Case study: Installation performance of the Clark-Drain CD 434 Linear Drainage Channel.


The railway engineer faces many challenges as a result of the privatisation of the United Kingdom Rail Network. Network-Rail, as the client for works undertaken on the rail infrastructure, often looks for continuous innovation and improvement with regard to materials and methodology on the part of the contractor. Furthermore, Network Rail’s own clients, the Train Operating Companies, expect works undertaken to both finish on time and deliver the benefits promised.

In the current competitive, commercially aware environment, the opportunity exists for engineers to challenge traditions and utilise new ideas, technologies and materials to drive more efficient use of possession time. In addition, the regulatory framework within which the rail contractor must operate becomes more comprehensive as each day passes. For example, the CDM regulations place a duty on the designer of a scheme to consider how that scheme will actually be implemented on site and in effect to design in, from the earliest stage, the safety of the works. In order to comply with the regulations, civil engineering designers must demonstrate that they have considered all the risks that can reasonably be foreseen and that they have selected methods, materials and strategies, which if adopted, will minimise those risks as far as is reasonably practical.

In relation to this and their linear drainage requirements, Network Rail recognised a need for an upgrade from traditional polymer concrete channel. For their programme of station redevelopment they wanted a more innovative product capable of meeting future environmental, cost saving and reliability needs.

To support its clients within the railway renewals and refurbishment industry, Clark-Drain conducted an extensive 8 month research and development programme to find a solution. As a result, Clark-Drain has developed a Polypropylene/Nylon alternative to the traditional Polymer Concrete Channel.

The outcome was a better, more flexible product. Where the traditional Polymer Concrete Channel is   extremely robust and ideal for heavier loading applications such as industrial environments, goods yards and railway sidings; the new CD 434 channel performs better in specific applications such as the redevelopment of station platforms, car parks and concourses. In addition, where Network Rail had highlighted limitations in relation to ease of installation and relative cost, the new CD 434 can be easily installed by one person as it only weighs 5 kg complete with grating. It can also be clipped together in multiple lengths of 4 units for quick installation into a pre-dug trench. This offers a much greater saving in possession time and reduces considerably the risk of overrun and the accompanying financial penalties.

CD 434: Linear Drainage.

Light weight – The one meter length channel and grate is lighter, weighing 5kg, compared to traditional concrete products weighing 20kg or more without being detrimental to its strength for EN1433 B125 loading.  

Reduced manual handling – Light-weight design and simpler, easier and safer installation provides greater emphasis on health and safety, reducing work related injuries.    

Easy and quick to install – Installing up to four lengths in one go enables faster levelling, taking 25% less time than traditional polymer concrete.  

Anti-slip and narrow slot finish – Reduces the potential for tripping and slipping, helping to improve public safety.  

Dual Locking - The Catchlock system simplifies locking of the grating yet enables safe and speedy access for maintenance. The optional anti-tamper bolt locking system provides added security against theft, reducing  time and cost spent on replacing lost gratings.

100% recycled – ‘Green’ credentials help toward reducing the carbon foot-print and act as a theft deterrent due to having no intrinsic scrap value. 

Enhanced durability – Carefully designed load transfer structure improves product life span and lowers maintenance and replacement costs.

Heat resistant – The polypropylene/nylon properties make the CD 434 channel ideal for hot tarmac installation.  

In addition, the light-weight design makes the CD 434 easier to install. When fitted correctly and finished with a top coat of either, tarmac, concrete, block pavior or traditional slabs, the CD 434 provides an extremely robust end product, as evidenced in recent rail platform and car park installations at Preston, Billericay and Liverpool Lime Street.

It is also flexible enough for platforms that curve and has the ability to follow the curve of the platform edge, giving uniformity and enhancing the visual appearance when laid to the same contour.

Of the new product, Ian Coneyworth, Construction Manager at the Spencer Group says:

“I have used many different specifications of surface drainage products over the years, but must congratulate Clark-Drain on a design I have found far better for simplicity, speed of assembly, manual handling and costs compared to other similar products, coupled with the fact it has a B125 loading. I will make sure I recommend the CD 434 to our Procurement Department for use on other contracts we have in the area and also for future use.”

Chris Roberts, Civil Engineer at Network Rail also confirms the advantages of using the new channel product:   

“I am very impressed with the drainage products available from Clark Drain, particularly with respect to the efficiencies that they offer on site due to high strength, high quality and lightweight materials. The products also appear to offer clear cost saving compared to other suppliers which identifies them as a favourable supplier on future schemes”

Abu Wadie, Building Surveyor, Network Rail Infrastructure Projects says:

"I recently specified the CD 434 to be used on Liverpool Lime Street, platform refurbishment. The product was ideal as it could be laid quickly, easily and most importantly safely in long lengths in a short duration. I have now specified the CD 434 on several rail schemes and will continue to specify on future schemes."

- Uploaded 30/10/2013