LWHP II TBM arrives: naming tradition begins

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The Lesotho Highlands Development Authority (LHDA) is delighted that the first of two Double Shield Tunnel Boring Machines (TBMs) arrived at Maydon Terminal in Durban, South Africa on 26 August 2024 to excavate the 38km Polihali Transfer Tunnel from the Leribe side.

This milestone represents significant progress in the construction of the second phase of the Lesotho Highlands Water Project (LHWP II).

It will take at least four days to unload the machine aboard the Thor Mercury, a ship that brought the machine from China to South Africa.

The TBM will then be loaded onto a fleet of unusually heavy-duty transporters to transport the TBM to the site in Ha Bereng, Leribe. On July 20, 2024, TBM components including shield machine and cutterhead were shipped from Shanghai Port, China. The arrival of this giant machine, which weighs more than 900 tons and is 350 meters long after assembly, marks the acceleration of tunnel excavation activities.

In keeping with tunnel construction tradition, the TBM will be given a Sesotho name that will live forever in the legacy and narrative of the Lesotho Highlands Water Project.

The Lesotho Roads Authority is inviting Basotho people from across the country and abroad to participate in a Tunnel Boring Machine naming competition to celebrate the arrival of the Lesotho Railway. The competition begins on the 28thday In August 2024, it will be broadcast on multiple platforms including Facebook, Twitter, LinkedIn and local radio stations

Contest participants should consider one or more of the following criteria when selecting a name:

• This is the legend of the Leribe area (the tunnel digging area).

• A leader who has demonstrated strength, resilience and dedication to his community.

• A leader committed to fostering relationships in community and with others.

• A Mosotho scientist or science and mathematics pioneer who encourages young people to pursue science-related fields.

• A leader committed to peace between Lesotho and South Africa.

• Individuals who have made significant contributions to the infrastructure, education or business sectors of Leribe.

• In other words, the name embodies strength, power and perseverance, and is associated with Lesotho and Leribe as the area where the first TBM will be working.

The LHDA invites the public to submit their suggestions for the TBM name by sending a direct message to the LHDA page inbox on Facebook and LinkedIn, in person at any LHDA office in Maseru, Mohale, Katsi, Muela and Polihali or by calling the LHDA radio programmes held on various radio stations.

LHDA will further conduct outreach to schools, communities and city centres to allow the public to make suggestions for TBM names.

An internal judging panel will select the 10 most meaningful and creative names which will be announced on the same platform. The Lesotho Highlands Water Authority will then conduct a public vote on the same platform to determine the winning name which will be awarded to the TBM upon its arrival in Lesotho. The contestant who came up with the winning name will become part of the history of the Lesotho Highlands Water Project and will be recognized and awarded a prize at the naming ceremony.

Once in Lesotho, the TBM components will be transported to the Katse TBM access in Ha Bereng, where preparations to receive the TBM have already begun. Assembly of the TBM is expected to take approximately 50 days before the excavation journey begins.

The tunnel boring machine was manufactured by China Communications Construction Tianhe Company and was specially built for digging the Polyhali to Katz transfer tunnel. It was designed by Robbins, an American company known for its expertise in tunnel boring technology.

In addition to the much-anticipated arrival of the tunnel boring machine (TBM) in the country, a major milestone was achieved in the construction of the transfer tunnel in August.

These works included the successful breakthrough of the upper diversion tunnel into the lower diversion tunnel on August 19 after seven months of excavation, and the start of raise boring for the Polihali reservoir gate shaft on August 26. The diversion tunnel will allow water from the 5,042-hectare Polihali reservoir to enter the transfer tunnel and then be transported to the Katse reservoir, the centerpiece of the Lesotho Highlands Water Project.

The Polihali to Katse Transfer Tunnel is a key component of the second phase of the Lesotho Highlands Water Project. It will facilitate the gravity transfer of water from the Polihali Reservoir to the Katse Reservoir. The tunnel will be excavated from both the Leribe and Polihali ends using tunnelling and drill and blast methods. The Polihali TBM is scheduled to be delivered to Lesotho early next year and will be similarly named.

The Polihali Transfer Tunnel Project includes the intake works and sluice shafts of the Polihali Reservoir, the outlet works and sluice shafts (underwater connection to the lake) of the existing Katse Reservoir, access to the waterway and associated construction infrastructure.

The tunnel was designed by MSKC, a consultancy that oversaw its construction, and built by the Kopanok Matla joint venture consisting of Yellow River Corporation, Sinohydro Third Engineering Bureau and Unik Civil Engineering.