Bridge challenge: the force of nature

The two Jaso flat tops and the much smaller J80PA luffer on the central pylon of the Chacao Bridge in Chile

Construction of the Chacao Bridge – the longest suspension bridge in South America – is progressing well even under constant and extremely challenging prevailing weather conditions.

This ongoing project in Chile, 1,150 km south of Santiago in the Los Lagos region, will see a new bridge link the continent with Chiloe Island across the Chacao Channel. It will replace the existing ferry service.

Costing US$1.2 billion, Puente Chacao will be 2.75 kilometres long and carry four road lanes. The crane on the tallest pylon will stand well over 200 metres.

Challenges on the job which is in an open salt water channel of the South Pacific, are mainly the extremes of terrible weather, including tsunamis, buffeting winds, major earthquakes and strong currents.

The project is served by large Jaso tower cranes, namely a J380PA luffing crane on each of the side pylons and two J360.24 low tops sharing the central foundation on Whirlpool Rock. The fifth crane, a J80PA luffer, is a service crane on the central pylon. The cranes had to be specially modified to meet many non-standard site requirements and to withstand the extreme conditions.

The bases for the two main low top cranes on the central pylon

Going at it

The bridge is being built for Chile’s Ministerio de Obras Publicas which makes it a high profile project. Lead contractor in the joint-venture company constructing it is Hyundai Engineering and Construction from Korea which has extensive experience constructing suspension bridges.

Hyundai E&C built bridges in Korea and Turkey with long spans. The one it built in Turkey, the Yavuz Sultan Selim Bridge, has a main span of 1,408 metres. The 1915 Canakkale Bridge, also in Turkey but not built by Hyundai, is claimed as the current world record holder for the longest span, at just over 2 km.

The Chacao contract in Chile started in 2019 and the cranes went up in 2021. Completion is scheduled for October 2028. Heavy Duty, a Chilean specialist engineering contractor and Jaso tower crane dealer for Chile, was contracted by Hyundai for the supply, operation and maintenance of the five tower cranes serving the bridge’s pylons.

Emilio Bouchon, general manager at Integral Group, owner of Heavy Duty (see sidebar) here explains the challenges his company faces in building the bridge.

A peculiarity of the new bridge is that it doesn’t just have two pylons, one at each end, Bouchon says. Instead, it has three, with one of them being offset from the middle, supported on a rock below the surface of the water. It makes the bridge asymmetrical, with 1,055 metres on one side and 1,155 metres on the other, between the pylons.

Total length, including the fixed sections each side outside the pylons, will be 2.75 km. Clearance height for ships to pass underneath will be just over 50 metres.

Good progress

The two low top Jaso J360.24 towers and the J80PA luffing jib service crane at work on the central pylon

The project is well over half finished, Bouchon says. In June construction had just hit 65 per cent done. The aim is to have all three pylons complete, at their full height by the end of the year (2026).

The three pylons are different heights. The South pylon, on the Chiloe Island side, will be 155 metres tall and is served by road. Also, served by road is the North pylon, tallest of the three – 199 metres – and on the mainland. The central pylon, on the submerged Whirlpool Rock, will be 179 metres tall and is served by barges.

One of the many major challenges on this job is the daily battering by 115 km/h winds. Another is a large number of earthquakes in the area. The largest earthquake ever recorded, a magnitude 9.5, occurred nearby, back in 1960.

A strong funnel-like movement of water through the channel where the bridge is being built creates very strong currents moving left and right four times a day. It generates a tidal range of more than 6 metres. Two high and two low tides a day means only five hour windows to get in and out with all the people, materials, spare parts, and everything else needed for the construction of the central pylon for a massive bridge.

In addition to difficult access and the marine environment, the cranes had to be strong – able to lift 23 tonnes, and tall. Maximum required final hook height, for the J380PA crane on the north pylon, is an impressive 260 metres. The same crane on the south pylon will have a final hook height of 206 metres.

At the top of the pylons, 244 metres up, the cranes have to be strong and rigid enough to pull the steel bridge cables that go up and over the pylons.

Also, being in the middle of the ocean, means the cranes need to be very accurate and precise in their movement and load placement, Bouchon explains.

The two J360.24 low top cranes on the centre pylon were specially configured so they could assist each other when raising their height. They will have final hook heights of 181 and 192 metres. Both have 45 metre jibs.

As work progresses the lengthening, non-standard, ties for the tower crane masts become apparent

Special planning and customisation is necessary for the cranes, it is not an application for which you can pick everything from a catalogue or off the shelf, Bouchon explains. The centre pylon tapers in towards the top so as the cranes go higher their bracings (five for each crane) get much longer – up to 18 metres – and heavier than standard.

This non-standard approach applied to the cranes themselves and to their installation, testing and maintenance, Bouchon says, also applies to the people. Only the best operators are chosen, for example, and the people looking after the cranes is another crucial element.

Maintenance is calibrated to marine exposure, not catalogue hours. Coating inspection, touch up and torque audits are on a shorter cycle than you find on a city jobsite.

Technicians are on site around the clock. You can’t wait and call them when something goes wrong because it is five hours by plane, or 12 hours driving, to get there Bouchon says.

Other people need to be on site at all times, too. When so many things are changing, the weather is bad and so on, you can’t plan everything and rely on that because things need to be changed along the way in response to changing conditions and situations.

Unsurprising perhaps that with all the bad weather, the cranes spend more than 50 % of their time winded off. This negatively impacts productivity but safety is the top priority and progress is till good.

Emilio Bouchon

Emilio Bouchon

This article was written from a presentation given at the 2026 Tower Cranes North America (TCNA) conference by Emilio Bouchon, general manager at Heavy Duty Chile (Integral Group) an industrial, engineering and construction support company in Chile which is also a distributor for Jaso tower cranes. It is the lifting contractor on the Chacao Bridge project.

Bouchon is an industrial engineer from Universidad de Chile, with an MBA from Universidad Adolfo Ibáñez and executive programmes at Wharton in the USA and IMD headquartered in Switzerland. For more than three decades he has run businesses across Chile and Latin America, mostly in ports, energy, water and industry.

He also runs Inversiones y Asesorías Baco, his M&A and project development advisory, founded in 1994. Bouchon speaks Spanish, English and French.