The development of class II systems wouldn’t have been possible without the cooperation of equipment manufacturers. A number of companies are involved in the project, and class II enclosures and other products are now available. Peter Dickson of iLECSYS explains what it means to the supply chain:

“New technology is born out of necessity, the needs may be varied but often follow a pattern of faster, cheaper and more reliable. The momentum of the new technology is often maintained by justification, sometimes legislation and more often the concept of a new idea or product being better than the existing one.

“The necessity behind the Class II system may follow this same pattern; however the impact and momentum generated seems to have gone far beyond the vision of those at the conception. The technology itself carries a long list of ‘tick boxes’. The concept of double insulated switchgear is not a new one, sectors with the utilities and renewable energy have embraced the ‘touch safe’ concept for a number of years .

“Working in the world of composites and double insulated enclosure solutions, the requirement for a class II 650V Signalling power supply enclosure has rather ‘landed in our lap’. That said, by supplier standards, we are new to the rail industry and therefore are very mindful of the learning and listening that must take place in order to embrace the needs of a new business sector. One message we picked up on was to consider a non-metallic solution to trackside equipment and therefore reduced dependence on earthing.

Collaboration is the key

“Putting aside the product, for us the impact of Class II is clearly a major catalyst for a new level of supplier engagement, such is the level of innovation ‘whipped up’ by the new technology. There is now a clear platform on which suppliers and Network Rail technology work groups can get round the table, and innovate together. When the mind is opened fully there are always more answers than questions. This has been our findings in the various meetings with work groups. Practical, collaborative engineering, allowing a balance of innovation between suppliers and their customer does seem to open doors and generally leads to the right product hitting the streets.

“Getting new technology moving, whether at systems or product level is the hard job. Once the concept of change is on the move it becomes vital to keep the momentum. It is clear that innovation and the adoption of new technology is dynamic and has now spawned new workgroups looking at sustainability and further improving trackside safety.”

iLECSYS is one of a number of suppliers which have whole-heartedly embraced the class II concept. The new Class II POWER BLOCK is a family of Class II 650V switchgear units built from essentially off the shelf components. The range covers all the applications within NR/ELP/27409 and also offers the switchgear fully enclosed in Network Rail PADs approved composite enclosures. Specific designs are available for legacy equipment cases and all the units will be available with Cu and Al compatible terminals up to 150mm2.

Robust SafeBoxes and SIGBoxes

Henry Williams has introduced a range of Class II SafeBoxes, named after their robust electrically insulated construction and the safe switching arrangement which is all on one level and removes the need to move live 650V parts to isolate the feed. The form 4A construction of the box also allows for the upper chamber to be isolated so that all of the fuses are safe whilst the loop in and out function of the box remains live.

This product was designed from first principles and manufactured totally in house. Tahir Ayub and Ernie Brigden of Network Rail assisted the Henry Williams team in drawing up the specifications and during the development and product approval process.

CSE Rail, a brand name of Control Systems and Equipment Ltd, used the new Network Rail specifications to develop a class II version of its well-known SIGBox range in the same space envelope as the original units.

The basis of the design was to blend the robustness of metal with the insulating properties of plastic. This was achieved following in depth research and the development of RailcoatTM. Utilising a mild steel chassis along with a special cleansing process before application of the insulation allows a dielectric strength of 6000 volts to be achieved.

All the class II SIG Boxes have the same form fit and function design of the previous solutions ensuring a legacy fit and featuring the double insulated coating providing protection against electric shock.