Yellow Line (Bangkok)

The line starts at the intersection of Ratachadapisek and Lat Phrao roads where it interchanges with the MRT Blue Line at Lat Phrao station. The line then heads east along Lat Phrao road to Bangkapi junction and south to Lam Sali station to interchange with the MRT Orange Line and the future MRT Brown Line. The line continues further south along Srinagarindra Road to Hua Mark where it will interchange with the Airport Rail Link at Hua Mak station.

From Hua Mark, the route continues south along Srinagarindra Road past Bangna-Trat Road all the way to Thepha Rak Road in Samut Prakan Province, then heading west along Thepha Rak Road where it terminates at Samrong and interchanges with Samrong of the BTS Sukhumvit Line.[9]

The line will be built from Lat Phrao (YL1) to Samrong (YL23) and the depot will be located at Debaratana Road adjacent to Si Iam station (YL17).

The Yellow line was first proposed in the mid 1990s as a monorail line by Japanese consultants with little or no progress for 10 years. In 2004, the Office of Transport and Traffic Policy and Planning (OTP) reworked the proposal as a heavy rail line with underground and elevated sections as part of the 10 line metro plan which was taken to the February 2005 election. In 2009, it was suggested to change the line to an elevated monorail line as a cost saving measure. In December 2011, the MRTA was instructed by the MOT to divide the Yellow Line into two phases for tender and construction purposes and to reduce land appropriation costs.[10] In June 2012, the MRTA contracted consultants to undertake detailed designs of the line. In February 2013, OTP stated that the tender for the Yellow Line should be ready by late 2013 for tender in early 2014.[11] By August 2013, this timeline had changed to a mid 2014 tender date.[12]

However, similar to the MRT Pink Line, delays in finalising the technical requirements of the tender in relation to the selection of monorail rolling stock which determines the type of track to be constructed resulted in further delays. The subsequent political turmoil of late 2013 and early 2014 caused even more delays. Thereafter, a coup in May 2014 resulted in a new military administration and the tender being deferred while a review of all mass transit projects was undertaken for a period of 18 months. The MRTA was instructed by the junta government to change to a PPP tender process which was subsequently not released until mid-2016. In early December 2016, The BSR consortium consisting of BTS Group Holdings (75% majority stake) with Sino-Thai Engineering and Construction (STEC), and Ratchaburi Electricity Generation Holding (RATCH), won the bid construct and operate the Yellow Line. The BSR also won the bid to build and operate the MRT Pink Line.[13]

On June 16, 2017, the contract was signed for the project between the Mass Rapid Transit Authority of Thailand and BSR consortium. The BSR established the Eastern Bangkok Monorail Company Limited (EBM) to operate the line. A proposed 2 station extension of the route north from the Lat Phrao terminus to link to the BTS Sukhumvit Line at Ratchayothin station has also been proposed by the BSR Joint Venture.[14] However, this extension is opposed by the MRT Blue Line operator BEM due to concerns regarding loss of revenue.[15]

Construction of MRT Yellow Line on Lat Phrao road

Construction of the Yellow Line began in March 2018 with the BSR consortium establishing a number of preparation work sites along the Lat Phrao Road with the closure of lanes along this traffic dense east–west corridor. By August 2018, construction had expanded to along the Srinakarin rd section which is also where the depot will be built.[16] By 30 September 2018, overall construction had progressed to 9.61%.[17] At the end of March 2019, construction has progressed to 30.40%.[18] By the end of July 2019, civil construction had further advanced to 39.92%.[19] At the end of October 2019, construction had progressed to 45.88%.[20] By the end of January 2020, construction had progressed to 51.81%.[21] By the end of May 2020, construction had progressed to 59.42%.[22] At the end of July 2020, construction had progressed to 62.44%.[23] At the end of September 2020, progress was at 66.31%.[24] By the end of 2020, 1549 guide beams had been installed of the project total of 2388 individual guide beams. At the end of November 2020, construction had progressed to 70.64%.[25] Construction progress was 77.97% complete by the end of February 2021.[26] Construction progress had advanced to 82.46% complete by the end of April 2021.[27] Construction progress was 85.53% by the end of July 2021.[28] Construction progress was 88.14% by the end of October 2021.[29]

On 29 November 2021, daily testing began on a 6 km (3.7 mi) section of the line between the depot at Si Lam and Srinagarindra 38 station. Testing will be conducted at a maximum speed of 25 km/h (16 mph). After 3 months, testing will be undertaken at higher speeds and expanded to a longer section of the line.[5]

BSR selected Bombardier Innovia Monorail 300 rolling stock for the Yellow line.[30] The BSR has announced that they will purchase 28 4-car sets to operate the Yellow line.[31] These trains will be manufactured by CRRC Puzhen Bombardier Transportation Systems (joint venture of Bombardier Transportation and CRRC Nanjing Puzhen) in Wuhu, Anhui, China. The first set has been assembled and was shipped on 4 September 2020 with delivery to Thailand at the end of September 2020.[32] The first set arrived in Thailand on 1 October 2020 at Laem Chabang port with a handover ceremony attended by the Thai Prime Minister, BTSC Chairman, MRTA and Canadian Ambassador.[33] Two more sets arrived in mid December 2020 for a total of 5 sets by the end of 2020. By July 2021, 8 sets had been delivered and were being tested.[34] As of the end of October 2021, 12 sets had been delivered.[35] By the end of November 2021, the BSR stated that 20 sets had been delivered with the remaining sets expected to be fully delivered by the end of March 2022.[5] However, as of mid April 2022 only 26 sets had been received and were progressing undergoing testing.[36]

The remaining sets are expected to be delivered by July 2022.

Innovia Monorail 300, Line 15 (Silver), São Paulo Metro, Brazil

Technical Characteristics

• Low profile vehicles/low floor height above beam[37]
• Distinct sloped nose/end-cap
• Inter-car walkthrough[37]
• Rubber-tires and permanent magnet motor[37]
• Aluminium body, steel underframe, composite end cap
• 4-car sets have a capacity of 24,100 pax p/h each way and 8-car sets a capacity of 49.600 pax p/h each way with a 75-second headway.[38]
• Innovia Monorails are all fully automated and are equipped with CITYFLO 650 communications-based train control for driverless operation to increase reliability, shorten head ways between trains and lower maintenance costs.[39]

The BSR has stated that the pax capacity for 4-car sets will be 17,000 p/h each way.

The 30.4 km Yellow Line will have 23 stations (with a proposed extension of two stations):[42]

Code	Station Name		Transfers	Opening	Province
	English	Thai
YLEX-02	Phaholyothin 24 (proposed extension)	พหลโยธิน 24	BTS  Phahon Yothin 24	Planned	Bangkok
YLEX-01	Chankasem (proposed extension)	จันทรเกษม
YL1	Lat Phrao	ลาดพร้าว	MRT  Lat Phrao	June 2023[43]
YL2	Phawana	ภาวนา
YL3	Chok Chai 4	โชคชัย 4
YL4	Lat Phrao 71	ลาดพร้าว 71
YL5	Lat Phrao 83	ลาดพร้าว 83	MRL  Chalong Rat (proposed)
YL6	Mahatthai	มหาดไทย
YL7	Lat Phrao 101	ลาดพร้าว 101
YL8	Bang Kapi	บางกะปิ
YL9	Yaek Lam Sali	แยกลำสาลี	MRT  Yaek Lam Sali (under construction)  MRT  Chalong Rat (design phase)
YL10	Si Kritha	ศรีกรีฑา
YL11	Hua Mak	หัวหมาก	SRT  Hua Mak (tender in 2023)  ARL  Hua Mak
YL12	Kalantan	กลันตัน
YL13	Si Nut	ศรีนุช
YL14	Srinagarindra 38	ศรีนครินทร์ 38
YL15	Suan Luang Rama IX	สวนหลวง ร.9
YL16	Si Udom	ศรีอุดม
YL17	Si Iam (Depot)	ศรีเอี่ยม	BTS  (planned)
YL18	Si La Salle	ศรีลาซาล
YL19	Si Bearing	ศรีแบริ่ง			Samut Prakan
YL20	Si Dan	ศรีด่าน
YL21	Si Thepha	ศรีเทพา
YL22	Thipphawan	ทิพวรรณ
YL23	Samrong	สำโรง	BTS  Samrong

A proposed 2 station extension of the route north from the current Ratchada terminus to link to the BTS Sukhumvit Line Extension at Ratchayothin station has also been proposed by the BSR Joint Venture.[14] However, this extension is opposed by the MRT Blue Line operator BEM,[15] estimating about 988 million baht loss on the extension's first year of service and 2.7 billion baht throughout the 30-year concession period.[44]

The extension was approved in February 2021, with construction set to be completed in 2024.[45] However, EBM has repeatedly denied MRTA's request to provide a compensation for BEM, which may result in a cancellation of the extension if no decision has been made.[44][46]

When completed the Yellow Line will terminate at Samrong. A future extension from Samrong across the Chao Phraya River to link with the MRT Purple Line at Rat Burana was canvassed by the OTP in the early 2010s. However, the location and design of Samrong station excludes any further extension of the line west of Sukhumvit rd.

Wikimedia Commons has media related to MRT Yellow Line.

• "MRTA Yellow Line website
• Airport Rail Link, BTS, MRT & BRT network map
• MRTA