It could only be London – the energy, the din, the bustling humanity. One of the city’s red double-deckers plots a course through the traffic; half-a-dozen folk wait in line for it. A thirty-something woman, tanned by Cuprinol, perches on inexplicable heels. Her partner shoulders the spoils of shopping: four assorted bags. She jabs him – “Youz gorra cob on?” Others look around. He feigns a smile, clearly unnerved by an Ann Summers purchase. If only the underground was open – less conspicuous down there; anonymity in the shadows. But the station’s shut for refurbishment. They board the bus – a perilous operation – and vanish. Show’s over.

It could only be London. Britain’s 37th busiest underground station. 17.9 million passengers in 2010/11 – more than Marble Arch, Warren Street, Tooting Broadway. A £20 million investment transforms another crucial gateway. The price – a four-month shutdown; August will bring the first benefits. It must be London. But the bus was a red herring, exported from the capital to keep people on the move. “Heels” spoke fluent Scouse. It could only be Liverpool Central.

Capital gains

The station began life above ground on 2 March 1874, becoming the Cheshire Lines Committee’s (CLC) city centre terminus and headquarters. From its six platforms, travellers could journey to London, Hull, Harwich or Southport, and reach Manchester Central in 45 minutes. In January 1892, Low Level platforms were added to serve trains arriving from the Wirral via an extended Mersey Tunnel.

The 1960s brought Beeching’s “reshaping” to Liverpool, with many services refocused on Lime Street. Central High Level closed in 1972. But Merseyrail emerged, integrating a collection of lines into a single system via new tunnels driven under the city. One brought the former CLC route down to Central’s Low Level platforms; a second branched off the Mersey Tunnel, pushing northwards to join the approach lines into the former Liverpool Exchange, creating a through route from Hunts Cross to Southport; a third took Wirral trains in a clockwise loop, serving a single deep-level platform at Central. Although some grander plans have not yet been realised, subsequent expansion has pushed the network’s route-mile count upwards to 75, featuring 67 stations.

Liverpool Central was resurrected in its current configuration on 9 May 1977. Passenger use climbed rapidly through the Noughties, peaking at 19.6 million in 2008/9. A major overhaul of the Loop Line stations was pledged late in 2007 with the aim of raising passenger capacity and easing flows. Coalition cuts put the scheme in jeopardy, but an alternative funding package of £40 million – coming from Network Rail, Merseytravel and the European Rail Development Fund – was secured last September, allowing improvement works to proceed at James Street, Lime Street and, most substantively, at Central.

Access is everything

Mustard no longer cuts it as a colour scheme; the Seventies have much to answer for. But the benefits of Central’s project – well, two projects actually – will go far beyond aesthetics, bringing light and space to the concourse, more room on the Northern Line platforms and compliance with today’s fire regulations, specifically the Fire Precautions (Sub-surface Railway Stations) England Regulations 2009 which were made in exercise of the powers conferred by article 24 of the Regulatory Reform (Fire Safety) Order 2005. You’ll be tested later.

Upstairs, the transformation of the concourse is being delivered by Merseyrail through its contractor Strategic Team Group. Downstairs, Morgan Sindall is forging ahead with the Network Rail-led scheme on the platforms, escalators and passageways. Given the physical constraints here, access arrangements are critical and the teams have invested a great deal of time getting them right. All the equipment and materials have to go through the concourse where designated routes have been established to facilitate this. There’s a handover period every evening when the 24-hour Network Rail operation takes temporary ownership of the concourse until the Merseyrail site starts up again the following morning. Matters arising are sorted out at a daily interface meeting.

Around all this trains continue to run, separated from the worksite by Heras fencing which offers passengers a glimpse into the future as they trundle past. Creating a high street environment has allowed the project to benefit from non-rail techniques and specialists, working around-the-clock rather being restricted to four hours overnight. For most activities, this cuts through the need for Sentinel competencies, lessening both the training burden and the associated costs.

Within the wider railway community, there had been some initial difficulty with the concept that this is no longer a sub-surface station with all the attendant regulations. For the next few months it’s a building site. But that mindset has been reshaped through positive communication. The knowledge and experience accrued by Morgan Sindall undertaking similar works on London Underground has also proved invaluable. No-one had ever seen a worksite being hoovered before!

Continued access to the operational railway clearly remains vital, requiring the briefing and induction of maintenance staff in fair numbers before the site was mobilised. Provision has also been made for the emergency detraining of passengers through the station, something they had chance to practice in the first week following a power failure. All went as it should.

Move along now

Closing Central – which serves as the city’s main shopper and commuter gateway – is obviously a big deal, but fears expressed in the run-up have not generally come to fruition. The publicity machine was in overdrive as D-day approached. Timings were set with landmark events in mind – avoiding the Grand National and reopening to Wirral Line trains in time for this August’s Mathew Street Music Festival. October sees the Northern Line’s return. At a micro commercial level, Central brings footfall to the adjoining shops so events have been staged to coax people back through their doors. And beyond, the replacement bus service continues to do good business, relieving the pain by feeding travellers seamlessly to alternative services nearby.

One of the works’ key aims is to ease passenger management by creating extra space. During April’s Titanic commemorations, three giant marionettes visited Liverpool attracting crowds in excess of 250,000. This led to an hour-long queue just to get into the station. So the single ticket line is being staggered and walls are coming down to increase the concourse footprint, with staff accommodation moving to a new building on the former High Level station site.

Glazed walls, courtesy of System Glazing, and an ETFE (ethylene tetrafluoroethylene) roof from Novum Structures will transform the outlook of this formerly dingy place. Access to the lift is being brought indoors which should encourage more use of it. There’ll be bigger and better toilet facilities. Although all this involves everyday fabrication processes, getting cabins and components into the heart of the station was a head-scratcher that could only be overcome with cranes – and big ones at that.

Along with new wayfinder signage, the siting and number of information screens is being addressed to hopefully stifle the urge of some passengers to run for their trains. The Northern Line platforms will be opened up by removing redundant infrastructure and relocating equipment. This will enable two plant rooms to be demolished. Removable seating will offer even more capacity during the city’s bigger events. By resolving the pinch points, the overall affect should be to improve passenger flows.

Ups and downs

The 35-year-old escalators have a role to play in this: of the station’s ten, four are being replaced. These will come by road, brought through the concourse, except for the longest – connecting the Northern and Wirral lines – which an RRV is due to deliver. The existing one disappeared by rail during a 29-hour possession on 17 June.

The escalator’s skeleton has to be jacked off its support plinths onto specially installed trackways and is then winched out in 4metre sections. Posing the most substantial test is the main motor, weighing 1½ tonnes, which sits under the floor at the bottom. Its replacement is smaller and more efficient, and placed at the top. Size wise, the other new components have been designed to mimic the old, easing the installation process.

But inserted into the works is a small Eurocode spanner. Three level treads are now specified for both entry and egress rather than two previously, meaning that the base dimension of the new escalators is about a metre longer. To minimise the physical implications, existing foundations and connections are being retained at the top whilst the bottom end is to be extended further into the undercroft. Although this will eat into the space available, with modern escalators there is no longer any need to send manpower underneath; they are maintained entirely from the surface.

All fired up

Cellactite is a ubiquitous product in sub-surface stations, comprising corrugated steel sheeting coated in bitumen and reinforced with asbestos fibres. It’s used as a wall-mounted barrier that enables penetrating water to be collected and managed. But Cellactite was implicated in the devastating fire that claimed 31 victims at King’s Cross Underground Station in 1987. Today, whenever such stations are refurbished, the requirement is to remove, neutralise or protect it.

Throughout Liverpool Central, all the existing fire doors and floor tiles are being stripped out; so too is the wall cladding although its sub-frame is being retained. Specialist contractor Firesafe is then fitting Riblath, a keying and anti-cracking mesh, above the Cellactite before applying a 20mm coating of Mandolite to give 60 minutes fire resistance at 300°C. This works in conjunction with other systems (fire blankets or boarding) for cable protection. Over that is going new powder-coated steel cladding or, alongside passenger areas, vitreous enamel. SAS International is fulfilling this element.

Maintenance possessions are exploited to access the Wirral Line tunnel, providing nightly work periods of about 3½ hours. The Riblath goes up one night; the spraying is done the next – both require scaffolding. Time wise, considerable discipline is demanded as the Mandolite has to be sprayed and set before the morning’s first train comes through. Fortunately, the existing Northern Line fire protection is relatively new and doesn’t need substantive attention.

More of the same

It’s not only Liverpool Central. When the work here is done, the Network Rail team will move on to James Street Station, finishing in April 2013, and thereafter to Lime Street. Both projects involve fire protection measures only, the latter having to close fully as it just hosts a single platform.

Making judgements about a scheme part way through it is fraught with danger. It’s best not to tempt fate. But externally, Liverpool seems not to have missed a beat despite Central being right at the heart of its transport network. Proactive communications keep passengers in the loop whilst well-planned bus services get them where they need to be. And internally, the close working relationship developed by the two teams ensures both can do what they need to without unduly impacting on each other, despite the physical constraints. There’s a clear commitment to make things work.

It could only be London – the capital’s Underground system is unique. But the approach adopted by contractors to deliver improvements in its sub-surface stations has wider logistical and budgetary value. In these days of heightened scrutiny, the industry is wise to learn lessons from wherever it can. They’re doing just that at Liverpool Central.

Many thanks to Lucianne Lord of Network Rail, Merseyrail’s Simon Olorenshaw and John Boothman from Morgan Sindall for their technical help with this article.