R/€ = 15.41Change: 0.14
R/$ = 13.73Change: 0.05
Au 1137.45 $/ozChange: 1.00
Pt 917.50 $/ozChange: 11.50
Note: Search is limited to the most recent 250 articles. Set date range to access earlier articles.
Where? With... When?

And must exclude these words...
Close Main Search
Close Main Login
My Profile News Alerts Newsletters Logout Close Main Profile
Agriculture   Automotive   Chemicals   Competition Policy   Construction   Defence   Economy   Electricity   Energy   Environment   ICT   Metals   Mining   Science and Technology   Services   Trade   Transport & Logistics   Water  
What's On Press Office Tenders Suppliers Directory Research Jobs Announcements Letters About Us
RSS Feed
Article   Comments   Other News   Research   Magazine  
Jan 18, 2008

Tunnel-boring machine embarks on 14-month odyssey

© Reuse this The Gautrain tunnel-boring machine (TBM) has started work on the three-kilometre tunnel stretching from the project's Rosebank station to Park station.

The 145-m long, 885 t machine is expected to take 14 months to complete the structure.

The remaining 12 km of tunnel for the rapid-rail link - from Park station to the Marlboro portal - will be excavated using more conventional drill-and-blast methods.

The R300-million TBM has been named 'Imbokodo', or 'hard rock'.

It was designed and custom-built by Herrenknecht, in Germany, in order to cope with the complex underground geological conditions south of Rosebank, which renders drilling and blasting impossible.

Geology in this area features a high-water table as well as varying degrees of hard rock, sand, and soft, water-clogged soil.

At the front of the Gautrain TBM machine is a rotating cutting wheel, which excavates the ground. Behind this wheel is a chamber where the excavated material accumulates, before being extracted by a pressure relief discharge system called a screw conveyor.

Excavated soil is then transported on a conveyor belt back up to the Rosebank shaft opening.

The front cutter head of the machine advances at roughly 220 m a month.

The concrete tunnel lining is built ring by ring in the rear.

These precast segment rings form a watertight concrete cylinder.

In this way the tunnel structure is completed, section-by-section, as the TBM inches forward like a giant earthworm.

The cutter head is driven by seven motors and features 150 drag teeth for soft rock. It also comprises 45 single-disc cutters and four twin disc-cutters for hard rock conditions.

A computerised guidance monitoring system provides information to the TBM pilot on a continuous basis.

It also allows the pilot to steer the machine, and to continuously monitor the actual position of the TBM in relation to the theoretical centre line of the tunnel at any given location along its route.

It is not the first time a TBM is used in South Africa.

The undersea tunnel in the Durban harbour was built with a refurbished Herrenknecht TBM, used previously in Hong Kong.

Although this type of TBM would have been appropriate for the Rosebank tunnel, the machine's diameter of 4,4 m was too small to accommodate the Gautrain. (The Gautrain TBM has a diametre of 6,81 m).

The Durban harbour tunnel carries water, sewer, power and communication services.

The Lesotho Highlands Water Project also made use of six hard-rock TBMs excavating three tunnels.

These water transfer and delivery tunnels each had an internal diameter of between four metres and five metres.

The tunnels ranged in length from 32 km to 45 km.

However, again, none these hard-rock TBMs were the right size for the Gautrain project, as well as not being suitable for the soft-ground conditions in Rosebank.

It is not yet clear which will make more economic sense for the Gautrain TBM: The cumbersome task of returning the machine to the surface in order to sell it to an interested party, or to simply leave it underground.

Bombela, the consortium which is to build and operate the Gautrain, consists of international partners Bombardier and Bouygues Travaux Publics, and local stakeholder Murray & Roberts, along with empowerment company the Strategic Partners Group.

The R25-billion rail project is a public-private partnership between Bombela and the Gauteng government, and will link Tshwane, Johannesburg, and the OR Tambo International Airport by 2011.

Fact box:
Aurora, Delilah, and the Emerald Mole

According to global tunnelling tradition, a tunnel-boring machine (TBM) cannot start work until it is given a name. This tradition also sees most TBMs being named after women.

The Gautrain TBM name, 'Imbokodo', flows from the women's protest march to the Union Buildings on August 9, 1956. This march saw the birth of the phrase 'wathinta abafazi, wathinta imbokodo' or, 'if you strike a woman, you strike a rock'.

Other TBM names around the world include 'Xiaolongnu', which is a 80-metre long machine constructing the Kowloon southern link, in Hong Kong.

This TBM is named after a famous heroine of the popular Chinese martial arts book 'The Return of the Condor Heroes'.

Project officials chose the name because they believed the TBM will do her work with the "agility and effect of a super kung fu master, yet with a feminine touch of tenderness and softness as she tunnels her way through soft ground and hard rock".

'Terra Nautilus' and 'Pipi' are the names given to two TBMs used on the Gold Coast Desalination project, in Australia.

A seven-year old boy gave the name 'Emerald Mole' to a TBM which will be used to build light-rail tunnels in Seattle, US.

A biblical 'Delilah' is boring a tunnel for a sewage improvement project, in the UK.

In turn, 'Aurora' was named after the Roman goddess of daybreak. This custom-made, 120 metre long TBM built the Green Heart tunnel for a high-speed rail project in the Netherlands.

Caption 1:
The TBM ready and waiting at the Rosebank station - See Gautrain TBM naming.JPG - PIC BY DUANE

Caption 2:
The TBM being assembled at the Rosebank station - See GT TBM Assembly Nov 07.2.JPG

Edited by: Creamer Media Reporter
© Reuse this Comment Guidelines (150 word limit)
Other Construction News
  JSE-listed property company Emira has appointed chartered accountant Greg Booyens as CFO, effective January 1, 2016.
DROVISION GOGGLES. Magnet has added personal protective equipment to its product range
Electrical solutions consultant Magnet was appointed Southern African distributor for Dromex personal protection equipment (PPE) in April this year. MD Brian Howarth said that Magnet had recognised an urgent need in the electricity industry for increased safety for...
DUAL BIOMETRICS SCANNER Black Ginger 48 has introduced biometric scanners at its on-site stores
Personal protective equipment (PPE) manufacturer and distributor Black Ginger 48 has implemented facial recognition technology at two of its clients’ on-site stores to counter identity fraud and reduce theft. Black Ginger 48 GM Jevan Malan tells Engineering News that...
Latest News
In the boom times when the price of gold was soaring, Ebenezer Sam-Onuawonto had a dream job and a dollar salary many times the national average in this mining town in southwestern Ghana. When the price fell, he lost his job as human resources chief at a mining...
Property developer Balwin Properties aims to raise between R713-million and R1.6-billion ahead of its listing on the real estate holding and development sector of the JSE on October 15. It would use the funds to settle existing debt facilities and fund future...
The information and communications technology (ICT) in education leg of Operation Phakisa has been launched to transform the basic education sector and leverage ICTs to strengthen teaching, learning and administration of the education system. The Operation Phakisa...
Recent Research Reports
Liquid Fuels 2015: A review of South Africa's liquid fuels sector (PDF Report)
Creamer Media’s Liquid Fuels 2015 Report examines these issues in the context of South Africa’s business environment; oil and gas exploration; fuel pricing; the development of the country’s biofuels industry; the logistics of transporting liquid fuels; and...
Road and Rail 2015: A review of South Africa's road and rail sectors (PDF Report)
Creamer Media’s Road and Rail 2015 report examines South Africa’s road and rail transport system, with particular focus on the size and state of the country’s road and rail infrastructure and network, the funding and maintenance of these respective networks, and...
Defence 2015: A review of South Africa's defence sector (PDF Report)
Creamer Media’s Coal 2015 report examines South Africa’s coal industry with regards to the business environment, the key participants in the sector, local demand, export sales and coal logistics, projects being undertaken by the large and smaller participants in the...
Real Economy Year Book 2015 (PDF Report)
There are very few beacons of hope on South Africa’s economic horizon. Economic growth is weak, unemployment is rising, electricity supply is insufficient to meet demand and/or spur growth, with poor prospects for many of the commodities mined and exported. However,...
Real Economy Insight: Automotive 2015 (PDF Report)
Creamer Media’s Real Economy Year Book comprises separate reports under the banner Real Economy Insight and investigates key developments in the automotive, construction, electricity, road and rail, steel, water, gold, iron-ore and platinum sectors.
Real Economy Insight: Water 2015 (PDF Report)
Creamer Media’s Real Economy Year Book has been divided into individual reports under the banner Real Economy Insight and investigates key developments in the automotive, construction, electricity, road and rail, steel, water, coal, gold, iron-ore and platinum sectors.
This Week's Magazine
Energy analyst and EE Publishers MD Chris Yelland warned recently against excessive optimism regarding timescales for the proposed construction of new nuclear power plants (NPPs) in South Africa. He was speaking at a Nuclear Roundtable in Johannesburg. “I think we...
Malawi’s Lilongwe Water Board (LWB) is inviting eligible bidders to prequalify for the board’s efficiency improvement works, which will be implemented as part of the E24-million Lilongwe Water Resources Efficiency Programme.   LWB CEO Alfonso Chikuni explains that...
CROATIA, AN EU MEMBER BUT NOT A TDCA MEMBER On July 1, 2013, Croatia officially became the twenty-eighth member of the European Union (EU). Despite Croatia’s accession into the EU, it is yet to become party to the Trade, Development and Cooperation Agreement (TDCA)...
The Council for Scientific and Industrial Research (CSIR) has announced that its new Inundu airborne electronics testing, evaluation and training pod had made its first test flight on September 10. The successful flight was undertaken from Lanseria International...
The Development Bank of Southern Africa (DBSA) – which disbursed a record R13-billion during 2015, from R12.7-billion in the prior year – remained optimistic that it could ramp-up loan disbursements to R25-billion a year by 2018 as it sought to give greater emphasis...
Alert Close
Embed Code Close
Research Reports Close
Research Reports are a product of the
Research Channel Africa. Reports can be bought individually or you can gain full access to all reports as part of a Research Channel Africa subscription.
Find Out More Buy Report
Engineering News
Completely Re-Engineered
Experience it now. Click here
*website to launch in a few weeks
Subscribe Now for $96 Close
Subscribe Now for $96