June 20 - Dragados Sisk Joint Venture (DSJV) contracted WWL ALS (Wallenius Wilhelmsen Logistics Abnormal Load Services) to deliver the tunnel boring machine, Jessica, through London from Stepney Green to Limmo Peninsular as part of the Crossrail project.

The 1,300-tonne Herrenknecht S-721 tunnel boring machine and back-up equipment had to be transported in as large individual components as possible, so that DSJV could complete the relocation quickly, efficiently and cost-effectively.

Nine months of intensive planning was required to determine a suitable route for the transport, obtain permits and liaise with multiple statutory authorities regarding the removal of street obstacles, traffic management and street parking suspensions.

WWL ALS' project team secured the necessary Be16 special order, VR1 and TTRO permits.

Extensive surveys were undertaken by WWL ALS to determine possible routes for the project. As part of this process, three-dimensional laser mapping was used for scanning overhead gantry, bridge and tunnel heights and widths on dual carriageway sectors of the route, where manual means of checking clearance would have been too hazardous.

The route decided upon went eastbound via the A13 Limehouse Link Tunnel, which had a height and width clearance of just a few centimetres for the largest items. The route also involved travelling contra-flow on a 750 m section of the A13 for transport of the two largest loads.

After completing a 2.7 km underground drive from Pudding Mill Lane, Jessica was dismantled into oversize pieces and transported by road. Due to the congested nature of the inner-city rote, between seven and 12 police escort vehicles were required for each abnormal load movement, in addition to the private escorts provided by WWL ALS.

An assortment of low loader and semi low loader vehicles were used to transport the cargo, the largest items of which had the dimensions 18.2 m x 7.1 m x 4.35 m and weights of 72 tonnes.

The Metropolitan Police commented that these were "the widest loads moved within central London since records began".

Within the next month, WWL ALS will begin the relocation of Jessica's sister tunnel boring machine, Ellie, also from Stepney Green to Limmo Peninsular.

Watch a video of the project here: