Twenty-four hours a day, seven days a week, a giant machine is digging Israel’s longest tunnel – a 13.5-kilometer-long water tunnel from Moshav Kisalon to Jerusalem’s Ein Karem neighborhood.
The huge pipeline, which is meant to supply Jerusalem and its suburbs with water for decades to come, is one of Israel’s biggest infrastructure projects. It was approved by the Mekorot Water Company a decade ago.
The first Israeli water pipeline to Jerusalem was built during the 1948 War of independence along the so-called Burma Road, which ran from Kibbutz Hulda to Jerusalem. It was meant to replace a British pipeline damaged by the Arab forces besieging the city. Its diameter was 19 inches.
The next pipeline, built in the 1950s, had a 24-inch diameter. The third, inaugurated in 1979, had a 36-inch diameter, and the fourth, inaugurated in 1994, had a 46-inch diameter. The latter pipeline was also the first to be connected to the national water system.
The new pipeline, however, will be more than twice as big, with a diameter of 102 inches.
This is Israel’s biggest water project since construction of the National Water Carrier in 1950. And its crown jewel is the Yael Tunnel, which will run about 300 meters underground.
Unlike most other water tunnels worldwide, in which the water flows downhill, the Yael Tunnel will carry water uphill under high pressure. This means the entire system must be built to withstand enormous pressure, which necessitates extra engineering precautions. For instance, a huge pit will be dug in the middle of the tunnel, and in the event of a shock wave that could damage the tunnel, water will be able to flow into the pit to relieve pressure on the tunnel.
The tunnel is being dug by German company, Zublin, using a huge, specialized machine known as a TBM, for tunnel boring machine. It moves forward on robotic legs, its jaws crushing the earth, while conveyor belts carry the earth away and the machine’s robotic arms plant steel supports for the tunnel’s roof.
Workers must work 12-hour shifts, during which they never leave the tunnel. Should the tunnel collapse while work is in progress, there is a bomb shelter equipped with oxygen, water and food in which workers could survive for up to 12 days.
The project got off to a rocky start. After just 450 meters, the TBM ran into a huge stalactite cave, and work had to be halted while the cave was surveyed and sealed with concrete.
Due to this and other geological obstacles, the machine advanced just 800 meters in the first 11 months. But over the last there months, progress has been faster, and another 1.2 kilometers have been dug. If all goes well, the TBM will emerge from the earth near the Ein Karem Junction in about a year.
Much of the work stems from the need to build power stations throughout the length of the tunnel. Effectively, this is an energy project no less than a water one. Mekorot, leery of the recent fights in the cabinet over infrastructure work on Shabbat, stressed that all work on Shabbat in this tunnel is done by either German employees of Zublin or Palestinians.
The tunnel was named Yael after Elisha’s daughter. The TBM itself has been nicknamed Jezebel. And at the entrance to the tunnel is a small niche with a statue of St. Barbara, the patron saint of minors and tunnel builders worldwide, which was placed there by the German workers.
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