18 Terex Tower Cranes At Work in Denmark on One of its Biggest Construction Projects

The challenge:

Constructing the Copenhagen Metro -- one of Denmark's biggest construction projects -- including a total of 17 stations along the 9-mile underground rail line

The players:

Copenhagen Metro Team

The process:

Eighteen Terex CTT flat top tower cranes are helping at the fourth and final phase of the Copenhagen Metro City Circle Line -- one of the biggest construction projects in Denmark.

It was decided in 2005 to expand the Metro to include the new City Circle Line. The new nine-mile underground line has 17 stations -- 12 newly-built, three conversions of existing stations and two existing -- and will carry about 275,000 passengers each day. Initially, the flat top tower cranes will be used to remove excavated tunnel material then to lift in new concrete and materials for the new construction.

Work on the new line started in 2012, and, when finally completed in 2018, will increase the number of Metro stations to 37 and tie together Copenhagen’s different neighborhoods.

The two new lines of the City Circle Line -- the M3 and M4 -- form a giant ring across the present M1 and M2 metro lines allowing passengers to transfer between the new and the old metro lines at the Kongens Nytorv and Frederiksberg stations. New metro stations will be built at busy hubs such as Copenhagen's Central Station, Rådhuspladsen, Nørrebro Runddel and Trianglen in Østerbro.

When work is completed in about four years, it will make moving around the city much easier, faster and more convenient.

The project is being built by a consortium of companies – the Copenhagen Metro Team (CMT) – with individual companies having the lead on different aspects such as safety, drilling, material processing, track laying and construction. CMT purchased 18 tower cranes – all Terex CTT 231 models with maximum lift capacities of up to 26,455 pounds and with different under hook heights and jib lengths – because of their combination of good lift capacity with precise and easy control of movements. CMT purchased the cranes as part of the "Full Terex Package" which includes expert advice on configuration, its positioning, erection, maintenance, training and support. This support is ongoing throughout the project and adjusts for the changing demands and client requirements for the equipment in future projects.

One example of this support was to comply with a local Danish regulation that required all cranes over 82 feet to have an elevator for the operator to reach the cab. Terex Cranes liaised with a Swedish elevator supplier in nearby Malmö and not only solved the problem with a turnkey solution but also trained the maintenance company’s engineers to help support the crane. Terex also helped with the logistics involved in delivering the cranes into the busy city centre, including the completion of calculations for special traveling rail-mounted bases and tracks needed for some of the cranes, a detailed plan to erect the cranes and guidance on short jib applications.

Initially, it was thought that half of the CTT 231 tower cranes will have a traditional concrete base while the others will have a traveling rail-mounted chassis. However, due to the continual changes in the configuration of some of the sites and geological variations, just one crane has so far been erected on a traveling chassis with 98 feet of rails. Five more cranes are scheduled to be erected on rails, but this will depend on various factors.

“The cranes have to perform two different activities – first lifting tunnel spoil from the pit and then moving the construction materials,” said Ivo Romanelli, service manager, Terex Cranes. “We are continually advising the client on the best setup of each crane including jib length and whether to have a traveling chassis or normal foundation after talking with the site manager for each station.”

The initial phases of construction have also resulted in the largest ever archeological excavation in Denmark providing archeologists with the opportunity to improve knowledge of Copenhagen’s history. One discovery already made is of an eighth-century harbor which means that the city is about 300 years older than previously thought.