Ask anyone today how long electronic systems are supposed to last and the answer will likely be between five and ten years. Technology advances so quickly that equipment rapidly becomes outdated.

Manufacturers love this situation and sales personnel are geared up to telling customers that systems will not be capable of being supported for very much longer and therefore it would be best to plan a replacement right away. None of this sits well with railway philosophy, where a 40-year life for trains and signalling is regarded as the norm.

Have you been taken in by this obsolescence approach? Probably, but is it right and is there an alternative?

The London Underground scene

Like many long established metro systems, London Underground has a plethora of telecom assets from many different manufacturers which supplied systems on a project-by-project basis as new and upgrade work was authorised. The result is a variety of assets across the network, many of which are showing reliability problems with the associated challenge of keeping systems in service. Whilst most are infrastructure-based, a growing number are train-borne, making the challenge even greater as responsibility for service continuity involves more than one department.

Warwick-based communication specialist Telent Technology Services often supplies new telecom systems with ongoing support services, but it has also gained many maintenance contracts for existing legacy equipment.

Telecommunications means much more in a railway sense than just telephone and data systems. The portfolio includes customer information systems (CIS), CCTV
for both security and platform monitoring, video recorders, passenger help points, public address including long line application and voice alarm usage, access control equipment, fire detection and alarm systems plus telephones and associated concentrators.

Typical of this diversity is the Northern Line system providing CCTV monitoring of platforms with an in-cab display enabling the driver to ensure no one is trapped in a door before the train moves off. Transmission between platform and train is by means of a radio wireless link so the system is quite complex. It is classified as a safety-critical activity and getting it wrong can result in injury or even death, so reliability is absolutely essential.

The equipment was 15 years old and reaching the end of support from the original manufacturer. Replacement with new equipment would be expensive as well as being operationally disruptive. Telent reviewed the options and put forward a proposition that would extend the life of the system for a further 15 years, thus avoiding the disruption and capital investment.

Extending life

There is no magic bullet for this. A number of ways of achieving life extension are possible, including:

  • Obtaining a ‘last time’ buy from the original manufacturers before the equipment goes out ofproduction;
  • Obtaining equivalent components and design these into the system – normally at assembly board level but this can go down to individual components under certain conditions;
  • Designing a replacement unit that can be integrated into the existing system and use the displaced items as a source of spares for other units in the system;
  • Sourcing a second-hand component, but great care needs to be taken to ensure that any replacement is fully tested and possibly enhanced before being fitted;
  • Bespoke servicing of systems, once data sheets and service manuals have been obtained;
  • Finding partners who can assist with the environmentally controlled storage of components.

Importance is given to the creation of a risk register for every asset as there needs to be a rigorous test regime set up to determine whether the work will be acceptable.

This includes such factors as temperature, fan control and dust ingress. Sometimes, this will mean destructive testing of the replacement component to ensure all those stocked are still fit for purpose.

Often the units of a system are mounted in purpose- built housings that fit in with the ‘ambience’ of the station and architects and environmental managers get upset if a new housing is proposed. Thus re-engineering often has to include the physical as well as electronic aspects of the installation.

Analogue versus digital

Another public perception is that analogue=bad, digital=good. We have been conditioned to believing everything digital is state of the art with good performance and reliability. It is a myth, and many analogue systems give equal or even better performance than their digital equivalent.

However, the supply industry is geared to designing new products around digital technology and analogue hardware is increasingly difficult to obtain. The challenge is to keep a system in good working order without having to replace everything. This, of course, requires a detailed knowledge of the system infrastructure and subsystems.

In one recent example, at Canary Wharf, on the Jubilee line, the CCTV cameras were replaced with digital ones. Telent fitted these with a bespoke ‘software box’ to fool the control system that the cameras respond to the same analogue commands. This solution allowed full reuse of all the existing legacy cable and infrastructure, and enabled a complete changeover in engineering hours without a single period of operational disruption. The recovered cameras were then overhauled and used as spares for the rest of the line.

Getting the expertise

Having the knowledge to delve into the electronics and workings of a legacy system takes a special kind of person. Generally, these will be seasoned engineers who probably started their working life as a field technician and have first- hand experience of installing and maintaining electronic systems.

They will have instinctive knowledge of how the system operates, how the various individual components are connected together, the test equipment required to measure performance and a geographical awareness of where other similar systems are still in operation so that a source of spares might be found. These people are qualified in the ‘university of life’ and know all the tricks.

However, nobody lives forever and Telent is mindful that younger engineers will be needed to take over from the ‘old hands’ as they retire. Thus, apprentices and graduates are being recruited to learn the tricks of the trade and ensure an ongoing retention of knowledge.

Work will need to embrace both on site replacement/testing plus workshop-based activity for failed component repairs. In London, Telent rail operates from two sites – one at Canning Town in the East End, which is the main depot, the other at Feltham in the west. Software development is undertaken at the company’s main HQ in Warwick.

The work is broadly categorised as ‘reverse engineering’ and is seen as a growing business stream. At present, the team is about 10 people but this is set to grow as more customers become aware of the advantages.

To pay or not to pay?

Does all of this make financial sense? Certainly, from a customer perspective, it does since expensive and premature renewals can be avoided. For Telent, it is very much mix and match and will depend on the maintenance contract put in place.

London Underground has different contracts for different lines. The Northern Line track-to-train CCTV contract, for instance, is a whole-life contract with all the obsolescence and reliability risk being borne by Telent. On other lines, obsolescence management is a joint activity with LU.

Where reverse engineering makes sense, Telent will sometimes bear the cost in house. The value of ‘goodwill’ must not be underestimated and is part of the company’s business philosophy of delivering ongoing value and service excellence.

Whilst this article has centred around London Underground, Telent is a business that extends way beyond the rail sector. The BT System X digital exchanges date from the 1980s, and this is another technology where the obsolescence factor is a major worry. Similar reverse engineering work has been adopted for both hardware and software, leading to remarkable new innovative ‘products’ being introduced from which the general public gains benefit as everyday users of the telephone network.

The Telent MICA system for station management, as described in issue 147 (January 2017), is there to integrate different types of legacy equipment into a single control package and act as the hub for the convergence of digital systems. It’s all part of driving new levels of efficiency into the infrastructure whilst also managing the obsolescence problem.

Telent would like customers to be mindful of the term ‘vendor agnostic’ in the hope that readers, seeing this article, will think twice before committing to a full blown renewal programme when valuable life remains in the existing equipment. It’s an important message.

Written by Clive Kessell

Thanks to Reg Cook, Telent’s director for asset management, and to Adil Kazmi, obsolescence and reliability manager, for their thorough explanations.