PRESS RELEASE

SOUTH TUNNEL BORING MACHINE HAS REACHED BAROSS SQUARE STATION
CONSTRUCTION OF THE FIRST SECTION'S SOUTH TUNNEL IS FINISHED NOW

This morning the south TBM has reached Baross Square station without any major technical difficulties, so the last 450 meters of the first section is finished. The construction of the south tunnel has been completed, but also the north tunnel will soon be ready, and 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 TBMs did not cause notable movements on the surface or building damage. 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.
The south TBM was launched for the final phase on the 10th of May. As it was typical for the entire work, in order to minimize surface movements the north TBM followed it a few days later. The Rottenbiller Street overpass was strengthened by the time, so the TBM could pass underneath it without technical difficulties. On the last 150 meters the TBM passed the clayey soil and finished the last phase in looser stratum with gravel. If everything goes as planned, the north TBM will reach the station by the first half of July, so by mid-summer the full construction with the borers can be ended for the first section. The disassembling of the boring machines will take place in the autumn and the Pest side structural engineering works will be finished.

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.

By the autumn of 2009 because of the delays accumulated by the contractor, it could be seen from the work program, that it was impossible to finish the tunnel before the autumn of 2010. However, a significant attitude change occurred: the DBR was not bowing to the pressure, the discussions were forced into a contractual framework, so the BAMCO consortium started to represent a completely different attitude. This was the result that the Pest side was completed in a much shorter period and without any trouble than the Buda side – summer of 2010 rather than the previously projected autumn of 2010.

Interesting numbers of the tunnel construction:

• The record was 31.5 meter/day (the most that a TBM built in one day)
• The 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, 18th June 2010
DBR Metro Project Directorate