A Look Under Kingsway

Our previous excursion into the disused City Widened Lines beneath Smithfield prompted a certain amount of thought. The opportunity arose thanks to the need to carry out compensation grouting ahead of the passage of the Crossrail TBMs below, leading to the Line’s being temporarily occupied by Crossrail themselves as a worksite. Given the length and route of the Crossrail tunnels therefore, and the likely need for grouting elsewhere, what other sites within the City might this present a rare chance to take a closer look at?

It was Crossrail themselves who swiftly spotted a similar opportunity and helpfully arranged access – the Kingsway Tram Tunnel.

As with the Widened Lines, the new Crossrail tunnels will pass at depth beneath Kingsway, with a crossover connection also present. Strengthening the ground within the immediate area of Southampton Row is thus required in order to mitigate any risk of subsidence. The presence of the remains of the Kingsway Tram Tunnel is thus rather fortuitous, as it allows two shafts to be driven down from within through which the grouting can be carried out, without disruption to one of London’s key thoroughfares above.

Construction of the first of those shafts is now under way, and photos of this can be found below. Perhaps more importantly, the relatively early stage of the works also meant an opporunity to push on further into the remains of the northern section of the Tunnel to Holborn Tram station and beyond.

As with the Widened Lines, Ianvisits was our companion on this trip. The Indiana to our Henry Jones, his look at the Tunnel can be found here, and is well worth a read.

An Opportunity for Joined Up Thinking

Before looking at the state of the Tunnel today, it is perhaps worth providing some historical context. As the end of the Nineteenth Century approached, London County Council began to look at a variety of options for sorting out the increasingly congested streets north of Waterloo Bridge and above the Strand. After much debate, and in the face of some opposition, it was decided that a radical and complete reworking of the Holborn area was necessary, with a considerable amount of the existing area demolished in order to make way for a new, wide thoroughfare stretching from High Holborn in the north down to the Embankment. This plan would create Kingsway and Aldwych, as we know them today.

From a relatively early stage, the Council realised that the construction of this new thoroughfare presented a rare opportunity to carry out some major transport works as well, allowing tram traffic and road traffic to be properly separated. A shallow tram tunnel – the first of its kind – could be built beneath the new thoroughfare, with much of the work being carried out using a cut-and-cover method during the schemes works.

Initially the LCC’s plans for the tunnel were rather ambitious. They argued for a scheme that would see the tram tunnel run as far as Westminster. Ultimately, however, a more limited scheme was agreed, with the track dipping below the surface just south of Theobalds road and then proceeding beneath Kingsway and Aldwych with stations at both the Holborn and Aldwych ends. Indeed even as construction on this section of the tunnel proceeded, there was considerable debate about the ultimate destination of the tunnel in the south. As late as 1905, argument continued, and indeed the first services run through the tunnel in 1906 terminated at Aldwych.

Finally, it was agreed that the tunnel would curve under the strand and link through to the Embankment by Waterloo Bridge, with a proposed station on the corner of Wellington Street and the Strand becoming a casualty in the design process. This section finally opened, allowing through traffic for the first time, in 1908. As with the most northerly section at Southampton Row, two iron-ringed tubes were bored were the tunnel passed beneath existing roads.

Construction of this final section of tunnel was not without incident. The route of the tunnel meant passing beneath Wellington Road, the viaduct-based road which connects Waterloo Bridge to the Strand. During excavation of the tunnel it was discovered that piers on which the viaduct had been constructed simply sat on a wooden raft which floated on the Thames mud beneath. The replacement of this with piers bedded on a heavy duty concrete frame was quickly carried out, at some cost in both money and time.

Ultimately, tram services ran through the tunnel until 1952, when the replacement of trams services through the tunnel with diesel bus services made it redundant.

Almost immediately, the possibility of using the tunnel (or a section of it) for road traffic began to be mooted. It was not until 1957, however, that a concrete plan for this began to emerge. By 1964 this had finally come to fruition, with the southern section of the tunnel becoming the Strand Underpass.

Heading into the tunnel

The section of tunnel that remains today is the “orphaned” Northern end, stretching from where the tunnel dips beneath the surface on Southampton Row almost as far as the site of the old Aldwych tram stop to the south. As can be seen from the photos below it has been (and indeed still is) used largely as a convenient Central London storage space by both Camden and Westminster Councils up until the current day.

As can be seen above, the gradient on the northern entrance is rather steep – 1:10 – which caused a certain amount of trouble for the earlier trams that used the tunnel. The walls of the tunnel portal are lined with white ceramic tiles. The original plan was for these to run throughout the tunnel, but ultimately only the portal and the station spaces were tiled in order to save money.

Eagle eyes will have noticed that the tunnel entrance today differs greatly from that pictured in the early twentieth century photo above. This is more obvious in the close up image below, in which the original iron tubes are clearly visible.

This change came about due to the need to rework the tunnel to accomodate double-decker trams. There had been considerable pressure from various parties to “future-proof” the tunnel for double-decker trams at the time of its construction. This would have required the tunnel to be built to a height of 17ft rather than 14ft, but it was decided that the increased cost and complexity this added to the project outweighed the benefits. By 1929, however, it had become clear that the tunnel needed to accomodate double-deckers to be effective value for money and a large conversion project was undertaken. This saw the old iron tube sections removed, the entrances reworked and the tunnel floor dropped by several feet. Double-decker services began to run through the tunnel from 1931 onwards.

The Crossrail shaft sits just within the tunnel entrance. It’s a tight space, with relatively little room to manoeuvre.

Crossrail’s presence within the tunnel provides a short stretch of illuminated tunnel section. This gives a good idea of the size of the tunnel, and also the roofwork – which includes a support frame obviously added at some point after the tunnel closed to tram traffic.

Moving beyond the Crossrail site, the tunnel floor dips slightly. This is due to the presence of the Fleet sewer above, which was too costly to divert. Beyond this point, the lighting becomes much more limited. Indeed by Holborn station and beyond the tunnel becomes a dark, dusty place. Most of the photos beyond this point are lit largely by flash, although some with natural light levels are included to give context.

Much of the structure of Holborn station still remains, although it is now largely unlit. It’s an island platform, with track on both sides. The tiling has long since gone, although the advertising spaces are still visible. Much of the space is now occupied by stockpiled municipal furniture.

It’s a long platform, with two narrow entrances granting access to it from the street above.

A small office space sits below the northern entrance, now stripped of all its contents.

Moving beyond Holborn station, the tunnel proceeds on the same level in a straight line towards Aldwych. A dark space filled with a wide variety of municipal furniture and paving supplies, torchlight reveals the occasional pile of bollards or road signs.

The southern end of what remains of the tunnel is occupied by a power substation. This will shortly be permanently relocated out of the tunnel in order to allow the second grouting shaft to be dug out. It effectively marks the point beyond which further travel is not possible, where the remains of the tunnel meet the Strand Underpass, roughly at the point where Aldwych station once sat.

Looking back from the substation, the tunnel stretches off north into the darkness.

Overall, it’s clear that a considerable amount of space still remains beneath Kingsway, despite the repurposing of the southern end of the Kingsway tunnel as the Strand Underpass. That said, it is perhaps one of the few areas of forgotten transport infrastructure beneath the centre of the City for which no practical transport use could arguably be found. Whether that means it is destined to remain a storage space forever though, will be interesting to see.