The 39 stations are operated by ScotRail
ASL will work in conjunction with Babcock Rail to replace the LLPA system

ASL Safety & Security are working with Babcock Rail in Glasgow to replace Network Rail’s legacy long line public address (LLPA) system at 39 stations operated by ScotRail around the city centre and surrounding urban areas as part of an infrastructure upgrade.

ASL’s VoIP-based iPAM long line PA solution is operating from intelligent amplifier mainframes installed at individual stations encompassing an area as far as Newton, Barrhead and Neilston. Amplification is provided by highly efficient modular amplifiers using proprietary Adaptive Class-D technology.

The IPAMs combine routing, Ethernet connectivity and loudspeaker line monitoring in a compact 2U fanless frame which is rigorously tested for rail and other transport infrastructure applications. The Glasgow project uses iPAM400 amplifier units running the VIPA operating system. VIPA is ASL’s scalable Voice over Internet Protocol (VoIP) public address software, a library of IP-enabled solutions such as text to speech, message fragment storage and multicast functionality for Windows and Linux platforms.

ScotRail’s operational hub for the area is at Paisley. Here, the operator oversees the system’s front end using ASL’s mini-iVENCS® PA/VA control and monitoring platform which offers real-time display of announcement zone status and translucent overlay of customisable PA/VA zones. iVENCS® uses distributed architecture with a messaging backbone based on the Open Source XMPP messaging and presence protocol.

Ian Findlay, Senior Project Engineer at Network Rail, said: “The adoption of this innovative technology in our stations will deliver a reliable and high-quality service to the travelling public and make journeys a more enjoyable experience by providing clear, up-to-date train information.”

ASL’s iPAM400 amplifiers have been developed specifically for rail projects where close integration of PC/DVA (Digital Voice Announcements) with Customer Information System (CIS) functions is called for. Operators and maintainers receive status information on all PA equipment via mini-iVENCS, with a seamless upgrade path allowing related safety and security subsystems such as CCTV, access control and passenger help points to be controlled and monitored using the same 2D or 3D GUI.

Peter Andrews is ASL’s Head of Projects.  He said: “Babcock Rail, in cooperation with Network Rail, has put together a well-engineered solution and a delivery team who are committed to working with ASL and Cisco as suppliers to provide an equipment replacement strategy that guarantees high-quality message delivery while working reliably on legacy copper.  Another notable success was Network Rail’s unusual decision to record announcements using a member of staff. This has introduced a bright, fresh and friendly accent to Strathclyde’s commuters.”

He continued: “In contrast with the previous generation of public address systems, VIPA allows assembly of message fragments at the station level. Operators are merely triggering data that is stored locally. Telecoms engineers will immediately recognise the bandwidth efficiency and built-in redundancy of this approach.”

Babcock Rail is the Glasgow-based rail division of Babcock International. It is a major player in the UK rail infrastructure market, delivering track renewals works, signalling and control systems as well as rail power solutions. Babcock is the largest track renewals contractor in the UK.

Network Rail is the rail network infrastructure owner and maintainer, and is Babcock Rail’s client for the LLPA equipment renewal project.

ScotRail is a member of FirstGroup plc, Britain's leading transport provider. The company operate 95% of passenger rail services in Scotland, providing 2,000 services a day. ScotRail also operates all but three of Scotland's 344 passenger stations, of which 142 are staffed.