Case Studies
National Stations Improvement Programme benefits from Clark-Drain linear drainage and steel access covers  

The refurbishment of platforms is part of Network Rail’s government funded National Stations Improvement Programme (NSIP ). The five year programme aims to deliver £179 million worth of station improvements to a minimum of 150 medium sized stations in England and Wales.

An overarching objective of the programme is to achieve a noticeable improvement to the passenger perception of stations whilst providing value for money in station investments. Part of this remit involves aspects of customer comfort and safety, including ensuring that the control of surface water runoff is efficiently and effectively managed. For this project Murphy Group were commissioned by Network Rail as the main contractor.

Clark-Drain has provided a total of 740m length CD 434 linear drainage channel for installation in three of the station‘s platforms to drain the surface water at a maximum rate of 4.6 l/s into silt box
traps before discharge into the mains.

The silt boxes work by retaining runoff to allow deposited silt to settle to the bottom of the basket before the water is discharged via the outlet pipe connection. The basket is located so that it is
easily removed for periodic cleaning. 

Both the channels and silt boxes are lightweight and designed for easy handling, installation and maintenance. The bodies of the channel are constructed from recycled hard wearing polypropylene to protect them from damage and ensure long lasting durability. A BS EN 1433 Class B125 quick-fit grating with ‘CatchLock’ retention system provides all the strength required for the 12.5 tonne loading it was designed and tested to withstand and perfectly suits high trafficked station platforms.

The narrow-slot ‘heel-guard’ design reduces the potential for tripping and slipping and provides a useful safety feature for passengers and rail staff.

The weight of each one meter length, at 5kg, made it very easy to install enabling Murphy Group Engineers to lay several lengths in one go for faster levelling and taking 25% less building time   than heavier polymer concrete options. 

As part of the aesthetic appeal of the platform refurbishment, the CD 434 was specified because of its flexibility to follow the curve of the platform edge, giving uniformity and enhancing the visual appearance when laid to the same contour.

In addition, the linear drainage channel was supplied with 450 x 450mm, 600 x 600mm and 750 x 600mm steel recessed covers and frames. These enabled 60 of the stations lighting cable access chambers to be securely covered and in-fi lled with the marble effect paving specified for the station floor as part of an attractive and functional design for the public to enjoy.


Lightweight – 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 – Lightweight 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.

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.

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

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.