Dubai: One of the most critical phases in the Dubai Metro project is the construction of 12.6km underground tracks, which run under the Central Business District on both sides of the creek.

But the Rail Agency at the Dubai Roads and Transport Authority has been doing it with precision and has completed tunnelling work on the Red Line about 45 days ahead of schedule.

Tunnel work for the 4.7km underground track on the Red Line was completed with the excavation of three tunnels. The first achievement was completion of the tunnel between Union Square and BurJuman underground stations.

The 1.47km tunnel runs under the creek and is a masterpiece of construction. Work on it started on January 31, 2007, and completed on September 15.

Another tunnel completed on the Red Line is from Union Square station to Al Rigga station. Boring on the 948-metre tunnel started on April 3 last year and finished on August 30.

The third and final tunnel on the Red Line has also been completed. Boring of the 1,168-metre tunnel between Al Rigga station and Deira City Centre station was a big challenge.

The most difficult and critical phase of the tunnel work was to pass under the Dnata building. It went 30metres under the building and is now the deepest of all the tunnels for the underground tracks.

The tunnelling work on the Green Line has also started. The Green Line will have 7.9km of underground track at the Central Business District area.

The first tunnel has been completed on the Green Line. It is from Union Square station to Salahuddin station.