A Demag AC 1000-9 all-terrain crane was recently used to lift a 100-t tunnel boring machine (TBM) on the Mumbai Central Metro Station project. Owned by Indian crane service provider Steel Carriers Infrastructure Pvt Ltd, the crane features a 1,200-t capacity.
The job site is situated right in the middle of Mumbai. “We had to pick up a 100-t tunnel boring machine at a radius of 20 m from below ground and bring it up to the surface,” explained Sunil Makad, owner of Steel Carriers. “No other all-terrain crane in India would have been able to do this, and using a crawler crane was out of the question due to issues of cost-effectiveness. In fact, setting up a crawler crane under the tight space conditions at the work site would have taken significantly more time, which would have been wildly out of proportion to the short project duration of eight days.”
Despite the suitability of the AC 1000-9, setting it up on the job site posed some challenges for Steel Carriers. The restricted space required the team’s extensive skills and experience when it came to setting up the crane in such a way as to ensure that the demanding lift would be successful. And this was no mean feat given the load’s weight and the lift’s large radius - which meant that the AC 1000-9 had to be equipped with its full 228-t counterweight for a boom length of 30 m.
Before all these preparations could be carried out, however, the crane had to travel from the Steel Carriers workshop in Mumbai to the job site. In order to avoid the Indian metropolis’ daily traffic, the team took the crane and the trailers carrying its equipment to the site late at night with four trips every night.
“The reason we had to split up the transport that way was that space at the work site was really tight, so having the crane come in with all its equipment at once was simply impossible,” said Mr Makad. The team managed to put the crane together and have it ready for the lift in just one day, with only four people: the crane operator, a supervisor, and two assembly technicians.
A tight schedule
In addition to the powerful crane required for the job, staying on schedule was one of the crucial factors in the project, as the deadline for completing the new metro line was fast approaching.
Speaking about the challenges, Mr Makad said, “During the lift, the load on the crane hook and the working area itself were not in the operator’s field of view. In other words, he was completely dependent on the instructions provided by his co-workers through their walkie-talkies, as well as on their hand signals.”
Nevertheless, the expertise and perfect coordination of the Steel Carriers team made it possible to carry out the lift with utmost precision. “Our team did an extraordinary job. We showed once again that we can carry out the toughest jobs with the AC 1000-9 and our experience and meet our customers’ expectations,” enthused Mr Makad.
“The response times are extremely fast, spare parts are reliably delivered, and all other forms of assistance are absolutely dependable. And we know that with this support behind us, we can tackle any job without hesitation and help strengthen India’s infrastructure network.”
The Demag AC 1000-9 has been named ‘Gajraj’ by Steel Carriers. “This means ‘King of Elephants,’ which is what our employees decided to call our AC 1000-9 due to the fact that it’s the biggest and only telescopic crane of its type in all of India,” revealed Mr Makad.
Based in Mumbai, Steel Carriers was the first Indian company to put a new Demag crane into operation with the AC 200-1 about 15 years ago. The company's fleet currently includes telescopic and crawler cranes with lifting capacities ranging from 50 to 1,200 t. Apart from crane hire, Steel Carriers also offers transport services and storage of industrial goods and steel products.