Crane arrival marks start of bypass viaduct work29th Mar 2011

THE first of two giant cranes arrived in Porthmadog yesterday (Monday March 28) in readiness for work on a landmark viaduct over the Afon Glaslyn that will form the centrepiece of the new £35m Porthmadog bypass.

The 160-tonne main body of the hydraulic crawler crane entered the town on a special transporter vehicle, which arrived from Caernarfon having travelled through North Wales along the A55.

Attachments including the tracks, jib, boom and counterweight will be fitted to the crane’s main body using a state-of-the-art self-assembly kit. The crane’s jib will be 30m (98ft) high.

The Liebherr LR 1160 crane will then be used to splice together 18 paired steel girders. The girders will be lifted into position and installed using a second, larger crane due to arrive in Porthmadog on Monday, April 4.

Weighing 630 tonnes, the giant Sany SCC6300 crane will be assembled on site and equipped with a 60m (196ft) jib that will be visible for miles around. Its attachments will be delivered in 15 wagon loads.

Assembly of the second crane will take up to a week, with the steel girders being lifted into position between April and May. The crane will be disassembled, moved across the river and re-assembled midway through the project.

A joint venture partnership of Balfour Beatty and Jones Bros Civil Engineering UK is building the bypass for the Welsh Assembly Government.

Subcontractor Cleveland Bridge UK, which is carrying out the viaduct work for the joint venture, has hired both cranes from Belgian contractor Sarens Group.

The long-awaited new section of the A487 carriageway will improve journey times, ease congestion and significantly improve environmental conditions by enabling current through traffic to bypass Porthmadog, Tremadog and Minffordd.

Once complete the 140m, three-span viaduct will carry traffic over the Glaslyn estuary. It will run parallel to the existing Cambrian Coast Mainline railway bridge.

Wyn Daniels, bypass partnership project manager, said: “The Afon Glaslyn bridge will be the defining feature of the bypass scheme.

“The arrival of the second crane is likely to result in some delays on the A roads between Caernarfon and Porthmadog, and we apologise in advance for this.

“The local community has been incredibly patient and supportive throughout the work. We would like to thank the people of Porthmadog, Tremadog and Minffordd for their ongoing patience and co-operation.”

It is anticipated that part of the new road past Tremadog will be completed this summer. The entire bypass should be completed and open to the public before the end of this year.