Kumar. "It is a wheel-based carrier having four legs and 16 tyres and can launch 'U' girders up to a height of 22 metres and 'I' girders up to 20 metres. It can move 180 degrees with the load and so it will help in saving time and increase speed of work," said B G Pawar, Joint Metropolitan Commissioner, MMRDA. Sources in the MMRDA said at many places along the alignment tall pillars have been erected but work to raise girders is pending. While the average height of pillars on Metro 6 line is 16 meters, at Gandhi Nagar in Kanjurmarg, the tallest pillar stands at 38 metres — the tallest in India. The machine, however, will not be used to launch girders at this point as the MMRDA is contemplating another technique to lay the viaduct here. The corridor will be above the LBS Marg, Jogeshwari-Vikhroli Link Road (JVLR) and the upcoming Metro-4 (Wadala-Kasarvadavli) line that is 20 metres above the ground. Both corridors will also have stations at the junction and be connected with a foot overbridge. Currently, the tallest Metro corridor is the Metro line 4 in Delhi near Haiderpur, which is 28-metre tall from the ground level. It is followed by the Metro line in Bangalore, which is 23-metre tall from the ground, and Metro line 4 in Mumbai, connecting Wadala-Kasarwadavli-Thane, which is above 20 metre from the ground level.