Case Studies
A5-M1 Dunstable Link Road benefits from exacting standards of manhole covers and grates

Experience and expertise in the highways sector enabled Clark-Drain to contribute to a £162 Million road scheme in Bedfordshire. The A5-M1 Dunstable Link Road opened in May 2017, creating 2.8 miles of dual carriageway, with three junctions and six bridges.

The road was built by Costain Carillion Joint Venture, who asked Leeds-based merchants Keyline to source suitable drainage products. Keyline has a relationship with Clark-Drain dating back a number of years and are very familiar with the company’s product range, and the levels of service that can be expected.

Daniel O’Hagan, Nationals Sales Negotiator for Keyline, picks up the story: “Clark-Drain carry a full range of castings compliant with Highways England specifications, so it was easy for us to offer our customer products that fully met their requirements for this project. “We always find that Clark Drain are very competitive in their pricing, and prices for this contract reflected the large quantities of product involved. They also assured us of guaranteed stock availability and continuity of prices throughout the project.”

In order to meet the project requirements, Clark-Drain supplied 531 Ductile Iron Manhole Covers and Frames, and 201 Ductile Iron Hinged Gully Grates and Frames.

“As is usually the case with Clark-Drain, there was good communication throughout the project,” says Daniel O’Hagan. “In fact, there was a good working relationship between all three parties and this was key to the success of the collaboration. I had no problems getting in touch with either Clark Drain or the customer, and all in all this was a good example of a well organised order.”

Ray Jones, Operations Director at Costain Carillion Joint Venture, confirms how important cooperation and communication was on this project: “Clark-Drain were especially helpful in terms of delivery times. They committed to delivering between 9.00am and 3.00pm during school term time, which was an important planning requirement.

“But more significantly, they always let us know exactly when they would be on site. This meant we could be waiting for them with the right forklifts and personnel to unload the products. It avoided delays and meant nobody was rushing around, which was important as it helped to reduce the risk of accidents.”

The link road opened on schedule, improving east-west connections between the A5 and M1. Other benefits of the scheme include reducing congestion in Dunstable and delivering infrastructure for 7,000 new homes to be built.


Meeting Highways England specifications – Clark-Drain’s Ductile Iron Manhole Covers and Frames and Hinged Gully Grates and Frames are compliant to Highways England’s HA104/09 Design Requirements document. Additionally, the Hinged Gully Grates are compliant to HA102/00 Design Requirements

Kitemarked products – the Manhole Covers and Gully Grates carry third party BS EN124 certification.

Class D400 – both products are classified at D400, with a loading capacity of 40 tonnes for carriageway installation.

Design – Clark-Drain’s advanced ‘Load Dispersion Modelling’ techniques optimise the dispersion of stresses through the structures and to the bedding below.

Matching profile – the Gully Grating is profiled to perfectly match the concrete drainage channels used at the sides and centre of the carriageway.

Non-rocking – the Manhole Covers feature three-point suspension and the Gully Grates a taper-lock system: both designs ensure non-rocking in situ.

Drainage performance – the Gully Grating supplied is Q rated under the requirements of Highways England’s HA102/00 specification, delivering excellent surface water drainage performance within a compact size and conforming to site specification requirements.