The annual awards recognise excellence and innovation in civil engineering and celebrate its contribution to quality of life.

The Forth Replacement Crossing, with the Queensferry Crossing as its centrepiece, won the Greatest Contribution to Scotland award with the Shieldhall Tunnel picking up the much-prized Infrastructure award.

The Awards attracted 12 entries from across Scotland and included submissions for harbours, bridges, tunnels, motorways, distilleries, railways, public spaces and flood protection schemes.

The state-of-the-art 1.7 mile Queensferry Crossing – the longest three-tower cable-stayed bridge in the world – safeguards a vital transport corridor and enhances the iconic location alongside the Forth Bridge and Forth Road Bridge with its elegant design. The judges recognised its importance in creating resilience in Scotland’s transport network and the professional excellence displayed in all aspects of its design and construction. It boasts several ‘firsts’ including the world’s longest continuous underwater concrete pour and longest free-standing cantilevers.

The Shieldhall Tunnel is a key part of a £250 million partnership programme to transform how Glasgow manages rainfall to end uncontrolled flooding and improve water quality in the Clyde. It is the biggest storm water storage tunnel in Scotland and represents the largest investment in the sewer network since Victorian times.

The project involved the construction of a 5km tunnel, wide enough to fit a double decker bus inside and required considerable mineworking consolidation along a challenging route – passing beneath three railway lines, three parks and the M77. More than 90% of all excavated material was recycled, and the £100m project was delivered within an astonishing two years.

The Designed in Scotland award went to Morrison Construction for a new health centre in the world’s most remote inhabited island - Tristan da Cunha; the Building award went to Macallan Distillery and a Regeneration award was presented to Glasgow’s Sighthill for ground remediation.

Presenting the main awards at a special ceremony at the National Museum of Scotland in Edinburgh, Kate Forbes MSP, minister for public finance and digital economy, said: “I was pleased to see the Shieldhall Tunnel win this year’s Infrastructure Award. To complete such a large project in a busy urban area with so little disruption is truly worthy of recognition.

“And I am of course delighted that the newest Scottish icon, the Queensferry Crossing has been recognised for its contribution to Scotland. It is delivering extensive benefits to users and communities whilst safeguarding vital transport connections, helping families and businesses right across the country.

“These projects and the many others that are being taken forward create a legacy for the people of Scotland.”

Convenor of the judging panel, Ainslie McLaughlin, said: “Our awards showcase the incredible feats of civil engineering and the unsung heroes behind them. The scale and complexity faced in delivering the Forth Replacement Crossing and Shieldhall Tunnel projects make them very worthy winners but all the entries showcase the ingenuity, expertise and dedication required to overcome technical constraints whilst maintaining safety and quality standards and minimising environmental impact. The projects are already demonstrating their worth by protecting communities from flooding and safeguarding vital transport connections.”

Professor Sally Mapstone, president of the Saltire Society, added: “Civil engineers design, build and maintain the vital infrastructure on which our quality of life depends and these projects show Scotland at its best. The Saltire Society celebrates the Scottish imagination and talent and nowhere is this more evident than in the ‘art and science’ of civil engineering.”