Road-rail vehicles (RRVs) are now accepted parts of the railway engineer’s tool box, often preferred to rail-bound equipment. They can be brought to the nearest access point to the work-site by road, without the problems of special routing, making them especially valuable in emergency situations.
However, the disadvantage of RRVs is that they need space at the access point to actually get onto the track. A review in 2011 revealed that, apart from at level crossings, Wessex was not best served for RRV access points.
Therefore, early in 2011, Network Rail Wessex decided to provide additional permanent road-rail access points (RRAPs) at strategic points throughout the Route. The project, led by Robin Cooper, set out to provide 36 permanent RRAPs by March 2014. It was important to Network Rail that these access points were designed to the highest standards, with a planned life expectancy of 30 years.
Typically, RRAPs are 9.9m long (measured along the track), and will have reinforced concrete aprons between the tracks and at the access point. Nine have already been installed, at Walton-on-Thames, Ewell West, Bracknell, Farnham, Esher, Oakley, Kingsworthy, Weston and Upwey. The highest profile RRAP will be at Nine Elms, about 2 miles out of Waterloo on the main lines to Portsmouth and Windsor. It will cross six tracks, and will have a significant impact on Network Rail’s ability to do work efficiently in a crucial part of the Wessex Route.
Occasionally, when designing RRAPs at the most advantageous locations, obstacles such as platforms or S & C units need to be overcome. In these cases two RRAPs are built, one for initial access onto a single track, the second well away from the obstacle with decking across multiple tracks. This second crossing will allow RRVs to change tracks.
Having considered options for within the 4 foot, innoSTRAIL rubber crossings became the preferred system. Each crossing is a mat of full-depth textile-reinforced rubber panels. The recycled rubber is vulcanised, a heat and pressure process which fuses rubber granules into a homogeneous mass, making each panel extremely tough with properties similar to those of vulcanised vehicle tyres. As with all STRAIL crossings, the interlocking panels are tied together with full-length high-tensile steel rods and the addition of mineral grit provides a skid resistant surface.
Occasionally there are two or more different types of sleeper in the same crossing, in which case tapSTRAIL is recommended as it can accommodate different sleeper shapes.
Each RRAP is individually designed following an initial scoping visit carried out by Robin Cooper. As Wessex is mostly a third rail electrified system, a conductor rail gapping design is completed in house by the EMP Woking team run by Dean Moss.
A detailed design proposal is prepared by STRAIL (UK) Ltd. The Strail design will identify key variables, such as rail section, sleeper and fastening type, the number of tracks, geometry and cant, which will be taken into account in the manufacture of the innoSTRAIL. Sleeper spacing is not significant because both innoSTRAIL and tapSTRAIL are independent of it.
Once all is agreed, Network Rail places an order for the crossing components and issues an invitation to tender for the installation work. Approved installers include B & M McHugh, Dyer and Butler, Keltbray and Amco.
If all goes according to plan, by the end of March 2014 Wessex will be able to move road-rail plant and equipment quickly to wherever a new task presents itself, thus bringing the seven day railway one step nearer to fruition.