The purpose of signal and sign sighting is to ensure that a train driver is able to quickly and accurately read and interpret information provided by a signal controlling the movement of their train so that the driver can take appropriate action.
At line speed, in variable lighting and weather conditions, with varying demands on the driver’s attention and with a multitude of other signal and signs controlling other adjacent lines, this is not a trivial task.
The signalling design engineer (SDE) and the signal sighting committee, comprising stakeholders from multiple organisations, need to sign off the signal or sign sighting form. This is typically achieved by reviewing the proposed technical design, by considering operational use cases, assessing associated sighting risks and by the committee undertaking a site visit.
The signal sighting process is undertaken either as part of a signalling scheme design process or following a reported Signal Passed At Danger (SPAD). Clive Kessell’s article elsewhere in this issue describes the latest thinking on this topic.
Different paper and electronic tools exist across the rail industry to support the production of sighting forms to Network Rail standard ‘NR/L2/ SIG/10157 Signal Sighting’.
The problem with spreadsheets
The existence of different tools (from paper to spreadsheets) with corresponding variations in sighting form layout and content, combined with local process variations across the Network Rail routes, signalling design centres and sub- contractors, meant there was an inconsistency and a lack of standardisation.
SSiFT v2 was a complex spreadsheet-based sighting form that attempted to address the issue of standardisation, with only partial success. This was because users were still able to edit the sighting form, increasing the risk of introducing computational errors as the spreadsheet increased in complexity.
Spreadsheet-based sighting forms also suffered from manual version control and the industry had no easily searchable centralised repository for electronic sighting forms. It was also impossible to identify if parallel design activities were being undertaken on the same signalling asset by two different teams or organisations.
The process of creating a signal sighting form was also time and effort-intensive with information having to be manually re-entered from other design tools. The sighting committee also could spend significant time on, potentially, multiple site visits, with their inherent safety risks.
Through the Network Rail Signalling National Innovations Portfolio (SNIP), SIG is delivering a suite of integrated signalling design tools.
The purpose of these tools is to enable signalling scheme designs to be quickly, easily and iteratively created, updated and shared between different design tools without any manual re-entering of information. This is achieved using Network Rail’s System Design Exchange Format (SDEF) XML schema.
Another objective is to reduce the requirement to attend site visits by developing tools to allow site surveys to be undertaken from the designer’s desk. This removes exposure of staff to risk trackside, reduces cost and saves time.
The SNC-Lavalin Rail & Transit team delivered SSiFT v3 in April 2015 and it fulfils each of these objectives. It is a web-based solution powered by SNC-Lavalin’s clyx.net rail industry portal.
It can be accessed using any standard web browser (IE11+, Chrome, Firefox) and is available to any authorised organisation that undertakes signal-sighting activities in conjunction with Network Rail assets.
It offers designers the ability to quickly and easily create sighting forms, either manually, using an Excel template batch-based import feature, or an SDEF import feature from other design tools. Automated form creation allows up to 70 per cent of the form to be created with no additional input from the user. Forms have defined versions and a workflow process manages draft, published, withdrawn and superseded forms. It also identifies and supports parallel design activities where this cannot be avoided.
The user interface was designed to be intuitive, validated through user-driven human factors testing. Batch editing functions allow custom groups of forms or forms for a specific project to be edited in specific ways at the click of a single button.
At any time in the design process, a sign or signal sighting form can be generated by the user, which delivers a professional PDF document in less than one minute, either by email or by download from the website. The designer is also able to generate an output SDEF file to allow additional design information determined using SSiFT v3 to flow onward into other design tools.
A training version was also delivered, allowing users to practice, learn or experiment in safe environment away from the master database.
To streamline the signal sighting process where there remains a need to visit a site trackside, there is also a fully integrated mobile application for iPad and iPhones. This allows the designer or signal sighting chairman to prepare the form in advance, download the data to their device and then undertake site based activities whilst updating the form (photos, geographic information, distances). Upon completion of the site visit, the form can be re-synced with the website seamlessly at the touch of a button.
SSiFT v3 has enjoyed a high level of adoption across Network Rail and the wider industry, with currently 150 active users across 17 different organisations. Adoption within Network Rail continues to increase as projects and routes make the decision to switch to it. In the last 12 months 526 sighting forms have been published within SSiFT v3 with another 1,162 draft forms currently being worked on.
Users have reported significant time savings being achieved with examples such as 20 sighting forms being produced in two hours (six minutes per form) rather than two days/14 hours (42 minutes per form). If this typical time saving is applied to the 1,688 active forms in SSiFT v3, it would represent an estimated total time saving of 1,012 person hours or 145 person days.
These efficiency improvements lead to time and cost savings through SDEF integration, substantial automation and batch editing of forms. Savings are also delivered through the seamless and immediate integration between desk and site work offered by the SSiFT mobile app. Control and ownership of the form and the underlying data is clearly retained by the designer and the project.
Through integration with other SIG design tools, fewer site visits are required and less time is spent on site. This increases safety and reduces staff exposure to trackside risks.
During the first 12 months, a wide range of user- driven changes and enhancements have also been delivered by the SSiFT v3 project team, further increasing automation, standardisation and flexibility. Network Rail and SNC-Lavalin are keen to maintain the user community’s enthusiasm by remaining responsive to their needs.
In July 2016, the project team will commence work on further user-requested high priority enhancements to SSiFT v3, due to be deployed in late summer 2016.
A revised signal sighting standard at Network Rail is expected to be introduced in late 2016 and the impact of that on SSiFT is also being evaluated, with further substantial features (such as assessment plans, competence and electronic signatures) and enhancements being considered to more closely integrate with Network Rail’s design processes. Network Rail is also considering the use of SSiFT v3 for managing the master signal or sign sighting record nationally.
Looking further ahead, it is possible that the SSiFT mobile app will be made more widely accessible via mobile phone devices and, potentially, other platforms.
Written by Simon Perkin, section head – systems and information solutions at SNC-Lavalin
This article was first published in September 2016.