A piercing white flash shot from a bubbling crucible of molten metal clamped to two lengths of steel rail, lighting up the dusty red earth of northern Australia's Outback.
"Beautiful," Ben Castle said as he used a small ax to chip away the ceramic mold around the weld when it cooled a few minutes later.
The weld was one of the last in Australia's most ambitious and long-awaited civil engineering projects -- an $845-million rail link joining the nation's populous southeast with the north coast, and its access to Asia.
The final weld was made Sept. 25, more than a century after the railway was first proposed, and the first trains are expected to begin running early next year.
The 1,864-mile line will mainly be used by freight trains to get Australian goods to the northern port of Darwin and Asian goods to the south. Currently, much of that cargo travels on "road trains" -- huge, multi-trailer trucks that thunder along the highway between Darwin and Alice Springs, the old rail terminus in the middle of the country.
A passenger train will also run on the new route.
"The passenger train provides the glamour, but the freight pays the bills," said Gordon Beggs of ADrail, the group building the railway for the Asia Pacific Transport Consortium, which will operate the line for the next 50 years.
The research firm Access Economics estimates that Australia's gross domestic product will grow by up to $2.9 billion as a direct result of the rail link in its first 20 years of operation.
"It's an export corridor for us from a coast facing Antarctica to a coast facing Asia," said Mike Rann, premier of South Australia state.
But the route also will be "one of the great railway journeys of the world," he said.
The first passenger train is scheduled for Feb. 1-3. Fares start at $490 Australian, or about $323 U.S.
A transcontinental railway was first proposed in 1858, but the project stalled in 1929 when tracks had stretched from the southern city of Adelaide to Alice Springs in Australia's Red Center -- named for the color of its earth.
Back then, working on the railroad meant hauling rudimentary equipment into the Outback on camels and camping in tents or under the stars. It was far different from the highly mechanized work that began in June 2001.
Dull thuds reverberated as a huge locomotive dropped 507-pound concrete ties onto a raised dirt embankment at the rate of about 780 an hour. About 2 million were used for the Alice-Darwin tracks.
The same train -- with caterpillar treads at the front of the lead locomotive -- laid long strings of rails on the ties, building the railroad as it went. A machine followed, clamping the rails down.
That was followed by another train that dumped crushed stone on the tracks -- 2 tons of rock for every yard of track. A third locomotive pushed the ballast under and around the rails and ties, and set them at a precise height and alignment.
Although the modern-day rail construction workers lived a more luxurious life than their pioneering counterparts, many of the challenges they faced were the same. They lived through searing daytime temperatures and chilly nights, and had to cross deserts, rivers, forests and swamps.
When it got too hot -- summer temperatures in the Outback can top 122 degrees -- some crews started work at 2 a.m.
"We thought there would be a fair amount of opposition, but the guys liked it," Beggs said. "They got back for a few beers at lunchtime, then crawled into bed and slept through the hottest part of the day."
There were even some new challenges, notably the need to avoid damaging Aboriginal sites. Some stretches of track had to be routed to avoid trees and rocks considered sacred, Beggs said.
It was a family affair for Castle. He and his brother, Adam, worked together welding the rails, and their father and a cousin also worked on the line.
The romance of the railroad is in their blood. "I once tried working in concrete, but I always come back to the rails," he said.