Extreme Engineering: Megastructure-Building Machines

There is something gratifying about watching machines build masterpieces. When it comes to the mega-sized ones, it gets even more enjoyable.

Have you ever wondered what it takes to build some of the world’s largest skyscrapers? Are you curious about what type of equipment it takes to lay the foundation for a bridge underwater? Sometimes it seems like they do the impossible. But with a few large tools, they manage to complete some miraculous structures.

Let’s look at several of the world’s most powerful megastructure-building machines and how they do what they do.

#1 — SLJ900/32 Segmental Bridge Launcher

When you think about bridge construction, you may envision large cranes lifting each section into place as they build the structure, and you wouldn’t be wrong. This isn’t the only way now. There is a massive machine in China that redefines bridge construction as we know it.

The SLJ900/32 Segmental Bridge Launcher is 580 tons and manufactured by the Beijing WowJoint Machinery Company.

It drives onto the bridge’s pillars, lowering a pneumatic support structure, anchoring the machine to the first pillar, which allows it to extend itself out to the second and third pillars. It then deposits the girder it’s carrying.

From here, the workmen can weld everything into place while moving onto the next girder. The transport relies on 64 wheels split into multiple sections, rotating 90 degrees to steer on space-confined ground.

The development of this machine has fast-tracked infrastructure development in China. 24,000 miles of railway track is planned for construction by 2025 — more than the combined railway structures in the European Union, which rests at 13,841 miles.

#2 — Tunnel Boring Machines

Have you ever wondered how engineers dig road, rail, and utility tunnels without disturbing the busy cities above? Tunnel boring machines make this possible.

One example is the ongoing construction of Australia’s Forestfield-Airport Link. It currently requires the use of two tunnel boring machines designed by the German company Herrenknecht. The devices cost about $20 million each.

They have 39-foot radius rotating cutter wheels, helping them efficiently break material away from the tunnel’s rock walls. The gravel is then transferred to the belt conveyor system, while the hydraulic system pushes the machine forward.

Reinforced concrete segments are installed, matching the tunnel’s curvature. These segments form rings that support the tunnel as the machine bores. Once each concrete ring is complete, the machine’s hydraulics can push against the new ring to propel it forward.

In Australia’s airport link project, they are placing around 9,000 rings along the project’s 5-mile-plus tunnels.

In order to avoid vibrations that would cause significant disruption above, technology like this needs to move very slowly. Because of this, Australia’s Airport project started in 2017 and won’t be finished until late 2020.

#3 — Tower Cranes

Cranes are one of the most miraculous machines that city-dwellers see every day. One of the world’s leading crane companies, Liebherr, always puts their engineers and machines to the test.

Construction site ground space is a precious commodity. Having multiple vehicles and lifting equipment can be more of a hassle than a help. Tower cranes remove that complication by hosting all lifting and moving activity, using airspace above the site, which frees up ground room.

Depending on the series, Liebherr’s tower cranes can lift as high as 1,500 feet for specialized constructions of exceptionally tall buildings, such as St. Petersburg’s Lakhta Tower.

While most tower cranes aren’t quite that tall, the shorter ones are still pretty impressive — some can lift loads of up to 42 tons using incredibly thick steel lifting cables with thinner strands around the large central core to distribute the weight.

The modular design of tower cranes means they get quickly erected by other smaller cranes and disassembled similarly. Some tower cranes can even climb while inside a building — reaching higher as construction progresses.

#4 — Georgia Nuclear Power Plant

Sometimes you need something that can reach farther than even tower cranes can reach. The Georgia Nuclear Power Plant can reach up to 3,200 acres. In large plants, crawler cranes are the weapon of choice for several reasons.

Units 3 and 4 of the Georgia Vogtle Expansion Project had nuclear containment roofs weighing in over 900 tons apiece. They were 135 feet in diameter and 37 feet tall.

The Lamson LTL 2600 fits the job — it can lift up to 1,200 tons.

#5 — AASTA Hansteen Rig Spar

Ever wondered how an oil rig is constructed so far out at sea? The world’s largest oil rig, the AASTA Hansteen, was built in South Korea and measured 656 feet long and 164 feet in diameter. It weighs over 46,000 tons.

The rig needed transporting from Korea to the coast of Norway. The Boskalis Dockwise Vanguard is a semi-submersible transport vessel that can sink over 90 feet beneath the water, allowing heavy machinery to float onto the platform instead of being lifted.

#6 — Thien Ung Project

Oil workers need a place to live and store equipment at sea while working on oil rigs — built on top of the rig, since none of it ever gets built in the middle of the ocean.

The top of the Thien Ung KK TNG Field Rig is one example. Built offshore, the project required a 4,200-ton topside, with an 850-ton living quarter.

At the time, they used the world’s most massive nautical lift installation — the Asian Hercules III, an offshore heavy lift sheer leg crane. This self-propelled instrument is 350 feet tall and can carry over 5,000 tons.

#7 — Wikinger Wind Farm Installation

Onshore wind turbines can reach 575 feet in height, but offshore they can get to 853 feet. They need an array of mega machines to put them into place.

In 2017, the Wikinger Wind Farm Installation used over 70 turbines off Germany’s coast. The Fred Olsen Windcarrier was used to complete the most fundamental stages of the project — a jack-up vessel, a ship that contains four self-elevated legs sitting on the ocean floor that push the boat above the waves.

#8 — Wiggins Island Tandem Cranes

The goal behind the Wiggins Island Coal Export Terminal design was to export over 120 million tons of coal from Australia’s east coast every year.

To do this, coal stacking bridges are an essential component alongside mobile cranes with rotational flexibility. For the 1.1-mile project, they called for two Lamson LTL 2600 transit lift cranes working in tandem to lift the gigantic structures into place. Once they got everything moved, it was a matter of welding everything in place.

#9 — Cofferdams

Ever wonder how the legs of bridges get built right in the middle of the water? The process involves sheet piling and cofferdams.

Sheet piling involves the interlocking and overlapping of substantial steel beams, a method used to produce large cylinder structures known as cofferdams. These objects get dropped into the water where the structure needs building, and the water gets drained out — allowing a dry area for construction workers to create.

The cofferdams are lifted and then floated into position with large cranes. In some cases, the shape, weight, and height of the cofferdam make it difficult for this kind of positioning — in these cases, the cofferdams may be launched straight off a slope right into position.