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Wednesday 29 December 2010

Linear Park Surfacing: updated

Works to Linear Park will commence on 5th January, with the route split into five sections as follows:
  1. Devonshire Tunnel Portal – Hiscocks Drive Bridge.
    10-23rd January, access from Bloomfield Road open space.
  2. Hiscocks Drive Bridge – Monksdale Road.
    24th January - 6th February, access from Monksdale Road.
  3. Monksdale Road – St Kildas Road.
    7th - 20th February, access from Monksdale Road (and no access from St Kildas Road).
  4. St Kildas Road – Millmead Road.
    21st February - 6th March, access from Millmead Road (and again, no access from St Kilda's Road).
  5. Millmead Road – Bellots Road Bridge.
    7th - 20th March, access from Millmead Road, no access from Bellotts Road.
Further details of closures will be given during the works. When works commence, please revisit the blog for updates and images.

Here's a link to Sustrans Two Tunnels Route's pages, with information on the impending work.

Thursday 23 September 2010

New bridges over Dartmouth Avenue and Monksdale Road - Drawings


Drawings of the new bridges which will be used in support of the planning application for their construction, and due to be submitted shortly by Sustrans, are attached in pdf format.



Dartmouth Avenue bridge


Monksdale Road bridge


 

Find a link to the planning applications themselves from the Bridges page on the Two Tunnels web site.

Thursday 24 June 2010

Whaaat!?!

Seen on the fence ...
first shipworm, and now an enigma.

Oh, hang on, its not an enigma, it's a qr code.
Bath's Spot the Lion has some of these ...

It looks like the project's getting some information up at the worksite. Good. Now, what does it say?

First one to post the answer in the comments gets ... a big collective grin from the committee!

Sunday 20 June 2010

Three new friends of the Two Tunnels route

The lack of activity on the ground does give the impression that everything's at a halt. Behind the scenes though, there's the nitty gritty work on the planning of the exact form of the route - the project plan isn't slipping all round the calendar, physical work is currently booked to restart in the autumn.

Meanwhile, up at 'The fence' at Devonshire Tunnel, we're looking out signage to inform visitors to the site about the project and its goals. It's quite usual for projects to use any hoardings to proudly announce the constructing partners, contractors and an outline project plan, but people probably thought that no one would visit Linear Park to see what's going on.  Not so, as 'The fence' has had visitors from far and wide, as well as from Bath residents.

Bath's Holborne Museum's Extension project (their site's pictured to the right, planted firmly at the end of Great Pulteney Street and 'A bit high viz') even pins the projected completion date on its fence.

We're pretty proud of the Two Tunnels project, so we'll see what we can bring about at the Devonshire Tunnel work site. It may be less prominently sited than the Holborne but it still has its visitors, and the fence will be in place for this year and most of next.

Which brings us to the other problem - the fence blocked any hope of a view of the works.

It's not unusual ... for a construction site to have viewports in its perimeter fence.

Thanks to Nigel Bryant and a Sunday morning, visitors can now view the site through no less than three holes, and this being the Two Tunnels project, we think of them as three new supporters who each have a name.

Arthur Ole
The first attempt. Something went terribly wrong and the air turned blue. The hole's image has been tinted blue in honour of the work that went into this first attempt and the language it provoked.
Ann Ole
The first successful hole, this one's for tall people, Ann Ole is well off the ground.
Anna Ver Ole
Thinking that small people would also like to see the works, Nigel cut a third hole at a suitable height ...

Of course we'd never suggest that these are used in the same way as the once common fairground sideshow, with willing volunteers pelted with wet sponges from the other side as a fundraiser ...

... that's because we'd be those volunteers ...


The final photos show the fence with the viewports, and the newly greened-over approach cutting. Behind it, the topsoil that dressed the cutting's sides has greened over well. You might notice that the tunnel portal's excavation stopped slightly short of its full depth. This is because it was found to be about a metre more deeply buried than initial estimates.

To deepen the excavation would have either implied steeper cutting sides - and they were quite old fashioned enough already - or far more excavation and hence spoil to remove, so it was decided to stop slightly short of the 'Trackbed depth' - at a point at which the tunnel portal will still provide more than adequate headroom.

There's something else. In this photo, can you find the moon?

Sunday 23 May 2010

Back to the future: the making of Linear Park

Well, things on the construction front are at a stand - the project plan always did indicate a bit of a pause at this point, but in several ways we'd rather not have had this further opportunity to gather our thoughts - while the project itself perhaps risks a stall.

I'm checking its pulse, as there are doubtless still people who think that the clearly expressed wish by a great many for a 'Two Tunnels route' is bothersome, counts for nothing, and they might be tempted to encourage the idea to quietly drift off to sleep. If needed, the supporters group has to step in as the alarm clock. The more supporters, the louder the clock can ring, see the postscript ...

The most recent task on the Devonshire Tunnel site was to erect tidy fencing to the top of the tunnel cutting, and a temporary security fence across the cutting itself, behind which further work can take place.

Curiously though, the gate in that fence is of 'Garden gate' proportions. We'd find it encouraging to see a gate of 'Path machinery' proportions.

The first image shows the posts for the new fence in place and awaiting rails and sheets of ply. The second is courtesy of a visitor - Alexander Cunningham - it captures the atmosphere of this part of the route as well as any we've seen. Now the fence itself is blocking the view, we've requested that a viewing port be cut in it, as is common at construction sites that are of public interest - and we've provided the source for some signage as well.

Is this journey really necessary?
Our serious campaigning began in March 2006 and included some market research:

'We may think this is a good idea, but is there wide public support for this, the support to justify the time and investment?'

The answer was a resounding 'Yes' - for all sorts of reasons.

That view was reaffirmed by the public support shown for the planning application, and then for the Sustrans Connect 2 project.

After which, the King Bladud's Pigs took off in all sorts of ways, in part because of the cause for which they were fundraising. The Pigs benefitted the City - visitor numbers well up in what was a wet summer - and themselves have laid the foundations for Bath's 2010 arts project, 'Lions of Bath'. There's Elvis (above) - find him in Bath's Guildhall Market. The lions project will be a fundraiser for a number of local charities, and, like the pigs, the project will build and strengthen a network of contacts between diverse groups of people who would otherwise likely not meet - a good way to strengthen one of the cornerstones of economic activity. Do enjoy them if you can.

The photo above's the 'Two Tunnels Pig' - from the artist Sophie Howard -painted after a research visit to shade-dappled Lyncombe Vale one day in July 2008 - and given the speed at which the Two Tunnels project is progressing, the placement of the hedgehog is entirely appropriate! So is the inclusion of a person using a wheelchair - opportunities for independent exploration can be few and far between, and the route will offer a great resource if you happen to be in a wheelchair.


So, while we understand the institutional reluctance we've seen along the way, its all the more frustrating that while Sustrans and B&NES came to us very quickly and said that they'd support this, it's then taken so long to get so much as a spade into the ground - and now with the first work complete, things have now halted.

Speaking of spades, when it went into the ground, it was partly of our making - that's the Two Tunnels' ceremonial spade, fashioned in stainless steel in China - and decorated by Nigel Bryant in Bath on the morning of the 8th March. You'll see a small design at the bottom right of the blade, can you guess what it represents?

But ... back to this pause. It is in the project plan ... so we'll attempt to put to one side the fact that this small project - just six months work - could be done and dusted before the completion of Southgate, or the Holburne Museum extension ...


Let's abandon the bike for a moment and fire up the DeLorean, rolling it down that slope to the tunnel to turn the clock back to the seventies. Bath Library contains just a few documents relating to the decision taken by the then Bath City Council that rather than use the old line for piecemeal redevelopment, much would become a community resource - Linear Park.

This was an unusual and enlightened move for the time: many old lines in town and city were cannibalised at that time. A present day walk along the route could easily now find a new road between Bellotts Road and Dartmouth Avenue, patches of housing, an expanded industrial estate at Monksdale Road, and a small housing estate on the site of the infilled Devonshire Tunnel portal, ninety odd years of an historic and characterful railway reduced to a concealed manhole cover in a suburban garden.

The 'Linear Park vision' didn't actually extend to the line's tunnels: those were perceived as a hazard. While it's now more commonplace to acknowledge the benefits and bring paths through old rail tunnels where practicable, even a few years ago this was very much against accepted practice. This document does suggest retaining the first few feet of Devonshire Tunnel as a 'shelter' - something that would have been more successful in the seventies than in today's society, where through routes work, but cul-de-sacs may not.

The four page pamplet on the left has details of the original proposals to deal with what was rapidly becoming a dumping ground. Once plans were made, the council having  bought the three stretches of line from British Rail for a token sum, work started. Unfortunately, while a lot of the demolition tasks were completed, 1973 saw the price of oil abruptly quadruple, (the graph on the right's from Wikipedia, note what happens in 1973). Away went the budget, with a conseqent hit on the 'Amenity-creation' factor.

While the demolition and earth moving component of the Linear Park task was completed, much of the landscaping didn't survive the oil price shock. The resulting Linear Park was a bit of an obstacle course even on foot, and the current resource is the product (and credit) of years of piecemeal improvement work from B&NES Parks department and local residents. The Two Tunnels campaign has raised Linear Park's profile, and it is now rather more easy to negotiate than it was when the campaign started. This of course may simply be a coincidence.™

While the document intended a stretch of parkland and a small display of railway artefacts in front of a sealed Devonshire Tunnel, when the work was carried out, to the great surprise of some people, the tunnel mouth was simply buried, seven  years after it saw its last train.
This year's work at Devonshire Tunnel has, so far, part-realised the original plan - albeit with a buried telegraph post standing in for the 'Railway artefacts' and many people have noticed how pleasant a stretch this part of the route already makes - between Maple Grove bridge and the tunnel portal. There's something to be said for landscaping to this section to somewhat clear the view of the tunnel from the bridge and vice versa - so we're looking forward to further work, now that the major physical obstacle to completion of the route is out of the way.

A postscript - while the document touches on the Lyncombe Vale stretch of the route "... which is already extremely attractive and on which only the minimum treatment will be necessary" the proposal misses the fact that to this day, while it's an open space, public access is limited to the reasonably fit and agile. The Two Tunnels project will address this, at least by opening up the subterranean approaches!

In the event, the only treatment meted out to Lyncombe Vale appears to have been the sealing of Devonshire's south portal - and even this may have been done by its owners British Rail, it is they who have maintained the tunnel to the present day. The builders of the small steel grill replacement bridge close to Devonshire Tunnel are a mystery - though perhaps a reader knows more.

The report also recommended the sealing of Combe Down "Which will also be sealed within twelve or fifteen feet of its entrance" - they were fond of that approach.

As it happened, Combe Down wasn't sealed for a decade, and a walk through Combe Down Tunnel became part of a regular outing for very many years - when it closed its historic national collection of crisp packets and the odd beer can were encapsulated in the darkness.

The last paragraph of the article is unsettling, suggesting as it does the completion of Linear Park as a series of linked project over a time period of five or six years. Bearing in mind that the engineer who would later complete the Severn Rail Tunnel organised the entire S&D new line into being in less than two - using 3000 men with hand tools ... perhaps in the 21st century we could aspire to something better, given that the Two Tunnels route is a small fraction of the length, and minimal construction is involved?

You are invited to join us in regarding the clock as having started ticking in early March 2006.

It might be that once again we'll need the supporters to speak out in favour of the route - we've a great many, but you're not all signed up to our mailing list - it's always somehow easier to build up big numbers campaigning against something rather than for it. If you know someone who'd be keen to support the Two Tunnels route, now would be a good time to talk them round to joining either our mailing list or the 400+ people on our Facebook group.





Monday 19 April 2010

Northern Link to the Bath to Bristol Railway path

Slightly off topic as construction of this section is some way off, but Rob was enquiring about getting to and from the Bath to Bristol Railway path across the Lower Bristol Road. As this is something that has had little exposure I thought it might be worth a posting, albeit well in advance of any work starting. (nb - this section will be managed by B&NES as part of the Bath Transport Package (BTP) which is currently held up by legal challenges over the compulsory purchase elements of the Rapid Transit Route. If BTP funding were withdrawn as a result then this section would need to be funded from the annual Government transport grant which cannot be guaranteed. So, we await developments.)

Access would be via Inverness Road, which runs into Burnham Road.

Above is part of a draft plan produced by The Council Highways Dept (with my additional scribbling). It shows:
  • Where Burnham Road joins the Lower Bristol Road, a widened [shared use] footway/cycleway would be created towards Jews Lane to the west.
  • The current ‘Pelican’ crossing would be upgraded to a ‘Toucan’ crossing.
  • The short section on the northern side of the road to Fieldings Road bridge would become a [shared use] Footway/Cycleway.
  • The Fielding Road Bridge would then give access across the river to the Bath to Bristol Railway path.
Assuming this becomes a reality B&NES is to be congratulated on providing an excellent link between the two paths.

Another link into the city centre via the Western Riverside Development has also been discussed but is a bit more complicated and no plans are yet in place.

Note also the Herman Miller building that runs along the length of this section which LIDL has applied for planning permission (Reference 09/02140/FUL) to turn into one of their stores. Well done them in placing a bike store at the western end of the proposed building, thereby making life a little easier for cyclists. It has also been requested that, if the planning application is successful, the company should site any refreshment facility at the western end of the building to provide easy access to the many hungry and thirsty pedestrians and cyclists passing by!

Thursday 15 April 2010

The next dig thing

Just a few short weeks, and the new route's brought great changes to the top end of Linear Park. The current newcomer being what appears to be a red carpet, rolled out perhaps to honour two particular teenagers who along with their footsteps appear to have been quietly haunting the place.

The Devonshire Tunnel excavation isn't representative of the work needed to the rest of the Two Tunnels route - most of it doesn't involve excavating to a depth of around seven metres.
We're grateful for the forbearance of the immediate neighbours to this task, some of this work has not been quiet, it's involved the removal of trees, and much has invoked what have been described as 'Dragons' or 'Dinosaurs' rather than the 3000 or so pairs of hands that originally built the railway. (At other times we know them as diggers)

At the same time, many have seen the work first hand, and have also enjoyed the sight of the surprising number of visitors who've been up to the various fences to view the emerging tunnel, now in plain view, albeit behind the block wall. Some of these visitors have travelled a surprising distance to see the work in progress - if you can beat Glastonbury (by bus), do tell us - post a comment.

This phase of the contract being almost at an end, we continue to be grateful to the contractors Hope and Clay for turning out such a professional job - as has been remarked on in the steering group, something that was remarked on in the latest steering group meeting notes. This has been more than an ordinary excavation and as at least one visitor has observed, in the eyes of many thousands of people the old railway between Bath and Midford deserves to be as much of a world heritage site as any other location with that distinction. It's also the (unintentionally beautiful) product of a great deal of human endeavour, and while it's most unlikely to host trains once more, it is at least being thought of in one piece again.

Not that the old line can't produce a few surprises as far as trains are concerned. Late on Wednesday afternoon, a small party from the Two Tunnels committee visited the excavation courtesy of a neighbour. We were a little late, but at the moment we stepped up to the neighbour's garden fence and the portal of Devonshire Tunnel hove into view, a loco whistle from 35028 Clan Line sounded clearly across Oldfield Park from the present-day line through Bath - another truly scalp-tingling moment. To cap this, five minutes later, down in the cutting in warm sunlight, a heavy beat as the loco accelerated from its stop at Bath Spa caused us all to glance down beneath Maple Grove bridge - just to be sure.

So, what's next? Several weeks hiatus, especially because we're awaiting a bat licence, and the block wall will be coming down. Devonshire Tunnel will in due course be providing access to the Lyncombe Vale section, but before that, remedial work both to the tunnel and its portals. Whilst it's in surprisingly good condition after 35 or so years protection beneath the ground, the stone is very wet and will be drying for months, and it also merits a certain amount of removal of harmful concrete pointing and replacement with something more sympathetic. So, onward and upward, or in the case of the ramp, downward ...

Sunday 11 April 2010

Time for some Drainage

The blog post titles just get more gripping, eh?

When first visiting the excavation just a few weeks ago at the end of a cold March day, I remarked that the new excavation was drier underfoot than I expected. The person in charge pointed to a strip of freshly exposed stuff that looked much the same as the rest: 'There's a drain'. I'd not noticed the filled trench - filled with rather grubby railway-ballast-sized stuff, and not easy to see for the uninitiated. The contractors would have continued to put their observational skills to work for the following weeks as they excavated and in some places rearranged the material in the cutting, when they weren't prising it off the tunnel portal. Something's coping, because even the downpours of Good Friday didn't produce more than a puddle or two, though the excavation ran with water. It's obviously going somewhere.

Last Thursday evening provided a complete contrast to late March. It turns out that Devonshire Tunnel's cutting positively basks in evening sunshine, and the excavation was warming up nicely and exuding a fragrance that we'll kindly say was 'Earthy', and will in any case mellow in due course. Glancing light revealed the topsoil spread on the sides to have a thin covering of spider silk. A couple of crows were giving the ground the once over, while the badger sett entrance some way above the tunnel has seen the first small eruption of earth from its mouth for some time.

But, to progress. The contractors have for the most part shaped the down ramp to the tunnel, and much of the spoil that will be removed has now gone from the site. In the photos you'll see two part-completed fenced trenches running out from the tunnel portal. Revisiting, the following evening, the trenches had been extended and then filled with ballast-sized material - new drains to help keep the foundation of the down ramp good and firm. These will take water down the slope and out of the fill, it will then flow into the existing drainage which runs fairly energetically beneath the remaining material in the cutting.

The last two photos are from Friday evening, one shows the tunnel portal and newly filled drains - this image is taken 'Through the fence' from Linear Park - the work is for the present now thoroughly visible from there (with plenty of passers by stopping to look, some of them particularly curious because they remember the tunnel being buried). It will be good when this section is complete and in use as it's going to appear particularly pleasant as well as being dramatic. Chatting to two teenagers who were sitting by their bikes on a fallen tree down by the earth bund observing the goings on (been there done that), they said that while they'd been through Combe Down Tunnel on last year's open day, they couldn't wait to use the entire route.

(If you're interested in a Combe Down Tunnel open day, do put the 17th July in your diary and keep an eye on the web site)

The contractors will now be on site for around another week, and that will be the first work complete - the project's planning then indicates a hiatus for a month or so - preparations for the next stage of building the Two Tunnels route. They still have a little materials moving to complete, some of the ground has thrown up sections of brickwork, perhaps from demolished bridge once again. Much of this part of the route was built either in open country or on the edge of the built up area of the city, and both of the demolished bridges (and the surviving original arch of Claude Avenue overbridge) weren't originally built with the idea that they would cross urban streets - they were more of the nature of accommodation bridges, their traffic-constraining dimensions unfortunately ensured that they have not survived.

Blackthorn
The underbridge that has survived is the three arched structure, Englishcombe Bridge, with a really strong flowering Blackthorn at one end of this - and the viaduct walks you straight past it at tree-top height. The viaduct was photographed to good effect by the author of the 'Forgotten Relics' web site - but here's 'Forgotten Relics' on the Devonshire Tunnel excavation.

Monday 5 April 2010

Two Tunnels Route: a work in progress ...

Devonshire Tunnel loading bank
The excavation continues, and new for last week was the removal of some of the infill from the site. The contractors have laid a haul road right into the work site for this. About 40 lorry loads will go, leaving ... space to excavate some more stuff from the filled cutting. That 'Stuff' has turned out to be as indicated in the test borehole - clean subsoil, pretty heavy and 'Clayey'. Some of it, at a pinch, you could probably throw and fire to make small pots (The site's not a million miles from the location of Oldfield Park's Victoria brickworks too)


Devonshire Tunnel
We've now heard from one of the people who filled the cutting here in the seventies. Apparently, the length between the tunnel and the entrance to the public open space was filled with earthy material from the embankments, the length down to Maple Grove bridge with rubbly stuff from the demolished bridges themselves - hence a largish panel of brickwork that can be seen, flat in the ground to one side of the Linear Park path, not far from the overbridge itself.

This stage of the excavation has lowered the ground level sufficiently that the tunnel portal is now visible to passers by from Linear Park itself.

Devonshire Tunnel from Maple Grove Bridge
This week may also have answered the important question of whether any part of the portal will be visible to someone standing on Maple Grove Bridge. The photo on the left is actually taken from the bridge, and shows that it appears that this will be the case. We're pleased at this: the bridge itself has survived to be a touchstone to the past - generations of people would stand there to watch trains climbing the bank before vanishing into the improbably small mouth of the tunnel itself - some can remember that sight to this day, so it's good to bring this old sightline back into being.

Devonshire Tunnel excavation from above
The weather's not been too unkind, the snows of mid-week stayed in mid-Wales, but there have been a few heavy downpours, and on Friday the excavation was somewhat running with water and had almost managed to accumulate a puddle in the bottom.

When viewed from above, there's an impression of the amount of material that has been removed in the current week. This is a good vantage point for an overview of the work, though it's quite difficult to judge the depth of the excavation. The plan calls for a slope down to the tunnel that's a maximum of one in twenty - any steeper, and it would not be so suitable for anyone who happens to be in a wheelchair - and the 'New' Linear Park will be rather more accessible than the present one - any access ramps following the same 'Ruling gradient' if at all possible.

One resident who has lived in the area for a good many years confirmed the fact that trains in the tunnel very much made their presence felt in the houses above the entire length of it - the ground seems to have been particularly good at carrying the vibration, with the passage of locos, night and day, announced by a low and half-felt rumble, while mantlepiece ornaments tended to need to be stuck down to avoid them walking off the edge and into the hearth.

Looking into Linear Park from above Devonshire Tunnel
You can see that the view along Linear Park itself has somewhat opened out. Research indicates that bats actually appreciate a certain amount of structure in the landscape, as it allows them to navigate more easily. Another need is of course insects, and it will be good if Linear Park continues to be managed to provide habitats that encourage insects (though not to the extent that it becomes a swamp!).

Maple Grove Bridge, in the distance, is actually a three arched structure, and is in good condition - it's well built and has received a waterproof deck and maintenance when needed from the local authority.

Devonshire Tunnel south portal While this work goes on,  the other, now less-regarded portal, at the far end of Devonshire Tunnel awaits its own rather less intensive restoration. For various reasons the entrance is a bit of a swamp, but it's already seen a little activity, in that the contractors have been through from this end to place tell-tales at the northern end of the tunnel to check that the present work isn't causing unmonitored movement. And of course the tunnel itself has been the subject of regular inspections from its owners, the British Railways Board (Residuary). In the image, to the right of the tunnel, copious amounts of wild garlic. The Two Tunnels route is a vampire-free area - and from a historical perspective, there's a tradition that the wild garlic that grows profusely around Bath is a gift from the Romans ...

Work party, Lyncombe Vale, March 15th 2008
The entire length in Lyncombe Vale makes for a good explore, it's still showing the benefits of the Two Tunnels group's 'Litter pick and clearance' work party there one wet March day in 2008. For some years an overgrowth of saplings was threatening to forever close the deep summit cutting beneath Moger's bridge. Since the volunteer day, other smaller scale work (not by us) has ensured that the stretch has stayed reasonably clean and clear. Here's an image from the day that shows a great deal of small stuff on the deck (and if you happened to be there, thanks again!)

Monday 29 March 2010

Bath's Lost Underground Railway

Unseen since 1973, here it is at last. The contractors, Hope and Clay, have just a few feet to go now before they're down to the original level of the trackbed. Pleasingly, the excavation hasn't filled with water. As for the portal, it seems to have survived its burial rather well ...
Given the location, it's just about the most minimal structure possible. The same can't be said for the access shaft built when the cutting was filled - a supporter has suggested that this be retained and moved to a position opposite NCN 24's William Smith monument south of Midford where it can form a balancing counterpart.
Despite the minimalist design, it doesn't mean that the structure misses out on coping stones, or detailing. In the afternoon, the sun finds its way into the cutting. In the dark of the tunnel, the remains of plant fronds that once grew towards the light now wander in the darkness towards the block wall that sealed it. The wall stays for now, as the tunnel may have a few bats in it, and this is not yet a good time of year to disturb them.
It appears that the concrete block wall has not been 'Stuck' to the portal, making its removal rather more easy than if the contractors who filled the cutting had attached it more strongly. In fact they seem to have taken reasonable care to ensure the portal survived undamaged.

Sandbags act as markers for the contractors as they finish excavating the wing walls ... the cutting sides are already somewhat dressed with topsoil. In due course they'll be put to grass, cowslips and blue butterflies.
On the down side of the old line, the support wire for the signal post seen in this image emerges from the fill, one end anchored in the ground and the other perhaps still attached to the felled post. Behind the camera, the contractors still have much earth moving to do.

Friday 26 March 2010

Looks like this was some sort of transport system

Devonshire Tunnel portal excavation
The end of another working week. You'll see that Hope and Clay have been carefully plugging away to excavate the earth from in front of the structure. Their method has been to remove the load on the structure in an 'even handed' way, monitoring for movement as they go - tunnel portals can be sensitive, in that they sit at a junction between made ground and undisturbed material. Hence, they reward being treated appropriately.

The fill is now gone from the portal down to the level of the trackbed. Monitoring will now continue, as movement, if any, is likely to be gradual and occur over weeks in terms of time - and hopefully less than a smidge in extent. The portal, having shrugged off heavy vibration from passing trains for over ninety years, is not likely to be seriously troublesome. (There are several accounts from people who lived above this particular tunnel that mantlepiece ornaments had to be glued down ...)

Devonshire Tunnel portal excavation
The cylindrical structure is the access shaft built when the tunnel was sealed. At a later stage the original access was tending to bury itself, and the shaft had a bit of an extension added to its top - if you've visited the cutting you'll remember this, around four feet high and buried in brambles. The contractors have tidily removed the extension - they swiped it off in one piece with a bucket - Matt happened to be there at the time. After removing the extension they've put a new cover on the access shaft.

Devonshire Tunnel portal excavation
Both shaft and block wall stays put for the moment, as it's not yet a good time of year to alter the environment for the (very few if any) bats inside. Another aspect of the task is that topsoil and subsoil are treated separately, subsoil can then be reused where appropriate in the excavation and later covered with topsoil in which things will grow. The images show that some of the cutting sides are already dressed with topsoil - the final part of their treatment involves grassing them over, but the topsoil itself will also contain seeds from previous years growth and will provide continuity.

This unveiling is a bit like a birthday present for the project, after four years of anticipation. It's a present which is pretty well unwrapped now, but for the time being it's not easy to see and very much a work in progress - looking from the direction of Maple Grove bridge, the spoil heap's in the way.

There was a concern that they may have been damaged, but it looks as though the tunnel portal's wing walls - at either side - are going to be fine - the photos show a glimpse of the up side wall capped by its coping stones. Unlike our three other portals, this one seems to be 'As built'.

Lined up against the other architecture the city can provide, this structure is inconsequential. However, many of us find that it feels particularly good to have it back.

Wednesday 24 March 2010

Work continues at Devonshire Tunnel

Wed 24 Mar 10, and, despite the dreary weather, the Hope Clay diggers continue apace. Working in tandem, this YouTube video shows how one digger removes spoil from the tunnel portal and the other moves it back towards the spoil heap.

Thursday 18 March 2010

There's something in the pit ...

The contractors - Hope and Clay - have now dug an initial pit - with the intention of proving the location of the tunnel portal and also its condition - it was quite possible that the structure had been seriously damaged in the process of burying it.

However, a length of the capping stones to the portal itself are now in the light for the first time since the nineteen seventies, and it appears that the team that worked to fill the cutting all those years ago took good care not to damage it. This is thoroughly good news for the Two Tunnels project.

There could not be a greater contrast between this tunnel portal and that of Brunel's Box tunnel built some miles to the east and some forty years earlier but each tells its own tale and it will be good to have this one back. Please revisit the blog as we hope to have more photos online shortly.

If you intend to visit the works, please note that for the time being the tunnel portal will remain some way inside the safety fencing surrounding the works area. If you're on foot, the public road above the tunnel portal itself gives a good overview of the entire length between the tunnel portal and Maple Grove bridge.

On the subject of the contractors, we've the early impression that we're fortunate to have an experienced and well trained team working to shape the new entrance to Devonshire Tunnel on this as yet little recognised but landmark project for the city. Should you encounter or visit the works you can play a part in letting them know they're welcome - and making a not-straightforward job of excavating the tunnel portal without damage to it as easy as possible.