From Roader's Digest: The SABRE Wiki
|A74 Cumberland Gap|
|To:||Guards Mill (NY329670)|
|Length:||6 miles (9.7 km)|
|Now part of:||M6|
The Cumberland Gap is the term used by SABRE members, among others, for what between 1999 and 2008 was the last non-motorway stretch of the 400-mile route from London to Glasgow. It comprised 5.7 miles of A74 that remained between the north end of the M6 and the south end of the A74(M).
It ran from Greymoorhill or Kingstown Interchange on the M6, just north of Carlisle, to Guards Mill Interchange on the A74(M), just south of the Anglo-Scottish border near Gretna. It was a D2 road with several intermediate GSJs, and a small service area, Todhills.
Between July 2006 and December 2008, the Cumberland Gap was upgraded to become part of the M6. It was opened on December 5 2008, the 50th anniversary of the opening of the first section of M6, the Preston Bypass. All the Gap's intermediate junctions were closed, and Todhills became the first in a new generation of motorway rest areas.
History of the Gap
In the early 19th century Thomas Telford was commissioned to improve the road from Carlisle to Glasgow. As part of this work he built the first direct road between Carlisle and Gretna, crossing the Esk at the place which became known as Metal Bridge. Previously, traffic between England and western Scotland had had to go via Longtown on what is now the A7.
Telford's road became the A74 in 1922 and was one of the first batch of trunk roads to be designated (in the 1936 Trunk Roads Act).
The section of motorway immediately south of the Cumberland Gap, the M6 Carlisle Bypass, was opened in December 1970. By 1972 there was a continuous motorway route from London to north of Carlisle.
The dualling of the A74 through the Gap took place in three sections: Mossband Viaduct and approaches opened in 1964, southward from there in 1970 simultaneously with the adjacent M6, and north of Mossband as part of the Gretna bypass in 1973. The last of these was also the last stretch in the creation of a continuous dual carriageway from London to Glasgow.
The section of motorway immediately north of the Gap, the A74(M), an online upgrade of the 1973 Gretna bypass, was opened in December 1992. It was mostly in Scotland but extended a short distance across the border into England.
By the end of 1995, there was a motorway route from London to Glasgow, continuous except for the Cumberland Gap and a longer 18-mile gap some 25 miles further north.
The upgrade of the northern gap was completed in spring 1999 leaving just the Cumberland Gap.
For the continuation of this history, see "History of plans to fill the Gap" below.
Standard of the Gap
Contrary to what is sometimes suggested, the road through the Cumberland Gap was of a quite high standard. It was a fully grade-separated D2 with a continuous central reservation. It was excellently aligned horizontally and, except for the approaches to Mossband Viaduct, vertically. The southernmost two miles, as far as the Todhills exit, had hard shoulders, albeit somewhat narrower than usual on a motorway. The southbound approach to the start of the M6 had four lanes (two exit and two through), a hard shoulder and a gantry sign.
From 1992, there was a short section at the north end, immediately south of Guards Mill Interchange, on which, though technically part of the all-purpose A74, the northbound carriageway had three lanes and hard shoulder, and the southbound carriageway had a total paved width capable of accommodating the same layout.
Apart from this, the Gap had only two lanes on each carriageway, compared with three on the motorways at each end, though it carried more traffic than they did. Also there were five (six until 1996, when the southernmost was closed) intermediate GSJs which provided the main or only access to local hamlets, farms, minor roads and the MoD arms storage establishment at Mossband. These meant that local traffic mixed with long-distance traffic. The tapers to these junctions were short, and there were several laybys which contributed to a number of fatal or serious accidents.
A final problem was that whereas a hypothetical road of this standard, carrying this volume of traffic, situated in a less remote area, could be avoided by using alternative routes in the event of a blockage, the Cumberland Gap was the only high-capacity road crossing between England and Scotland, a point illustrated on 22 December 2004 when an HGV crossing the central reservation led to the route being closed for two days, with far-reaching effects.
The eventual motorway upgrade included the creation of a parallel local access road to the west (incorporating, at each end, sections of what had been the A74 prior to the original dualling in the 1960s and 70s). It was this that made possible the closure of the intermediate GSJs.
The two biggest structures on the Cumberland Gap were towards the north end. Mossband Viaduct, opened in 1964, carried the A74 over the West Coast Main Line at high skew. It developed problems with its post-tensioned stressing cables and was judged to have a limited life. Acoustic monitoring equipment was attached to detect any breakage of strands of the cables. In the motorway upgrade it was replaced by a new bridge alongside, carrying both the motorway and the local access road, and was demolished in late 2008 - early 2009.
The bridge over the River Esk at Metal Bridge was opened in 1970 to carry the D2 A74, replacing a bridge of 1916 which in turn had replaced Telford's Metal Bridge. In the motorway upgrade, a new bridge was built alongside to carry the southbound motorway, and the old bridge was refurbished to carry both the northbound motorway and the local access road. The new bridge has 4 spans; its piers are aligned with alternate piers of the 8-span 1970 bridge. Its superstructure was positioned by launching from the north end in two stages.
Further south were three two-span overbridges opened in 1970 to carry minor roads over the A74. The design of these (whether deliberately or accidentally is unknown) allowed them to be adapted to accommodate the full width of the motorway by cutting back their side slopes and, at two of the three sites, building small retaining walls under the bridges, in front of the abutments.
Three of the six original intermediate GSJs involved minor roads passing over these three overbridges. The other three involved minor roads or private accesses passing under the south end of the river bridge and both ends of Mossband Viaduct.
In A74 days there was a weighbridge adjacent to the northbound carriageway towards the south end of the Gap. In the upgrade this was replaced by a much larger HGV inspection facility for VOSA (the Department for Transport's Vehicle and Operator Services Agency) a little further north. Access to the VOSA site is by a turning off the slip road leading to the northbound Todhills rest area. Because of site constraints, HGVs resuming their northward journey after being called in for inspection have to use a short stretch of the parallel local access road, bypassing the back of the rest area, then go through a normally-closed gateway onto a special slip road which merges with the slip road from the rest area.
History of the name
The name Cumberland Gap is known to have been in use in this sense at least as early as 1997, two years before it became the only gap on the route.
The original Cumberland Gap is a mountain pass in the USA, important in the history of the spread of Europeans through the country. It is perhaps best known in Britain via the folk song of the same name, which probably dates from the 19th century and was recorded by, among others, Woody Guthrie and Lonnie Donegan.
History of plans to fill the Gap
The decision to create a continuous motorway from Carlisle to Glasgow was taken in 1987. The Scottish sections were pursued with great vigour for several years; for much more on this, see M74 and A74(M) History.
Planning was also done on the English section, officially known as M6 Carlisle to Guards Mill, with a preferred route being announced in June 1991, draft orders published in December 1995, and a public inquiry held in 1996. Ministers announced their intention to make the orders, but they were in fact never made in that form. This may have been because the 1997 general election intervened.
The incoming government held a review of almost all trunk road schemes for which contracts had not yet been awarded. When this review reported, it recommended an that a cheaper route be sought.
Meanwhile the last 18-mile section of the A74(M) in Scotland was built under a DBFO contract, which included an option for the English section to be built too. This option had to be taken up within two years. The Department of Transport and Highways Agency allowed it to lapse, having decided they could not take it up without sacrificing other priorities elsewhere in England.
(more coming soon here)