The first of 21 massive tunnel boring machines (TBM) to be used to dig parts of the Doha Metro has arrived in Qatar.
The TBM, named “Lebretha,” was made in Germany and will be put to work on the Red Line North, along with three other soon-to-arrive machines named Al Khor, Al Mayeda and Al Bidda.
Some 10 stations are expected to be completed for the Red Line North and eight stations for the Red Line South in the first phase of construction. It and parts of the Gold and Green lines will open to passenger traffic in 2019.
How it works
The TBMS will be used to cut circular holes in the ground beneath Doha for all the lines. Previously, Qatar Rail officials said all 21 machines would be working by 2015, adding that residents may feel “minor vibrations” during work.
In a statement, the company said:
“TBM Lebretha will travel a distance of approx. 7.954 km and will take approx. 22 months to complete – between Q3 2014 to Q2 2016). The average speed will be between 14m/day to 21 m/day, depending on ground conditions. And its daily excavation quantity will be approx. 680m³, with a predicted total excavation quantity of 5,408,720m³.
Each of the TBMs for the Doha Metro measure 7.05m in diameter and 120m in length, therefore to ensure transportation was successfully managed, TBM Lebretha was dismantled into 22 sections which were easier to transport including the cutter head.”
Lebretha is currently in the process of being reassembled after journeying to Qatar and is supposed to become operational in the third quarter of this year. It will work at the launch site of Al Wahda, next to the Qatar Exhibition Center.
In addition to the four TBMs that will be used on the Red Line North, Qatar Rail explained in a statement the distribution of the other machines for the first phase of the project:
- Red Line South will receive 5 TBMs;
- Green Line will receive 6 TBMs; and
- Gold Line will receive 6 TBMs.
Note: This article has been corrected to reflect the accurate spelling of the new TBM.