London Loop 9 Alternative via Feltham Marshalling Yards

Piles of abandoned sleepers are one of the few reminders of what was once the UK's biggest rail siding:
Feltham Marshalling Yards

Here’s an alternative routing of London Loop section 9 that provides a greener and more direct way between Richmond and Hounslow boroughs. The official trail currently follows a longstanding provisional route, leaving the obvious line of the river Crane for a rather awkward detour via Hounslow Heath, including a longish road walk. The detour persists because the status of the old Feltham Marshalling Yards site which straddles the river is still not entirely resolved. But for some time now, an informal path closer to the river has usually been kept open, and although it’s not widely publicised, it’s well-known locally.

The official route has its virtues, particularly as it includes Hounslow Heath, an attractive and interesting reminder of what suburban west London looked like before it was covered with concrete. But getting there involves a dull slog along Hounslow Road, and the walk back to the Crane follows an irritating zigzag around a golf course. The alternative is not only entirely off-road, more logical and 1.3 km shorter, but includes a large overgrown area of considerable nature and industrial history interest and a brief taste of the fascinating Cavalry Tunnel. Do remember that it’s still strictly informal: access depends on three gates in substantial fences being left unlocked; the site can feel rather desolate and isolated; and the Cavalry Tunnel section, though very short, is unlit and unmaintained.

I’ve revised the existing London Loop route description for sections 9 and 10, Kingston upon Thames – Hatton Cross – Hayes (Hillingdon), to include details of both options, and you can read more about the places on the Feltham Marshalling Yards alternative below.

Pevensey Road Nature Reserve

The woodchip path through Pevensey Road Local Nature Reserve.

I’ve said more about the river Crane, one of the most substantial Thames tributaries in Greater London, in my commentary on London Loop section 9. Like many urban rivers it forms a green corridor, which the Loop first joins at Hospital Bridge, between Fulwell and Whitton. The trail follows the river through Crane Park, on the site of the old Hounslow Gunpowder Works, and past the famous Shot Tower to reach the main Hounslow Road at Hanworth. Here, the official Loop sets off northeast along the road to Hounslow Heath, but the observant walker will spot tempting damp woodlands across the road. On the east bank is an extension of Crane Park known as Little Park, but our route crosses the river to enter the space on the west bank.

The land adjacent to the river here was acquired by the old Middlesex County Council before World War II. Part of it was then allocated as the South West Middlesex Crematorium, controlled by its own statutory board made up of a partnership of local authorities. This opened in 1954 as part of the post-war proliferation of such municipal facilities – it was the 74^th local authority crematorium to open in the UK since the war.

A margin of woodland, wetland and scrubby meadow surrounded the site on three sides: inherited by Hounslow council, this was included in the area designated the Pevensey Road Local Nature Reserve (LNR) in 1994, and is now partly maintained by The Conservation Volunteers. This southern section of the site is also known as Peter Cribb Park, dedicated to the late former superintendent of the crematorium, a keen naturalist who made a major contribution to the conservation of local green spaces.

The watercourses here are a legacy of the former gunpowder mills to the south: the river itself follows a managed course, while a parallel millstream, also labelled as the Crane on most contemporary maps, runs to the east. The trail crosses the river then tracks its western bank through the reserve on a recently improved woodchip path, although the water isn’t always easily visible through the trees. After a while you climb a sharp slope into a more open scrubby area, the site of the former Feltham Urban District Council sewage works, built in the 1920s but disused by the 1950s and now part of the LNR. Following the woodchip path left here will take you to the Feltham Circles, the remains of the sewage works tanks, now covered in graffiti. But these are off our route, which runs alongside and then through the fence surrounding the Marshalling Yards site.

Feltham Marshalling Yards

Into the depths: entrance to the Cavalry Tunnel.

For such a huge facility, the Marshalling Yards had a relatively short life of a little over fifty years. Construction started in 1916, largely carried out by prisoners of war on fields immediately to the south of the London and South Western Railway (L&SWR) main line east of Feltham station. Its purpose was to replace the company’s freight facilities at Nine Elms which were becoming overwhelmed by demand, and the location was chosen partly because of the space, partly for the convenience not only for the L&SWR’s own line, opened in 1838 from Nine Elms to Woking as the London and Southampton Railway, but for links to other railways. 

Like much of this area, the land had originally formed part of Hounslow Heath before the latter was gradually inclosed and developed in the 19^th century, as explained under Loop 9. First operational in 1918 and completed in 1921, Feltham was once the busiest railway siding in the country, handling almost 3,500 wagons a day, over 51 km of track. During World War II it was used for moving war supplies, including materials destined for the 1944 Normandy Landings, and was duly targeted for bombing.

Traffic declined after the war as more freight moved onto the roads, and the facility didn’t survive the phasing out of steam traction on British Rail during the 1960s. It finally closed in 1969, after which nearly all the infrastructure was removed. Since then much of this huge site – about 30 ha – has been left derelict and quietly returned to nature. Huge clumps of buddleia and stands of silver birch now sprout where wagons once gently rattled by, and the habitat has proved particularly welcoming to reptiles. All in all, it’s a valuable and rare example of what happens to a large brownfield site abandoned for the best part of half a century.

The yard is still under railway ownership, now that of British Rail’s successor Network Rail, and most of it has since been designated as Green Belt and a Site of Metropolitan Importance for Nature Conservation. But proposals for its future management have so far failed to bear fruit. Meanwhile, it’s enjoyed informally by local people who are aware of the access points – and unfortunately occasionally for less benign use such as illegal off-road motorcycling and anti-social behaviour.

There’s a longstanding aspiration on behalf of local councils and the Friends of the River Crane Environment campaign group (FORCE) to incorporate the Marshalling Yards more fully into the Crane Valley corridor, with a recognised walking and cycling route running through it as part of the wider riverside route.

This looked like it might finally happen in the late 1990s when planning permission was granted for a contentious proposal by Railtrack, the company that briefly and disastrously took over custody of infrastructure following the privatisation of British Rail, and the Royal Mail to build a giant sorting office on the northeast portion of the site. The permission was subject to a ‘section 106’ (s106) agreement to provide and maintain formal access to the rest of the yards. A dispute between the London Borough of Hounslow and Network Rail about ongoing responsibility for maintenance followed and as a result, though money was set aside and some work was done, the promised new network of paths was never completed.

The latest document to address the future of the site is the council’s masterplan for the redevelopment of Feltham, published in 2017. This envisages building around 600 homes on parts of the site – though the rest would be taken into public ownership and conserved and managed as public space. FORCE and other local groups are understandably concerned about the building proposals, but a more strategic approach to conserving the rest of Yards as a community and natural resource could well be the way forward. Meanwhile the gates that interrupt the through-route are left tacitly open – not least because if locked they’re rapidly vandalised by motorcycle scramblers.

Walking into the site, you soon cross the trackbed of one of the sidings, and follow it right through a very tall gate into another scrubby area. The earthworks round here are relics of the two humps that once played an integral part in the yard’s operations: wagons would be hauled to the top then allowed to run into the correct sidings under gravity. Once through the tall gate you turn left and walk along a gulley: the path here runs parallel to one of the site’s best-known surviving features, the Cavalry Tunnel, and you’ll shortly descend to see more of it, between two concrete blocks installed as crude motorcycle barriers.

The tunnel was the solution to dealing with the river Crane. The L&SWR line bounding the site to the north already crossed the river, which passed beneath in a tunnel, so the engineers redirected the flow into a new culvert and extended the tunnel over it, leaving an uninterrupted surface above. A second, narrower, tunnel was provided alongside the main one, primarily to cope with overflows in times of flood. An urban myth quickly grew up that the real purpose of this 686 m passageway was to allow cavalry troops stationed at the barracks on Hounslow Heath access under the tracks. But although the overflow tunnel undoubtedly provided an informal pedestrian route for those courageous enough to brave the darkness, this seems unlikely. The structure is also sometimes known as the 40-Acre Tunnel, presumably after a field that once stood here.

Among the work carried out under the sorting office s106 agreement before it was paralysed by dispute was the cutting of a new pedestrian and cycle subway into the northern end of the tunnel, which you now use to cross the still-operational railway and leave the site. It’s a strange place: in a dusty and neglected space at the bottom of a gritty slope, there’s a sudden eruption of formal civil engineering, with hard surfaces, tactile paving and signing, looking like a discovery from some post-apocalyptic science fiction drama. On the right, you can peer through iron bars along the rest of the dark and gloomy tunnel as it heads south: certainly not a comfortable environment even for a cavalry regiment.

Your way is left, along a few slightly spooky metres before you emerge through another gate and back out onto the riverside path: look right again to see the Crane emerging from the main tunnel.  Not much further on, the official Loop route rejoins across a bridge on the right and continues ahead through Brazil Mill Woods to Baber Bridge, as previously described.

• Download full route description (PDF)
• View Google map