Improving the connections for businesses between Edinburgh, Glasgow and beyond is expected to contribute more than £1 billion to Scotland’s economy, more than justifying the £500 million cost of upgrading the core of Scotland’s motorway network.

The M8 M73 and M74 Motorway Project saw the completion of the motorway route between Glasgow and Edinburgh, cutting 20 minutes off journey times.

And while the 58km-long Aberdeen Western Peripheral Route was said to be the largest ever infrastructure project in Scotland, the ‘missing link’ surpassed it as the largest asphalt contract with in excess of 825,000 tonnes laid.

A monumental effort

Even for Hillhouse – one of Scotland’s largest privately owned heavy building materials businesses – this project was a big ask but the company rose to the challenge.

Robert McNaughton, managing director of Hillhouse Quarry Group, said this had been achieved by a combined team effort from Hillhouse Quarry Group and Lagan Asphalt Group. What’s more, he said it was all the more impressive given that the supply was carried out by an SME whilst maintaining its ongoing customer base.

He said: ‘This has been a monumental effort by the team given the resource deployed to carry out the works,”.

Logistics and materials

A large volume of temporary surfacing was necessary in order to keep routes open while the work progressed. This was particularly important at Raith and Shawhead, two of the busiest junctions in the whole of Scotland, where much of the work had to be carried out at night (between 8pm and 6am) to minimise traffic disruption.  What’s more, work at Raith also involved the creation of a complex new junction.

The base binder utilised basalt from Hillhouse Quarry Group’s own Hillhouse Quarry in Troon, Ayrshire – one of the largest independent whinstone quarries on mainland Scotland.

The surface courses used a mixture of 60, 65 and 68 PSV stone from various sources in Scotland and Ireland, as well as asphalt sand from Hillhouse’s Garpel Quarry, near Muirkirk in East Ayrshire. This greenfield site gained planning permission in 2014 and has about 25 years of reserves of concrete and asphalt sand. Lagan Group, one of whose companies – Lagan Asphalt – constructed the roads, supplied the bitumen from another of their companies, Lagan Bitumen.

The surface material specified was Lagan Asphalt 942, a polymer-modified bitumen, assured by a strict quality-control procedure overseen jointly by Lagan’s and Hillhouse’s technical teams working together at Hillhouse’s production sites. The result was an exceptional compliance rate for material supplied on site across the project.

Justin Gill, Hillhouse’s operations director described it as “amazing considering the volume, and testament to the dedication of all staff involved”.

Effective solutions

Hillhouse Quarry Group received its first order for material in February 2015 and the project got underway.

By spring 2018, the length of new and upgraded roads delivered in Scotland over a 12-month period was be 175km, including more than 61km of motorway and 75km of dual carriageway, plus more than 54km of cycle routes and footpaths.

Following the delivery of the M80 Stepps to Haggs motorway and the M74 completion project, the M8 M73 M74 improvements have completed the Central Scotland motorway network, closing that ‘missing link’.

Transport Scotland was committed to delivering these improvements in a safe and effective manner with due regard for local communities, the natural environment and road users.

Project in numbers

• 6.5 million man hours worked
• More than 8,000 people on site at various stages over three years
• 418,000 trees and shrubs planted
• 95 per cent of on-site waste recycled
• 16km of combined foot/cycle routes built or upgraded
• 43 new structures, including 15 new road bridges and two railway bridges
• 25km of carriageway built or upgraded
• 2,500,000m2 of new road pavement laid
• 3,500,000m3 of cut, 2,500,000m3 of fill and 100km of drains laid.

Collaboration and quality assurance

The start of the procurement process was announced in December 2011, with bidders competing for the contract throughout 2013. The successful bidder was a consortium called Scottish Roads Partnership (SRP), a joint venture of Ferrovial Agroman and Lagan.

Through consortium member Amey, SRP is responsible for managing, operating and maintaining this core section of the motorway network for 30 years following the completion of the construction work.

This meant it was particularly keen to ensure the right product was being laid properly. Therefore Lagan Asphalt’s technical manager, Craig Baskin, and his team took more than 5,000 cores from the finished roads to check in-situ asphalt compliance.

Hillhouse Quarry Group worked closely with Lagan Asphalt UK, which constructed the roads.

Reflecting on the project, a spokesperson from Lagan Asphalt said: “We are proud to have been a part of delivering the outstanding M8 M73 M74 Motorway Improvements Project. The successful delivery of these types of high-quality projects is due, in part, to partnerships developed with the top companies in the industry, such as Hillhouse Quarry Group.

“The demanding nature of this high-volume project required a collaborative team approach and Hillhouse was able to deliver on multiple levels to ensure efficient, effective and safe production and delivery of quality materials.”

Meeting the challenge of high volumes

The logistics of getting material to site as and when needed represented the biggest challenge. The asphalt was delivered from Hillhouse Quarry, where a third asphalt plant was installed to accommodate this project, and Hillhouse Group’s Glasgow Asphalt business in Cambuslang, just south of Glasgow, where a state-of-the-art Ammann plant was opened in 2014.

Gordon Hogg, manager of Glasgow Asphalt, praised customer service manager Caroline Woodburn and her team for keeping everything on track – which meant delivering up to 60,000 tonnes a month to the project.

This could involve as many as three runs a day from Troon and another three from Cambuslang. The Hillhouse fleet made most of the deliveries, supplemented when necessary by contractors. The asphalt was delivered to site whereupon shuttle buggies would serve the pavers, sometimes working up to 12m wide and demanding large volumes of material at any one time.

The project included:

• A new motorway section between Baillieston and Newhouse, completing the M8
• Improvements to Raith Interchange on the M74
• A new, all-purpose A8 road between Baillieston and Eurocentral
• Upgrading the existing M8 between Easterhouse and Baillieston
• Upgrading the M73 between Baillieston and Maryville that links the M8 and the M74
• Upgrading the M74 between Daldowie and Hamilton.

This meant four new and improved junctions on the M8 and three on the M74 section of the project, as well as improvements at the Shawhead and Raith junctions on the A725, where there is a new underpass that would, in other circumstances, have constituted a major contract on its own.

A new trunk road was built as a local distributor route on the new A8 to connect to the new part of the M8 and an extra lane was added to the M8 for eastbound traffic between Junction 10 (Easterhouse) and Junction 8 (Baillieston).

Honouring wider commitments

Although this was a massive project for Hillhouse Quarry Group, operations director Justin Gill said the company had to ensure it did not compromise the regular business of the Group supplying long-standing customers, including local authority framework contracts.

This meant operating at least one plant 24h a day, seven days a week for more than a year. However, Hillhouse was up to the task with preparations made to recruit more people, share resource between existing operations, and invest in plant and equipment.

“That’s something we can do – we are flexible,” said Mr Gill, who believes this helped Hillhouse win the contract.

“The fact that we were open to procuring another plant at Troon, and were willing to work with them and partner them, meant they saw us as their most beneficial partner.”

Gordon Hogg added: “It was extremely demanding over a long, long time, with one big push after another, but now, on reflection, it was a great achievement.

“Weekly project meetings meant issues were resolved quickly and I liaised with Lagan Asphalt’s technical team daily. There was a joint desire to get the job done right first time.”

Hillhouse is justifiably proud of the job that has been undertaken.

Justin Gill concluded: “We have combined a strategy of employing the best people from the industry and investing in modern, flexible equipment. The two together give you the capability to supply these major projects.”