Yorkgate to Donegall Quay Dualling — Design Checking Services.

Descriptions

Donegall Quay — Yorkgate Duelling (Dargan Viaduct) — Design Checking Services.The current Dargan viaduct was constructed 1994 to connect the Larne line with the rest of the network. The structure largely comprises single track between Yorkgate station and Lagan Junction with the exception of a single passing loop at Donegall Quay. The passing loop was designed for 20 m long carriages (rather than current 23 m) and is too short for a modern 6 car set configuration. Combined with its proximity to Yorkgate station is of limited operational benefit. Following the opening of the Beach Green — Antrim line in 2001 Ballymena and Derry/Portrush trains were diverted from the mothballed Antrim/Knockmore line to connect with Central via the Dargan viaduct. Transport NI are currently progressing a separate project to develop a new Westlink / M2 / York Street Interchange (YSI) which will substantially interface with the Dargan viaduct. A proposed access road would underpass the railway viaduct close to an existing pier. Further to an initial assessment using Translink's own Structural Framework consultants, Translink engaged with Roads Service's design team (URS) to undertake more detailed analysis for the sub-structure.The key objectives of this stage are:— to confirm Proof of Concept for widening the existing viaduct;— design pier and pile strengthening solutions for twin track;— construct works for piers and foundations in Section A.The project scope includes:— category 3 Checking in accordance with Railway Standard NR/L2/CIV/003;— design certification process which, in certain aspects, departs from the norm whilst maintaining a level of integrity acceptable to Translink.Translink anticipate the contract duration lasting 6 months starting July/August 2015.The Contracting Authority has voluntarily chosen to advertise this requirement in the OJEU but as per Regulation 8(1) of the Utilities Contracts Regulations 2006 provides that the Regulations do not apply to this procurement process.