PRESS RELEASE

THE FIRST PHASE OF THE TUNNEL CONSTRUCTION WAS COMPLETED FOR METRO 4

THE NORTH TBM ALSO REACHED THE BAROSS SQUARE STATION
The north TBM has reached the Baross Square station without any major technical difficulties so the tunnel construction with TBM is finished in the new line’s first phase. Soon the disassembling of the boring machines will be started and expected to be finished by the end of autumn. The metro construction – after the most spectacular phase is completed – to be continued, since in a couple of months the internal construction on the Pest side, track construction could be started, next year the systems, the power installations, and during all this time the surface area work will be carried out.

By 18th of June the south TBM has finished the last 450 meters of the construction. As it was typical of the entire work, in order to minimize surface movements, the northern TBM was following by 50 to 100 meters behind, so now reached the Keleti Railway Station. On the last 150 meters the TBM passed the clayey soil and finished the last phase in looser stratum with gravel. The disassembling of the boring machines will be expected to be finished by autumn. On the Pest side a number of work sessions can be carried out after the passing of the tunnel borers, so soon the remaining structural engineering works will be finished on the stations. The tunnels were built at very high quality and it is equally important that the tunnel borers did not cause notable movements on the surface or building damage.

BACKROUND:

As it is known the Metro 4 tunnel boring machines left Etele square on April 3rd 2007 for their 7.4 kilometers run. Then the contractor, BAMCO consortium, undertook 107 weeks in its contract to finish the tunnels of the first section of the metro, so by mid-summer 2009, the 6.1 meters in diameter and 110 meters long machines should have reached Keleti Railway Station. During the first few hundred meters there were some technical difficulties, but it is natural for each TBM test run. Later, however, delays were caused by land acquisition issues, approval process delays, the legal and technical disputes between the client DBR and the contractor BAMCO and the series of stopping because of excess claims.


The Pest side was built without any problems, instead of the projected autumn 2010 it was ready during the summer of 2010. Nevertheless, the fact remains that on the Pest side was finished in 56 or 52 weeks – half a year later – than the 28 weeks which was agreed in the contract.

Interesting numbers of the tunnel construction:

• The record was 31.5 meter/day (the most that a TBM built in one day)
• TBM average pace on the Buda side was approx. 11, on the Pest side approx. 16 meters/day.
• A total of 3750 No of tunnel rings were used.
• The number of the tunnel segments is about 22500 (a ring is made of 6 segments)
• Total weight of a tunnel ring is 18.5 tons.
• The weight of the tunnel (calculated by the number of rings) is about 70000 tons.
• About 60 people worked on the TBMs in shifts, and a lot more helped servicing of the boring machines and the surface related jobs.
• During the construction of the tunnel approximately 135000 cubic meter of earth was excavated

Budapest, 1st July 2010
DBR Metro Project Directorate