With track on the Borders project being laid at the rate of 1.3 kilometres a day, it took less than a month from the start of track laying for the new rails to cross into the Scottish Borders on 5 November. This was a newsworthy event as, since losing its last rail link 46 years ago, this region is the largest in the UK without a railway station.
October’s start of track laying on the UK’s longest new domestic railway for over a hundred years was also particularly newsworthy and so is unlikely to have escaped the attention of our readers. However, little has been said of the actual process for laying these rails and the logistics of supplying the vast quantities of materials required. The Rail Engineer was keen to find out more and so, on 11 November, spent a most interesting few hours with project director Hugh Wark to observe track laying close to Heriot, six kilometres into the Scottish Borders.
Borders track-laying uses a technique developed by BAM Rail of Holland which was used on the construction of the Dutch high speed line. This needs bottom ballast and sleepers to be in place beforehand. The 65 new single-track kilometres of the new Borders railway requires 130,000 tons of bottom ballast delivered to the trackbed by dumpers from local ballast stockpiles. Together with the 93,000 sleepers required, this is being delivered by road in around 7,500 lorry movements.
Once the bottom ballast is placed and compacted, surveyors paint a line on the ballast showing sleeper end position. The sleepers are delivered in bundles of five and are positioned by an excavator with a special grab that picks up five sleepers at a time. Before being placed in position, the grab spreads out to provide the correct sleeper spacing. In this way, one machine can lay around 650 metres of sleepers per day. The sleepers are pre-fitted with Pandrol Fastclips.
Although BAM Rail’s track laying technique is a slick process, it is not automated. Instead, it relies on a squad of about fifteen who work effectively together to operate the bespoke track-laying plant that pulls 108-metre rail lengths off the rail train’s delivery wagons and fixes them to the sleepers. Once this is done, the train moves over the newly-laid rail to repeat the process.
Switch and crossing units are laid before plain track. When track-laying reaches an S&C unit, rail is pushed off the train to butt up with the unit and is cut to length. In this way it typically takes from 09:30 to 16:00 to lay the twelve pairs of 108-metre rails on the train, although curves can take slightly longer. Hugh commented that this is slightly quicker than in Holland for two reasons. One is the use of class 66 locomotives which has a slow-speed control that can also programme distance to be travelled. This has proved to be a more effective way of positioning the train than the radio-controlled shunters used on the continent.
The other reason is that the Vossloh screw fastenings used on the continent take longer to secure the track than the Pandrol Fastclips.
From Scunthorpe to Scotland
Tata Steel in Scunthorpe is supplying 7,000 tonnes of rails to the Borders project. These rails are supplied on special trains of five wagons that carry twenty-four 108-metre rails. There are four such trains, one on site, two travelling to or from Scunthorpe on the National Supply Chain’s trunk route, and one being loaded at Scunthorpe. Crew and traction for these trains is provided by GB Railfreight and DB Schenker Rail, delivery is therefore ‘just in time’. Hugh explained that the provision of a buffer store would have been costly and that, to date, there had only been one day of track laying lost due to problems with train deliveries.
The rail trains have a Class 66 locomotive at each end and arrive at the folding buffer stop (as described in issue 119, September 2014) at the start of the Borders railway in the early hours of the morning. This arrival becomes progressively earlier as journeys to railhead get longer.
They then proceed to the nearest completed dynamic loop to the railhead at a maximum speed of 10 mph. There, the lead locomotive is placed at the rear of the train which is then propelled at 5 mph to the railhead where it is connected to the track laying plant. A train controller is positioned at the front of the train in a secure position with a safety harness, directing the movement with a fail-safe radio.
Scotland’s heaviest train?
A week after the rails are laid, the hopper train arrives with top ballast of which 90,000 tons is required for the project. This is a 30-wagon train with a class 66 locomotive at either end. Freightliner provides the traction and crews for this train.
At 2,900 tons gross, 1,800 tons net, this is considered to be amongst the heaviest trains operated in Scotland. However, as it originates from the Millerhill ballast stockpile, it actually travels for less than a mile on Network Rail’s current network.
With top ballast in place, the 108-metre rails can be welded together using a flash butt welding machine. The finished track is then tamped and the rails stressed after which an automatic finishing machine provides the correct ballast profile.
Each day sees the lengthening Borders railway carrying its rail and hopper trains and various on-track plant, including a machine to collect items left over from the track laying such as rail clamps and wooden sleeper packing. It is starting to become a real railway although, as yet, there is no signalling system. Instead there is a rail logistics coordinator at Millerhill who uses a whiteboard to authorise all movements on laid track and the hand- cranking of points on the dynamic loops.
Rails or sleepers first?
Prior to leading the Borders project, Hugh was the senior project manager of the Airdrie to Bathgate project. These two projects account for 101 new track kilometres, most of the UK’s new domestic railways in recent times.
In 2010, the 46 new track kilometres of the Airdrie to Bathgate project was laid using Balfour Beatty’s track laying train which, in contrast to the BAM Rail process, requires continuous welded rail (CWR) on the new trackbed before track laying. With such different techniques used on the two projects it was interesting to get Hugh’s views on their advantages and disadvantages.
Laying rail by the track in advance of conventional track renewals from a CWR train is relatively straightforward. However, this is not the case for a new railway. Hugh advised that, on the Airdrie to Bathgate project, track renewal was done in six-kilometre stages as this was found to be the maximum practical distance that rails could be dragged along the new formation.
An advantage of the Balfour Beatty train was that it avoids the need to deliver sleepers by road. The train carried sufficient steel sleepers for 1.2 kilometres of track, less if concrete sleepers are used. Laying sleepers in advance would have been problematic on the Airdrie to Bathgate project which, for various good reasons, had separate Civil and Track contractors requiring a formal handover of each section before track laying could start.
In contrast, the Borders project has only one principal contractor, BAM Nuttall. This makes it straightforward to position sleepers close to ongoing civil engineering work.
So which is the best technique? The Rail Engineer saw the BAM Rail team lay a pair of 108-metre rails in 35 minutes, which is comparable with the 200 metres an hour achieved by the Balfour Beatty train. Hugh explained that the track laying technique was the contractor’s choice and that there were only marginal advantages and disadvantages between the two systems.
On track for completion
Completion of Borders track laying, scheduled for early February, is a major project milestone. At the current rate of progress it is likely that this date will be achieved. However some risks remain including delays to rail trains and heavy snow, the only type of weather that could be problematic.
At the time of writing there were civil works at the southern end of the line, including Galashiels station. These will no doubt be clear of the trackbed when the rail train arrives.
Sadly a track worker was recently seriously injured as a result of a sleeper breaking free. As a result the project decided to stand down the site for five days to ensure lessons were learnt before work resumed.
As there is contingency for such unforeseen delays, the milestone of 10 May for commissioning, when the line comes under the control of the Edinburgh Signalling Centre, seems to be assured. Shortly afterwards is the scheduled project handover on 7 June when the line will become part of Network Rail’s system allowing commencement of driver training ahead of the start of service on 6 September.
Then, for the first time in nearly fifty years, the Scottish Borders will have a passenger train service. Much credit is due to those who have worked to make this happen, including the Dutch team which laid the rails for these trains.
An inscription on the track laying plant puts it another way – “For the finishing touch, God created the Dutch”.