When developers in Shanghai wanted to build on the site of an 85-year-old primary school, engineers devised a way to “walk” the building to a new location rather than see it demolished.
The five-story Lagena Primary School was relocated using a “walking machine”, developed by Shanghai Evolution Shift in 2018.
Lan Wuji, chief technical supervisor on the project, said this involved attaching 198 mobile supports under the building, which acted like robotic legs. The building’s pillars were then truncated and the robotic legs extended upward so it could begin its walk.
The legs were split into two groups which alternately rise up and down — imitating the human stride — while sensors attached to the building helped to control its forward propulsion.
“It’s like giving the building crutches so it can stand up and then walk,” Wuji said.
It took 18 days for the building to be rotated 21 degrees and moved 62 metres to its new location, where it will become a centre for cultural education.
Relocating historic sites
The Lagena Primary School project represents the first time Evolution Shift’s walking machine has been used, but it is just the latest in a long list of historical site relocations in China.
In fact, the practice has become so common as the nation deals with rapid urbanisation that it has spawned an entire industry, with approaches varying from sliding buildings into new positions on rails or entirely disassembling a building and reassembling it in a new location.
In 2000, officials in Chongqing relocated the grand Zhangfei Temple, which was originally built on a steep hillside during the Song dynasty (960 to 1279) and reconstructed after a flood in 1870.
It was moved some 32 kilometres at a cost of more than $16 million to make way for the Three Gorges Dam.
In 2003, the Shanghai Concert Hall, built in 1930, was moved to make way for the construction of a new road.
The building was first raised 1.4 metres, placed on a pre-made track and slid 66.4 metres. It was then raised by 1.88 metres while a new foundation was constructed for it.
Other countries are finding similar relocation solutions to preserve historic sites.
In Turkey, a new dam project threatened to flood the ancient town of Hasankeyf on the Tigris River. Engineers managed to transport a 15th century mosque and an 800-year-old bathhouse three kilometres to a new site on a 256-wheeled self-propelled modular transporter.
Believed to be one of the oldest continuously inhabited settlements in the world, there is evidence of people living on the site as long as 12,000 years ago.
Other impressive feats
The farthest known building location is believed to have been achieved in Canada in 2006, when a house was transported almost 2000 kilometres over 40 hours, using beams and dollies.
But that has nothing on Romania, which in 1987 moved an entire apartment building, about 100 metres long, to create space for Transylvania Boulevard.
According to the city’s website, engineers split the 7600 tonne structure in two.
“One half was moved on the right side of the boulevard, the other one on the left by digging under the building, putting railways and wheels and moving it 55 metres away with the help of a network of hydraulic jacks placed under the framework that was fixed under the structure to support its weight,” according to the site.
The operation took less than six hours and was completed while the building remained connected to water, gas, electricity, telephone and sewerage systems.
Meanwhile, the United States quite literally scaled new heights in building relocation in 1999, when engineers relocated seven historic structures within the Cape Hatteras Light Station in North Carolina some 880 metres due to shoreline erosion.
Engineers replaced the original foundations of the station, which took 23 days to move due to its delicate condition, with a grid of steel beams for better support when hydraulic jacks lifted the landmarks onto a system of rollers and tracks.
During the transportation, which took place at about 2.5 centimetres per minute, 60 automated sensors placed inside and outside the lighthouse monitored issues such as the tilt, vibrations and wind conditions the structure was experiencing before it was successfully reinstalled in its new home.