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BTS Silom Line
A BTS Train at Talat Phlu Station
Owner Bangkok Metropolitan Administration (BMA)
Locale Bangkok
Color on map    Dark Green
Type Rapid transit
System BTS Skytrain
Operator(s) Bangkok Mass Transit System
Public Company Limited
Depot(s)Mo Chit, Bang Wa, Khu Khot (Backup)
Opened5 December 1999
Line length14 km (8.7 mi)
Number of tracks2
Track gauge1,435 mm (4 ft 8+12 in) standard gauge
Electrification 750 V DC  third rail
Signalling Bombardier CITYFLO 450 moving block CBTC ATC under ATO GoA 2 (STO), with subsystems of ATP, ATS and CBI [1] [2]
Route map

National Stadium
  BTS  (Up arrow Khu Khot – Kheha Down arrow)
  MRT : Si Lom (Left arrow  Lak Song –  Tha Phra (via Bang Sue) Right arrow)
Sala Daeng
Chong Nonsi
Saint Louis
Si Rat Expressway
Saphan Taksin
Chao Phraya River
Krung Thonburi   BTS 
  SRT  (planned): (Hua Lamphong Up arrow)
  MRT  (planned): (Left arrow  Khlong Bang Phai –  Rat Burana Right arrow)
Wongwian Yai
Pho Nimit
Talat Phlu
SRT Maeklong Railway (  SRT  planned): (Maha Chai Down arrow)
Bang Wa
  MRT : (Left arrow  Lak Song –  Tha Phra (via Bang Sue) Right arrow)
Light Depot

The BTS Silom Line ( Thai: รถไฟฟ้า สายสีลม) is an elevated rapid transit line of the BTS Skytrain in Bangkok, Thailand. It is operated by Bangkok Mass Transit System PCL (BTSC), a subsidiary of BTS Group Holdings, under a concession granted by the Bangkok Metropolitan Administration (BMA). The line serves Silom and Sathon Roads, the central business district of Bangkok, terminates at National Stadium and Bang Wa. The line is 14 km in length and consists of 14 stations. [3]

Route alignment

It runs eastward from the National Stadium Station in Pathum Wan District over Rama I Road and interchanges with the Sukhumvit Line at Siam BTS station, then turns southward, following Ratchadamri, Si Lom, Narathiwat Ratchanakharin and Sathon Roads to Taksin Bridge where it crosses the Chao Phraya River to the Thonburi side of Bangkok and Wong Wian Yai. It continues west along the Ratchapruek rd corridor before it terminates at Bang Wa Station in Phasi Charoen District.


Originally consisting of seven stations from National Stadium (W1) to Saphan Taksin (S6) when the BTS first opened 5 December 1999. A planned station at S4 was not built originally but was completed in 2021. Its formal name is The Elevated Train in Commemoration of HM the King's 6th Cycle Birthday 2nd line ( Thai: รถไฟฟ้าเฉลิมพระเกียรติ 6 รอบพระชนมพรรษา สาย 2). A 2.2 km (1.4 mi) extension across the river to Wongwian Yai (S8) opened on 15 May 2009 after two years of delay. A further 5.3 km (3.3 mi), 4 station extension from Wongwian Yai (S8) to Bang Wa (S12) opened on 5 December 2013 after delays caused by the Bangkok floods of late 2011.


Route map as of 2015
Curved viaduct between Siam and Ratchadamri

All stations are in Bangkok

Code Station Name Interchanges Location
English Thai
National Stadium
( RTGSSanam Kila Haeng Chat)
สนามกีฬาแห่งชาติ Pathum Wan
( RTGSSayam)
สยาม   BTS 
Ratchadamri ราชดำริ
Sala Daeng ศาลาแดง   MRT  ( Si Lom) Bang Rak
Chong Nonsi ช่องนนทรี BRT (Sathon)
Saint Louis
( RTGSSen Lui)
เซนต์หลุยส์ Bang Rak and Sathon
Surasak สุรศักดิ์
Saphan Taksin สะพานตากสิน   Mine Smart Ferry    CHAOPHRAYA EXPRESS 
Krung Thon Buri กรุงธนบุรี   BTS  Khlong San
Wongwian Yai วงเวียนใหญ่
Pho Nimit โพธิ์นิมิตร Thon Buri
Talat Phlu ตลาดพลู BRT (Ratchaphruek)
Wutthakat วุฒากาศ Maeklong Railway (Wutthakat Halt) Thon Buri and Chom Thong
Bang Wa บางหว้า   MRT , Khlong Phasi Charoen boat service Phasi Charoen

Extensions and current construction

Summary of BTS Silom Line Extensions:

  • 5 December 1999: National Stadium (W01) – Saphan Taksin (S06)
  • 15 May 2009: Saphan Taksin (S06) – Wong Wian Yai (S08)
  • 12 January 2013: Wong Wian Yai (S08) – Pho Nimit (S09) [4]
  • 14 February 2013: Pho Nimit (S09) – Talat Phlu (S10)
  • 5 December 2013: Talat Phlu (S10) – Bang Wa (S12)
  • 8 February 2021: Saint Louis (S4, infill station)

1st extension to Wong Wian Yai

On 18 October 2005, with no approval from the central government forthcoming, Bangkok Metropolitan Administration (BMA) decided to fund and complete the 2.2 kilometers (1.4 mi) Silom Line route extension to Krung Thonburi Station (S07) and Wongwian Yai Station (S08). Construction began on 13 December 2005 with completion originally expected within two years for a late 2007 opening. However, problems with the tendering and installation of a new Bombardier open signalling system repeatedly pushed back the schedule. The extension finally opening on 15 May 2009. However, the single platform Saphan Taksin station which has only one track, has caused repeated delays during rush hour. In 2012, the BMA announced plans to demolish Saphan Taksin station in the future. There are now plans to construct new platforms and remove the bottleneck and keep the station which provides an important link between river boats. The plan includes redesigning the road bridges either side of the viaduct to fit the new station.

2nd extension to Bang Wa

The third extension to the network, a 5.3 km (3.3 mi), a four station extension from Wongwian Yai (S8) to Bang Wa (S12) in Phasi Charoen District began construction in the 2nd quarter of 2011, with a deadline of the end of 2012. Only the stations had to be constructed as the viaduct had been completed some years prior. However, construction was delayed for many months by the Bangkok floods of late 2011. It eventually opened in stages. Pho Nimit opened on 12 January 2013, Talat Phlu opened on 14 February 2013, with the last two stations opening on 5 December 2013. [5] The extension was initially operated by a separate 6 car shuttle service due to the absence of a turnout between Wongwian Yai (S8) and Talat Phlu (S10). The remaining two stations Wutthakat (S11) and Bang Wa (S12) were opened on 5 December 2013.

Saint Louis (S4) station – Silom Line

In 2018, it was decided to finally build the missing Saint Louis (S4) station (originally named Sueksa Wittaya), the EIA was finalised in March 2019. [6] Construction of the station began in August 2019 and by the end of 2019 had reached 25% progress. [7] By August 2020, construction had reached 50% but was 30% behind schedule due to COVID related delays. [8]

The station was opened on 8 February 2021. [9]

Future extension plans

South: Bang Wa to Taling Chan

After the opening of Wutthakat (S11) and Bang Wa (S12) stations 5 December 2013, the BMA announced a new proposal to further extended the Silom Line by 7 km (4.3 mi) from Bang Wa (S12) station, by six stations to Taling Chan. [10] At Taling Chan it would connect with the SRT Light Red line.

A public hearing was held in 2015. [11] Three route options were considered, with construction intended to start in 2017. [12] Part of the basis for this further extension by the BMA is that it would provide proximate access to the Southern Bus Terminal. The BMA Transport and Traffic Office completed an economic evaluation of the extension in October 2018 which found a cost benefit ratio of 2.37. [13] The study recommended that an EIA be completed in 2019 but this was delayed.

Once the extension to Taling Chan is built the BMA has canvassed the possibility of a further future extension north to connect with the MRT Purple Line at Rattanathibet Road.

West: National Stadium to Yot Se

The BTS Silom Line is planned to be extended by two stations west from National Stadium (W1) to link with the SRT Dark Red line at Yot Se station. However, no time frame for this extension has been announced and this section of the SRT Dark Red Line will not be built until after 2022.

Originally, the plan was to extend the Silom Line west from National Stadium into Chinatown, then north to Democracy Monument where it would then run west to Rattanakosin Island and Sanam Luang, tunnel under the river to the Thonburi side before terminating at Phran Nok. However, this plan was shelved back in 2009 and much of this route has been replaced by alignment changes to the MRT Orange line which is under construction.


  1. ^ "Mass transit signalling". Bombardier Transportation. Archived from the original on 1 January 2022. Retrieved 16 June 2020.
  2. ^ "Bombardier Projects in Mass-transit signalling" (PDF). Archived from the original (PDF) on 23 November 2021.
  3. ^ "Structure and Stations : Routes". Retrieved 23 July 2023.
  4. ^ "Sukhumbhand woos commuters". The Nation. 16 January 2013. Retrieved 26 June 2014.
  5. ^ "BTS Skytrain starts it's [sic] new station Pho Nimit today and comimg more near to metro park sathorn". 12 January 2013. Archived from the original on 1 January 2014. Retrieved 26 June 2014.
  6. ^ "ไฟเขียว BTS ขึ้นค่าตั๋วส่วนต่อขยาย 16 เมษาฯ เร่งเชื่อม'หมอชิต-เซ็นทรัลลาดพร้าว' สิงหาฯนี้". Prachachat. Bangkok. 4 March 2019.
  7. ^ "20 ปีบีทีเอสจาก 35 ขบวนจ่อ 98 ขบวน ปีที่ 21 ของรถไฟฟ้าสายแรกเมืองไทย". Thairath. Bangkok. 30 December 2019.
  8. ^ "บีทีเอส"สร้างครึ่งทางแล้วเปิดต้นปี 64". Dailynews. Bangkok. 25 August 2020.
  9. ^ "บีทีเอสเปลี่ยนชื่อสถานี ศึกษาวิทยา เป็น"เซนต์หลุยส์" ตามชื่อโรงพยาบาล-โรงเรียน ในพื้นที่ พร้อมเปิดสถานี ให้บริการประชาชน เดือนก.พ.นี้". Spring News.
  10. ^ "One month free on metro between Taksin and Bang Wa". Thai Rath. 4 December 2013. Retrieved 4 September 2014.
  11. ^ "BTS Silom Line extension to Taling Chan moves forward". Coconuts Bangkok. 5 March 2015. Retrieved 4 December 2016.
  12. ^ "Skytrain looks West". Retrieved 4 December 2016.
  13. ^ "เกาะติดเมกะโปรเจ็กต์ : รถไฟฟ้าสายสีเขียว (บางหว้า-ตลิ่งชัน) ยกระดับคุณภาพชีวิตด้านการเดินทาง". Bangkok. 25 October 2018.

External links

See also