The Haymarket, a £200 million joint venture development in Edinburgh between Interserve and Tiger Developments, is approaching its first significant milestone – the successful completion of phase one, the pre-construction enabling works.

Taking nearly two years of painstaking work, the strengthening of the two Network Rail tunnels underneath the site, took over 30,000 man-hours to complete before any above groundwork could start.

The reinforcement of the North and South tunnels, which carry all East-West traffic from Edinburgh to Glasgow and beyond, was further compounded by the necessity that labour was carried out at night to avoid any disruption to train services.

The complexity of the underground phase was unprecedented: the requirement to strengthen the Victorian tunnels, which transport around 856 trains every single day, involving the installation of 4000 stainless steel masonry stitch bars placed with pin-point precision. In addition, some 350,000 litres of cement grout was injected into the tunnel linings through nearly 5000 holes cored into the Victorian brick linings.

According to Tim Shepherd, Senior Project Manager with Interserve, it was an ambitious phase in the development that tested the technical nous of the project team.

Tim explained: “The engineering and logistical challenges were immense, with the impact of working on the Victorian tunnels in the dead of night where access was severely limited. Working on a live site which connects the capital with the rest of the UK has been extremely demanding but we have worked closely with Network Rail to ensure no disruption to rail services.”

Now almost complete, above groundwork for the prominent H5 office building, Q-Park and StayCity apart-hotel element will commence, on schedule, in summer 2015 with progress on the first buildings, designed and delivered jointly by award winning Richard Murphy Architects and CDA Architects, completed by mid 2017.

Interserve Director, David Westwater said: “The demand for a development of this size and calibre is so intense that the challenge is managing market expectations. Strengthening the tunnels has been a demanding and meticulous task that’s taken time, however we now have a robust foundation on which we can progress development of the site.”

The Haymarket is one of Edinburgh’s largest commercial schemes to come online in the last 10 years. It will comprise 320,000 sq ft of office, 54,000 sq ft of retail & leisure, 350 hotel / apart-hotel rooms and a 300 underground car park. It is considered to be the best-connected business district in the Capital situated opposite the busy Haymarket train station as well the Haymarket Tram stop providing excellent access to Edinburgh Airport in only 20 minutes.

Cllr Frank Ross, Convener of the Economy Committee, said: “It is really encouraging to see work progressing on this key ‘Edinburgh 12′ development site. tHe Haymarket Edinburgh will support around 300 jobs during construction and is anticipated to create around 3,500 jobs upon completion.”

Graham Haydon-White, Development Director, Tiger Developments added: “As one of the UK’s most significant schemes outside London with excellent access to train, bus and tram networks, the benefits of this landmark development to potential occupiers are unparalleled. The appeal of Edinburgh as a UK head office location is unquestioned; prominently positioned with Grade A office specification and flexible floor plates; The Haymarket will provide global companies with a high profile office space designed to their exacting requirements. This is good news for Edinburgh and for Scotland.”

Tenants already signed up for The Haymarket’s initial development phase include Q Park, Tesco and serviced apartments’ provider Staycity. Food chains Prezzo and Pret A Manger have committed to the second development phase and advanced discussions are currently taking place with other occupiers for a further 70,000 sq. ft. of retail and office space.