Saturday, 10 April 2021

#LDNCycleSafari Goes Solo: A Trip To Thamesmead - Part 1

In the late 1990s/ early 2000s, I worked in Thamesmead, Southeast London. It is the place where I was exposed to all sorts of interesting construction. It is also the place where I worked on a project which helped me become a chartered civil engineer, so I will always have fond memories of the place.

I haven't been back since 2004, but on a chilly Good Friday, I made a pilgrimage back to Thamesmead to see what has changed in the intervening years as well as what was as I remembered it. In this week's post, I will be looking at some of the old and in next week's, I shall be looking at some of the new.

Thamesmead straddles the modern London boroughs of Greenwhich and Bexley, but there is a long history of human activity in the area. For a few hundred years, it was part of the Royal Arsenal which was established on the Plumstead and Erith marshes.

My stint in the area was working for Thamesmead Town Ltd, a company set up by the London Residuary Body which was responsible for the disposal of the assets of the Greater London Council (GLC) which fell victim to being abolished by the Conservative Prime Minister, Margaret Thatcher. I'll explain some of the engineering as I go on, but looking back I really do think that the loss of the GLC was a huge loss for London and the UK as a whole in terms of innovation. But that's a story in its own right.

Thamesmead is probably most famous for the GLC-era development of what was essentially a new town - The Town of Tomorrow. It was meant to be a modern development of high density housing, schools, communitry facilities, open spaces, water and everything else people needed. The development welcomed its first residents in 1968 and at the time, people were vetted to make sure they would be able to afford to live there (it was going to be quite exclusive). 

Changes in social housing policy and approach meant that the original vision was short lived and the new development became what was known as a "sink estate"; a pretty derogatory euphemism for a place and its people gradually starved of investment of both financially and socially. The original part of the development is also infamous as providing the backdrop to some of the scenes in Stanley Kubrick's disturbing dystopic 1971 film "Clockwork Orange"; itself based on Anthony Burgess's 1962 novel. In many ways, this was a watershed moment for this short-lived Utopian vision for a new town in London.

The photograph above is Southmere Lake. One of the scenes from A Clockwork Orange was filmed beyond the Lakeside building with the orange hoarding at Binsey Walk. The lake and Lakeside building were also the backdrop for the 2009 - 2013 TV show, Misfits. Everything here is now boarded up and being redeveloped. 

Thamesmead has probably got examples of housing from each decade after the 1960s and 70s. My turn of the 21st Century experience there saw a mixture of houses and flats being built, but Thamesmead Town was there to facilitate development by remediating industrial land and building core infrastructure including roads, sewers and canals. The old Royal Arsenal lands are contaminated with all sorts of nasty chemicals from explosives manufacture and ancillary services, including the wonderfully named "Blue Billy", a byproduct of gasworks. 

One of the key pieces of work I was involved with was ground remediation which was the removal of the top layer of contaminated soil and replacement with a water-permeable membrane and clean sand. One of my schemes was Meadowford Close where I oversaw the remediation process and one one occasion ended up getting the Metropolitan Police bomb squad out to check something we dug up. It turned out to be old Royal Arsenal ordnance, but inactive thank goodness! In fact, most of the nasty stuff dug up on the site were home-grown weapons of mass destruction.

I also got involved with the completion of the new roads, footways and cycle tracks. There is some interesting walking and cycling networks in Thamesmead which reflect their eras, but sadly they haven't really reached their potential. I also got involved in building sections of canal. Thamesmead is built on reclaimed marsh which is protected by a river wall, itself being part of the London flood defence system of which the Thames Barrier is part.

The photograph above was taken in May 2000 of the walking and cycling bridge between Delisle Road and New Acres Road over one of the newer sections of canal in the area south of Gallions Reach Park which was originally called Gallions Reach Urban Village. There's a spine cycleway along here, which unfortunately ends at Barnham Drive (as seen today, below) which should have continued east through the site of the Thames Gateway Bridge to connect up with routes to Thamesmead Town Centre (I'll come back to this later).

The town has a canal system which links a series of large lakes. As well as providing amenity (including sports on the lakes), open space and ecology, the system is vital for fluvial flood prevention - in other words, it's not the Thames which is the main issue, its the water coming from the upstream catchments. 

The water level in the lakes and canals are at the same level as the general groundwater and in a flood event, the levels rise and it's that rise over the whole area of the water courses which provide flood storage. The canals are only 610mm deep (2 feet) and so easy to walk through (although I seem to remember that Southmere Lake is twice that depth for boating - I can't remember the details of the others). Obviously the hydrology isn't without complexity, but the storage above the general water level does mean water seeps into the ground beyond, but far slower than it being pumped out.

From memory, the original GLC design for the system was for a 1 in 205 year storm event which was well ahead of its time with roots in work Bilham did in the 1930s. I can't quite remember which year, but there was some extensive flooding around Plumstead when I worked in the area with Thamesmead having the odd canal path with some puddling - that's how good the system is.

The original canals had concrete walls and bases (although not watertight). More recently (well, 20 years ago), the canal system was still engineered, but this time in a more naturalistic way. The photograph above from August 2002 was taken from the southern tump of the "Twin Tumps" canal looking out to what is now Waterside Close - you can see the very shallow shelf for marginal plants. A tump is a little hill and in the case of the Twin Tumps, they are old Royal Arsenal structures each of two C-shaped earth bunds with the smaller 'c' back to front overlapping the larger 'C'. This arrangement was for sending explosions from stored ordance up rather than out.

Depending on the tides in the Thames, water is either stored in the Thamesmead system or discharged into into the river via suices or pumps. Lake 4 Pumping Station is shown in the photograph below and uses 4 Archimedes screw pumps. Recently upgraded, it can apparently shift 2.4 tonnes of water a second!

The original parts of the development also had habitable rooms from first floor level and some of the more contemporary developments had townhouses without living accommodation at ground floor (just garages and utility rooms). This was a second line of defence from flooding. The original parts of the development also had above ground walkways connecting buildings and blocks away from traffic which perhaps added to some of the social and security issues which blighted the estate.

Thamesmead has a network of large dual carriageways which looking back are completely over-capacity and create severance issues. There have been some alterations with bus lanes and surface level crossings, but they both remain a barrier and make it easy to drive around the area. They are part of a wider and incomplete network of roads. 

For example, the Thames Gateway Bridge (a revised and descoped version of the originally planned East London River Crossing - ELRiC) was part of earlier plans for network of motorway-style roads across and around London with a link connecting the A406 North Circular, south to the A2, but the work never got beyond Thamesmead. 

Where the walkways were built for the original parts of the development, slightly later phases carried on with grade separation, but with walking and cycling being taken under the roads, often next to the canals.

The photograph above is on the edge of the town centre, taking walking, cycling and a canal under Central Way. You can see the stepped arrangement keeping walking and cycling separate and the view through the underpass. The wall to the left of the footway in the photograph below is a sealed section of canal wall because the route is lower than the water level in the canal. This arrangement really has a Dutch feel to it.

On the other side of the underpass, the design changes to something more 80s where the footway and cycle track end up at the same level (below). The 80s to 00s saw development of the walking and cycling network like this. The earlier sections simply have a different surface (block paving for walking, green asphalt for cycling) with later sections having a tactile block between the two. 

What I think has happened is the underpasses were built with the original main roads with connections made as development progressed through the years. Unfortunately, the original vision seems to have been lost going forward.

A bit further south along this route is Hutchins Road where there's a typical shared area junction for walking and cycling (above), but it also hints that the walking and cycling networks do operate independently of the driving network as the left and right options here go through areas that cars cannot.

The local cycling network could do with some investment be quite a lot of it is both showing its age and also that separated infrastructure does last a very long time and is not hammered by constant traffic. From the Hutchins Road junction, I chose to turn left to head east which takes one through an area of open space. There is a wide section of shared use, but then the separate and stepped infrastructure returns with a bridge over a canal and an underpass beneath Bentham Road

This underpass (above) also has a the canal running under, but the walking and cycling route is above water level. Bentham Road in this case is taken over the bridge on a long hump which means the vehicles make the effort not the people walking and cycling. Because the bridge is piled, the carriageway either side is susceptible to settlement and 20 years ago there was work to reconstruct the approaches.

A little further on and we reach a junction outside Hawksmoor School. However, this is no ordinary junction because it is a cycle track junction with adjacent stepped footways (below).

It's a wonderful thing to see - a wonderfully safe environment from which to access the school, although the paths will feel lonely at some times of the day and night not helped by the housing to the west of the school facing away from the walking and cycling network.

A little further west and there is at least a sports court to entice some activity and the route carries on following the canal (which eventually links to Southmere Lake. A little further on and the route becomes shared as is passes in front of a local shopping parade at Claridge Way (below).

From here, I threaded my way onto some local streets which isn't always easy because the wayfinding fails a bit. I was looking to head south towards Southmere Lake, but that requires crossing the Southern Outfall Sewer which crosses the area from west to east in an embankment which also carries a greenway known as the Ridgeway. Eventually I worked out that I needed to access Poplar Place and a shared path beyond - the access wasn't clear because of a recent bit of redevelopment which could have treated the path far better rather.

I was aiming for the junction of Eastern Way and Carlyle Road, a huge and over-engineered grade separated junction through which a shared path runs to connect wth the Ridgeway and the earliest part of the Thamesmead development to the south of the Southern Outfall Sewer. This route through the junction is an incredibly lonely place to be because it is so tucked away from housing. Threading my way up and south took me to a bridge crossing Eastern Way, but at a lower level than the junction. It's an impressive piece of period architecture and engineering from the early 1970s.

This sort of brings me full circle as I started talking about the earliest part of Thamesmead built around Southmere Lake and I'm nearly back there with the walking and cycling route. This part of the journey will continue in another post, but now I want to head back over to the newer parts of the development to the west of the town centre.

The Thames Gateway Bridge project saw a corridor of land reserved for the construction and operation of the project to the west of Thamesmead town centre. Once complete, the long term plan included the connection of the canal and road system from the western part of the town centre to the town centre itself with the area under the bridge becoming part of a local open space. The bridge was cancelled by Mayor Johnson in 2008 and so it simply isn't clear what will happen to this piece of land.

The photograph above was taken from the top of Gallions Hill, a constructed landmark feature of Gallions Reach Park. The wooded area just beyond the more formal park contains the Tripcock Wetlands, a project I led the design on and which I used as part of my chartership submission. This project uses bioremediation to treat waste water from an adjacent engineered land fill site used to contain contaminated soils arising from the wider development, thus reducing the need to shift materials. I put out a thread on this project on Twitter

Anyhow, it is over this undevelopable area that the bridge was meant to rise from around the Western Way/ Central Way junction (below) to connect with a junction at Royal Docks Road on the north side. The yellow lines on the image below show the approximately extent of an originally planned toll plaza. Had the bridge been built, then I guess technology would have rendered the plaza obsolete.

Curiously, part of the junction on the north side has been built. There is a southbound slip road from the A1020 Royal Docks Road which has an odd stub looking towards the southern side of the Thames (below).

The slip road is then carried over the A1020 on a bridge which is way too wide for a one-way slip road (below). This is where the Thames Gateway Bridge would have ended, but it now leaves a curious piece of 20th Century urban infrastructure.

What this all means is that the western side of Thamesmead out to the Royal Arsenal neighbourhood is now pretty cut off from the town centre. Driving is easy along Western Way and Central Way, but walking and cycling only really have the river path which is now part of Quietway 14. In fact, in order to access the town centre, one must travel east beyond the town centre itself and then circle back via Linton Mead and Central Way. 

The photograph above is part of Quietway 14 along the Thames, recently upgraded - it used to have a long gravel section around Tripcock Point. The route is a trip through history with sections of an earlier vintage (below). In fact, this is all part of a the Thames flood defences - some were made accessible when built and some have been open up in more recent years.

The stub of Barnham Drive I mentioned earlier has a doppleganger on the other side of the Thames Gateway Bridge Corridor at, well, Barnham Drive. In fact, in connecting up, there would also be a walking and cycling spur to Newmarsh Road which already provides a quiet and mainly traffic-free route out to the east - it would have been via another underpass at Central Way, but unfortunately it has been buried in favour of a toucan crossing. Getting this underpass back into use and connecting up the route was another project I worked on, including the link to Pitfield Crescent.

The photograph above is the Central Way underpass in June 2000, shortly after we opened it up and had the water pumped out.

So, we're back again to the west of the town centre and the Gallions Reach Urban Village part of Thamesmead. There are walking and cycling routes running along the canal (below) between the stub of Barnham Drive and the river in the east (connecting to Q14) at Princess Alice Way.

One final curiosity this week is the roundabout junction of Merbury Road/ Warepoint Drive/ Miles Drive in the heart of the Gallions Reach Urban Village part of the development. Warepoint Drive and one arm of Merbury Road have cycle tracks. They are only on one side, it's not clear that that are two-way and to be honest, the roads are pretty quiet (below).

Where they meet the roundabout, an annular cycle track is provided and when you cycle, you're kind of led to go around clockwise. For the eastbound direction from Warepoint drive, this means you end up crossing 3 arms of the roundabout to continue on Merbury Road where crossing one arm and going anti-clockwise might make more sense (and I assume anyone who does cycle here regularly on the track does this).

The crossing points have small refuges (too small for most users), but we have a compact roundabout with an annular cycle track and tight geometry for traffic. Like lots of place around Thamesmead, if you half close your eyes on a sunny day, you can almost see the Dutch design principles!

I shall leave you this week with a video of my ride around Thamesmead.

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