Your browser is no longer supported

For the best possible experience using our website we recommend you upgrade to a newer version or another browser.

Your browser appears to have cookies disabled. For the best experience of this website, please enable cookies in your browser

We'll assume we have your consent to use cookies, for example so you won't need to log in each time you visit our site.
Learn more

Trade track to Asia

Australia Cross-country railway

The 1,420km Darwin to Alice Springs railway will slash the time it takes freight to cross the country.

Steve Turner reports on one of the biggest infrastructure projects ever undertaken in Australia.

Arailway connecting the Australian states of Northern Territory and South Australia was first mooted way back in 1911. But only now, after many years of negotiating and route planning, work is going ahead with the ADrail consortium making steady progress through some of the most inhospitable terrain in the world.

The route consists of a single line track with passing loops, and runs 1,420km from Darwin in the north to Alice Springs in the centre of the country. At Alice Springs it will connect to the existing line to Adelaide in the south, and the southern states rail network.

This should reduce the time it takes freight from the south to reach the port of Darwin where it continues on by ship to the vital Asian market. Currently freight is either shippped round the coast, or transported along the Stewart highway, built in the 1880s.

The first rails were laid last April, and on completion in 2004, combined with a massive redevelopment of the port of Darwin, the line will provide new opportunities for Australia's overseas trade.

It is hoped that when completed the railway will also increase reliability and safety.

Design and construction consortium ADrail is contracted to Asia Pacific Transport, formed to design, build and operate the new railway. It is headed by Halliburton KBR, along with Barclay Mowlem, Macmahon and John Holland. Total project cost is A$1.3bn (US $700M).

Cost targets are stringent, and because of this the team is not trying a groundbreaking approach but is finding ways of doing ordinary things more cheaply.

Design and construction overlap. Although nearly 30% of the civils is complete, design work will continue for the next months; but the team is managing to stay ahead and there have been no delays .

The major works for the last nine months has been the formation. The line sits on a 1m high and 6m wide embankment of natural soil found along the route. As project design manager Charles Duncan explains:

'We are being selective, but basically we are stuck with what is there.'

Material is excavated by scraper, formed, watered and compacted. Culverts are then put in to allow water to pass through.

Two construction depots are being used as bases for the job, in the north at Katherine and in the south at Tennant Creek.

These are also the starting points of the work and through them will pass the estimated two million sleepers, eight million clips, 2.3Mt of ballast and 2,800km of rail required. The rail is delivered on lorries in 27m lengths and welded into 384m lengths, ready for the track laying trains.

The camps also house two massive sleeper factories, each capable of producing 2,400 sleepers a day.

Six days a week, the track laying trains leave each base loaded up with sleepers, rails and ballast, travelling towards each other. Working on a 24 hour cycle, each train is programmed to lay 1.6km of track a day, and it is hoped to complete the 700km distance between the depots by the end of the year.

Work will then start going north and south from the two depots at the same rate. Only when the trains are travelling more than 360km from the depots will the 24 hour cycle become unachievable.

That such rapid progress has been made so far in such difficult conditions is a testament to the staff working in the intermediate camps, spaced every 100km between the depots. The heavily vegetated terrain is very flat and ill defined and it has proved difficult to locate where watercourses will appear in the wet season. 'There are not many records available, and estimating the appropriate flood flows for designing the waterways has proved difficult, ' says Duncan.

A total of 1,500 stream crossings need culverts and the 100km of corrugated steel pipe required is being manufactured on site to reduce transport problems.

All work so far has been carried out in the dry season but this has also created hydrological problems of a different kind, finding the water vital for numerous construction processes.

Drilling teams with hydrologists have been prospecting ahead of the teams to find suitable locations to drill wells. Ideally these are required every 20km, but this has proved difficult.

As well as the streams, 92 more substantial waterway crossings require bridges. To reduce design work and cost, the consortium is making use of standard components. 'It is not quite Meccano, ' says Duncan, 'but we configure the system to suit sites as we come across them.'

The substructure uses driven tubular steel piles or steel tubes placed into bored holes standing on or socketed into rock and concreted in. The piles are joined by a fabricated steel headstock on top of which sit precast concrete beams.

Decisions can be made on site as whether, say, six, seven or eight spans of 12m are used to get across the waterways.

There are five exceptions to this system, over rivers where water flows all year. Bridges over the Katherine, Edith, Cullen, Elizabeth and Adelaide rivers have insitu concrete piles, pile caps and column stubs, explains British bridge engineer Mark Jordan, based in the Adelaide design office. Fabricated steel columns, precast prestressed concrete Tee Roff girders support cast insitu reinforced concrete deck slabs.

The Katherine river has an 18m river surface level range, and there was debate as to whether to lift or launch the bridge deck across the gorge, says Jordan. 'The river however reduces to a small flow during the dry season and so lifting from the bed is possible, ' he says.

The largest bridge crosses the Elizabeth river near Darwin, its 17 span, 500m length dealing with an estuary tidal range of 8m.

Rights of way

One of the main reasons the project took so long to come to fruition was the difficulty establishing a route. A major part of the line passes through aboriginal country, and years of liaising with local leaders were needed to secure rights for the line.

'We were given a corridor just 100m wide, which gave us little room for manoeuvre, ' said project design manager Charles Duncan.

The consortium has established an ongoing system of consultation and deals closely with the Aboriginal Areas Protection Authority (AAPA), set up to administer the 1989 Sacred Sites Act.

A detailed archaeological survey was undertaken to ensure that the corridor avoided damage to any objects that may be sensitive or sacred to traditional culture.

ADrail has archaeologists working full time in the field with AAPA representatives. Duncan said: 'If there is a way of avoiding something we will do all we can.

Obviously if a tree is in the way and we can't get round it has to go.'

Although there has been certain limited disruption to Australia's traditional culture, the line has also provided benefits to the local residents.

As part of the contract the consortium agreed to ensure that a large percentage of the labour and contracts engaged was local, of which a proportion are aboriginal.

'We have made extensive use of the local catering contractor who is a major employer of aboriginal people, ' said Duncan.

More generally, Australia is benefiting from the objective for three quarters of the materials to be sourced from inside the country, with all the steel coming from the state of South Australia.

'So far the consortium is well in excess of our target of 75%, ' said Moretti.

Moving freight

The line has being designed to carry trains at up to 115km/h, though it is not anticipated that traffic will operate at this speed.

On completion the line will be operated by the consortium's freight train operating company, Freightlink.

Because of the low train frequency and the remote location there is very little in the way of signalling on the line. A train control system, based on satellite telephone communications and a global positioning system, will operate from a centre in Adelaide.

At the crossing point, train drivers will operate the fixed points system by remote control, setting the switch to the direction they are travelling.

In recent months the consortium has been in discussion with interested passenger operators.

Winning concession Asia Pacific Transport (APT) is made up of Halliburton KBR, Barclay Mowlem, the John Holland Group, Macmahon, Australian Railroad Group and SANT Holding.

The US$700M project - US$431M of which is being contributed by APT with US$258.3M coming from the Southern Australian and Northern Territory governments - is being run under a build, own, operate, transfer (BOOT) contract. APT is contracted to run the line for 50 years from the completion date.

As part of the deal APT also has the concession to operate the container terminal at the port of Darwin. After 50 years control of the railway and port passes to the Australian government.

In the longer term the cost benefits of the railway for the government are massive, believes APT chief executive operator Franco Moretti.

'There are environmental benefits through reduced fuel consumption, savings in road maintenance, and after 50 years they get it back maintained to a guaranteed specified standard.'

Contracted to the APT consortium is ADrail, the design and construction joint venture, made up of Halliburton KBR, which owns 50%, with contractor Barclay Mowlem, Macmahon and John Holland.

Expressions of interest were first invited in August 1997, and took six months. Tendering then took a year to March 1999. APT was nominated as preferred contractor in June 1999, but a financial close on the deal was not reached until April 2001.

Moretti says the consortium bid won because of the strong business plan. 'We were competitive in terms of the amount of money the government had to put in. We were also very innovative in construction, with a very tight and aggressive programme that was reflected in the pricing. We also had an advantage in that we have some big balance sheet companies in the consortium that enables us to raise the required amounts of debt and equity.'

Staff supply

In total 820 people are working on the project along with the 160 ADrail engineers and supervisory staff. Some 600 are based in the field with 40 in the two design offices in Adelaide and 200 in the project management office Darwin.

Most of the workforce is Australian, Moretti explains, from a market that has a pretty good supply and demand balance. 'We have not had any problems recruiting engineers. The four large companies in the construction consortium, each have a large capacity. This type of company can move staff about from contract to contract and even country to country to bypass any localised skills shortages.'

Have your say

You must sign in to make a comment

Please remember that the submission of any material is governed by our Terms and Conditions and by submitting material you confirm your agreement to these Terms and Conditions. Please note comments made online may also be published in the print edition of New Civil Engineer. Links may be included in your comments but HTML is not permitted.