Liebherr crawlers complete railway bridge hoist in Manchester

The crawler cranes performed a tandem hoist for a 560t arched bridge over the River Irwell in Manchester.

The 750t LR 1750 was used for six months to set up the lower section of the bridge immediately over the river and to assemble the 90m 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 72m main boom and 42m derrick boom over a period of four days for the job. The large crane had to handle the majority of the weight and position one end of the bridge arch on the opposite bank of the River Irwell.

This hoist constituted a massive load case for the LR 11350 as a result of the required radius of 51m. The 357t gross load could only be managed at this distance because the extended guide frame on this crane model makes it possible to extend the radius of the derrick ballast pallet from 25m to 30m. This configuration of the crane, known as SLDB2, enables it to handle an additional load case of almost 50t with a radius of around 50m.

Before the enormous bridge arch could be hoisted over the river, the crawler cranes had to move it around 30m in stages up to the bank. The synchronous transport was interrupted several times because the cranes had to be fitted with additional ballast.

An LTR 1100 telescopic crawler crane stacked the derrick ballast of the LR 11350 up to the maximum of 600t. Together with the central and turntable ballast, ultimately there were 830t of counterweights on the crane. The bridge arch was in position less than three hours after the load had been picked up.