Contract C305 represented the most substantial design-bid-build construction contract within the Crossrail project. This contract is specifically focused on the 23km twin bore eastern running tunnels that form a crucial part of CRL’s central section, from Victoria Dock in the East to the new Crossrail Farringdon station in Central London. The works encompassed the construction of launch shafts and SCL (Sprayed Concrete Lining) launch adits for the Tunnel Boring Machines (TBMs) at Limmo Peninsula, along with SCL caverns and launch adits for TBMs at Stepney Green. Additionally, it involved the creation of 10 SCL cross passages between the running tunnels, with impressive lengths of up to 30 meters.