BACKGROUND – AN OVERVIEW OF THE CURRENT SITUATION
In May 2015 RSS were asked by Carillion Rail working near Kettering Station in Northamptonshire to provide adjacent Open Line ALO Safe System of Work using ATWS. This area consists of 4 lines known as the Down fast, Up fast, Down slow and Up slow. They were having issues with carrying out the renewal of the Up Fast between St. Pancras Station and Tapton Junction.
The Down slow being the ALO, could only be taken under possession during the night and had to be open to trains by 0800. Line Blocks were considered, but not appropriate as they would have caused problems for the train operators. This led to a short window of opportunity to complete the work with machines working ALO.
SOLUTION – HOW WE IMPROVED SAFE TRACK ACCESS
At first we were asked to use ATWS with Special Application (detonator protection) on the Down slow where some sections are Bi-Directional. Special Application of ATWS means detonators are used along-side the ATWS so if a train has to be stopped on the approach to the warning zone / dig area, detonators would explode causing the train to stop safely.
However, signal LR62 on the Up slow would have caused complications during the operation of the ATWS in Special Apps mode as a Signallers Instructions would need to be in place. After discussions with Carillion and the Signaller the plan was to drop the Special Application aspect and to use ATWS for machine warning with EWK warning devices mounted on the OTP.
A Signallers instruction would need to in place to prevent trains setting back once initiating the warning.
CONCLUSIONS / RESULTS – WHAT BENEFIT WAS THIS FOR THE CLIENT
The ATWS was successfully used and the renewal of the Up Fast was completed on time and without incident. This Safe System of Work proved to be successful without the need for Line Blockages being taken allowing the OTP to work more effectively with minimum stand down time. Carillion Rail have used ATWS on regular occasions in the past for ALO working and have always found the system to be safe, reliable and beneficial to ALO working reducing the need for line blocks.
Without the ATWS in use the 400 yard renewal would have been reduced to a mere 200 yards, so conclusion is a 50% increase in productivity.