Dhoby Ghaut MRT station is an underground Mass Rapid Transit (MRT) interchange station on the North–South (NSL), North East (NEL) and Circle (CCL) lines in Singapore. Located beneath the eastern end of Orchard Road shopping belt in Dhoby Ghaut, Museum Planning Area, the station is integrated with the commercial development The Atrium@Orchard. The station is near landmarks such as The Istana, the MacDonald House, Plaza Singapura and Dhoby Ghaut Green.
Dhoby Ghaut station was part of the early plans for the original MRT network since 1982. It was constructed as part of Phase I of the MRT network which was completed in 1987. Following the network's operational split, the station has been served by the North–South Line since 1989. To construct the North East Line platforms, which were completed in 2003, the Stamford Canal had to be diverted while excavating through part of Mount Sophia. The Circle Line platforms opened in 2010 along with Stages 1 and 2 of the line.
Dhoby Ghaut station is one of the deepest and largest stations, with five underground levels. Its deepest point is at below ground. The station features many forms of artworks, three of them under the Art-in-Transit scheme in the North East Line and Circle Line stations, a set of Art Seats at the Circle Line platforms, and an art piece above the North–South Line platforms. It is also the first triple-line interchange station on the MRT network.
History
North–South Line (NSL) station
Dhoby Ghaut station was included in the early plans of the MRT network in May 1982. It was to be constructed as part of the Phase I MRT segment from the Novena to Outram Park station; this segment was targeted to be completed by December 1987. Phase I, which would be part of the North–South Line (NSL), was given priority as it passes through areas having a higher demand for public transport, such as the densely populated housing estates of Toa Payoh and Ang Mo Kio and the Central Area. The line was aimed to relieve the traffic congestion on the Thomson–Sembawang road corridor.
Before construction began, tenants of Amber Mansions were compelled to relocate; the land had already been marked for acquisition in 1978. Contract 106 for the design and construction of Dhoby Ghaut NSL station was awarded to a joint venture between French contractor Campenon-Bernard and Singapore Piling and Civil Engineering Company Limited. The S$51.3 million(US$ million in ) contract, awarded in October 1983, included of tunnelling works between the Somerset and City Hall stations.
Due to the soft marine clay at the station site, In January 1985, the soft soil led to a tunnel cave-in, which formed a wide hole near Cathay Cinema. The hole was refilled and the soil was further strengthened by injecting a concrete mixture. On 17 June, an engineer died when a crane fell into the work shaft and crushed him. Investigations revealed that the three pieces of timber intended to support the crane were not properly fastened and inadequate in providing support. The contractor was fined S$1,000 (US$ in ) for failing to ensure that the crane was capable of handling the load. Despite the incidents, structural work for the station was completed that September.
To help people familiarise themselves with the system, the Mass Rapid Transit Corporation (MRTC) organised an open house at the station on 6 December 1987. Train services commenced on 12 December when the line extension to Outram Park station was officially completed. The station was part of a line service that ran continuously from Yishun station in the north to Lakeside station in the west. From 28 October 1989, it began to serve the NSL with the operational split of the MRT system. In September 2000, the Land Transport Authority (LTA) installed lifts to allow barrier-free access to the station.<!-- ←Need more completed citation---><!--Dhoby Ghaut was one of four stations used for Exercise Northstar V, a mock terrorist exercise held on 8 January 2006.--->
North East Line (NEL) station
thumb|alt=Photograph of NEL station platforms, with curved seats, station information signages and an escalator leading to the upper levels|NEL platforms
Plans were made in 1986 for a new line from Outram Park station via Dhoby Ghaut to Punggol station in the northeast. These were finalised as the North East Line (NEL) in January 1996. In August 1997, the LTA awarded Contract C707 for building the NEL station to Obayashi Corporation. The S$268 million(US$ million in ) contract included the construction of two commercial buildings above the station. Construction began in 1996,
Construction difficulties included having to reroute the Stamford Canal, which bisected the station site, to a temporary canal. The old canal box was rebuilt and replaced by a new, larger box, which lies above the second level of the station. The new canal was temporarily supported by steel piles while the NEL station box was being constructed. This made it difficult to install the site's temporary retaining walls because of the many voids in between the station levels.
Circle Line (CCL) station
thumb|Map of the planned [[Marina MRT Line|Marina Line|alt=A map showing the Marina Line plans as announced in October 1997. The line, coloured in orange, has five branches connecting to (clockwise from north) Kallang, Paya Lebar, Tanjong Pagar, Chinatown and Dhoby Ghaut. The Kallang and Paya Lebar branches converge into one branch, before branching out again into three branches to Tanjong Pagar, Chinatown and Dhoby Ghaut]]
The station box for the Circle Line (CCL) had been put in place when the NEL station was being constructed. It was planned for Dhoby Ghaut station to be the terminus of a branch of the Marina line (MRL). The MRL was finalised to serve six stations from this station to Stadium station in November 1999. The station became part of CCL Stage 1 (CCL1) when the MRL plans were incorporated into the CCL plans in 2001.
On 7 August 2001, the LTA awarded Contract 825 for the design and construction of the CCL station and associated tunnels to a joint venture among Shanghai Tunnel Engineering Co. (Singapore) Pte Ltd, Woh Hup Pte Ltd and NCC International AB. The S$343.94 million(US$ million in ) contract included building the Bras Basah, Esplanade and Promenade stations. During construction, part of Orchard Road had to be realigned for three months from 10 June 2002. The underpass, linking the NEL and NSL platforms, had to be stabilised while construction works took place underneath. Seven caisson piles were installed to enhance the support of the underpass and capping beams were then constructed to form the supporting system. Along with the other stations on CCL1 and 2,