LEVEL CROSSINGS: RUBBER OR CONCRETE? WHY ARE RUBBER PLATFORMS WINNING?

June 2005

Ever since the demise of the old slatted timber crossings, specifiers were limited to choosing concrete and asphalt replacements. Of course, asphalt is no longer deemed a surface sufficiently able to withstand traffic loads and meet safety requirements and so concrete platforms became the standard platform.

However, across the European networks there is a growing trend for engineers to replace concrete platforms with rubber crossing systems. We examine why.

There are around 9,000 level crossings in the UK with approximately 8,000 crossings on the mainline network, controlled by Network Rail. Level crossings on heritage railways and those within factory premises and docks, etc account for the balance. Of these, most are concrete based platforms. However, this is all changing.

The recent renaissance in the reputation of rubber follows a chequered history since its introduction some twenty five years ago, when US based OMNI and a German company were the only global manufacturers.

With the growing pressure to reduce road closure times, engineers were keen to test these new rubber surfaces. However, the obvious advantages in installation and tamping simplicity presented by these new modular systems were dogged by recurring problems relating to poor skid values, white lining adhesion and panel gapping (already a major issue in concrete crossings).

Indeed, for some years the predominant reason for choosing a rubber system would be speed and ease of installation and removal for tamping. There were otherwise few other benefits in choosing rubber.

There became a desperate need to improve the design and manufacture of rubber crossings to counter gapping and skid resistance problems. It is, indeed, new manufacturing techniques and a series of innovations which have now turned the tables and secured a bright future for rubber platforms.

Furthermore, it is a UK based company, HoldFast Level Crossings, who are recognised as leading these developments.

Such is the success of their system, they now export to 19 countries. They have been awarded the Queen’s Award for Innovation and were awarded Rail Supplier of the Year last year.

HoldFast’s Managing Director, Peter Coates Smith, explains: “An inherent weakness of early rubber systems was the need for a surface layer which was a weakness and could peel. Small panels and complicated fixing systems further weakened the crossings.

“We engineered production plant to manufacture panels as 100% solid recycled blocks of rubber. We also made the decision to reduce the number of components and make the panels larger to reduce the number of joints and improve stability. This does make the panels very heavy but we have recently introduced the HoldFast Lifting Pins to counter this”.

SAFETY
Level crossings represent the highest risk of a multi-fatality railway incident. The vast majority of level crossing incidents are caused by crossing users. Between 1993/94 and 2003/04 there have been 449 train incidents at level crossings, with a total of 130 deaths and 336 injuries.

In 2003/04, 17 members of the public were killed using level crossings, the highest figure since 1991/92. Of the members of the public, 8 were occupants of road vehicles and 9 were pedestrians, struck and killed while using the crossings.

In this context, it is clear that safety has become one of the key drivers in the trend towards rubber platforms. Coates Smith has spent some 20 years campaigning to improve safety at level crossings and is delighted to see the safety benefits of rubber being recognised by the networks.

He explains: “Over 90% of HoldFast’s crossings are now replacements for concrete systems where a combination of gapping between panels, crumbling, an uneven surface and track circuitry failure have created safety hazards for road and rail users.”

INSTALLATION
All engineers will be aware of the pressures to minimise road and track closures! This is where, time and time again, rubber is the winner.

Concrete crossings are inevitably cumbersome and take at least two full working days and a whole team of men to install, with the additional use of heavy machinery making the whole process long, drawn out and expensive.

CAREFUL
In contrast, modular rubber systems comprise of panels that will simply drop into place. A 40 metre crossing can be installed or replaced in three hours without the need for overhead electrical isolation. This is proving a major commercial attraction in selecting rubber.

Crossings can be delivered and off loaded direct from manufacturing plant to the installation site on the day (or night) of installation. This reduces fuel and road freight requirements.

HoldFast’s system does not even require bolts or screws. Instead, just small rubber backed base plates are used to sit (not fixed) on every fourth sleeper. This allows individual panels to be removed and replaced easily and quickly without disturbing adjacent panels, a considerable advantage when undertaking local track inspections.

TAMPING
The speed of routine removal and replacement of rubber crossings is no better illustrated than at a particularly complex crossing at Gloucester. The five track crossing comprises many full depth panels, but it took just two and a quarter hours to remove and stack two of those tracks prior to tamping them and no longer to replace.

The contractors, Fifth Rail Ltd, lifted out the panels using a p-ray bar on each of the panels and with just one man on each they levered the panels out without any mechanical assistance. They were then numbered and stacked and with a little lubrication (soap) the panels were easily re-inserted, without the need of even a JCB! As those of you who have been involved with tamping through concrete crossings, there is no comparison!It is estimated that there are now over 15km track of HoldFast’s rubber crossings alone installed on the UK network. Underpinned by the obvious benefits over concrete achieved through the accumulation of years of experience and product innovation, it is clear that rubber has finally come of age as the engineer’s preferred crossing choice.