3200 horse powers for the construction of the Metropolitan

The remaining components of the tunnel boring machines for the construction of the 4th line of the Budapest Metropolitan were delivered to the Etele Square Saturday morning and Sunday at dawn. The knocked-down machine came from Germany to Hungary.

The recently delivered components will be assembled to produce the key part of the tunnel construction device, the tunnel boring machine, which, in fact, is a closed steel tube. The control and guidance systems and eight powerful hydraulic drive motors generating a total torque of 4182 kilo - Newton meter at approximately 1200 kilowatt output are located inside the tunnel boring machine. The total output of the motors installed in the tunnel boring machine equals to nearly 1632 horse powers. The tunnel boring machine is installed at the beginning of the chain of machinery of almost 100 meter length; only the excavator wheel, that is, the „bit edge” precedes the TBM. The excavator wheel rotates at 1.3 per minute to mill and grind the rock excavated to the surface from the inside of the tunnel boring machine in mine-wagons.
The “lightest” piece of the recently delivered components including an excavator wheel and the knocked-down mechanism and motors of two tunnel boring machines weighs 30 tons, and the heaviest one - 90 tons. The total weight of the cargo exceeds 500 tons.
First the construction of the right-hand side tunnel commences, and after three weeks the second tunnel boring machine is started, too. The first tunnel boring machine will always go before the second one by 200-250 meter. This is required to minimize the chance of any surface subsidence. The two tunnel boring machines are expected to complete in 115 weeks the building of two tunnels of the 4th line of the Budapest Metropolitan of approximately 7.4 kilometer length each.
The first excavator wheel was delivered to Hungary last spring. Due to a dispute over real estate matters, however, the starting shaft of the tunnel boring machine had to be shifted back, so the construction of the tunnel may only begin this spring, with some delay compared to the initial schedule.