Power BoxTM History
There has been a long-standing problem of terminating large power cables into small isolating devices within location cases.
The original development of the Power Box goes back to 1995, when ABB Switchgear Ltd. and Bussman Fusegear Ltd approached us. They asked us to try to come up with a solution to this problem, using their products, which were approved and accepted by British Rail. We took some original British Rail wiring schematics for power distribution in location cases as the basis of our design. The result was the early Power Box.
Traditionally, inside location cases, separate isolators, switchfuses and fuses have been used to connect the signalling transformers to the incoming power supplies. This method takes up a lot of space and is not mechanically or electrically ideal. After an initial delay, in 1997 Railtrack North West looked at our proposals and as a result of their input and our further development, the first use of the Power Box was on the Manchester Victoria line in 1998.
We called it the Power Box because it seemed like a good idea at the time. SIG 3 came from the fact that it was used on SIGnalling systems and 3 because there were three isolating switches in it.
With the experience gained from that project, the input from installation and signalling engineers, the Power Box was further developed. It subsequently became used on many new installations, upgrades to level crossings, points and signal boxes.
The use of the Power Box has reduced the space required inside a location case for power distribution and management. This has allowed more space to be allocated to signalling components. In some cases, this has resulted in less location cases being required which in turn has saved a large amount of money. Using less location cases means less trackside space, less concrete bases, less installation and less money.
The Power Box has also been used on a considerable number of individual ‘one-off’ sites as an upgrade or retrofit to an existing location case. We have also supplied Power Boxes for use on Hong Kong Railways.
We approached Railtrack on more than one occasion with a view to gaining formal product acceptance and approval. As the Power Box has proven to be a very versatile device with many standard as well as ‘one-off’ versions, there did not appear to be a specific specification within the Railtrack system, against which the Power Box could be assessed.
The advice from Railtrack was, that as the unit is used within a location case, it is up to the location case supplier, (i.e. the signalling contractors), to take the responsibility for the location case and its internal components. They said if the contractor was happy to do that, then Railtrack would have no objection to the use of the Power Box.
Railtrack advised us that as the Power Box has already been successfully used on the Railtrack infrastructure and has been accepted and signed off by a Railtrack official, it now has a ‘Service History’. As such, it can be ‘cross accessed’ between the various zones and used by them on their own projects. At the time, Railtrack also said they were trying to promote closer relationships between their zones and were keen for products to be cross-accessed.
We continued to supply contractors with the Power Box in ever increasing numbers and developed the original design further to produce a family of products. The variety of the range offers the contractors a standard product that satisfies the majority of applications found on the infrastructure.
In the autumn of 2003, the Power Box was proposed for use on a specific section of the rail system infrastructure. The end client insisted only formally approved equipment could be used on this section of line. This brought to a head the whole issue regarding the approval of the Power Box.
With the demise of Railtrack and the creation of Network Rail, a decision was reached regarding the approval of the Power Box. After all the time trying to get Railtrack approval, Network Rail decided that as the Power Box uses established components, already being used on the rail infrastructure, it does not need specific approval through the product acceptance system. A letter to confirm this was received in November 2003, a copy is available for inspection if required and it is also published on our website. A number of SIG 5 Power Boxes were subsequently used on the Channel Tunnel Rail Link.
Autumn 2003 also brought the introduction of a specific web site dedicated to the Power Box. It is called ‘www.powerbox.org.uk’.
Spring 2004 saw the introduction of the SIG 8 and the SIG 10 .The SIG 8 has all the features of the popular SIG 3 but is fully enclosed and has universal fixing brackets for mounting in a traditional Location Case or surface mounting on a wall. The SIG 10 also has the features of the SIG 3 and has universal mounting brackets but with externally accessible isolators and fuses.
January 2005 saw the introduction of the Mark 2 range. This essentially is just an up dated version of the original designs. The main features are the addition of test points for the mains, captive fuses and reversible fixing brackets as standard.
The continuing popularity of the Power Box prompted the appointment of distributors. Unipart Rail, (formally NRS), have allocated their own numbers for the Power Boxes.
Various additional versions of the Power Box were introduced throughout 2005 and there are now 32 ‘Standard’ products to choose from. Network Rail had been monitoring the progress of the Power Box for some time and became actively involved with its evolution. They have offered suggestions and comments regarding applications etc. and many of these have been adopted into the products. The SIG 20 offered a number of innovative ideas such as a removable cross member to allow easier installation of large cables.
During 2005 we introduced the electrical safety device known as the RemLive. This device is in the final stages of Network Rail approval.
Development of the Power Box is on going and there are projects where it is installed in preference to FSP’s and saved Network Rail considerable amounts of money.
2006 has seen the Power Box become the preferred method of managing location case power in the industry and it is now a standard product with many signaling contractors and has been specified by Network Rail. The SIG 20 has become our most popular product. We also received our largest single order for over 300 units.
The REBBox was introduced in mid 2007. This product is for specific use in REB’s and similar applications such as signal boxes and stations. It was an instant success with orders received immediately on it’s release to the market
|
