View source for Waterloo & City line

{{short description|London Underground line}}
{{Redirect|The Drain|other uses|Drain (disambiguation){{!}}Drain}}
{{more citations needed|date=June 2022}}
{{Use British English|date=September 2024}}
{{Use dmy dates|date=September 2024}}
{{Infobox rail line
| name                            = Waterloo & City
| logo                            = London flag boxes - Underground Waterloo & City line.svg
| logo_width                      = 250px
| logo_alt                        =
| image                           = Bank station Waterloo & City line train.JPG
| image_width                     = 250px
| image_alt                       = Waterloo & City line 1992 stock train at Bank tube station awaiting departure towards Waterloo.
| caption                         = A [[London Underground 1992 Stock|1992 stock]] Waterloo & City line train at [[Bank and Monument stations|Bank]]
| type                            = [[Rapid transit]]
| system                          = [[London Underground]]
| start                           = Bank
| mapcolour                       = Corporate turquoise
| mapcolourlink                   = Tube map
| end                             = Waterloo
| stations                        = 2
| ridership2                      = 17.596&nbsp;million (2019)<ref>{{cite web |title=London Assembly Questions to the Mayor |url=https://www.london.gov.uk/who-we-are/what-london-assembly-does/questions-mayor/find-an-answer/tube-usage-1|publisher=London Assembly |year=2022 |access-date=29 February 2024}}</ref> passenger journeys
| open                            = {{plainlist|
* {{start date and age|1898|08|08|df=y}}<br />(line opened)
* {{start date and age|1994|04|01|df=y}}<br />(transferred to London Underground)
}}
| character                       = Deep tube
| depot                           = [[Waterloo Underground Depot|Waterloo]]{{ref|map 3|map 3}}
| stock                           = {{cslist|[[London Underground 1992 Stock|1992 Stock]]}}
| linelength_km                   = 2.37
| linelength_footnotes            =<ref name="linefacts"/>
| tracklength_km                  =
| gauge                           = {{Track gauge|sg|allk=on}}
| electrification                 = {{750 V DC|conductor=fourth rail}}<ref>Per 'Secrets of the Underground' Series 2 Episode 2. The change in electrification was part of the modernisation by Network Rail in the mid 1980s. Network Rail opted for their standard of 750 volts for DC lines (though they actually converted the W&C to four rail to solve problems with earth currents in the cast iron tunnels). The W&C consequently has its own electrical sub station located in the depot at Waterloo. The line was subsequently transferred to London Underground in 1994. Consequently the Waterloo and City is the only deep level tube railway operating at 750 volts (all other lines being 630 volts).</ref>
| website                         = {{Official URL}}
| map_name                        = [[Transport for London]] {{nowrap|rail lines}}
| map                             = {{London rail lines}}
| map_state                       = collapsed
}}

The '''Waterloo & City line''', colloquially known as '''The Drain''',<ref name="Drain1">{{Cite news|url=https://www.telegraph.co.uk/travel/destinations/europe/united-kingdom/england/london/articles/London-Underground-Tube-line-trivia/|title=London Underground: Tube line trivia|last=Mason|first=Mark|year=2018|work=The Telegraph|access-date=13 October 2018|language=en-GB|issn=0307-1235|archive-url=https://web.archive.org/web/20180905214717/https://www.telegraph.co.uk/travel/destinations/europe/united-kingdom/england/london/articles/London-Underground-Tube-line-trivia/|archive-date=5 September 2018|url-status=live}}</ref> is a [[Shuttle train|shuttle line]] of the [[London Underground]] that runs between [[Waterloo tube station|Waterloo]] and [[Bank and Monument stations|Bank]] stations with no intermediate stops. Its primary traffic consists of commuters from south-west London, [[Surrey]] and [[Hampshire]] arriving at [[London Waterloo station|Waterloo main line station]] and travelling forward to the [[City of London]] financial district. For this reason, the line has historically not operated on Sundays or public holidays, except in very limited circumstances. The line was closed during the [[COVID-19 pandemic in United Kingdom|COVID-19 pandemic]]; since reopening in October 2021 it is open only on weekdays.<ref name=":7">{{Cite web |date=20 October 2021 |title=London Underground's Waterloo & City line to return to full weekday service following pandemic reductions |url=https://www.intelligenttransport.com/transport-news/129845/waterloo-city-line-full-service/ |access-date=23 June 2022 |publisher=Intelligent Transport |quote=Following closure due to the pandemic and then operating a limited service from June 2021, TfL has announced that the Waterloo & City tube line will now return to a full weekday service.}}</ref> It is one of only two lines on the Underground network to run completely underground, the other being the [[Victoria line]].

Printed in [[Turquoise (color)|turquoise]] on the [[Tube map]], it is by far the shortest line on the Underground network, being {{convert|2.37|km|abbr=in}} long,<ref name="linefacts">{{cite web |title=Up to date per line London Underground usage statistics |url=https://www.whatdotheyknow.com/request/up_to_date_per_line_london_under#incoming-1109167 |url-status=dead |archive-url=https://web.archive.org/web/20200702135908/https://www.whatdotheyknow.com/request/up_to_date_per_line_london_under#incoming-1109167 |archive-date=2 July 2020 |access-date=29 April 2018 |publisher=[[TheyWorkForYou]]}}</ref> with an end-to-end journey lasting just four minutes. In absolute terms, it is the least-used Tube line, carrying just over 17&nbsp;million passengers annually. However, in terms of the average number of journeys per kilometre it is the third-most intensively used line behind the [[Jubilee line|Jubilee]] and [[Victoria line|Victoria]] lines.<ref name="linefacts"/>{{GeoGroup}}

The line was built by the Waterloo & City Railway Company and was opened in 1898 (at the time, Bank station was named "City").<ref name="culg">
{{cite web |url=http://www.davros.org/rail/culg/waterloo.html | title = Waterloo & City Line | date = 14 December 2007 | work = Clive's Underground Line Guides | publisher = Clive Feather | access-date = 30 June 2008 | archive-url=https://web.archive.org/web/20150412031513/http://www.davros.org/rail/culg/waterloo.html | archive-date = 12 April 2015 | url-status = live | df = dmy-all }}</ref> When it opened it was the second electric underground railway in London, following the [[City and South London Railway]] (now part of the [[Northern line]]). Its construction was supported by the [[London and South Western Railway]], whose main line trains ran into Waterloo, and for many years it continued to be owned and operated by the LSWR and its successors as a part of the national railway network, not as part of the London Underground network it resembled. Following a major refurbishment and replacement of rolling stock by [[Network SouthEast]] in the early 1990s, operations were transferred to London Underground in 1994.

==History==
===Background===
The [[London and South Western Railway]] (LSWR) reached Waterloo Bridge on 11 July 1848, serving routes from Southampton and Richmond. It was officially renamed Waterloo in October 1882.{{sfn|Jackson|1984|p=215}}

That the station was not within walking distance of the [[City of London]] was viewed as a serious shortcoming.{{sfn|Glover|2003|p=24}} The LSWR had hoped to build a line eastwards to near London Bridge but because of the slump following the [[railway mania]], and the high cost of building through the area, this idea was abandoned.{{sfn|Jackson|1984|p=215}} When the [[South Eastern Railway (UK)|South Eastern Railway]] opened an extension from London Bridge to Charing Cross in 1864, a connecting railway line from it to Waterloo was built, but friction and competitive hostility between the companies meant the line saw no regular passenger movements.{{sfn|Jackson|1984|pp=216–217}} Under pressure from the LSWR, the SER constructed Waterloo Junction station, now called [[Waterloo East]], on the Charing Cross line.  The station opened in January 1869, but through ticketing was refused and the onward connection remained frustratingly unsatisfactory.{{sfn|Jackson|1984|p=217}}{{sfnp|Gillham|2001}}

====Independent proposals====
A [[Waterloo and Whitehall Railway]] was promoted in 1864, to construct a tube railway from [[Great Scotland Yard]] to Waterloo. It was to use air pressure to propel the vehicles northwards, and exhaust air to draw them southwards, using a pressure differential of {{frac|2|1|2|}} oz per sq in (about 11 mbar). The trains themselves would be the pistons. The company capital was to be £100,000. It was suggested that there could be a branch to where the [[Embankment station]] is now located: it is not clear how a junction would be managed in a pneumatic railway. There were to be three vehicles, one loading at each terminal and one in motion in the tube, so they must have been intended to pass at the terminals. There were to be three classes of accommodation in the coaches.

Work started on 25 October 1865, but less than a year later it was obvious that the capital was grossly inadequate. Authority for extension of time and more capital was obtained, but by then few investors had any confidence that their investment would gain a return. In 1868, a further extension was granted, but little further work was done, and nearly all the money had gone.

In 1881, an independent Waterloo and City Railway was promoted, to build a surface line to Queen Street. The cost was formidable at £2.3&nbsp;million, and the proposal soon collapsed.{{sfnp|Gillham|2001}}

====The Waterloo & City Railway Bill====
[[File:W&C map.jpg|thumb|Map of the Waterloo & City Railway as originally planned]]

In 1891, the Corporation of the City of London made a statistical survey which it published ancillary to the National Census taken in that year. 37,694 persons lived in the City, but the daytime occupation was 310,384. On 4 May 1891, 1,186,094 entries to the City were made, i.e., many people entered more than once. Separate statistical information is that about 50,000 persons arrived at Waterloo daily, of whom about 12,000 proceeded to the City by some means.

In November 1891, a bill was deposited to build an underground electric railway from Waterloo to the Mansion House in the City; the capital was to be £500,000; the proposal was supported by the LSWR but was independent. Three other "tube" railways were proposed in the same parliamentary session, the traditional cut-and-cover method being seen as impractical, as was an elevated railway on viaduct. Electric urban railways had been introduced in Germany in 1891 and in the United States of America, and were in daily, widespread use; but in the United Kingdom, only one example was in existence, the [[City and South London Railway]].

The progress of the bill through Parliament was slow, partly because of the novelty of considering tube railway schemes; there were several petitions from the authorities responsible for public works in the city. [[London County Council]] tried to insist that the tubes should be made large enough to carry ordinary trains, and that all trains arriving at Waterloo should continue through them to the City. This idea would have required a new subterranean terminal station at the Bank of at least equal size to Waterloo itself.

{{Infobox UK legislation
| short_title           = Waterloo and City Railway Act 1893
| type                  = Act
| parliament            = Parliament of the United Kingdom
| long_title            =
| year                  = 1893
| citation              = [[56 & 57 Vict.]] c. clxxxvii
| introduced_commons    =
| introduced_lords      =
| territorial_extent    =
| royal_assent          = 27 July 1893
| commencement          =
| expiry_date           =
| repeal_date           =
| amends                =
| replaces              =
| amendments            =
| repealing_legislation =
| related_legislation   =
| status                =
| legislation_history   =
| theyworkforyou        =
| millbankhansard       =
| original_text         = https://www.legislation.gov.uk/ukla/Vict/56-57/187/pdfs/ukla_18930187_en.pdf
| revised_text          =
| use_new_UK-LEG        =
| UK-LEG_title          =
| collapsed             = yes
}}
Numerous petitions against the bill, or requiring additional protections to be included in it, were presented, but eventually on 27 July 1893, the '''{{visible anchor|Waterloo and City Railway Act 1893}}''' ([[56 & 57 Vict.]] c. clxxxvii) gained [[royal assent]].{{sfnp|Gillham|2001}}<ref name = carter>{{cite book |first=E. F. |last=Carter |title=An Historical Geography of the Railways of the British Isles |publisher=Cassell |location=London |date=1959}}</ref>

====Construction====
Following royal assent, the company prepared for construction. The new company issued its prospectus in March 1894 and the subscription list closed on 21 April; 54,000 shares at £10 each were offered and there was a slight over-subscription. A dividend of 3% per annum payable out of capital was promised during the construction phase.{{sfnp|Gillham|2001}}

Tenders were acquired for the main tunnel work, and a contract was awarded to [[Mowlem|John Mowlem & Co]] for the sum of £229,064{{sfnp|Gillham|2001}} ({{Inflation|UK|229064|1894|r=-4|fmt=eq|cursign=£}}).{{Inflation-fn|UK|df=y}} The consulting engineers were [[W. R. Galbraith]] (of the LSWR) and [[James Henry Greathead|J. H. Greathead]], developer of the [[tunnelling shield]]. The resident engineer was H. H. Dalrymple-Hay. Mowlems' engineer in charge was William Rowell.<ref name = engineer>''The Engineer'' (periodical), 26 July 1895</ref>

Mowlem began work on 18 June 1894, first building staging in the river about {{convert|500|ft}} west of Blackfriars Bridge. Piles were driven for a [[cofferdam]] and two vertical shafts of {{convert|16|ft}} internal diameter were constructed as headings for the tunnel drive. The average depth of the tunnels is about {{convert|45|ft}}, with its deepest points at the River Thames, at {{convert|63|ft}} underground.

Driving the running tunnels started in November 1894, using the [[James Henry Greathead|Greathead]] system of shield excavation, cast iron segment lining, compressed air working, and compressed air grouting behind the tunnel lining. Twenty men worked in each heading.<ref name = engineer2>''The Engineer'' (periodical), 2 August 1895</ref>

[[File:W&C muck away.jpg|thumb|Removal of spoil in tunnelling the Waterloo & City Railway]]

The excavated material was removed from the staging near [[Blackfriars Bridge]]; it was conveyed there from the shields by a narrow gauge railway using electric locomotives supplied by the [[Siemens|Siemens Company]]. Two were in use and a third was on order at August 1895. They operated on {{convert|18|in|adj=on}} gauge track with a twin overhead trolley wire (i.e., not using the track for current return) at {{val|200|u=V|s=&nbsp;DC}}.<ref name = engineer2/>

The station works at Waterloo were constructed by Perry and Co. The station tracks run in separate but adjacent arches supporting the main line station, which run transversely to the main line track. The arch piers needed to be underpinned to about {{convert|8|ft}} lower than the original foundations.{{sfnp|Gillham|2001}}

====Civil engineering detail====
[[File:W&C Shield work.jpg|thumb|The Greathead tunnelling shield in use on the Waterloo & City Railway]]

The route starts from a point south-east of Waterloo main line station, halfway between Lower Marsh and the now-vanished Aubyn Street, which was destroyed in the station's early 20th century expansion and was located more or less where today's platforms 3 and 4 are.{{citation needed|date=January 2023}} Leaving towards the north west, the line turns in a {{convert|339|ft|adj=on}} curve towards the north east. The curve is constructed by cut-and-cover, and the twin tubes start immediately after it, under Stamford Street, turning north-north-east to pass under the [[River Thames]], converging with [[Blackfriars Bridge]] on the north bank. The line turns east there, under Queen Victoria Street, to the station adjacent to the [[Mansion House, London|Mansion House]], running for part of the way under the [[District line]]. The sharpest curves other than those at Waterloo are {{convert|603|ft|adj=on}} radius.

The northbound line falls at 1 in 30 for {{convert|900|ft}} from Waterloo; then the line falls at 1 in 120 and then 1 in 800 to the shaft in the river. The westbound line (considered in reverse to the direction of running) falls at only 1 in 60, and then 1 in 550 to the shaft. From there they run together, level for {{convert|100|ft}} and then climbing at 1 in 800 for {{convert|1300|ft}}, and then 1 in 88 to the terminus.

The tunnels are {{convert|12|ft|1+3/4|in|adj=on}} internal diameter, except for the {{convert|603|ft|adj=on}} curves, where they are {{convert|12|ft|9|in}}. Each {{convert|20|in|adj=on}} long section of tunnel wall was formed with a cast iron ring, made from seven segments and a key piece at the top. {{convert|1|in|adj=on}} bolts connect all the segments. Between each section there was a creosoted timber strip {{convert|3/8|to|1/2|in|adj=on}} thick, and varying the thickness of this enabled the forward course of the tube to be varied, except in the sharpest curves where the segments were cast to form the curve. There are seven cross-passages between the twin tubes.

Under the Thames the top of the tube is {{convert|23|ft}} below the bed of the river. The total length of the line is {{convert|1|mi|1012|yd|m}}.<ref name  = engineer/>

[[File:W&C air lock.jpg|thumb|The air lock used during compressed air working]]

The [[Waterloo tube station|underground station at Waterloo]] was located within the existing [[transverse arch]]es of the main line station, with the arrival and departure platforms in separate arches, and a staircase access. Siding accommodation and a reversing siding were provided beyond the platforms: after disembarkation of passengers, an arriving train would continue forward to the reversing sidings, and then return to the departure platform. An additional lay-by siding was provided later.{{sfnp|Gillham|2001|p=187}}

At the [[Bank–Monument station|new City station]] there were two platforms and either could be used by an arriving train, reversing in the platform. The track connections at the approach were a [[double slip]], not a [[crossover (rail)|scissors]], so a train could not leave while another was arriving.<ref name = ice>Diagram in ''Proceedings of the Institution of Civil Engineers'', 1899–1900, reproduced in Gillham, page 104</ref> The left hand platform line was extended by a train length and trains could be stabled in the extension.{{sfnp|Gillham|2001}} A large diameter Greathead shield was used to bore the section of tunnel where the track connections would be installed.{{sfnp|Gillham|2001|p=99}}

The tube section for the platform lines at the City station were {{convert|23|ft}} in diameter, the largest in the world at the time.{{sfnp|Gillham|2001}}

====Original signalling====
In late 1897, contracts were let for the signalling equipment; the electric interlocking was to be carried out by W. R. Sykes, who had a call-off contract with the LSWR; a supplement to their standard prices for the tunnel work was agreed.

There were signalboxes at Waterloo at the south end of the northbound platform, and at south end of the northbound platform at City. There were conventional [[railway semaphore signal|semaphore]] signals in the open south of Waterloo station, but all other signals were electric lights only. Sykes' lock-and-block system was used with depression-type treadles. Although there was only one signal section, advance starting signals were provided. The platform starting signals at Waterloo and at City had a lower arm, a "shunt-by signal" which when lowered indicated that the line was clear only to the advance starting signal. The main starting signal when lowered indicated that the line was clear to City.

An electrical traction current interrupt system was installed; a short length of contact bar was provided at each signal, connected to earth when the signal was at danger, and otherwise isolated. A "slipper" contact was fitted on the trains, and if it contacted the contact bar when it was earthed, the traction current was tripped.{{sfnp|Gillham|2001}}

====Traction electricity====
On 4 January 1897, a contract was signed with Siemens and Co for the electrical generating and distribution equipment, and the electrical train equipment, for £55,913. Although a German firm, Siemens had a large presence in the UK at the time. There were three lower tenders.

There were five boilers working at {{convert|180|psi|abbr=on}} driving five (later six) high speed steam engines developing {{convert|360|hp|abbr=on}} directly coupled to dynamos. The two-pole compound-wound dynamos delivered {{val|500|u=V}} at no load and {{val|530|u=V}} under full load; this gave {{convert|225|kW|abbr=on|order=flip}} at {{val|350|ul=rpm}}. Special attention was given to the closeness of the governing to ensure a stable supply voltage. The station lighting circuits were fed from the main switchboard and specially led to maintain lighting supply in the event of a traction current disruption. Station lighting used four lamps in series, with return current via the running rails. (Gas lighting was provided as a back-up.)

There was a short high-level siding within the Waterloo yard area; coal to fuel the boilers was brought in by ordinary LSWR wagons lowered to the running line by the carriage lift; the wagons were drawn through the northbound platform by an electric shunting locomotive, and another lift elevated them to the siding. Boiler ash was disposed of correspondingly.{{sfnp|Gillham|2001}}

====City station====
The City station was not originally called Bank. The [[Central London Railway]] (CLR, which became the central section of what is now the [[Central line (London Underground)|Central line]]) obtained an Act of Parliament in 1891 varying their previously intended route, to take them to the area of the present-day Bank station. The act required them to construct a central station and booking office and public subways connecting the surrounding streets.{{sfnp|Gillham|2001}}<ref name = carter/> The subways were to be regarded as public, although maintained by the CLR. Any other railway intending to have a station nearby was entitled to connect to the CLR station by subways. This obviously referred to the Waterloo & City line, and was designed to create a single station frontage in the congested street area. The CLR completed its construction after the W&CR but was obliged to finish the facilities necessary for the earlier opening of the W&CR. The [[City and South London Railway]] (CSLR) also operated from the station.

Gillham says:
{{blockquote|"Right from the start the joint station and circular subway area was always known as the 'City station' by the W&C but as the 'Bank station' by the CLR and the CSLR."{{sfnp|Gillham|2001|p=98}}}}

The W&CR station was located some considerable distance from the area near street level, and this later led to persistent complaints as it required passengers to climb a steep and lengthy gradient to reach the exit.

====Permanent way====
The ordinary LSWR permanent way was used, with {{convert|87|lb/yd|adj=on}} rails, but in the tubes longitudinal timbers were used instead of cross-sleepers. The sharp curves had [[guard rail (rail)|check rails]]. Cross-bonds paralleling the running rails electrically were provided every {{convert|100|ft}} and between tracks at the cross passages. The track gauge was the standard {{Track gauge|56.5 in}}.

The conductor rail was a steel inverted channel placed centrally, with its upper surface at the same level as the upper surface of the running rails. At pointwork a hardwood ramp was provided to raise the collector shoes {{convert|1+1/2|in}} above running rail level.

====Shunting locomotives====
[[File:SR 75S.jpg|thumb|75S, Siemens electric shunter]]

Part of Siemens's work under the supply of electrical equipment including a shunting locomotive; this was a four-wheel electric locomotive with a cab at one end only, It had two {{convert|60|hp|abbr=on}} traction motors and was delivered in 1898. Its main duty was the delivery of the generator station coal. Like the passenger vehicles, its brake system had air reservoirs charged from a static supply at Waterloo. It remained on the system until 1969, when it was transferred to the [[National Railway Museum]] at York.

In 1901, a second, more powerful shunting locomotive was acquired. Designed by the LSWR Chief Mechanical Engineer, [[Dugald Drummond]] it had two four wheel bogies and was intended for the rescue of failed passenger trains in the tunnel. In 1915, it was removed from the tunnel and put to work shunting coal wagons at Durnsford Road power station, having had its shoe collectors altered for the surface traction supply system.

====The Armstrong Lift====
[[File:Waterloo Depot Armstrong lift (1988).jpg|thumb|right|The Armstrong lift in 1988.]]

As the line had no connection to any other line, nor any ground level section, it was necessary to provide a hoist to bring the passenger cars to the line, and to get them out for heavy maintenance. This was provided to the west of the Windsor side of Waterloo main line station, and was known as the ''Armstrong'' lift, after the manufacturer, [[Armstrong Whitworth|Sir W G Armstrong Whitworth & Co Ltd]], who was paid £3,560. It was operated by water power; at the time of construction hydraulic power was commonly used in urban areas, supplied by utility companies, to operate hoists and lifts. The lift was to be capable of lifting {{convert|30|ST}}. It was completed in April 1898. There was a smaller {{convert|25|ST|adj=on}} hoist within the low-level siding area at Waterloo for the boiler fuel wagons; this had a smaller travel and was installed by John Abbot & Co for £595.{{sfnp|Gillham|2001}}

Before the construction of [[Waterloo International railway station|Waterloo International terminal]] in 1990, the vehicles were hoisted individually by the Armstrong Lift outside the north wall of Waterloo main line station. The procedure is now carried out using a road-mounted crane in a shaft adjacent to the depot, south of Waterloo main line station on Spur Road. This is only necessary for major maintenance work that requires lifting of the car body, as the Waterloo depot is fully equipped for routine maintenance work. The remaining stub of the siding tunnel that led to the Armstrong Lift can still be seen on the left-hand side of the train shortly after leaving Waterloo for Bank, but the lift itself was buried (along with the entire Western sidings) in 1992 as part of the construction of [[Waterloo International railway station|Waterloo International]] station.

===The line in operation===
[[File:Starting from Waterloo.jpg|thumb|Artist's impression of Waterloo station at opening to the public]]
Once works were complete and the Board of Trade inspecting officer passed the line as fit, [[Prince George, Duke of Cambridge]] formally opened the line on 11 July 1898. About 400 persons travelled from Waterloo to the City station and immediately back to Waterloo.

Arrangements had been made for the LSWR to work the line, but not everything was in place for immediate opening: there was a delay of four weeks.

The Waterloo & City Railway opened to the public at 8 a.m. on Monday 8 August 1898, with a train leaving each terminal simultaneously. The fares were 2d one class only, payable at a turnstile, but returns and season tickets, and add-ons to surface tickets were available. From 1900, the turnstiles were removed and conductors travelled on the trains, carrying [[Bell Punch]] ticket machines. The daily average receipts in January 1899 were £86,{{sfnp|Gillham|2001|p=187}} and with steadily rising passenger usage and income the Company was able to pay a 3% dividend out of income following the annual general meeting of February 1902.{{sfnp|Gillham|2001}} Sunday services were not considered at this period, and in 1906 it was stated that "it would cost £20 each Sunday to run the trains, and they would not get that back in receipts."<ref name = sunday1906>Gillham, reporting AGM 13 February 1906</ref>

Very soon after operation, it was realised that the line was running to capacity at the business peaks, then referred to as ''the rush'', and very lightly used for the remainder of the day. Accordingly, in the spring of 1899 an order was placed with [[Dick, Kerr & Co.]] for five new motor cars for single operation. The driving cabs were half width; the traction motors, two per car, were {{convert|75|hp|abbr=on|adj=on}} nose suspended with single reduction gear. As with the earlier cars, the air brake reservoir was charged from static equipment at Waterloo. Five of these single cars were delivered in February 1900 and entered service in the spring. From that time, they alone worked the off-peak service, and the original vehicles only worked the peak services.<ref name = gillham181>Gillham, page 181</ref>

===Absorption by the LSWR===
The line had been worked by the LSWR from the outset, and in 1906 the LSWR made overtures to the W&CR concerning an outright absorption. It was suggested at an extraordinary general meeting of the W&CR that increasing competition motivated the LSWR. An enabling Act was passed on 20 July 1906 and shareholders' approval being obtained, the transfer took place on 1 January 1907, with the shareholders receiving LSWR shares, and the W&CR ceased to exist.{{sfnp|Gillham|2001}}

In 1915, the LSWR started electrifying its suburban routes, and for the purpose it built a large generating station at Wimbledon, Durnsford Road. The power for train operation on the Waterloo & City line was supplied from this from December 1915, and the original W&CR generating plant now served only ancillary purposes in the line, but also heating and lighting of the main LSWR Waterloo offices. The traction voltage on the W&CR was increased from the original {{val|550|u=V}} to {{val|600|u=V}}.<ref>{{cite book |last1=Faulkner |first1=J. N. |last2=Williams |first2=R. A. |title=The LSWR in the Twentieth Century |year=1988 |publisher=[[David & Charles]] |location=Newton Abbot |isbn=978-0-7153-8927-0 |page=26 }}</ref><ref>{{cite book |last=Weddell |first=G. R. |title=LSWR Carriages in the 20th Century |date=March 2001 |publisher=Oxford Publishing Co |location=Hersham |isbn=978-0-86093-555-1 |id=0103/A1 |page=51 }}</ref><ref name = gillham226>Gillham, page 226</ref>

In 1921, it had been considered desirable to augment train lengths at the busy periods, and four new trailer coaches to the original specification were built at Eastleigh; 24 five-car trains were run per hour at the busiest times.{{sfnp|Gillham|2001}}

===Southern Railway===
By the [[Railways Act 1921]], the main line railway companies of Great Britain were grouped into four companies, effective at the beginning of 1923. The LSWR was now part of the [[Southern Railway (UK)|Southern Railway]]. Due to the Waterloo & City's status as part of one of the [[Big Four (British railway companies)|"Big Four" railway companies]], it was not taken over by the [[London Passenger Transport Board]] (LPTB) at the latter's formation in 1933, making the W&C the only tube railway in London not to fall under the control of the LPTB. Despite this anomaly, the line was included on most versions of the [[Tube map|Underground map]] produced by the LPTB and its successors up until the line's absorption into the London Underground network in 1994.

In 1934, the LPTB proposed that the Waterloo & City should have a new intermediate station at Blackfriars, connecting with the District line station there. They further proposed that the Waterloo & City line should be extended to Liverpool Street station and Shoreditch, the trains there continuing over the [[East London Line|East London Railway]] to New Cross and New Cross Gate. It is not clear whether the scheme had been costed, but nothing came of it.{{sfnp|Gillham|2001 |p=237|loc=&nbsp; and map on following page}}
[[File:487-TSO-inside.jpg|thumb|Interior of the [[Art Deco]] styled [[British Rail Class 487|Class 487]] trains]]

==== New rolling stock ====
In 1937, the Southern Railway carried out a thorough review of the technical aspects of the line, now 40 years old. This led to an immediate proposal to order new rolling stock in five-car formations, in association with the provision of escalators at the City station. The scheme was delayed and the declaration of war on 3 September 1939 led to cancellation of the escalator scheme. However, the rolling stock order was proceeded with, and the [[Art Deco]] style trains were delivered in 1940, later classified as [[British Rail Class 487|Class 487]].

The original central third rail to power the trains was replaced by a Southern Railway standard steel rail placed outside the running rails. Automatic signalling with train stops was also provided. The City signal box was abolished, and fully automatic working implemented there; the lay-by sidings were abolished. The new stock did not require travelling conductors, and tickets were issued at the terminals. When the line reopened with new trains on 28 October 1940, the City station was renamed ''Bank'' in conformity with the usage of the LPTB there.{{sfnp|Gillham|2001}}<ref name=":0" />

===British Railways===
On 1 January 1948, the Southern Railway, as well as the other main line railways of [[Great Britain]], was nationalised, forming ''British Railways''.

On 13 April 1948, a serious accident took place at the Waterloo Armstrong Lift; coal was still taken down to the original generating station which powered station offices at Waterloo. A shunt of wagons was being propelled on to the lift at the upper level; four pawls were supposed to be engaged to provide partial support to the lift table, but it appears that some had not engaged. The table tilted, drawing the wagons and M7 locomotive number 672 on to the table; the table and the entire shunt including the locomotive fell down the shaft. The locomotive and wagons were cut up in situ.<ref name = gillham275>Gillham, pages 275 to 281</ref>
[[File:Fahrtreppe london.JPG|thumb|[[Moving walkway]] at Bank station]]

====The Travolator====
When the line was built, the platforms at Bank (then known as ''City'') were located a considerable distance from the surface exits, and a long sloping tunnel had to be negotiated on foot. This led to constant complaints and from 1929 there were many proposals to improve the arrangements, as passenger numbers increased, adding congestion to the physical exertion. The proposals had included new escalators, direct connection to adjacent Central London Railway (later Central line) platforms, and new, closer, tunnelled exits.

In the 1950s, a ''Speedwalk'' system of [[people mover]]s consisting of a continuous rubber belt system, was implemented in certain American cities. After considerable delay considering this and alternatives, British Railways let a contract on 4 July 1957 for the civil engineering works in driving a new sloping access tunnel, in which a pair of [[travolator]]s (at the time often written ''Trav-O-Lator'') would be installed by [[Otis Elevator Company|Waygood Otis]]. Otis did not, at this stage, gain a contract.

However, as work was getting under way, the government imposed heavy cuts in capital expenditure on the railways, and after considerable deliberation, it was decided once again to defer alleviation of the problem; no financial benefit was anticipated from the scheme, whereas competing schemes would significantly reduce operational costs. The consulting engineers were directed to suspend work on 11 December 1957, although some enabling work, particularly a sewer diversion, proceeded.

The financial restrictions were not long-lasting, and on 10 July 1958 it was announced that the work would resume. It progressed without further major difficulties and a formal opening by the Lord Mayor of London took place on 27 September 1960, coming into public use immediately. There were two parallel travolators, each with a moving surface having 488 platform sections each {{convert|40|x|16|in}}; the whole length is {{convert|302|ft}} on an inclination of 1&nbsp;in&nbsp;7 (about 14.3%). There was a moving handrail. In the morning peak both travolators would operate upwards, with arriving passengers being required to walk down the original ramps; at other times one travolator operated in each direction.<ref name=":0">{{Cite web |url=http://content.tfl.gov.uk/research-guide-no-38-bank-station.pdf |title=Research Guide No 38: Bank Station |date=5 January 2017 |website=TfL Corporate Archives|url-status=live |archive-url=https://web.archive.org/web/20200413102322/http://content.tfl.gov.uk/research-guide-no-38-bank-station.pdf |archive-date=13 April 2020 |access-date=12 April 2020}}</ref> The original [[Otis Elevator Company|Otis]] ''Trav-O-Lators'' have since been replaced by [[CNIM]] machines.

In association with the work, some improvements were made to the station environment at the Waterloo station, and a {{frac|2|1|2}} minute frequency was implemented in the peaks; this involved some minor signalling changes, reversion to alternating platform use at Bank, and the use of turnover drivers and guards (where the arriving driver and guard are replaced by staff waiting at the appropriate place for the change of direction, sometimes referred to as "stepping up"). A ''Rear Cab Clear'' plunger is provided at Bank so that the arriving driver can confirm that he is clear of the cab and the "step-back" driver can depart when the signal clears. Overall, the work had cost £910,500.{{sfnp|Gillham|2001}}

==== Network SouthEast ====
[[File:Waterloo and City crane 2006 closeup.jpg|thumb|A carriage being lifted out of Waterloo depot]]

In the mid 1980s, British Rail was split into business sectors, with the line falling under the purview of [[Network SouthEast]] (NSE). The line was branded as Waterloo and City, and the elderly [[British Rail Class 487|Class 487]] trains were repainted in the red, blue and white NSE livery.<ref name=":3">{{Cite book |last1=Green |first1=Chris |publisher=OPC |title=The Network SouthEast Story |first2=Mike |last2=Vincent |year=2014 |isbn=978-0-86093-653-4 |location=Shepperton |oclc=872707499}}</ref> In September 1989, a [[total route modernisation]] project was agreed at a cost of £19 million. Both stations would be refurbished in the NSE style, track and signals would be replaced and new rolling stock was ordered.<ref>{{Cite web |title=The Waterloo & City line |url=https://www.ltmuseum.co.uk/collections/stories/transport/waterloo-city-line |access-date=2 May 2021|website=London Transport Museum |language=en}}</ref>

At the same time as the upgrade project, the [[Eurostar]] terminal at [[Waterloo International railway station|Waterloo International]] was being built over a large area on the north side of Waterloo station. This removed access to the Armstrong Lift that allowed rolling stock and other machinery to access the line, and therefore a replacement shaft near Spur Road was constructed to allow access to [[Waterloo Underground Depot|Waterloo Depot]].<ref name=":3" />

The modernisation project was completed by July 1993, following the delivery of five four-car [[British Rail Class 482|Class 482]] trains. These were built to a modified design from an order for [[London Underground 1992 Stock|1992 Stock]] trains by London Underground for the Central line.<ref>{{Cite web |title=Research Guide No 29: Brief History of the Waterloo & City Line |url=https://content.tfl.gov.uk/research-guide-no-29-brief-history-of-the-waterloo-and-city-line.pdf |access-date=2 May 2021|website=TfL Corporate Archives}}</ref>

===London Underground===
As part of the [[privatisation of British Rail]], on 1 April 1994 the line was transferred to London Underground Ltd<ref name="culg" /> for the sum of £1.<ref>{{Cite episode |title=Waterloo & City |episode-link= |url= |access-date= |series=Secrets of the Underground |series-link=Secrets of the London Underground |last= |first= |network=[[Yesterday (TV channel)|Yesterday]] |station= |date=15 May 2022 |season= |series-no=2 |number=2 |minutes= |time= |transcript= |transcript-url= |quote= |trans-quote= |via= |language=}}</ref> At the time, staff were given the option of transferring with the line or remaining in British Rail employment, and all except one chose the latter. The drivers are currently based at Leytonstone.<ref>{{Cite book |title=Tube Station Trivia |last=Marshall|first=Geoff |year=2018|pages=111}}</ref> The turquoise line colour was chosen by a lawyer working on the legal transfer of the line to London Underground.<ref>{{Cite web |last=Bull |first=John |date=15 February 2024 |title=The Big Split: Overground Line Names |url=https://www.londonreconnections.com/2024/the-big-split-overground-line-names/ |access-date=15 February 2024 |website=London Reconnections |language=en-GB |quote=As a junior lawyer she had worked as part of the transfer team. It had actually been one of her first jobs in transport law. And when it came time to pick the colour of the line, her colleagues had offered her the honour of doing so ... She agreed, and was shown a selection of pre-approved colours by the London Underground design office. Any of them would work, she was told. So just pick one. Noticing that one was quite close to turquoise – her favourite colour – she simply chose that.}}</ref> From 15 April 1996, the line began working to a new timetable, with three trains departing in each ten minutes during the morning peak.<ref name = gillham417>Gillham, page 417</ref>

In January 2003, the Waterloo & City was closed for over three weeks for safety checks after a major derailment on the Central line, which required all [[London Underground 1992 Stock|1992 tube stock]] trains to be modified. That same year, responsibility for the line's maintenance was given to the [[Metronet (British infrastructure company)|Metronet]] consortium under the terms of a [[public–private partnership]] arrangement.<ref name=":5" />[[File:Waterloo tube station Waterloo & City line Bank train.JPG|thumb|Refurbished 1992 stock train at Waterloo station]]

==== 2006 refurbishment ====
Between April and September 2006, the line was closed for five months for a £40{{nbsp}}million upgrade by Metronet.<ref>{{Cite web|date=1 April 2006|title=Waterloo & City Line closes for upgrade|url=https://www.railwaygazette.com/waterloo-and-city-line-closes-for-upgrade/27420.article|access-date=10 September 2020 |website=Railway Gazette International |language=en}}</ref> The work included refurbishment of the tunnels, platforms and depot, full replacement of the track and signalling, and repainting and refurbishment of the trains.<ref>{{Cite web|title=Waterloo and City line station refurbishment|url=https://vgcgroup.co.uk/case-studies/waterloo-and-city-line-station-refurbishment-2/|access-date=10 September 2020|website=VGC Group|language=en-GB|archive-date=26 September 2020|archive-url=https://web.archive.org/web/20200926030915/https://vgcgroup.co.uk/case-studies/waterloo-and-city-line-station-refurbishment-2/|url-status=dead}}</ref><ref>{{Cite web|date=31 August 2006 |title=Waterloo and City line to open after major upgrade |url=https://tfl.gov.uk/info-for/media/press-releases/2006/august/waterloo-and-city-line-to-open-after-major-upgrade|access-date=10 September 2020|website=[[Transport for London]]|language=en-GB}}</ref> Four new {{convert|75|hp|abbr=on}} battery-powered locomotives, named ''Walter'', ''Lou'', ''Anne'' and ''Kitty'', were built by [[Clayton Equipment Company|Clayton Equipment]] in [[Derby]] to haul materials and plant along the line during the closure. These works were expected to boost rush-hour capacity by 25% and line capability by 12%. It was also claimed that the average journey would be up to 40{{nbsp}}seconds shorter.<ref name=":5">{{Cite web |title=Metronet's plans for the Waterloo & City line |url=http://www.metronetrail.com/default.asp?sID=1079001987756 |archive-url=https://web.archive.org/web/20060505103149/http://www.metronetrail.com/default.asp?sID=1079001987756 |archive-date=5 May 2006 |access-date=13 July 2005}}</ref><ref name=":4">{{Cite web|date=5 May 2006|title=Waterloo & City line / 5 Month closure / Scope of works |url=http://www.metronetrail.com/default.asp?sID=1141210191343 |url-status=dead |archive-url=https://web.archive.org/web/20060505103521/http://www.metronetrail.com/default.asp?sID=1141210191343|archive-date=5 May 2006|access-date=2 May 2021|website=[[Metronet (British infrastructure company)]]}}</ref>

During the [[2012 Summer Olympics]] and [[2012 Summer Paralympics]] between late July and early September 2012, trains ran on Sundays to cope with the demand for travel in the City.<ref>{{cite news|last=Murray|first=Dick|date=13 June 2012|title=Tube link not used for 70 years to reopen for Olympics to ease congestion|newspaper=Evening Standard|url=https://www.standard.co.uk/news/transport/tube-link-not-used-for-70-years-to-reopen-for-olympics-to-ease-congestion-7847388.html|url-status=live|access-date=16 June 2012|archive-url=https://web.archive.org/web/20120616023855/http://www.standard.co.uk/news/transport/tube-link-not-used-for-70-years-to-reopen-for-olympics-to-ease-congestion-7847388.html|archive-date=16 June 2012}}</ref>

In the late 2010s, a new entrance at [[Bank and Monument stations|Bank station]] was constructed at [[Bloomberg L.P.|Bloomberg's]] new [[Bloomberg London|London headquarters]],<ref>{{cite web|date=August 2012|title=Bank Station Part 1: The Forgotten Upgrade|url=http://www.londonreconnections.com/2012/bank-station-part-1-the-forgotten-upgrade/|work=London Reconnections}}</ref> providing direct access to the line via four new escalators and two lifts – providing step free access to the Waterloo and City line platforms.<ref name=":22">{{Cite web|date=12 December 2018|title=New Waterloo & City line entrance relieves congestion at Bank station|url=https://tfl.gov.uk/info-for/media/press-releases/2018/december/new-waterloo-and-city-line-entrance-relieves-congestion-at-bank-station|access-date=12 April 2020|website=Transport for London|language=en}}</ref> Although step free access is available at Bank, there is no step free access at Waterloo – and therefore the line does not have step free access.<ref>{{Cite web|last=Anonymous|date=14 July 2014|title=Step Free Waterloo and City|url=https://www.london.gov.uk/questions/2014/2780|access-date=10 September 2020|website=Mayor's Question Time}}</ref><ref>{{Cite web|title=Step-free Tube Guide|url=https://content.tfl.gov.uk/step-free-tube-guide-map.pdf|date=December 2023|access-date=8 February 2024|website=[[Transport for London]]}}</ref>

==== Closure during the COVID-19 pandemic ====
In March 2020, following the UK government's implementation of lockdown restricting all non-essential travel due to the [[COVID-19 pandemic in the United Kingdom|COVID-19 pandemic]], the Waterloo & City line was suspended.<ref>{{Cite web |url=https://www.cityam.com/revealed-sadiq-khan-to-blame-for-tube-overcrowding-says-transport-watchdogs/ |title=Decision to cut Tube services caused overcrowding, say watchdogs|date=20 April 2020|website=CityAM |language=en-GB|access-date=23 April 2020}}</ref> The service remained suspended for 15 months,<ref name=":6">{{Cite news|date=7 June 2021|title=Waterloo and City London Underground line reopens ahead of schedule|language=en-GB|work=[[BBC News]]|url=https://www.bbc.com/news/uk-england-london-57381553|access-date=8 June 2021}}</ref> due to the low level of travel demand on the line, and TfL prioritising the use of train operators on the busier Central line.<ref name=":1">{{Cite web|date=10 December 2020|title=Waterloo & City line closure likely to last more than a year|url=https://www.london-se1.co.uk/news/view/10447|access-date=13 December 2020|website=London SE1}}</ref>

TfL stated that they did not expect to reopen the line until demand increased,<ref name=":2">{{Cite web|last=Thicknesse|first=Edward|date=26 January 2021|title=TfL commissioner: Waterloo and City line not a priority for reopening|url=https://www.cityam.com/tfl-commissioner-waterloo-and-city-line-not-a-priority-for-reopening/|archive-url=|archive-date=|access-date=29 January 2021|website=CityAM|language=en-GB}}</ref><ref name=":1" /> despite calls from business groups in August 2020 to reopen the line to serve returning office workers.<ref>{{Cite web|date=17 August 2020|title=London advocacy groups call for Waterloo and City Tube line to reopen|url=https://www.cityam.com/london-advocacy-groups-call-for-city-and-waterloo-tube-line-to-reopen/|access-date=10 September 2020|website=CityAM|language=en-GB}}</ref> By March 2021, TfL stated that they expected the line to return to operation in May or June 2021, observing that services could be restarted at short notice if required.<ref>{{Cite web|last=Thicknesse|first=Edward|date=17 March 2021|title=TfL says Waterloo and City line to reopen in May or June|url=https://www.cityam.com/london-underground-chief-says-waterloo-and-city-line-to-reopen-in-may-or-june/|access-date=18 March 2021|website=CityAM|language=en-GB}}</ref><ref>{{Cite web|date=27 March 2021|title=Waterloo & City line back in 'May or June' after year's closure|url=http://www.london-se1.co.uk/news/view/10511|access-date=18 March 2021|website=London SE1|language=en}}</ref> In May 2021, it was announced that the line would reopen from 21 June 2021.<ref>{{Cite web|last=Thicknesse|first=Edward|date=14 May 2021|title=Waterloo & City Tube line to reopen from 21 June|url=https://www.cityam.com/waterloo-city-tube-line-to-reopen-from-21-june/|access-date=15 May 2021|website=CityAM|language=en-GB}}</ref> The line reopened ahead of schedule on 4 June 2021, initially operating a peak hour only service on weekday mornings and evenings,<ref name=":6" /> before expanding to a full timetable on weekdays in November 2021.<ref name=":7" /> It was noted that Saturday services will not be reintroduced for the "foreseeable future", with TfL stating that ridership on a Saturday pre pandemic was around one-sixth of an average weekday. The line remains closed on Sundays, as previously.<ref>{{Cite web |date=28 October 2021 |title=London Underground Waterloo & City line to return to full weekday service |url=https://www.intelligenttransport.com/transport-news/129845/waterloo-city-line-full-service/ |access-date=30 June 2022 |website=Intelligent Transport |language=en |quote=Saturday services on the Waterloo & City line will not be reintroduced for the foreseeable future, but TfL will continue to monitor demand across the network and make service adjustments to meet growing demand. Pre-pandemic demand for the Saturday service on the line was low, at around one sixth of demand on an average weekday.}}</ref>

==Rolling stock==
{{main|British Rail Class 482|London Underground 1992 Stock}}
[[File:Waterloo-city-1992.jpg|250px|thumb|A train of 1992 stock in its original Network SouthEast livery stands at [[Bank and Monument stations|Bank]] on the Waterloo & City line.|alt=]]
Toward the end of the 1980s, the [[British Rail Class 487|Class 487]] rolling stock fleet built in the 1940s was increasingly unreliable. As part of the [[total route modernisation]] project by [[Network SouthEast]] (NSE), the decision was taken to purchase new vehicles as an addition to an order for new [[London Underground 1992 Stock|1992 Stock]] trains by London Underground for the Central line. Five 4-car trains were ordered, albeit in Network SouthEast livery and no provision for [[automatic train operation]].<ref name=":3" />

The trains were constructed in 1992–93 and were initially tested and commissioned on the Central line, before being delivered by road to [[Waterloo Underground Depot|Waterloo depot]]. Unlike the Class 487 trains, the new trains required a [[Fourth rail|fourth rail traction current system]], with a central aluminium negative rail installed as part of the upgrade works to the line.

On 28 May 1993, all of the old rolling stock was withdrawn, the train service being suspended temporarily. A temporary bus service was run while the old rolling stock was physically removed and the new rolling stock brought in. The line reopened on 19 July 1993, with a peak service frequency of {{frac|3|1|2}} minutes.<ref name=":3" /> In April 1994, the trains transferred to London Underground following the [[privatisation of British Rail]]. Despite this, the trains kept their NSE livery.

In 2006, the 1992 stock trains were overhauled, refurbished and repainted as part of the line upgrade by [[Metronet (British infrastructure company)|Metronet.]] As part of the work, seats were replaced, CCTV was installed, and the original [[Network SouthEast]] livery was replaced by the London Underground corporate livery.{{sfnp|Gillham|2001}} A 500 tonne crane was required to lift the trains in and out of Waterloo depot, to allow the trains to be transported to [[Wabtec]] in [[Doncaster]] for the refurbishment work.<ref name=":4" />

Since its introduction, the stock on the Waterloo & City has diverged significantly from that used on the Central line through modifications, including the adoption of [[automatic train operation]] on the latter, that the two are no longer interchangeable; the Waterloo & City line continues to use [[train stops]].

=== Future rolling stock ===
{{Main|New Tube for London}}
In the mid 2010s, TfL began a process of ordering new rolling stock to replace trains on the [[Piccadilly Line|Piccadilly]], [[Central line (London Underground)|Central]], [[Bakerloo Line|Bakerloo]] and Waterloo & City lines.<ref name=":43">{{Cite web |date=October 2014 |title=New Tube for London – Feasibility Report |url=http://content.tfl.gov.uk/ntfl-feasibility-report.pdf |url-status=dead |archive-url=https://web.archive.org/web/20160305014932/http://content.tfl.gov.uk/ntfl-feasibility-report.pdf |archive-date=5 March 2016 |access-date=26 June 2022 |publisher=[[Transport for London]]}}</ref> A feasibility study into the new trains showed that new generation trains and track remodelling at Waterloo could increase capacity on the line by 50%, with 30 trains per hour.<ref name=":43" />

In June 2018, the [[Siemens Mobility]] [[Siemens Inspiro|Inspiro]] design was selected.<ref>{{cite magazine |date=15 June 2018 |title=Siemens to supply London Underground deep tube fleet |url=http://www.metro-report.com/news/news-by-region/europe/single-view/view/siemens-to-supply-london-underground-deep-tube-fleet.html |magazine=Metro Report International}}</ref> These trains would have an open gangway design, wider doorways, air conditioning and the ability to run automatically with a new signalling system.<ref name=":14">{{Cite news |date=4 March 2021 |title=Piccadilly Line: Plans for new 'walk-through' trains unveiled |work=BBC News |url=https://www.bbc.com/news/uk-england-london-56273283 |access-date=5 March 2021}}</ref> TfL could only afford to order Piccadilly line trains at a cost of £1.5bn.<ref>{{Cite news |last=Harris |first=Simon |date=3 January 2018 |title=Plan to sell part of Tube fleet branded 'quite mad' |website=ITV News |url=https://www.itv.com/news/london/2018-01-03/plan-to-sell-part-of-london-underground-fleet-branded-quite-mad |access-date=6 March 2021}}</ref> However, the contract with Siemens includes an option for 10 trains for the Waterloo & City line in the future.<ref name=":32">{{cite press release |date=15 June 2018 |title=Siemens Mobility Limited to be awarded TfL contract to design and manufacture a new generation of Tube trains |url=https://tfl.gov.uk/info-for/media/press-releases/2018/june/siemens-mobility-limited-to-be-awarded-tfl-contract-to-design-and-manufacture-a-new-generation-of-tube-trains |access-date=16 June 2018 |publisher=Transport for London}}</ref> This would take place after the delivery of the Piccadilly line trains in the 2030s.<ref name=":14" />

As part of the financial bailout of TfL in the aftermath of the COVID-19 pandemic, the [[Department for Transport]] is working with TfL to create a business case for making the line driverless.<ref>{{Cite news |date=1 June 2021 |title=Driverless London tube trains under consideration in £1bn bailout deal |work=Financial Times |url=https://www.ft.com/content/9fb501cd-aac3-464e-ac9e-f9312e235656 |access-date=26 March 2023 |quote=The Department for Transport will run a joint programme with TfL to explore the business case for fully automated trains on the Piccadilly and Waterloo and City lines,}}</ref>

=== Historic rolling stock ===
{{main|Waterloo & City Railway electric units}}
After tendering, a contract for supply of the passenger vehicles was let to the [[Jackson and Sharp Company]] of [[Wilmington, Delaware]] in the sum of £21,675. The vehicles were to be shipped to Southampton in [[knock-down kit]] form, to be assembled at [[Eastleigh Works]] by the LSWR.

By 6 January 1898, a skeleton carriage could be run through the tunnels to verify clearances and the first fully assembled train of four carriages was run from Eastleigh to Waterloo on 4 March 1898. The lift for lowering rolling stock to the tunnel level, and some electrical work, were not ready, but on 4 June 1898 a successful trial run was made.

The motor coaches were {{convert|47|ft|1|in}} overall length, and the trailers were {{convert|46|ft|3+1/2|in}}, both being {{convert|8|ft|6|in}} wide at floor level and {{convert|9|ft|8|in}} high from rail level. There were 11 of each type, to run in four four-car formations with spares.

The accommodation was of the open saloon type, then a novelty in Britain; there were gate entrances at the end of the vehicles. The trailers seated 56 persons, and the motor coaches seated 46, with a raised section over the motor bogie.

The traction motors by Siemens were series-wound {{convert|60|hp|abbr=on}} gearless motors on the axles. The trains ran in a formation of four cars, the two outer vehicles being motor coaches.  The motor cars were constructed to allow an early form of multiple unit operation and the front car's controller was additionally able to control the rear car's motors. The two motors at each end were connected in series at starting, then reconnected in parallel (using open circuit transition) as the train accelerated in the well established (at that time) method. This required eight cables to be run the length of the train at roof level. <!-- Two for each armature A and AA; two for each field Y and YY; for each motor making eight cables. ---> A further cable making nine in all linked the collector shoes at opposite ends of the four-car set to avoid problems with the large gaps in the centrally mounted conductor rail.

There was a crew of six at first: driver, driver's assistant, guard and three gatemen; the driver's assistant was subsequently no longer required. The trains used Westinghouse brakes, and the air reservoirs were charged from static compressors at Waterloo. They were charged to {{convert|100|psi|abbr=on}}, running down to {{convert|70|psi|abbr=on}} before needing to be recharged. Lighting was run from the power circuit, with four lamps in series from the {{val|500|u=V}} nominal.{{sfnp|Gillham|2001}}

====New trains ordered by the Southern Railway====
{{main|British Rail Class 487}}
[[File:Class 487 at London Transport Museum Depot.jpg|thumb|Preserved 1940 stock at the London Transport Museum Depot]]

In the late 1930s, new rolling stock was ordered by the [[Southern Railway (UK)|Southern Railway]]. Despite the declaration of war in September 1939, the work was considered well advanced, and 12 motor coaches and 16 trailers were ordered from [[English Electric]], and built at the [[Dick, Kerr & Co.]] works at Preston. The [[Art Deco]] style trains were delivered through 1940, and the old cars were removed from the line on 25 October 1940, the new cars starting work on 28 October, with the line closed over the intervening weekend.

Constructed of welded steel, trains were run in five-car formations, Motor coach + trailer + trailer + trailer + motor coach, with spares for overhaul. The motor coaches had cabs at each end, enabling single-car operation by them; they had two axle-hung traction motors rated at {{convert|190|hp|abbr=on}} for one hour. The new trains had on-board compressors for the air brakes, and interior lights were in two circuits, one fed from the motor car at one end of the unit, and one from the other, avoiding total lighting loss in passing conductor rail gaps. The conductor rail was altered to the outside position normal for the third-rail system. There was no train power line, and each motor coach collected its own electric supply.{{citation needed|date=May 2021}}

==Extension proposals==
There have been proposals to extend the Waterloo & City line for over a century. After acquiring the Great Northern & City Railway (GN&C) in 1913 (the current [[Northern City Line]]), the Metropolitan Railway considered proposals to join the GN&C to the Waterloo & City or to the [[Circle line (London Underground)|Circle line]], but these never came to fruition. Any extension of the line north would be difficult because of the complex web of tube lines around Bank, and an extension south would be unlikely to provide demand that matched the cost. The narrow tunnels and short train lengths of the current route make any extension less cost-effective than larger projects such as [[Crossrail 2]], which cost more but start with modern tunnels and promise far greater benefits.

The London Plan Working Party Report of 1949 envisaged as its Route G the electrification of the [[London, Tilbury & Southend Railway]] (LTS), and its diversion away from Fenchurch Street to Bank and on through the Waterloo & City tunnels to Waterloo and its suburban lines.<ref>J. Glover, "London's Underground", 7th edition, Shepperton, Ian Allan, 1991, pp.61–62.</ref> The Waterloo & City tunnels would have had to be bored out to main line size to enable this, at prohibitive cost. In the event, only the electrification of the LTS took place, though the [[Docklands Light Railway]] tunnel from Minories to the Bank follows part of the envisaged route.

The revised Working Party Report of 1965 did not mention the Route G proposal, though it does conclude that "[t]he possibility of extending the Waterloo & City line northwards to Liverpool Street has been examined, but found to be physically impracticable."<ref>British Railways and London Transport Joint Working Party, ''A Railway Plan for London'', 4.32 p.31 [http://www.railwaysarchive.co.uk/documents/BRLT_RailwayPlanForLondon1965.pdf] {{Webarchive|url=https://web.archive.org/web/20120131073554/http://www.railwaysarchive.co.uk/documents/BRLT_RailwayPlanForLondon1965.pdf|date=31 January 2012}}</ref> 

Around 2009, the [[Green Party of England and Wales|Green Party]] revived the Metropolitan's plan of connecting the Northern City and Waterloo & City lines as a Crossrail route.<ref>"Green Party response to East Coast Main Line Route Utilisation Strategy Consultation". The Green Party. 2007–09. See ''Green Party Proposal'' under [[Northern City Line]].</ref>

== Map and stations ==
{{Waterloo & City line RDT}}
[[File:Waterloo & City Line.svg|300px]]
{{GeoGroup}}

{| class="wikitable"
|-
! Station !! Image !! Opened !! Additional information
|-
|[[Bank–Monument station|Bank]] {{rail-interchange|london|dlr}} || || 8 August 1898 || Opened as City, renamed 28 October 1940.{{ref|map 1|map 1}} Connects with [[Central line (London Underground)|Central]], [[Circle line (London Underground)|Circle]], [[District line|District]] and [[Northern line|Northern]] lines and [[Docklands Light Railway]].
|-
|[[Waterloo tube station|Waterloo]] {{rail-interchange|gb|rail}} || [[File:Waterloo tube stn entrance.JPG|100px]] || 8 August 1898 ||Connects with [[Bakerloo line|Bakerloo]], [[Jubilee line|Jubilee]] and Northern lines and [[National Rail]] services. The platforms at Waterloo{{ref|map 2|map 2}} are numbered 25 and 26 to coincide with the [[London Waterloo station|Mainline station]], a remnant of [[British Rail|BR]] days.<ref>{{cite book |last=Yonge |first=John |editor-last=Jacobs |editor-first=Gerald |title=Railway Track Diagrams 5: Southern & TfL |edition=3rd |date=November 2008 |orig-year=1994 |publisher=Trackmaps |location=Bradford on Avon |isbn=978-0-9549866-4-3 |at=map 38C }}</ref>
|}

== In popular culture ==
{{In popular culture|section|date=June 2025}}
The Waterloo and City line is closed on weekends; as a result, it has become a well-established and convenient location for film companies. When it was owned by British Rail and its predecessors, it could be used when London Transport were unable or unwilling to allow access to their own stations or lines.
* The film ''[[The Long Memory]]'' (1953) contains a suicide attempt on the railway.
* It can be also seen in the [[Norman Wisdom]] film ''[[On the Beat (1962 film)|On the Beat]]'' (1962), where filming took place on 12 August 1961.
* Scenes for a murder in the film ''[[The Liquidator (1965 film)|The Liquidator]]'' (1965) were recorded at Bank station.{{sfnp|Gillham|2001}}<!-- The location is correct, the date has to be wrong: the film was already released two years earlier. -->
* The second series of the [[BBC]]'s ''[[Survivors (1975 TV series)|Survivors]]'' was filmed on the line, representing various parts of the Central and Northern lines.
* In the television adaptation of ''[[The Tripods (TV series)|The Tripods]]'' (1984), Waterloo masquerades as [[Porte de la Chapelle (Paris Métro)|Porte de la Chapelle]] station on the [[Paris Métro]].
* Waterloo was also used in the [[Peter Howitt (actor)|Peter Howitt]] film ''[[Sliding Doors]]'' (1998), portraying Embankment and one other unknown District line station.

==Other details==
The remnants of one of the Greathead tunnelling shields used in the construction of the line can be seen in the interchange tunnel at Bank connecting the Waterloo and City line platforms with those of the Northern line and the [[Docklands Light Railway]].{{sfnp|Gillham|2001|p=409|loc=&nbsp; A plaque located at the site reads: "This Greathead Type Tunnelling Shield was left at this point 18&nbsp;metres below ground level in 1898. Exposed by Edmund Nuttall Limited in 1987 during the construction of the Docklands Light Railway City Extension."}} It is painted red.

The Waterloo & City line is colloquially known as ''The Drain'',<ref name="Drain2">{{cite news|url=http://news.bbc.co.uk/1/hi/england/london/5324094.stm|title=UK – England – London – 'The Drain' reopens after upgrade|publisher=BBC|access-date=30 January 2015|archive-url=https://web.archive.org/web/20070107031215/http://news.bbc.co.uk/1/hi/england/london/5324094.stm|archive-date=7 January 2007|url-status=live}}</ref> and it was given the [[Engineer's Line Reference]] code 'DRN' by British Rail.<ref>[http://www.railwaycodes.org.uk/elrs/_mileages/d/drn.shtm Engineer's Line References: Waterloo and City Line], Railway Codes website.  Accessed 2024-09-29</ref> The origins of this nickname seem to be uncertain; it may be due to the tunnels beneath the Thames continually leaking and the resulting water needing to be pumped out,<ref name="Drain1"/> or perhaps because passenger access to the platforms at Bank was by a lengthy sloping subway resembling a drain.<ref name="Drain3">{{cite web|url=http://content.tfl.gov.uk/research-guide-no-29-brief-history-of-the-waterloo-and-city-line.pdf|title=Research Guide No 29: Brief History of the Waterloo & City Line|work=tfl.gov.uk|access-date=5 September 2018|archive-url=https://web.archive.org/web/20170918204709/http://content.tfl.gov.uk/research-guide-no-29-brief-history-of-the-waterloo-and-city-line.pdf|archive-date=18 September 2017|url-status=live}}</ref><ref>{{Cite journal |last1=Bubbers |first1=Bernard Leslie |last2=Coles |first2=Denys Eimer |title=Installation of Trav-O-Lators at the Bank Station of the Waterloo and City Railway |year=1963 |url=https://www.icevirtuallibrary.com/doi/10.1680/iicep.1963.10704 |journal=Proceedings of the Institution of Civil Engineers |language=en |volume=24 |issue=4 |pages=541–564 |doi=10.1680/iicep.1963.10704 |issn=1753-7789 |via=ICE Virtual Library|url-access=subscription }}</ref>

Uniquely among London's Underground lines, virtually all infrastructure on the Waterloo & City line is completely underground, including all track, both stations, and the [[Waterloo Underground Depot|maintenance depot at Waterloo]]. (The [[Victoria line]] is also underground for the entire passenger route and all stations, but has a surface level, open-air depot for maintenance.)<ref name="Martin 2012 p. 110">{{cite book | last=Martin | first=A. | title=Underground, Overground: A Passenger's History of the Tube | publisher=Profile | year=2012 | isbn=978-1-84765-807-4 | url=https://books.google.com/books?id=vh3n5WD_YqsC&pg=PA110 | access-date=26 March 2023 | page=110}}</ref> There are no track connections with any other railway line; all equipment transfers to and from the line are accomplished from the shaft and road crane at the Waterloo depot.

==Similar services==
* The [[42nd Street Shuttle]] on the [[New York City Subway]] runs between [[Times Square (IRT 42nd Street Shuttle)|Times Square]] and [[Grand Central (IRT 42nd Street Shuttle)|Grand Central]].
* The [[Ramal (Madrid Metro)|Ramal]] on the [[Madrid Metro]], linking [[Ópera (Madrid Metro)|Ópera]] and [[Príncipe Pío (Madrid Metro)|Príncipe Pío]] stations.
* [[Barcelona–Vallès Line#Barcelona Metro (L lines)|Línia 12]] of the [[Barcelona Metro]] (managed by [[Ferrocarrils de la Generalitat de Catalunya]]: FGC) links only two nearby stations: [[Sarrià station|Sarrià]] (connecting to [[Barcelona–Vallès Line#Barcelona Metro (L lines)|L6]]) and [[Reina Elisenda (Barcelona–Vallès Line)|Reina Elisenda]].
* The [[Olympic Park railway line|T7 Olympic Park Line]] on the [[Sydney Trains|Sydney Trains Network]] connecting [[Olympic Park railway station, Sydney|Olympic Park]] and [[Lidcombe railway station|Lidcombe]].

==Maps==
{{refbegin}}
{{col-begin}}
{{Col-2}}
* {{note|map 1|map 1}}Bank – {{Coord|51|30|47|N|000|05|17|W|region:GB_type:railwaystation|name=01 - Bank station}}
* {{note|map 2|map 2}}Waterloo – {{Coord|51|30|09|N|000|06|47|W|region:GB_type:railwaystation|name=02 - Waterloo tube station}}
{{Col-2}}
* {{note|map 3|map 3}}Waterloo Depot – {{Coord|51|30|07|N|000|06|42|W|region:GB_type:railwaystation|name=03 - Waterloo Depot}}
* {{note|map 4|map 4}}Waterloo Lift Siding – {{Coord|51|30|07|N|000|06|39|W|region:GB_type:railwaystation|name=03 - Waterloo Lift Sidings}}
{{col-end}}
{{refend}}

==See also==
* [[List of crossings of the River Thames]]
* [[Tunnels underneath the River Thames]]

==References==
===Citations===
{{Reflist}}

===Sources===
{{refbegin}}
* {{cite book|last=Jackson|first=Alan| year = 1984 |orig-year=1969 | title = London's Termini | publisher = David & Charles | edition=New Revised| isbn = 0-330-02747-6|location=London}}
* {{cite book|last=Glover|first=John|year=2003|title=London's Underground|publisher=Ian Allan|edition=10th|isbn=0-7110-2935-0}}
{{refend}}

==Further reading==
* {{Gillham-Waterloo-City }}
* Nigel Pennick, ''Waterloo and City Railway'', Library of the European Tradition, Cambridge, 2000
* ''The Engineer'' periodical dated 26 July 1895 and 2 August 1895 gives much more detail of the construction of the tunnels, the Greathead shield, the compressed air working and the electric locomotives, including a diagram of them. On-line versions of the periodical are available at Graces Guide [http://www.gracesguide.co.uk/ Graces Guide].
* ''Proceedings of the Institution of Civil Engineers'', Volume CXXXIX, 1899 – 1900 gives an extensive description of the construction phase

==External links==
{{Commons category}}
* {{Official website}}

{{Waterloo & City line navbox}}
{{ThamesCrossings | west=[[Waterloo Bridge]] | east=[[Blackfriars Bridge]] }}

{{DEFAULTSORT:Waterloo and City Line}}
[[Category:Transport in the City of London]]
[[Category:Transport in the London Borough of Lambeth]]
[[Category:London Underground lines]]
[[Category:Railway lines opened in 1898]]
[[Category:Tunnels underneath the River Thames]]
[[Category:Standard gauge railways in London]]
[[Category:750 V DC railway electrification]]
[[Category:1898 establishments in England]]
[[Category:Metro lines with only two stations]]