Writes Dr Liesel von Metz, HM Inspector of Railways at the Office of Rail Regulation

The road-rail vehicle (RRV) has become a ubiquitous feature of engineering work on the modern railway.

Coming in many different guises, the RRV is fundamentally a road vehicle to which rail wheels have somehow been attached to allow the vehicle to convert from running on the road to running on the railway.

Many of the RRVs in use are 360° excavators, evolved from a base non-rail construction machine. During the past decade, the demands made of these machines have increased as they have become the “Swiss-army knife” of the railway. In response, RRVs have increased in size and theoretical capability, and layers of safety features and warning devices have been retro-fitted.

Every seven years, RRVs must undergo re-certification by a Vehicle Acceptance Body (VAB) along with upgrading to current standards so they can continue to operate on the Network Rail infrastructure. There is a significant maintenance requirement, and the rising cost of fuel (hence transport costs) has led to a trend towards more RRV maintenance being carried out on site. With many operators being on zero-hours contracts or working through agencies, and an inefficient work demand of peaks and troughs, it is little wonder the RRV industry is a challenging one.

Incidents – Causes and Solutions

There is a clear pattern of accidents and close-calls involving 360° RRVs, which fall into three clear categories:
– fail to stop (runaway)
– overturn
– collision with people.

In the past three years there have been over a dozen serious accidents involving RRVs, and findings from proactive site inspections by Inspectors from the Office of Rail Regulation (ORR) have revealed an underlying pattern of poor control of lifting activities and of the risk to people from RRVs. In consequence, some 23 ORR Enforcement Notices have been served on activities relating to RRVs on Network Rail infrastructure during this time, and ensuring that the industry deals with RRV risk has become an important part of the ORR Railway Safety Directorate’s work.

Common causes, common solutions

In response to this risk profile, and with strong encouragement from ORR, Network Rail formalised the RRV Safety Improvement Programme in the summer of 2011 as a cross-business initiative to drive rapid risk reduction in a number of clear areas agreed with ORR. These included the fail to stop risk of “high-ride” types, the overturn risk and the people-RRV risk.

Fail-to-Stop risk

There have been a number of incidents where “high-ride” type RRVs failed to stop and “ran away,” including those at Farringdon, Glen Garry and Raigmore. In all cases, the immediate cause was a lack of braking force caused by a loss of contact between the road wheels and the rail wheels. Whilst there were a number of reasons for this, these incidents would have been prevented had rail wheel brakes been fitted.

To address this cause, Network Rail are funding the development and fitting of rail-wheel braking to some 450 “high-ride” type excavator RRVs by December 2012. Also, following enforcement action by ORR in March 2011, Network Rail put interim risk controls in place (while rail wheel brakes where being developed) including more rigorous maintenance of the road-wheel/rail-wheel interface, restriction of the use of “high-ride” RRVs on gradients of 1 in 75 or steeper, and changed on-railing methods.

Three rail-wheel braking systems have now been approved and are being fitted, as reported in issue 89 of THE RAIL ENGINEER (March 2012). These are manufactured by AJH Plant, Rexquote and GOS

Overturn risk

The basic cause of RRVs overturning is from lifting a load that is beyond the capability of the machine. Examinations of incident causes, and observations from site, have revealed a culture that turns a blind eye to safety devices being switched off or overridden, the selection of machine by habit or cost, poor planning of the lifting operation, and a lack of competence amongst many of those planning lifting operations.

The solutions developed by the RRV Safety Improvement Programme have focused on combining the responsibility for planning the lift with the authority to specify the plant and lifting methods, and on ensuring that the lift planner is competent. Planning of lifting should be proportionate to the lift being undertaken, based on the site/load/machine/task, and realistic.

Hence, a new (non-Sentinel) role and competency of “RRV Lift Planner” is being created, with authorisation to prepare/amend RRV lift plans being taken away from crane controllers. The Lift Planner competence will be awarded through assessment or through training following a syllabus defined by Network Rail.

People and RRVs

There have been some serious injuries caused by people getting too close to an RRV when the operator did not see them. There are clear causes of people and RRVs being too close, including the machine operator having difficulty in communicating with the machine/crane controller, a lack of “exclusion zones” or ones which are unachievable, and sites which have no safe place in which to stand. This derives from poor site planning, lack of effective supervision and a culture in which people do not see a “yellow machine” as posing a risk.

Solutions include the use of duplex radio communications between the machine operator and the machine/crane controller. From March 2012, this is mandated on Network Rail infrastructure.

The RRV Safety Improvement Programme is also developing “simple rules”, so that people stay away from RRVs unless the machine is stood down, and hopes to integrate this into Personal Track Safety (PTS) training and Network Rail’s “Lifesaving Rules” initiative. Also being developed are systems for achieving a coherent plan to enable people to work and walk safely in engineering worksites in which RRVs are working or travelling.

Driving Change

In order to drive these changes home so they become the normal way of working, the RRV Safety Improvement Programme has piloted training to improve the skills of Network Rail staff tasked with site assurance. Roll-out of this training is planned for 2012/13. This should drive wider recognition, challenge and resolution of unsafe acts/states (for example lifting with a safety device over-ridden).

Identifying emerging risk

An advantage of Network Rail and ORR working collaboratively is the opportunity to identify emerging risk, such as Adjacent Line Open (ALO) working with RRVs. Lessons from mainland Europe highlight a number of incidents over the past 10 years where on-track plant (including RRVs) and passing trains collided during ALO working, and a close study of UK logs has identified near miss incidents and at least two collisions over the same period.

With the rapid increase in ALO working on the UK railway network, it is important to proactively seek to learn and apply the lessons of these incidents and near-misses. With ALO working, there is the opportunity to work to develop suitable methodology which delivers the risk control required by UK legislation. Of course, the irony is that when this initiative succeeds, most people will never know as it is extremely difficult to measure an accident prevented.

Progressing to Clear Risk Reduction

The RRV, in its current format, poses a risk to both railway and workforce. The challenge of achieving rapid risk reduction is significant but vital. Collaborative working between ORR and Network Rail on the RRV Safety Improvement Programme has shown how progress can be achieved when working together with a clear commitment to defined goals. An example of future collaboration is the work recently commenced on looking at safety control systems integrity being undertaken jointly by ORR, Network Rail and the Health and Safety Laboratory.

During the coming year, the developments put in place over the past six months should lead to a clear risk reduction during the use of RRVs on Network Rail infrastructure. As the industry seeks to work more closely together, perhaps this type of robust collaboration will be used to deliver other key changes. For its part, ORR is working to ensure that the RRV risks being tackled by Network Rail are addressed across the whole rail industry.