As we reported in our news section at the time, a joint venture of Skanska and BAM is main contractor for the £85m project, which will link the city's Piccadilly and Victoria stations and help ease a rail bottleneck. The steelwork was fabricated by Severfield, which managed the installation process.
The 89-metre single-span structure is Britain’s first asymmetrical network arch railway bridge and the second-longest of its type in the world. It was designed by BDP with engineers from WSP, Aecom and Mott Macdonald with a low curve in a tennis racket-style lattice.
The LR 1750 started work on site in July 2016. The 750-tonne capacity crane was used for six months to set up the lower section of the bridge immediately over the river and to assemble the 90-meter bridge arch. The massive steel structure had previously been transported to the site in the centre of the city in small segments.
Weldex sent its most powerful crawler crane to the site for the subsequent installation of the bridge arch using a tandem hoist. The assemblers erected the Liebherr LR 11350 with a 72-metre main boom and the 42-metre derrick boom over a period of four days for the job. The large crane would have to handle the majority of the weight and position one end of the bridge arch on the opposite bank of the River Irwell.
Its 357-tonne gross load was lifted at a radius of 51 metres because the extended guide frame on this crane model makes it possible to extend the radius of the derrick ballast pallet from 25 to 30 metres. This configuration of the crane, known as SLDB2, enables it to handle an additional load case of almost 50 tonnes with a radius of around 50 metres.
However, before the enormous bridge arch could be hoisted over the river, the crawler cranes had to move it around 30 metres in stages up to the bank. The crawling process had to be interrupted several times to fit additional ballast. An LTR 1100 telescopic crawler crane (100-tonne class) stacked the derrick ballast of the LR 11350 up to the maximum of 600 tonnes. Together with the central and turntable ballast, ultimately there were 830 tonnes of counterweights on the crane. The actual hoist over the water then took place slowly and with no complications with a great deal of care and precision. The bridge arch was in position within three hours of the load being picked up.
Severfield project manager Jarrod Hulme was both pleased and relieved after the lift went to plan and there was praise for the Weldex team led by Mark Hollett, who was responsible for the crane work. "Fantastic lads", said Hulme. "Weldex has never disappointed us in around 20 years of working with them."
He was also full of praise for the cranes. He had previously used Weldex’s LR 11350 to erect the enormous pylons in London for the cable car over the Thames – the so-called Emirates Air Line. "We use these crawler cranes very often", said Hulme. "I love the crawler cranes from Liebherr. It's good stuff."
Liebherr LR 11350 (SLDB2)
- Main boom 72 m
- Derrick boom 42 m
- Central ballast 30 t
- Turntable ballast 200 t
- Derrick ballast 600 t with a radius of 30 m
- Load case (gross) 357 t at max. 51 m radius
Liebherr LR 1750 (SLDB)
- Main boom 49 m
- Derrick boom 28 m
- Central ballast 95 t
- Turntable ballast 200 t
- Derrick ballast 350 t
- Load case (gross) 224 t at max. 26.8 m radius