It is midsummer in the UK, and here are some extracts from the news on the evening of the 28 June 2012:
“Major disruption has been caused by unprecedented levels of rainfall causing flooding and landslides which have cut off both main rail lines connecting Scotland and England. The West Coast line has been closed by a landslip at Tebay in Cumbria as well as flooding at Oxenholme Lake District station. Buses have replaced trains between Lancaster and Carlisle, adding about 60 minutes to journeys.
“On the East Coast line, a landslip near Berwick-upon-Tweed has caused serious disruption and added two hours to journey times. No trains are running between Durham and Berwick-upon-Tweed and no replacement bus service is available. Newcastle station is closed by a spectacular storm similar to those normally seen in the American mid-west. There is widespread flooding and a lightning strike has knocked out signalling.”
Flooding off the railway
One can’t help but feel sorry for the beleaguered passengers but, while reading this article, consider the pressure that the local engineering teams must have been feeling. Not only did they have to find engineering solutions for the myriad of problems that were emerging, but they also had to deal with other logistical problems caused by flooding in the area, such as roads and bridges being blocked or washed away.
How did they get essential items of plant and materials to sites, as well as the skilled workforce needed in such situations? The challenges become even more significant in view of the personal circumstances that many of the workforce were facing, having to deal with their own meteorological disasters on a domestic level.
To gain a better understanding of the difficulties involved, the rail engineer spoke with two senior Network Rail engineers about their experiences during this time.
Major roads blocked
Michael Ewart is Network Rail’s route infrastructure maintenance manager for London North East and the East Coast Main Line (ECML). Michael lives on the north side of Newcastle which experienced 93mm of rainfall in three hours – the normal monthly rainfall is only 60mm. He said that he has never experienced anything like it before. Not only were many parts of Newcastle closed to traffic but also the A1 road was impassable in many places. Just getting around the area to find out what was going wrong became a major challenge in itself.
There were many sites that were causing concern on his patch, but probably the most significant one was at Scremerston in Northumberland, three miles south of Berwick-upon-Tweed. At this location, more than 400 tonnes of formation material had been washed away from under the tracks situated on a high embankment. This was not a known problem site and normally this would not be a location that would cause concern.
Network Rail’s partnership contractor, Construction Marine Ltd (CML), based in Leeds, is responsible for landslip and drainage repair in the North East. Martin Weston, construction director, managed to ensure that more than 30 engineers reached the site. They then worked around the clock, from 16:00 Thursday 28 June to 08:00 Sunday 1 July, to reopen the route.
Vital local cooperation
In such circumstances you need all the friends you can get and fortunately, the local farmer was very helpful. CML was able to construct a temporary roadway and haul a site cabin and equipment across the farmer’s flooded fields to set up a site. To stabilise the bank, 1,000 tonnes of type 1 stone were brought in by two tracked dumper trucks. Two 16-tonne tracked excavators were used to remove the debris from the landslip and construct a 1200mm diameter chamber two metres deep that was connected to a 240 metre long network of drainage pipes that was installed into the embankment.
A ballast train operated by Network Rail maintenance staff imported 600 tonnes of track ballast to enable track gangs to lift and line both tracks ready for tamping. The Down Line was opened at 50mph at 13.00 Friday and the Up Line was open to traffic at 20mph at 08.00 on 1 July. Subsequently, 600 tonnes of top soil has been placed to complete the work. Fortunately, at this location the overhead stanchions and equipment remained intact.
It is worth recapping that all this work, including transporting 1,000 tonnes of stone across isolated and now flooded farmland, happened very quickly. The Down Line was opened within 21 hours and the Up Line was re-opened to rail traffic in the early hours of Sunday 1 July, little more than 48 hours after the landslide occurred. Michael emphasised that this was an excellent example of effective supply chain management.
Michael’s wasn’t the only team that was busy. Network Rail had to deal with similar issues on the ECML at nearby Spittal where Story Contracting was brought in by the maintenance team and cleared the cutting slips on the Down side on the first night after the floods, enabling the line to re-open.
There were flooding problems with other embankments, and track beds had been washed away in the Haltwhistle Station area on the Newcastle to Carlisle route, which also had to be closed. Stobart Rail helped the Network Rail maintenance teams reopen this section.
60 miles west of Newcastle, the West Coast Main Line (WCML) had similar problems. Darren Miller, Network Rail’s infrastructure maintenance engineer WCML, is based in Carlisle. He explained that, throughout the Lake District area, signalling equipment was damaged and many overhead power line structures were left leaning precariously in all directions. Also, many bridge piers were left needing emergency inspections to ensure that debris in the swollen rivers was not causing excess scouring.
Alongside the river Caldew near Carlisle, 50 metres of retaining wall which was supporting the railway formation was undermined and collapsed. The Caldew Viaduct piers supporting the deck over which the WCML runs, and Cummersdale Viaduct which carries the Carlisle to Whitehaven line, were both having to cope with unprecedented volumes of water passing under and around the structures, necessitating the need for divers to inspect and repair the damage both to these structures and a number of nearby culverts.
Fishing out stanchions
Many OLE stanchions were damaged but one of them, complete with its concrete foundation, was washed away into the River Caldew. The Environmental Agency was extremely concerned because a main sewer pipe lay in the middle of the river and if the stanchion base was to collide with the pipe the consequences could be both significant and most undesirable. Fortunately, as with the East coast, Network Rail has a Partnership supplier, Murphy Ltd, ready to respond to such issues. Using two back actor machines, they managed to carefully fish the structure out of the torrent before any damage was inflicted on the sewer pipe.
At Tebay, water regularly cascades down from the hills through well flushed culverts under the railway and into the river Eden. The volume on this occasion was so great that more than 600 tonnes of formation was washed away leaving the west coast main line unsupported. It had to be closed from 16.00 hrs on 28 June.
Fortunately, supplies of large quantities of stone are nearby and over 2000 tonnes of large 6G graded stone and 800 tonnes of type 1 stone were transported by road to access points then transferred into rail wagons and transported to site to fill the void. Within 14 hrs Murphy, working alongside Network Rail’s maintenance teams, was able to open the route to trains at 20mph and by early July, with regular monitoring, tamping and packing, line speed of 125mph had been restored.
Bird’s eye view
Darren explained that one of the most effective pieces of kit that they have had access to lately is a Network Rail helicopter. Darren spent three days during the flood period, flying around the network in the NW, checking all the trouble spots. From such a vantage point, he was able to review the condition of the adjacent land, as well as the permanent way itself, which proved invaluable. Using on-board cameras, he took 147 images from 50 sites and this form of inspection enabled him to identify trouble at two further sites that conventional inspections hadn’t picked up.
In addition, now that all the maintenance staff have been issued with iPhones, Darren was able to identify a location, establish the GPS coordinates and then send them to the local gang who were able to pinpoint exactly where the trouble spot was at ground level. It also gave everyone involved the added confidence that there would be no surprises as they are confident that they now know exactly what is going on at ground level.
This article has only been able to touch on a few of the many locations that have been subjected to significant engineering problems and challenges as a result of the extreme weather encountered over the last few months. There were bank slips at Dalton Bank and many other locations where ballast was washed away leaving the sleepered track suspended in midair. General flooding was extensive throughout the Lancashire area with the River Yarrow bursting its banks causing particular problems at Croston near Chorley.
However, what is clearly evident is that sound, professional and experienced suppliers, working as one with their client Network Rail, can overcome logistical problems that on the surface appear insurmountable, in a very short space of time. Also, wasn’t it a good idea to issue iPhones to all levels and not just senior managers? Incidents and the events described above helped the rapid justification of that investment. However, the basic engineering skills are still needed, along with copious supplies of graded rock and engineering nouse. The bad weather doesn’t seem to want to go away.