TheWirral line is one of twocommuter rail routes operated byMerseyrail and centred onMerseyside,^[7] England, the other being theNorthern line.

Wirral line
AClass 777EMU on a Wirral line service preparing to departChester.
Overview
Status	Operational
Owner	Network Rail
Locale	Merseyside Cheshire
Termini	Chester Ellesmere Port New Brighton West Kirby
Stations	34
Service
Type	Commuter rail
System	National Rail
Operator(s)	Merseyrail[1]
Depot(s)	Birkenhead North TMD
Rolling stock	Class 777
Technical
Line length	33 miles 46 chains (54.0 km)[2]
Number of tracks	Two (One through loop tunnel)[2]
Track gauge	4 ft 8+1⁄2 in (1,435 mm)standard gauge
Loading gauge	W6[3]
Electrification	750 V DC third rail[4]
Operating speed	70 mph (110 km/h) maximum[2][3][5][6]
Route map

v t e Wirral line
Legend
Birkenhead Railway toHooton West Kirby Station Road Hoylake Manor Road Meols Carr Lane Moreton New Brighton Leasowe Warren Reeds Lane Wallasey Grove Road M53 Wallasey Village Borderlands line toWrexham Central M53 Bidston Seacombe & Egremont Liscard and Poulton The Birket Birkenhead North TMD Birkenhead Dock Branch Birkenhead North Birkenhead Woodside Birkenhead Park Monks Ferry Birkenhead Town Conway Park Birkenhead Mollington Street TMD Birkenhead Hamilton Square Mersey Railway Tunnel underRiver Mersey Birkenhead Central James Street Liverpool Central Moorfields Northern line toHunts Cross Northern line toSouthport/Ormskirk/Kirkby Liverpool Lime Street clockwise only through loop Green Lane Tranmere Rock Ferry Rock Lane Bebington Port Sunlight Spital Bromborough Rake Bromborough Eastham Rake M53 Hooton Birkenhead Railway toWest Kirby Merseytravel limit Little Sutton Ledsham Overpool Eastham Oil Terminal Capenhurst Manisty Wharf M56 Ellesmere Port Mollington Hooton–Helsby line toHelsby Shropshire Union Canal Upton-by-Chester Chester–Warrington line toWarrington Bank Quay Bache Mid-Cheshire line toStockport,Manchester Chester & Connah's Quay Railway Mickle Trafford toShotton   toHolyhead &Wrexham General Chester Chester Northgate North Wales Coast Line toCrewe

The Wirral line connectsLiverpool to theWirral Peninsula via the Mersey Railway Tunnel, with branches toNew Brighton,West Kirby,Chester andEllesmere Port.^[8][9] Beneath Liverpool, the line follows a clockwise circular route in a single-track tunnel called the Loop, built in the early 1970s.^[8][10]

The Wirral line has carried its present name since the opening of the Merseyrail network by QueenElizabeth II on 25 October 1978,^[11] during theBritish Rail period. The Wirral line is fully electrified with a DCthird rail,^[8] and has existed in its current form since May 1994 with the start of electric services toEllesmere Port.^[12][13] A total of 34 stations are served, with connections available to mainline services atLiverpool Lime Street,Bidston,Ellesmere Port andChester. The line also connects with the Northern line of the Merseyrail network atLiverpool Central andMoorfields.^[14]

The Wirral line was not originally conceived as a single route, but uses several railway lines built by individual privaterailway companies. Even after theGrouping Act of 1921, three of theBig Four companies were active on the Wirral Peninsula until thenationalisation of the railways in 1948, when all four were absorbed intoBritish Railways.^[15][16] During the 1970s, under British Rail, the Merseyrail network was developed.^[17]Privatisation during the 1990s has resulted in services once again being run by private operators.

Part of theChester and Birkenhead Railway forms the oldest section of today's Wirral line. The route between the two settlements was surveyed byGeorge Stephenson in 1830,^[18] but the railway company itself was not incorporated until 12 July 1837,^[19] after a previousbill had been rejected a few months earlier.^[20] Between 1830 and 1837, an alternative route was surveyed byFrancis Giles,^[18] but Stephenson's plans were favoured. Construction work started in May 1838 and was allocated to three different contractors. By October 1839, over 900 navvies and 40 horses were employed on the southern 5 miles 37 chains (8.8 km) of the route, which included the construction of Mollington Viaduct over theShropshire Union Canal atMoston, nowGrade II listed. In 2011 this viaduct underwent strengthening work at a cost of around £800,000.^[20][21][22] The total cost of the railway was around £513,000, more than double the original estimate of £250,000, and the full length of14 miles71+3⁄4 chains (23.97 km)^[23] opened as asingle-track line on 23 September 1840 between temporary termini atGrange Lane inBirkenhead and Brook Street in Chester, close to the present location ofChester railway station.^[24][25] The inaugural service was operated by locomotive "The Wirral", taking 50 minutes to travel the length of the line from Birkenhead.^[20] In 1842, the company purchasedMonks Ferry station^[24] and extended the railway north from Grange Lane to reach the new combined rail and ferry terminal, which opened on 23 October 1844.^[25] On 22 July 1847, the line was merged with theBirkenhead, Lancashire and Cheshire Railway into theBirkenhead, Lancashire and Cheshire Junction Railway, who doubled the track.^[26] Chester General station opened a year later on 1 August 1848,^[20][27] still extant today as the southern terminus of the Wirral line and renamed to simply "Chester" in 1969 following the closure of Chester's other station,Chester Northgate.^[28] In 1859, the Birkenhead, Lancashire and Cheshire Junction Railway shortened its name to become the Birkenhead Railway, but was taken over in 1860 by theGreat Western Railway (GWR) and theLondon and North Western Railway (LNWR), who operated the line as ajoint affair known as the Birkenhead Joint Railway.^[26][29]Birkenhead Woodside station opened on 31 March 1878 as a new terminus to replace the facilities at Monks Ferry. To connect the new station to the railway, a 0.5 miles (0.80 km) tunnel was dug using thecut and cover method.^[30]

On 28 July 1863, the Hoylake Railway was incorporated due to the Hoylake Railway Act 1863 being grantedroyal assent,^[31][32] which authorised the construction of a railway line between Birkenhead andHoylake.^[33] A 5 miles 22 chains (8.5 km) single track line was constructed betweenHoylake andBirkenhead Dock (adjacent to Wallasey Bridge Road),^[34] and the railway opened to passengers on 2 July 1866.^[32] The railway had ambitious plans that included the construction of a bridge across theDee Estuary to join the LNWRNorth Wales Coast Line atMostyn,^[35] but due to financial difficulties the company went into receivership on 13 February 1869.^[32] The railway was bought by the Hoylake and Birkenhead Tramway Company, who passed a bill for a new tramway from the Bridge Road station toWoodside Ferry Terminal on 18 July 1872.^[36] The Hoylake Railway reopened on 1 August 1872, and in 1878 was extended to West Kirby to the west and an interchange with the tramway and theMersey Docks and Harbour Board railway system to the east where Birkenhead Dock station had been built.^[32][34] The tramway was sold to the Birkenhead Tramways Company on 11 October 1879^[34] which was already operating other tramways in Birkenhead.^[37] On 18 July 1881, the railway became theSeacombe, Hoylake & Deeside Railway Company and acts were passed for lines toSeacombe,Deeside andWarren Drive, later extended to New Brighton.^[34] Before these extensions were complete, the railway became theWirral Railway Company and a decision was made to double the track as far as the western terminus at West Kirby.^[32]

Whilst the new lines to Seacombe and New Brighton were being surveyed and built, a new joint company, later to become theNorth Wales and Liverpool Railway Company (NW&LR), took over the construction of the Deeside line due to a lack of Wirral Railway funds.^[38] The planned NW&LR route would pass through the heart of the Wirral Peninsula fromBidston on the Wirral Railway toHawarden Bridge inFlintshire,Wales where it would meet theChester and Connah's Quay Railway and theWrexham, Mold and Connah's Quay Railway (WM&CQR).^[32] The North Wales and Liverpool Railway opened for passengers on 18 May 1896, but powers to extend the service from Bidston to the more appealing destination of Seacombe were not granted until 1898.^[34] The NW&LR and WM&CQR were both acquired by theGreat Central Railway (GCR) on 1 January 1905,^[39][40][41] and due to a high level of goods traffic the GCR opened a new connection to the docks in 1907 as part of what forms the now-disusedBirkenhead Dock Branch.^[32][42] Today, the railway from Bidston to Hawarden Bridge forms the northern part of theBorderlands line which is the only railway line on the Wirral that does not form a part of the present-day Wirral line.

The first proposal to connect Birkenhead and Liverpool by a rail tunnel was made in 1864 by the Liverpool and Birkenhead Railway Company. The bill received the support of the chairman of the Mersey Docks and Harbour Board and ofJohn Laird, theMember of Parliament for Birkenhead at the time, although ultimately it was unsuccessful due to strong opposition from the LNWR.^[44] A second tunnel proposal was made in 1865 bySir Charles Fox, who planned to build a single trackpneumatic railway under theMersey between the two settlements. TheMersey Railway Act 1866 was passed , although the project was hindered with knowledge of engineering difficulties and limitations with pneumatic railways in other parts of the country.^[45][46] On 22 December 1869, Fox held a meeting with Liverpool businessmen and merchants where it was decided that the pneumatic single track railway would be substituted with a conventional steam double track line. Powers for the Mersey Railway Company to build a steam railway were granted in 1871 as well as those to extend the original planned route to connect with the jointGreat Western andLondon and North Western railway atRock Ferry.^[47]

A contract was made withJohn Dickson to raise the necessary funding and then construct the railway, but he soon became bankrupt.^[47][48] Work on constructing the tunnel did not commence until December 1879 when a preliminary contract was entered withMajor Samuel Isaac, a London businessman, to dig a pilot tunnel for determining the nature of the strata beneath the Mersey.^[47] Isaac subcontracted the construction work toJohn Waddell & Sons ofEdinburgh who appointedJames Brunlees andCharles Douglas Fox, eldest son of Sir Charles Fox, as engineers in chief.^[49][48] Two shafts were dug in the grounds of the Mersey Docks and Harbour Board for the pilot tunnel - one in Birkenhead with a diameter of 17 feet 6 inches (5.33 m) and the other in Liverpool of diameter 15 feet (4.6 m).^[49] It was determined that there was an almost uninterrupted stratum of red sandstone beneath the river^[50] and as a result construction began in August 1881,^[51] before the pilot bore had been completed.^[49]

A total of three tunnels were constructed – the main railway tunnel, a ventilation tunnel and a drainage tunnel. The railway tunnel was horseshoe shaped^[51] and bored to a width of 26 feet (7.9 m) and height of 19 feet (5.8 m) for twostandard gauge tracks.^[52] With six layers of brickwork through sandstone and eight courses through clay,^[51] a total of around 38 million bricks were required.^[52] The drainage tunnel sloped down from the centre to pumping shafts on each side of the river each 52 metres (171 ft) deep, lined with cast iron through water-bearing strata, and with a capacity of 364 cubic metres (364,000 L) of water.^[51] Whilst water was encountered during the construction work, it was not a serious problem and the ground under the riverbanks was found to be wetter than that under the river itself.^[48][52] The ventilation tunnel is 7 feet 2 inches (2.18 m) in diameter and was bored 20 feet (6.1 m) parallel to the main tunnel.^[50] In 1883, the rate of work was greatly improved with the deployment of a Beaumont Cutter which was a compressed air boring machine invented byColonel Frederick Beaumont of theRoyal Engineers.^[48][51]

Liverpool Pumping Station was built adjacent toGeorge's Dock and contained a pair of pumps connected to a steam engine. On the opposite bank of the riverShore Road Pumping Station was constructed in Birkenhead. The pumping plants were designed with the capacity to deal with up to four-times the amount of water that entered the drainage tunnel and subsequently the pumping shafts.^[53] Steam-driven ventilating fans were installed atJames Street, Shore Road and midway betweenHamilton Square andBirkenhead Central. The fans combined could draw out of the tunnel 600 cubic yards (460 m³) of air per minute which meant a complete change of air in the tunnel every seven minutes.^[54][50]

At the start of 1884 construction work was pushed ahead with 1,400 men and 177 horses underground.^[53] On 17 January of the same year, two tunnel headings met 1,115 yards (1,020 m) from the Birkenhead shaft. A ceremony marked this occasion withHenry Cecil Raikes PC, Major Isaac, Colonel Beaumont, James Brunlees, Charles Douglas Fox, Robert Paterson (Mayor of Birkenhead) and David Radcliffe (Mayor of Liverpool) present.^[48][55] The tunneling work was complete by the end of 1885 and thousands of members of the public took the opportunity to walk through the gaslit tunnel ahead of its official opening.^[56]

King Edward VII, thenPrince of Wales performed the opening ceremony on 20 January 1886, accompanied byPrince Albert Victor andPrince George, later to become King George V. All three had spent the previous night atEaton Hall and travelled on theRoyal Train betweenChester and Rock Ferry where the locomotive was swapped for a Mersey Railway 0-6-4tank engine and a temporary connection to the Mersey Railway traversed ahead of the journey through the tunnel to Liverpool.^[56] At1 pm, the Prince inaugurated the railway in James Street before attending a meal atLiverpool Town Hall.^[57] The first Mersey Railway passenger service ran ten days later on 1 February 1886.^[57] Around 36,000 passengers travelled on the railway on the first day of service and 2.5 million passengers were carried during the first six months.^[58]

Upon opening, the railway ran from James Street in Liverpool to Green Lane in Birkenhead via intermediate stations atHamilton Square andBirkenhead Central. A branch from Hamilton Square toBirkenhead Park opened on 2 January 1888, where it connected with the Seacombe, Hoylake & Deeside Railway, later to become the Wirral Railway. Once this extension was complete, passengers were able to travel from Hoylake to Liverpool without changing trains as only the locomotives were changed for the Mersey Railway tunnelled section.^[59] On 16 June 1891, an extension was opened from Green Lane to Rock Ferry for connections with the Birkenhead Joint Railway.^[59] A further extension opened in Liverpool on 11 January 1892, from James Street toLiverpool Central^[59] increasing the total length of the railway to 8.4 kilometres (5.2 mi).^[51] This extension was tunnelled using thecut and cover method due to a ban on the use of explosives in Liverpool city centre.^[51][58]

Despite the four ventilation fans, passenger numbers on the railway declined due to the steam engines filling the air with smoke and soot. Coupled with the high cost of running the fans and drainage pumps, the railway found itself bankrupt by 1900.^[51][60] Not long afterwards,George Westinghouse, an engineer and inventor, offered to fund and carry out electrification work on the line.^[61] By the end of April 1903, and at a cost of £300,000, the electrification work was complete,^[62] making the railway Britain's first steam-operated line to be converted to electric traction.^[60][61] A generating station adjacent to the pumping station on Shore Road was built and installed with threeWestinghouse generators which provided 650 VDC to thefourth rail system.^[63] The last steam train departed Liverpool Central on 3 May 1903 at 12.26 am and electric operation commenced that afternoon after a long morning of driver training.^[64][65] Passenger numbers rose again after electrification and the Mersey Railway carried over nine million passengers the following year.^[60]

To operate electric services,24 motor and 33 trailer carriages were constructed ofBaldwin-Westinghouse design.^[66] They were 60 feet (18 m) long, of an American styling, and were manufactured at theBaldwin Locomotive Works inPhiladelphia,Pennsylvania.^[67] Four additional trailer vehicles of the same design were built during 1908 by G. C. Milnes Voss & Company in Birkenhead.^[67][68] The electric Mersey Railway trains all used amultiple unit control system developed by Westinghouse which enabled trains with motor carriages at both ends to be driven from a single cab. From 1904, driving controls were also fitted to selected trailer vehicles which enabled trains to be divided into shorter units during quieter times, yet still be drivable from both ends.^[68] Additional vehicles were added to the fleet in 1925 and 1925, constructed byCravens ofSheffield, and in 1936, built by theGloucester Railway Carriage and Wagon Company.^[69]

TheRailways Act 1921 took effect on 1 January 1923, when most railway companies in Britain were grouped into one of theBig Four. The Wirral Railway became part of theLondon, Midland and Scottish Railway (LMS) company, while the GCR, which it met at Bidston, was absorbed into theLondon and North Eastern Railway (LNER).^[32] The Birkenhead Joint Railway and the Mersey Railway were both unaffected by the grouping of 1923 and remained in existence until thenationalisation of the railways in 1948.

The Wirral Railway had considered electrification since 1900, but plans were not taken any further until 1935, when increasing traffic prompted the LMS torevive the scheme.^[70] Authorisation was granted for the West Kirby and New Brighton lines, and work was completed by February 1938.^[32] The LMS had adopted a650 V DC third rail system which differed from the fourth-rail system of the Mersey Railway.^[34] To allow through services to run to Liverpool, all trains had to be able to operate with both systems, and automatic changeover devices were installed between each set of rails at Birkenhead Park.^[71] The LMS ordered 19 three-car units to operate their new electric services, which were later to become theClass 503 under theTOPS numbering system.^[72] The vehicles were built in Birmingham byMetropolitan Cammell and theBirmingham Railway Carriage and Wagon Company,^[72] and were maintained atBirkenhead Central TMD.^[73] Station improvement and modernisation work also accompanied the electrification work atWest Kirby,Hoylake,Meols,Moreton,Leasowe andNew Brighton.^[34]

With Mersey Railway trains able to use the LMS electrification system and vice versa, on 13 March 1938 the Mersey Railway was given operation of the line from Birkenhead Park to New Brighton in exchange for LMS running powers between Birkenhead Park and Liverpool Central, thus removing the need for passengers to change at Birkenhead Park for travel to Liverpool.^[70] The first direct services from West Kirby and New Brighton to Liverpool Central ran on 14 March 1938, the LMS operating the West Kirby services and the Mersey Railway running the New Brighton services.^[34] To keep LMS and Mersey Railway workers familiar with each other's routes, on Sundays the LMS worked the Rock Ferry services, and the Mersey Railway trains ran to West Kirby. The Mersey Railway also ran additional services to West Kirby onbank holidays to cater forday-trippers.^[74]

During theSecond World War, theLiverpool Blitz of 1940–1941 caused severe damage to the Mersey Railway. While overground services were disrupted on several occasions, underground services always continued, despite damage to station buildings.^[73] The explosion of aparachute mine just west of Birkenhead Park station demolished the carriage shed that was located there; damaged vehicles were sent toWolverton works and extensively rebuilt.^[73] The importance of a rail connection between Liverpool and Birkenhead during the war was such that four redundant six-car trains from theHammersmith & City line of the formerMetropolitan Railway were reconditioned by theLondon Passenger Transport Board and transferred to temporary LMS ownership; however, these trains never saw passenger service on the Wirral, despite being stored at Birkenhead North and Hoylake.^[75]

Nationalisation of the railways took place on 1 January 1948, under theTransport Act 1947.^[15] All lines on the Wirral, including the Mersey Railway, were absorbed into theLondon Midland Region ofBritish Railways. At first, services continued as before, with trains from New Brighton and West Kirby to Liverpool Central, and services on the former Birkenhead Joint Railway from Birkenhead Woodside to destinations such asLondon Paddington, Chester General,North Wales, West Kirby (via Hooton),Wolverhampton Low Level,Birmingham Snow Hill andShrewsbury General.^[30]

In 1955, the original Mersey Railway fourth-rail system was replaced with the third rail system adopted by LMS from Birkenhead Park to New Brighton and West Kirby, removing the need for automatic changeover switches.^[71][76] Despite the design already being 19 years old at the time, a new batch of 28 third-rail-only Class 503 units was delivered the following year. Of these, 24 were ordered as replacements for the original Mersey Railway trains, and the remaining four to replace stock damaged during the Second World War.^[72] As each new train was placed in service, a Mersey Railway train was withdrawn and hauled by steam locomotive toHorwich Works for breaking up.^[77]

In March 1963,Dr Beeching published hisfirst report on the future of the railways, recommending the closure of one third of the country's railway stations, including Birkenhead Woodside.^[78] His second report, in February 1965, proposed 'trunk routes' between major cities, including theWest Coast route between London and Liverpool/Manchester, which was then being electrified.^[79] Once Birkenhead to Birmingham and London services were replaced with electric trains from Liverpool Lime Street, only local diesel services to Chester andHelsby remained using Birkenhead Woodside, which closed to passengers on 5 November 1967. Local services were terminated at Rock Ferry where a change to Liverpool city centre was available.^[30]

The programme of route closures in the early 1960s, known as theBeeching Axe, included the closure of two of Liverpool's mainline terminal stations,Liverpool Exchange andLiverpool Central high-level in Liverpool, and alsoBirkenhead Woodside terminal Station.

Riverside terminal station at the Pier Head was the fourth terminal station to close. This was not a part of the Beeching cuts: the demise of the trans-Atlantic liner trade forced its closure in 1971.

The Beeching Report recommended that the suburban and outer-suburban commuter rail services into both Exchange and Central High-level stations be terminated and that long and medium-distance routes be concentrated onLime Street station. Liverpool City Council took a different view, and proposed the retention of the suburban services and their integration into a regional rapid-transit network. This approach was backed up by the Merseyside Area Land Use and Transportation Study, the MALTS report. Liverpool City Council's proposal was adopted and Merseyrail was born.^[81]

The Merseyside Passenger Transport Authority, later named Merseytravel, was formed in 1969 with representatives from all Merseyside local authorities taking responsibility for the local rail network, henceforth known as 'Merseyrail'. At that time, the lines out of Liverpool Exchange, Liverpool Central Low Level and Liverpool Lime Street stations were completely separate and were given the names of 'Northern line', 'Wirral line' and 'City line' respectively.

The new Wirral line was to have a loop tunnel under Liverpool's city centre which would be an extension of the Mersey Railway tunnel. This arrangement meant trains would only terminate in the Wirral. Trains would leave Wirral terminus stations, run into Liverpool's city centre and loop back out. Four underground stations would be on this loop under Liverpool's city centre. A further underground Link Tunnel connection between a new Moorfields through underground station and Liverpool Central underground creating a Liverpool north-south crossrail was planned. Moorfields would replace Liverpool Exchange terminus station.

The Mersey Railway Extensions Act was passed in 1968 to authorise the first stage of these improvements. TheTransport Act 1968 established the Merseyside Passenger Transport Authority to control policy on public transport in the conurbation, and theMerseyside Passenger Transport Executive to manage ferry services and to make agreements with theNational Bus Company andBritish Railways Board.^[82]

The one track Loop Tunnel was designed to allow trains to run in a clockwise direction beneath Liverpool's city centre. It diverged from the Mersey Railway tunnel beneathMann Island extending the short Huskisson Dock branch tunnel. This short tunnel was designed to extend to Huskinson Dock for freight purposes, however the works never materialized. A new platform was built atJames Street. From James Street the tunnel continued to new deep-level platforms at Moorfields, Liverpool Lime Street and Liverpool Central before rejoining the existing Mersey Railway tunnel beneath theQueen Victoria monument to allow trains to continue serving one of the existing platforms at James Street. The existing 1886 tunnel from James Street to Liverpool central was relegated to shunting purposes.

The Loop is asingle-track tunnel, 2 miles (3.2 km) in length, 4.7 metres (15 ft) in diameter, and was driven during 1972 and 1973 through mainly sandstone rock. The depth of the tunnel varies between 17.6 metres (58 ft) and 37.8 metres (124 ft) lined with concrete. To bore the tunnel, three newDOSCO electro-hydraulic excavating machines were used, giving a maximum work rate of 57 metres (187 ft) per week.^[10]

In addition to the construction of the Loop Tunnel, aburrowing junction was constructed atHamilton Square, taking the line towards Birkenhead Park beneath the Rock Ferry lines. This would allow peak-time frequencies to be increased by removing interfering train paths at theflat crossing.^[83][84] A new platform was built at Hamilton Square for this diversion, and the new tunnel is 620.6 metres (2,036 ft) in length.^[10]

In 1974,Merseyside was created, withMerseyside County Council taking over the responsibilities of the Merseyside Passenger Transport Authority.^[82] TheNorthern line, including the new Link Tunnel between Moorfields and the original Mersey Railway platforms at Liverpool Central, was opened to passengers on 2 May 1977 and the Loop Tunnel opened a week later with Wirral line trains serving Rock Ferry, New Brighton and West Kirby. The first phase of theMerseyrail development was formally opened byQueen Elizabeth II on 25 October 1978, when she visited Liverpool Central station and rode toKirkby on the Northern line.^[80]

To operate the new Merseyrail services, procurement of new stock began for the Wirral line. Following extensive testing ofPEP stock, 43Class 508 units were ordered and constructed atBREL York during 1979–1980.^[85] Due to a stock shortage in theSouthern Region, the new four-car trains were first introduced to operate inner-suburban services fromLondon Waterloo.^[86] This allowed the few remaining4-SUB trains to be withdrawn so that their electrical equipment could be reclaimed for the newClass 455 units. In 1981, the first two Class 508 units were sent north to Birkenhead, and three more were transferred in February 1983 as Class 455s began to enter service.^[85][86] The new Class 455/7 units were originally specified as having four vehicles, but they were delivered with only three vehicles as it was decided that one trailer would be removed from each Class 508 unit before being sent north to Birkenhead.^[87] The remaining Class 508 units were reduced to three carriages and delivered to Birkenhead by December 1984, allowing the Class 503 units to be withdrawn.^[85]

In the early 1980s, plans were made to extend the Wirral line from Rock Ferry toHooton along the former Birkenhead Joint Railway route. Third rail electrification work was carried out during 1985, and Hooton to Liverpool services started on 30 September that year, at a 15-minute frequency.^[88]Bromborough Rake station opened along the line to coincide with the introduction of electric services, anddiesel multiple units provided onwards connections at Hooton to Helsby and Chester.^[12] Further electrification work to Chester andEllesmere Port was planned to start in 1990.^[89] Electric services through to Liverpool from Chester commenced on 3 September 1993 and from Ellesmere Port on 29 May 1994.^[12]

Theprivatisation of British Rail began in 1994 under theRailways Act 1993 and allowed separate parts of the railway to be transferred to theprivate sector. The Merseyrail network continued to operate as part of theRegional Railways sector of British Rail until 11 December 1996 whenMTL was announced as the preferred bidder for the Merseyrail franchise.^[90] MTL ran the Merseyrail franchise as Merseyrail Electrics until 2000, when MTL was sold toArriva by its shareholders and later rebranded asArriva Trains Merseyside.^[91] The franchise was then run asArriva Trains Merseyside.^[17]

In 2003,Merseytravel took over responsibility for the Merseyrail franchise from theStrategic Rail Authority.^[17] In conjunction with this, on 20 July 2003, the franchise was awarded to Serco-NedRailways (nowSerco-Abellio), a 50-50 joint business venture betweenSerco andAbellio, a subsidiary of Dutch national train operatorNederlandse Spoorwegen.^[92][93][94] Merseyrail Electrics 2002 Ltd was established by Serco-Abellio and the franchise is run under the "Merseyrail" brand with a 25-year contract ending in July 2028 and a review taking place every five years in line with the Merseyside Local Transport Plan.^[95]

All railway lines are built to1,435 mm (4 ft 8+1⁄2 in)standard gauge. The majority of the track has aloading gauge of W6 and the line has aRoute Availability (RA) of RA 8 except for the New Brighton branch which is RA 6.^[96] This makes the whole line fairly restrictive and not very attractive for freight traffic.^[3]In 2017, the track laid in the late 1970s which runs under the Mersey was replaced by Network Rail over a six-month period.^[97]

The whole network iselectrified using the750 V DC third rail system.^[3] The Mersey Railway was electrified in 1903, making it the first railway in the world to be converted entirely to electrification.^[98] The former Wirral Railway, by then part of theLondon, Midland and Scottish Railway (LMS), was electrified in 1938.^[13] The opening of the Loop in 1977 led to three electrified terminals on the Wirral: New Brighton, West Kirby and Rock Ferry. Electrification south from Rock Ferry to Hooton followed in 1985, with extensions to Chester and Ellesmere Port in 1993 and 1994 respectively.^[13][99]

In 1938, following the electrification of the former Wirral Railway, the LMS introduced new trains with air-operated sliding doors. Theseelectric multiple units were eventually designated asClass 503. Further Class 503 units were built in 1956 to replace the former Mersey Railway carriages. The entire Class 503 stock was replaced in 1983 withClass 508 units originally built in the late 1970s for services fromLondon Waterloo.^[100] A few years earlier (1978–1980), almost identicalClass 507 units had been introduced on the Northern line to replaceClass 502 stock. Following theprivatisation of British Rail in 1993, Class 507 and 508 units were used interchangeably on both the Wirral and Northern lines and in 2003–2004 the 59-strong Class 507/508 fleet was refurbished byAlstom'sEastleigh Works at a cost of £32 million.^{[13][101][102][103]}

Maintenance of the Class 507 and 508 fleet was carried out atBirkenhead North TMD andKirkdale TMD. Birkenhead North TMD, just west ofBirkenhead North station, focused on major overhauls of the electric fleet, whereas Kirkdale TMD, situated south ofKirkdale station on the Northern line, was used for undertaking minor repairs and cleaning activities. Train cleaning operations took place at the now-defunctBirkenhead Central TMD besideBirkenhead Central station until the late 1990s.^[9]

It was expected by Merseyrail that the 507s and 508s would be withdrawn around 2014 and replaced by a new EMU, but this was postponed and the trains were refurbished instead. In May 2012,Merseytravel announced that it had formally begun a project for replacement of the 507s and 508s.^[104] In December 2016, Merseytravel announced that Stadler had won the £460 million contract and that the newClass 777 trains would be delivered from summer 2019, with all the old trains replaced by 2021.^[105]

In May 2014, the lease on the Class 507s and 508s was extended to 2018. As part of the agreement withAngel Trains, the fleet would receive a refresh package including external re-livery, internal enhancements and engineering work.^[106]

During Monday to Saturday, trains run every 15 minutes from Liverpool to each of New Brighton, West Kirby and Chester, and every 30 minutes to Ellesmere Port. During peak times outside of theleaf-fall season in autumn, additional services run to (evening peak), respectively from (morning peak) Ellesmere Port, giving a 15 minutes frequency there in the peak direction only. Hooton is the point of interchange between trains to Ellesmere Port and trains to Chester, and is served by six trains per hour from Liverpool, four of which continue to Chester (only two call at Capenhurst) and two calling at stations to Ellesmere Port. Due to theCOVID-19 pandemic, these frequencies reduced as of March 2020.^[107] By mid-2022, frequencies have been increased back towards their original levels.^[108]

Interchange with the Northern line is available at Liverpool Central and Moorfields, and with theCity line at Liverpool Lime Street.Transport for Wales operate services fromBidston along theBorderlands Line toWrexham Central.^[107] Various proposals over the years have suggested the electrification of part or all of this route and incorporating it into the Wirral line, as well as also electrifying beyond Ellesmere Port through toHelsby.^[3][109]

Connections are available with otherNational Rail services at Liverpool Lime Street and Chester. There is also a connecting service from Ellesmere Port to Helsby andWarrington Bank Quay.^[110]

A number of incidents have occurred on the Wirral line.

Unit 508118, while in storage in the siding at Birkenhead North, was subject to an arson attack in 2001. The unit was scrapped.^[111]

On 19 May 2004, Unit 507009 derailed at points as it approached Birkenhead North station.^[112] The leadingbogie of four wheels came off the track, but the train remained upright. None of the 20 or so passengers on the train were injured.^[113][114] The cause was a worn switch rail and an imbalance in wheel loads across the leading carriage of the train.^[115]

At 17:41 on 26 October 2005, the rear bogie of unit 508124 derailed in the Loop tunnel between Liverpool Lime Street and Liverpool Central.^[116][117] Due to concerns by Network Rail as to the condition of the track, there had long been a temporary speed restriction of 20 mph (32 km/h) in the tunnel, although at the time of the derailment the train was travelling at only 12 mph (19 km/h). None of the 119 passengers were injured; the guard attended hospital overnight with a neck injury, but was not detained.^[113] In August 2006, a report by theRail Accident Investigation Branch (RAIB) cited poor track maintenance, inadequacy of therail fastening system, and the track infrastructure and trains not being designed as a complete system, as causes of the derailment.^[115][118] Liverpool-bound services terminated at James Street instead of going around the Loop while investigation and track renewal work took place.^{[119][120][121]}

On 19 April 2006, a small fire in the Mersey Railway Tunnel caused electrics to short circuit. The 06:30 service from Ellesmere Port to Liverpool Central was in the tunnel at the time of the incident. All 120 passengers were escorted 400 yards (370 m) through the tunnel toHamilton Square.^[122][123]

At 11:57 on 11 January 2007, unit 507019 hit the buffers at West Kirby as it was arriving from Liverpool Central. There were no injuries to the 20–30 passengers, but the driver and guard were treated for shock and minor rib injuries respectively.^[124] The train was travelling at around 5 mph (8.0 km/h) at the time of impact when it demolished the buffers and caused other minor damage.^{[125][126][127][128][129]} The unit was towed toCrewe Works and repaired.^[130]

On 30 October 2007, a fire broke out on a Liverpool Central to Chester service. The train was evacuated atBromborough Rake. The fire was caused by an electrical fault, and the carriage involved was damaged.^[131]

The West Kirby branch of the line has several level crossings, and accidents at these, involving pedestrian fatalities, have taken place in July 2007,^[132][133] January 2008,^[134][135] and November 2009.^{[136][137][138][139][140]}

• Commuter rail in the United Kingdom

• "Merseyrail loop tunnels to be finally pumped dry".RAIL. No. 323. EMAP Apex Publications. 28 January – 10 February 1998. p. 15.ISSN 0953-4563.OCLC 49953699.

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