DUAL-VOLTAGE CAPABILITY A MISTAKE

News Front

Speaking to Modern Railways at the launch of the service, Rob McIntosh, London North Eastern & East Midlands Route Managing Director at Network Rail, agreed that mistakes had been made during the planning of the project.

‘In essence we committed to a timescale and a cost for a project when we really didn’t understand what it was going to entail’ he explained. ‘People overlooked the fact that this was a pilot and we allowed it to become a political and commercial commitment.

That created a quite diicult dynamic within the project and the programme. People only wanted good news but if you’re doing something as innovative as this there’s going to be some bad news on the way, and that’s been a real challenge for us.’

One of the major hurdles, and a key contributor to the cost overrun, was the decision to use overhead line equipment capable of handling 25kV AC, which required the designing of some bespoke equipment and work to create clearances for the higher voltage, which turned out to be unnecessary. ‘If we were doing this again and someone asked if we could make it 750V DC but future-proofed for 25kV AC, I would show them the door and say “no thank you”‘ commented Mr McIntosh. ‘Sometimes these decisions are made with the best intentions without really understanding the consequences.

What that led to was the addition of a huge amount of cost and time into the programme. That decision is the key reason for the increased cost and the time taken for the programme to be completed.’ Mr McIntosh noted that adding in the future-prooing to allow for a change to 25kV in the future ‘…gave us more efort than the job itself. It was disproportionate.’

He also explained that the inal decision not to electrify at the higher voltage, despite the trams being constructed to work with it, was largely down to the realisation that this would have required a new National Grid substation.

This in itself would have involved a ive-year planning timescale and added around £100 million of cost to the project.

The use of 750V DC power has required the construction of a single new feeder at Ickles, roughly in the middle of the extension, although Network Rail accepts that this is only just about adequate, telling Modern Railways

‘The trams will stop working at 525V DC and at each end of the section we are below 600V. Any further extensions will require new feeder stations.’

Network Rail notes that in the time between inception and delivery the development of battery technology means that for an extension of this length lithium cells could have produced a cheaper solution, telling Modern Railways: ‘Going for a non-electriied solution would have taken around half of the cost out, and the business case dynamics would change overnight.’

LESSONS LEARNED

There was also some concern that lessons learned during the construction of the extension of the Tyne & Wear Metro system over Network Rail tracks to Sunderland were not taken on board, with one Network Rail source commenting ‘Whilst there is a diference between T&W Metro and tram-train, this is a tram that runs on the streets, running onto heavy rail tracks rather than from a segregated Metro network onto the main line. We could sometimes do with more corporate memory and too often we don’t look back to the lessons of the past when we do things.’

Despite this, there is a view that lessons have been learned from the project that can feed into future schemes such as those being discussed for Bristol, South Wales and Glasgow. However, as Mr McIntosh pointed out,

‘Network Rail doesn’t have to be the delivery partner.

We’ve found ourselves where everyone is asking Network Rail to deliver these things, and we could be a delivery partner, but we could be an enabler.

The role of Network Rail needs to be carefully considered with regard to how we do things.’ Mr McIntosh said NR is involved with discussions with various other authorities, adding: ‘The one thing I say to them all is “understand the passenger outcomes you want to achieve and understand the nature of the underlying assets. Before you commit to those outcomes be very clear about the path between the two because that’s where we got into diiculty on this job”.’