An urban centre’s drainage and sewerage network are the literal veins and capillaries that both bring life to a city and clear away the toxins. Such networks allowed for the creation of the great ancient cities of legend, Lothal, Knossos, Rome and Athens, and they make possible the increasing global trend towards urbanisation; just ask the more-than 50% of the world’s population who now live in cities. Certainly, Singapore’s own drainage and sewerage systems quietly take care of the less glamorous side of keeping the city functioning.
Singapore. The bustling high-tech city-state needs little introduction, such is its pre-eminent global standing as the world’s fourth-ranked financial centre. Now home to one of the world’s fifth busiest ports, and with the 8th highest GDP per capita in the world, you’d be forgiven for forgetting that what is now a rich and bustling metropolis was formerly an impoverished ex-colonial trading post, little more than 30-years ago.
But for its towering glass skyline, its first-rate metro system, its botanical gardens and immaculate streets, and all the other aesthetic trappings that come with being one of the world’s leading urban centres, such grandeur can only exist because of what lies hidden beneath its streets. As with all things subtle and yet essential, the key municipal infrastructure upon which a city is built is oft, if not always overlooked. Such infrastructure is the bedrock on which civilisation is built.
PIPE JACKING AND TUNNELLING EXPERTS WITH A CENTURY-LONG HERITAGE AND A GLOBAL REACH
That’s where, Ed Zublin AG’s Singapore-based Pipe Jacking Division; the established first port of call for the city-state’s civic planners and local authorities, comes in. Established in 1997 as a specialist arm of Stuttgart-based global construction and civil engineering Ed Zublin AG – itself a valued component of European construction giant, STRABAG – Zublin Singapore’s Pipe Jacking Division can call upon on over a century of heritage and industry experience in the design, production and installation of reinforced concrete jacking pipes of up to 5,100mm in over 50-countries around the world.
Oliver Chen said: “Ed Zublin was established in 1898 by Swiss Engineer Eduard Zublin. Today ED. Zublin AG forms part of the STRABAG Group, which ranks among the largest European contractors. The company is active in all areas of construction, including design, consulting, project management, general contracting and the production and supply of Jacking Pipes and Tunnel Lining Segments.
This extensive specialist expertise has now been channelled exclusively into Asia, where Zublin’s own state-of-the-art precast pipe production factory is located in Kota Tinggi, Malaysia, alongside the division’s Singapore headquarters. This extensive know-how means that everything step of the process takes place in-house, meaning services provided by the foundation, tunnelling, and turnkey departments, along with the others, is collaborative and interlinked, which in-turn fosters a culture of innovation and efficiency with regards to finding solution for clients.
On the state of the industry, Mr. Chen continued: “The Industry, within which we operate, is both buoyant and growing especially in South East Asian, both in the Pipe Jacking and Tunnel lining divisions. Competition is fierce but with more than 50 years’ experience in the design and production of all kinds of reinforced jacking pipes and tunnel lining segments we feel confident, that by providing good quality products and an efficient service, we can face such competition, challenges, obstacles and threats head on. We are well positioned to meet such challenges with full confidence”.
As its portfolio shows, in addition to the dozen or more multi-million projects that have been completed in Singapore and Thailand, the Zublin AG Pipe Jacking Division has undertaken colossal projects for international clients in Abu Dhabi, Russia, India, and Australia with contract values in the hundreds of millions of dollars.
ALKIMOS WASTEWATER TREATMENT SCHEME, WESTERN AUSTRALIA
An example of one of Zublin’s more lucrative international works, the Alkimos Wastewater Treatment Scheme, which was constructed in Western Australia, saw Zublin AG work alongside Zublin Australia and a number of other companies as part of the Alkimos Alliance from 2006-10. The AUD$275 million endeavour saw Zublin construct a 6.3km main sewer trunk serving an area of new suburb 45km north of Perth, 13 jacking shafts, which were constructed along the length of the tunnel, and 3.7km of 76” diameter ocean outfall pipeline. This project saw Zublin AG achieve a number of firsts, in that pipe jacking works were completed at a record pace, which saw the project reach completion 3-months ahead of schedule. Another came when Zublin employed a new Dual Mode Tunnel Boring Machine (TBM) for the first time during the project – a tool which is perfect for tackling challenging geological conditions which are highly variable in nature.
Another Australian-based project, the Southern Seawater Desalination Plant, also located in Western Australia, was completed ahead of schedule in 2011. Such was Zublin AG’s success in constructing 861m of dual-intake tunnels, and a 965m brine discharge tunnel to the facility, the company received the Tunnelling Project of the Year Award 2011. The company thoroughly deserved this accolade, having seized what was a highly challenging offshore tunnelling project by the horns.
EAST-WEST GAS PIPELINE PROJECT, GAUTAMI GODOVARI RIVER CROSSING, INDIA
Similarly, Zublin’s work on the East-West Gas Pipeline Project on the Gautami Godavari river crossing in Rajahmundry, India, was also an enterprise which showcased the company’s reputation for excellence. A total length of 2.4km of tunnel, using two Dual Mode TBM’s, was completed within the space of one dry season – an impressive achievement, bearing in mind the challenges posed by the project, and the short construction schedule which Zublin had to work to.
The remoteness of the jobsite, and its highly variable geographical conditions, which included silty sand, clay silt, clay sand, and intermittent pockets of sand and clay meant that an alternate approach to completing the project was required. Rather than rely on its Kota Tinggi production facilities in Malaysia, instead, a temporary pipe-production was set-up nearby, which allowed for timely production and transportation of pipes. This, along with the importation of the two TBM’s, plant and equipment led to the creation of a completely self-sufficient jobsite which instrumental in the project’s success.
DEEP TUNNEL SEWERAGE SYSTEMS: QUEENSWAY TUNNEL, SINGAPORE
It goes without saying that such feats of engineering and innovation have acted as the bedrock of Zublin AG’s successes at home in Singapore, as well as abroad. Amongst the biggest projects that it has taken on recently are the Deep Tunnel Sewerage Systems (DDTS) Queensway Tunnel, otherwise known as T-06, and the Upper Thomson Link Sewer. The first vast of these vast undertakings saw Zublin construct 9.6km of deep tunnel with circular diameters ranging from 3.3 to 6.0m beneath the heart of Singapore, along with six access shafts and a drop shaft, ranging from 21m to 49m in depth. The Queensway Tunnel, which is part of a wider long-term project encompassing 48km of tunnel stretching from Singapore’s Kranji to Changi districts, and 70km of link sewers and deep sea outfalls, was undoubtedly Zublin’s flagship home project.
As Oliver told us, “tunnelling may sound very simple in theory but the reality of tunnelling anywhere, let alone in Singapore where you have obstacles like our underground metro system, existing sewerage and drainage tunnels, electrical cables and other things, means that there is a lot of complex engineering involved.
USING A CULTURE OF INNOVATION TO FIND SOLUTIONS TO ADVERSE AND COMPLEX CHALLENGES
To circumvent such obstacles, we used what’s known as curve drives for the purpose of laying curved tunnels where its straight drives and tunnels weren’t possible. We also developed and used a new inner-sleeve technology to counteract the limitations of concrete pipe. It simply isn’t possible to enter pipe which is less than 1m in diameter, which can make sealing them very challenging. The application of the inner-sleeve, an HDPE liner, has removed the need for them to be sealed. A lot of work went into developing these techniques, and its changed the way that we’re able to approach projects”.
A tunnelling project of such magnitude through a region with such complex geographical conditions, and the many obstacles that are to be found beneath the streets of a bustling 21st-century metropolis, elevated the Queensway Tunnel project from being merely an overwhelming challenge to a truly herculean one.
“When we started tunnelling, our two TBM’s, which started off from a central point along the Queensway Tunnel alignment, were launched from 74m long launch chambers built using the New Australian Tunnelling Method (NATM)”.
TAKING ON SINGAPORE’S CHALLENGING GEOTECHNICAL CONDITIONS
He continued, “in total we constructed 9.6km of tunnel by means of two drives; the 5.6km North Tunnel and the 4km South Tunnel. The geological conditions of Singapore vary between solid rock to sand and reclaimed land. In the north conditions we encountered ranged from hard Bukit Timah Granite and mixed conditions to a short section of Old Alluvium. The South Tunnel encountered residual soil of Bukit Timah Granite to a section of Jurong Formation”.
With such challenging geotechnical conditions to contend with EdZublin AG turned to a specialist TBM which was up to the task. The shield of the Queensway Tunnel TBM had an outer diameter of 4.45m, and a total length of 90m, including the attached back-up system, while the cutting head was equipped with specially designed interchangeable discs able to handle the variable ground conditions. Powered by 24 thrust jacks, which thrust off a precast ling to propel the TBM forward, the TBM advanced in stages, with the aid of a hydraulic erector which extend the precast lining.
THE QUEENSWAY TUNNEL: A PRECURSOR TO, AND PLATFORM FOR ED ZUBLIN AG SINGAPORE’S FUTURE ENDEAVOURS
Completed in 2005, the US$91.8million Queensway Tunnel was a successful precursor to the many sewerage and drainage tunnel projects in Singapore which EdZublin AG has completed since, and continues to work on today.
With work on recently completed the vast South Stream Pipeline Shore Crossing project in Russia ongoing, and having recently completed the Bukit Panjang Underpass, and the Lorand Lida Hitam, Tuas South Avenue, and Jurong East and Jurong West sewerage system schemes in Singapore, Oliver Chen expects to complete Ed Zublin AG’s current big project, the US$39million T-3003 Advanced Sewer Diversion & accompanying pipe and effluent outflow by 2017.
HOW DOES ED ZUBLIN AG’S PIPE JACKING DIVISION SET THE STANDARD?
Upon concluding the interview, it was asked of Oliver what he believed to be the key drivers for Ed Zublin AG Pipe Jacking Division’s success.
He told us: “Ed Zublin AG stands out from its rivals. The Zublin Brand, which has evolved over many years, (the company was an innovator in the centrifugal process for concrete pipe production in 1923) is well established and synonymous with high levels of quality and excellent service whilst developing and establishing new production processes.
We consider ourselves to be at the forefront of Design, Development and in production of new techniques in our area of operations. ED Zublin AG is highly committed to its Gracious Policy by implementing the best practices, in public safety, noise and vibration, accessibility, communication and workforce management. Our Environmental Management Policy commits ED Zublin AG to be aware of the importance of environmental conservation and responsibilities”.
He continued, “In total, Ed Zublin AG has 13,780 employees (from a total of 73,800 within the Strabag Group). The group’s policy is to attract the most experienced and dedicated employees. This is achieved by encouraging employees to strive towards higher personal and company goals, whilst also turning to the open market when the needs arise. Ed Zublin AG places staff training at the top of its human resource management. Training is done both in house but where necessary external training programmes are undertaken.
We have 360 highly capable staff in Singapore alone, and a further 840 1,200 we can call upon for international projects. With the best available team we are able to find solutions to the most complex engineering challenges. Our equipment also gives us an edge,” with reference to Ed Zublin AG’s array of gantry cranes, TBM’s, telescopic excavators, de-silting centrifuges, and power plants, to name but some of it.
Lastly, Oliver credited the company’s adherence to international engineering standards, and access to the Pipe Jacking Division’s access to parent company Zublin AG’s global resources for its culture of professional excellence.
“We have access to a wide range of resources and personnel from across the world, and offer international quality standards that are the equal of anything our clients might find in even the UK, US or Australia. The reputation of German engineering precedes it, and our parent company is a German engineering leader! All of this means our clients are reassured from the start, and we are able to tender for the biggest contracts around, even the huge multi-million dollar projects”.
The coming years will, in Oliver Chen’s view, continue to prove lucrative for the company, as Ed Zublin AG continues its expansion into new territories and new operational fields. With its culture of success and continued application of the latest technologies, materials, and operational approaches, it would be a safe bet to assume that continued market dominance is assured for the foreseeable future.