Rail transport in Thailand

Rail transport plays a crucial role in connecting various regions of Thailand, transporting both goods and passengers through a range of transportation options that include inter-city and commuter rail, mass rapid transit, monorails, and airport rail links. The State Railway of Thailand (SRT) operates a network of intercity railways spanning 4,845.1 kilometers, covering 47 provinces across the country. SRT is committed to developing railway lands through its subsidiary, SRT Asset (SRTA), which focuses on transit-oriented development (TOD) initiatives. The Krung Thep Aphiwat Central Terminal in Bangkok serves as the primary transportation hub for rail transport in Thailand, connecting various types of rail transportation throughout the country. It covers an area of 274,192 square meters, making it the largest railway station in Southeast Asia, and is situated in a new central business district (CBD) that is currently being developed.

To further expand and improve its railway network, particularly through the construction of double-track railways, Thailand has invested in several expansion projects. The first phase of this expansion project covers seven routes, two of which have been completed, while the remaining five are under construction. The second phase of the expansion project is expected to begin construction in 2023. There are also plans for 12 new railway routes with a total distance of 2,419 kilometers, which will increase the number of provinces with railways passing through them to 61.

The mass rapid transit system in Bangkok and its surrounding areas has been operating since 1999. It comprises elevated, ground-level, underground, and under-river electric trains, spanning 211.94 kilometers with 11 routes and 141 stations. The network is expanding with five new lines and six extensions currently under construction, bidding, or preparation.

Thailand is also investing in high-speed rails to enhance its rail transport system. Currently, the Bangkok–Nong Khai route and the Bangkok–U-tapao route are under construction, covering 608 kilometers and 220 kilometers, respectively. There are also plans to construct two more high-speed rail lines, the Bangkok-Chiangmai route and the Bangkok-Padang Besar route, in the near future.

History
Rail transport in Thailand has a long and varied history. Its earliest recorded railway-related event dates back to 1855, when King Rama IV received a model railway as a gift from Queen Victoria. The country's first railway line, the Paknam Railway, was built under a 50-year concession with a Danish company and opened to the public in 1894, after being constructed in 1891. Alongside the Paknam Railway, Bangkok also had an early form of rail transport in the form of a tram system. It was initially a horse tram system that started operating on 22 September 1888, and was later electrified in 1892, becoming the first electrified tram system in Asia. The tram system, however, ceased operations on 11 October 1968, after nearly 80 years of service. On the other hand, the Paknam Railway was electrified in 1925 and operated for almost 68 years until its closure on 1 January 1959.

In 1890, King Rama V established the Department of Railways under the Ministry of Public Works to oversee the construction of a railway network in the country. The construction of the Bangkok-Ayutthaya railway began in 1891 and was completed on 26 March 1896, which marked the establishment of the railway business in Thailand. Subsequently, the railway service was extended to Nakhon Ratchasima in 1900, forming the original section of what is now known as the Northeastern Line. The Northern Line, which extended to Chiang Mai, was constructed from Ayutthaya, and the Lopburi segment was the first part of this railway route to become operational, opening for service in 1901. The line to Phetchaburi, later known as the Southern Line, was inaugurated on 19 June 1903, while the Eastern Line connecting Bangkok and Chachoengsao began operations in 1907.

Initially, the Northern, Northeastern, and Eastern Lines were constructed to standard gauge (1,435 mm.) while the Southern Line was built to meter gauge (1,000 mm.). However, in September 1919, a decision was made to regauged all lines to meter gauge, which took 10 years to complete. On 5 June 1917, King Rama VI issued a royal command to change the name of the Department of Railways to Royal State Railways of Siam (RSR) by merging the Northern Railway Department and the Southern Railway Department together. The RSR was later renamed the State Railway of Thailand (SRT) on 1 July 1951, under Prime Minister Plaek Phibunsongkhram.

In 1916, the construction of Bangkok railway station, also known as Hua Lampong railway station, was finished and it was inaugurated during the reign of King Rama VI. Initially erected under the reign of King Rama V, the station served as a crucial railway transportation center in Thailand until Krung Thep Aphiwat Central Terminal was constructed.

In the late 1990s, Thailand's rail transport underwent a modernization with the introduction of rapid transit systems. To organize mass transportation systems in Bangkok and its surrounding areas by electric train, the Mass Rapid Transit Authority of Thailand (MRTA) was established in 1992. The BTS Skytrain, which was the first rapid transit system in Bangkok, is owned by the Bangkok Metropolitan Administration (BMA), began operations in 1999 and is operated under a concession from the BMA granted to Bangkok Mass Transit System (BTSC). The Bangkok Metro, with its first line being the Blue Line, is the first underground railway that opened in 2004. It is owned by the MRTA and operated by the Bangkok Expressway and Metro (BEM) under a concession granted by the MRTA. The Airport Rail Link, which opened in 2010 and has transformed commuting in the capital city, is owned by the State Railway of Thailand and operated by its subsidiary, the SRT Electric Train (SRTET). Since then, the government has embarked on several high-speed rail projects to connect different parts of the country. The Bangkok–Nong Khai route, a 606-kilometer line, was initiated in 2014 with an MOU between Thailand and China for co-financing. However, in 2016, the Thai government decided to finance the entire project, and it is 100% Thai invested and operated for construction. China is assisting in the civil works, including the design, supervision, and installation of electrical and mechanical systems. The first section, from Bangkok to Nakhon Ratchasima, is already under construction and expected to be completed in 2026, with the second section, from Nakhon Ratchasima to Nong Khai, scheduled to begin construction in 2023. The Don Mueang–Suvarnabhumi–U-Tapao route, a 220-kilometer line connecting three major airports, was signed in 2019 with construction scheduled to start in 2023. The Bangkok–Chiang Mai route, which covers a distance of 688 kilometers, has been the focus of joint efforts by Thailand and Japan since the signing of a Memorandum of Cooperation (MOC) in 2015. As of 8 March 2023, the project's economic and financial feasibility study has now been completed, and the results show that it is worth the investment. The section of the project will connect Bangkok to Phitsanulok, while the second section will connect Phitsanulok to Chiang Mai.

Since 2017, Thailand has been upgrading its railway signaling systems with the implementation of the European Train Control System (ETCS), starting with the Eastern Line and followed by the Red Line. This upgrade has gradually been extended to mainlines throughout the country, with Automatic Train Protection (ATP) being put in place to ensure the highest safety standards for railway transportation. On 15 April 2019, the Department of Rail Transport (DRT) was established as a government agency under the Ministry of Transport to oversee the national rail transport system in Thailand. The DRT is responsible for regulating and standardizing policies, strategies, and plans for supervising rail transport businesses throughout the country, with the goal of improving safety, efficiency, and reliability.

As of 2020, the State Railway of Thailand (SRT) operates a total of 4,814.862 kilometers of intercity railways across the country, and is working on upgrading its lines to double-track railways. Double-track railways have several advantages over single-track railways, such as higher capacity, safety, and speed. Passenger trains on double-track railways can travel at an average speed of 100-120 kilometers per hour, while freight trains can travel at an average speed of 60 kilometers per hour. Double-track railways also eliminate level crossings and install fences along the line, which help to reduce accidents and improve safety. The SRT has embarked on several expansion projects to further extend and enhance its railway network. The first phase of the expansion project covers seven routes, two of which have been completed, while the remaining five are under construction. The second phase of the expansion project, which is expected to begin construction in 2023. Furthermore, there are plans for 12 new railway routes with a total distance of 2,419 kilometers. As a result, the number of provinces with railways passing through them will increase to 61.

On 30 April 2021, SRT Asset was established, following the approval of the Cabinet on 29 September 2020, with the main objectives of managing and developing the assets of State Railway of Thailand, and developing transit-oriented development (TOD) projects to increase connectivity and accessibility within the country. The company is currently focusing on the areas around Krung Thep Aphiwat Central Terminal, Thonburi, and Mae Nam with plans to develop them into major mixed-use projects. In the same year, the first phase of the Red Lines, a commuter rail line in the Bangkok Metropolitan Region, opened for service after several years of construction. And in 2022, the newly constructed Krung Thep Aphiwat Central Terminal replaced Bangkok railway station as the country's central railway transportation hub. The terminal is the largest station in Southeast Asia, with a total floor space of over 274,000 square meters, and it has 24 platforms: 12 for inter-city and commuter rail, 12 for future high-speed rail and airport rail link. It also has an underground connection to the MRT Blue Line.

State Railway of Thailand
State Railway of Thailand (SRT) is responsible for overseeing the operation of intercity railways in Thailand, offering diesel-hauled and electric-powered passenger trains, as well as freight services across the nation. However, the SRT has gained a reputation for inefficiency and poor maintenance, resulting in delayed trains and outdated equipment. In 2010, the SRT reported a preliminary loss of 7.58 billion baht. Despite multiple attempts at restructuring and privatization in the 2000s, strong union opposition has prevented significant changes. As of a 2022 report, the SRT has taken measures to improve safety by closing 122 level crossings and illegal crossings throughout Thailand and constructing overpasses and underpasses in double-track railway project to address level crossing issues.

Bangkok Mass Transit System
Bangkok Mass Transit System (BTSC) operates the Skytrain system in Bangkok under a concession granted by the Bangkok Metropolitan Administration (BMA). The investment for the structure and system were fully supported by BTSC. The Gold Line is also operated by BTSC under a 30-year contract.

Bangkok Expressway and Metro
Bangkok Expressway and Metro (BEM) operates two metro lines in Bangkok, the MRT Blue Line and MRT Purple Line, under 25-year concession agreements with the Mass Rapid Transit Authority of Thailand (MRTA). BEM was formed in 2015 by the merger of Bangkok Expressway Public Company Limited (BECL) and Bangkok Metro Public Company Limited (BMCL).

Asia Era One
Asia Era One (AERA1) currently operates the Airport Rail Link, which was previously operated by the SRT Electrified Train (SRTET), a subsidiary of the State Railway of Thailand (SRT). However, in October 2021, the operation of the line was transferred to a new entity led by a consortium including Charoen Pokphand (CP) and partners such as Ch. Karnchang (CK), Bangkok Expressway and Metro (BEM), Italian-Thai Development (ITD), and China Railway Construction Corporation (CRCC). This new entity rebranded the service as AERA1 and will also operate the upcoming Don Mueang–Suvarnabhumi–U-Tapao high-speed railway.

SRT Electrified Train
SRT Electrified Train (SRTET) is a wholly owned subsidiary of the State Railway of Thailand (SRT) and operates the Red Lines, a commuter rail service in the Bangkok Metropolitan Region. The company also formerly operated the Airport Rail Link until the operation of the line was transferred to Asia Era One (AERA1) in October 2021.

Northern Bangkok Monorail and Eastern Bangkok Monorail
Eastern Bangkok Monorail (EBM) and Northern Bangkok Monorail (NBM) operate the Yellow and future Pink monorail lines respectively. The companies were established by the BSR consortium consisting of BTS Group Holdings (BTSG) with Sino-Thai Engineering and Construction (STEC), and Ratchaburi Electricity Generation Holding (RATCH), who won the bid to construct and operate both monorail systems in early December 2016, and signed contracts with the Mass Rapid Transit Authority of Thailand in June 2017.

Inter-city rail
Thailand's inter-city rail network covers a distance of 4,814.862 kilometers, serving 47 provinces, and is managed by the State Railway of Thailand (SRT). The network is divided into four main routes: Northern Line, Northeastern Line, Eastern Line, and Southern Line, with single tracks covering 3,391.513 kilometers, double tracks covering 1,103.192 kilometers, and triple tracks covering 320.157 kilometers.

The country is currently expanding its railway network through the double-track railway project, which aims to upgrade existing single tracks to double tracks. The project covers a total of 3,157 kilometers, with Phase 1 already completed for two out of seven lines spanning 993 kilometers. Phase 2 is currently underway, consisting of seven routes totaling 1,483 kilometers. Double-track railway project is expected to significantly increase transportation capacity, with annual railway freight transport projected to rise from 11 million to 46 million tons by 2027.

Two new railway lines covering 681 kilometers are also currently under construction, and the next phase of the new railway project will add 12 new routes covering 2,419 kilometers. Upon completion of all phases, the railway will pass throughout a total of 61 provinces.

Commuter rail


The State Railway of Thailand (SRT) manages the commuter rail system in the Bangkok Metropolitan Region, which primarily serves individuals traveling to work, school, or business within a 150-kilometer radius of Bangkok. With stops at every station along the way, several commuter rail lines are available for passengers, such as the Northern Line connecting to Lopburi, the Northeastern Line connecting to Kaeng Khoi Junction, the Eastern Line connecting to Prachinburi, and the Southern Line connecting to Ratchaburi and Suphanburi. The fully electrified Red Lines, which is powered by overhead lines, is a commuter rail system consisting of two lines: the Dark Red Line and the Light Red Line. Both lines fall under the category of commuter rail. The Maeklong Railway, on the other hand, is a separate entity consisting of two sections that are not connected to the main commuter rail lines. The first section links Wongwian Yai to Samut Sakhon, while the second section connects Ban Laem, Samut Sakhon, Maeklong, Samut Songkhram.

The SRT has plans to upgrade the existing railway system by electrifying the metre-gauge railway, with the aim of moving away from the current diesel-powered system. The proposed electrification plan will begin by transforming the commuter rail lines within a 100-kilometer radius of Bangkok in Phase 1, expanding to a 250-kilometer radius in Phase 2, and eventually to a 500-kilometer radius in Phase 3.

Rapid transit


Bangkok's rapid transit system comprises several lines, including the BTS Skytrain (Silom Line and Sukhumvit Line and Gold Line ), MRT (Blue Line and Purple Line and Yellow Line), Airport Rail Link, and Red Lines. While the Mass Rapid Transit Authority of Thailand (MRTA) was established in 1992 to oversee the planning and development of the city's rapid transit system, each line is operated by a different company under concession agreements with various government entities.

The BTS Skytrain, which started operating in 1999, was the first rapid transit system to be launched in Bangkok. The system is a public-private partnership between the Bangkok Metropolitan Administration (BMA) and the Bangkok Mass Transit System (BTSC). The BMA signed an agreement with the BTSC in February 1992 to launch city's first elevated railway. The BTS Skytrain includes two lines, the Sukhumvit Line and the Silom Line, and serves the city's central business district, commercial areas, and major tourist destinations. The initial investment for the system was 50 billion baht, with the BTSC as the main investor for 30 years. The BMA oversaw land procurement and appropriation, while the BTSC invested in infrastructure such as tracks, station buildings, maintenance centers, rolling stock, signaling systems, and electrical systems, as well as system operations and maintenance.

The MRT was launched in 2004 with the first line being the Blue Line, which was the first line to have underground stations. The second line, the Purple Line, was opened in 2016. Both lines are operated by Bangkok Expressway and Metro (BEM) under a 25-year concession agreement with the MRTA. The Yellow Line while also part of the MRT is instead operated by Eastern Bangkok Monorail, and opened in 2023.

The Airport Rail Link connects Phaya Thai to Suvarnabhumi Airport and was launched in 2010. Initially operated by the SRT Electrified Train (SRTET), a subsidiary of the State Railway of Thailand (SRT), the operation of the line was transferred to Asia Era One in October 2021.

The Red Lines are a fully electrified commuter rail system that operates as part of the rapid transit network, using overhead contact system (OCS) and operates on a meter gauge rather than standard gauge, making it the first in Bangkok to use OCS for electrification on a meter gauge railway. It is operated by SRT Electrified Train, a subsidiary of the State Railway of Thailand (SRT). The Cabinet approved the project in May 2007, and it finally opened in August 2021. The lines are the fastest meter gauge railways in Thailand, with a maximum speed of 160 km/h. The Red Lines consist of two lines: the Dark Red Line and the Light Red Line. The plan for future expansion is to connect suburban areas in all directions and adjacent provinces. Once the expansions are complete, the Dark Red Line will cover a distance of 185 kilometers from Ayutthaya in the north, through Bangkok, to Ratchaburi in the southwest, while the Light Red Line will span a distance of 124 km, running from Nakhon Pathom to Chachoengsao in the east–west direction.

As of 2023, Bangkok's rapid transit system consists of a total of 9 lines covering 289 kilometers and 163 stations. As of 2022 there were five projects currently under construction covering 112.20 kilometers and 74 stations, two projects under bid covering 31 kilometers and 28 stations, six projects under PPP covering 71.49 kilometers and 38 stations, and nine planned projects covering 120.78 kilometers and 81 stations.

The plan for rapid transit in Bangkok has been in existence since 1994 when the Thai cabinet approved the Mass Rapid Transit System Master Plan (MTMP) for Bangkok. The plan aimed to extend the mass transit lines and build new constructions to achieve a total length of 103 kilometers, including the Bangkok Elevated Road and Train System (BERTS). When the BERTS project was canceled, the MTMP was renamed the Urban Rail Transportation Master Plan in Bangkok and Surrounding Area (URMAP). URMAP proposed a mass transit system with 375 kilometers in total length, separated into three phases. The first phase of 141.9 kilometers was scheduled to finish from 2001 to 2011, followed by the second and third phases of 158.2 kilometers and 75.3 kilometers, respectively. However, the plan's implementation was postponed, and the Bangkok Mass Transit Master Plan (BMT) replaced it in 2004. BMT proposed seven lines with a total length of 291 kilometers, but only 41 kilometers of new tracks were added. Thus, the Office of Transport and Traffic Policy and Planning (OTP) revised the plan again in 2009, calling it the Mass Rapid Transit Master Plan in Bangkok Metropolitan Region (M-MAP), with 12 lines, including eight primary and five feeder lines. However, the Thai government faced some issues with M-MAP, including inaccurate demand forecasting and lack of integration with urban development plans. As a result, they formulated the Second Mass Rapid Transit Master Plan in Bangkok Metropolitan Region (M-MAP2), with a new route development plan, and JICA assisted in its formulation. In March 2017, JICA and the OTP agreed to create the Blueprint for M-MAP2.

Tram
The first tram in Bangkok was introduced in 1888 by a Danish company under government concession. Initially, horse-drawn trams were used, but in 1894, the system was electrified, making Bangkok the first city in Asia to have an electric tram system. By 1903, the system carried approximately 10 million passengers annually. However, the tram service ceased on 11 October 1968, after 80 years of operation, in order to make room for automobile traffic.

A short-lived tram service operated in Lopburi between 1955 and 1962.

Rail transport in other provinces
Currently, Bangkok is the only city in Thailand that has urban rail transit. However, other major cities in the country are planning to implement light rail projects to address their growing urban transport challenges. These include Phuket, Phitsanulok, Chiang Mai, Khon Kaen, and Nakhon Ratchasima. Pattaya is also planning a light rail project which is currently under a public consultation process. The project will also link to the Don Mueang–Suvarnabhumi–U-Tapao high-speed railway.

Airport Automated People Mover
The Suvarnabhumi Airport Automated People Mover is an automatic people mover in Suvarnabhumi Airport, first opened for service on 28 September 2023, running between the main terminal building and Satellite-1 terminal (SAT-1), with a distance of 1 kilometer. Currently, there is only one service in Suvarnabhumi Airport.

High-speed rail


While there is currently no high-speed rail in Thailand, The State Railway of Thailand has carried out a high-speed rail project to connect different regions of the country in order to improve inter-regional travel, promote economic growth, and enhance trade markets between countries. The project comprises four lines that cover all regions of the country: the northern, eastern, northeastern, and southern. The project has been divided into three phases: urgent, medium, and long-term. In the urgent phase, which includes 4 routes covering a total of 1,208 kilometers, the focus is on developing three main lines: the Northeastern Line from Bangkok to Nakhon Ratchasima, which second section will be extended to Nong Khai; the Eastern Line from Don Mueang to U-Tapao; and the Northern Line from Bangkok to Phitsanulok. The medium phase, covering 3 routes and a total of 689 kilometers, aims to connect the Southern Line from Bangkok to Hua Hin, the Eastern Line from Rayong to Trat, and the Northern Line from Phitsanulok to Chiang Mai. In the long-term phase, covering 2 routes and a total of 759 kilometers, the plan is to further extend the Southern Line, first from Hua Hin to Surat Thani and then further to Padang Besar.

The Bangkok-Nong Khai route, which covers a distance of 606 kilometers, is a joint venture project between Thailand and China that started in 2014. However, in 2016, the Thai government decided to fully finance and operate the construction of entire project itself, and China is now assisting in the civil works. The construction of the project commenced on 21 December 2017. The first section of the project, from Bangkok to Nakhon Ratchasima, is currently under construction and expected to be completed in 2026, while the second section, from Nakhon Ratchasima to Nong Khai, is scheduled to begin construction in 2023, both of which are part of the urgent phase.

The Don Mueang-Suvarnabhumi-U-Tapao route, connecting three major airports over a distance of 220 kilometers, signed a joint venture agreement on 24 October 2019. The agreement was signed with Eastern High-Speed Rail Linking Three Airports, a consortium led by The Charoen Pokphand (CP) and consisting of Italian-Thai Development, China Railway Construction Corporation, CH. Karnchang, and Bangkok Expressway and Metro. In September 2021, the consortium changed its name to Asia Era One, which will operate the route. Construction is expected to begin in 2023, with the second section to Trat included as part of the medium phase of the project.

The Bangkok-Chiang Mai route spans 688 kilometers, is a joint effort between Thailand and Japan since the signing of a Memorandum of Cooperation (MOC) in 2015. The project has been divided into two phases: urgent and medium. The urgent phase includes the first section connecting Bangkok to Phitsanulok, for which a feasibility study has been conducted by the Japan International Cooperation Agency (JICA) since 2017. On 8 March 2023, JICA completed an economic and financial feasibility study which analyzed the direct and indirect benefits of the project. The study found that the project is worth investing in, with an economic return (EIRR) of 17.3 percent, 12 percent higher than the threshold, and a positive net present value (NPV) over the period of operation. Japan has suggested using Shinkansen trains, which are capable of reaching a maximum speed of 300 km/h. The medium phase will include the second section connecting Phitsanulok to Chiang Mai.

The Bangkok-Padang Besar route spans 759 kilometers and is divided into three sections and two phases. The medium phase includes the Bangkok-Hua Hin section, which is the first section of the route. The long-term phase includes the second section from Hua Hin to Surat Thani and the third section extending to Padang Besar. All of which are currently being prepared for study.

Rail links to adjacent countries

 * 🇲🇾 Malaysia - yes - same gauge
 * Laos - yes - gauge across Mekong River on Thai-Lao Friendship Bridge
 * 🇰🇭 Cambodia - yes - same 1,000 mm (3 ft 3 3⁄8 in) gauge
 * Myanmar - no - defunct - (see Death Railway). But projected extension will rebuild the route.

Locomotives


The State Railway of Thailand (SRT) operates both diesel and electric locomotives for long-distance passenger and freight train transportation. The SRT also reserves steam locomotives for special services only, such as the SRT Class Japanese Mikado (DX50), JNR Class C56, and SRT Class Japanese Pacific (CX50), which are used on special excursion services on specific days. The first steam locomotive was used in 1893, and in 1961, the SRT established a railway museum to preserve and display steam locomotives.

In 2020, the SRT procured 50 diesel-electric locomotives, model CDA5B1, from CRRC Qishuyan. These locomotives have a top speed of 120 kilometers per hour for passenger trains and 70 kilometers per hour for freight trains. Weighing 16 tons per axle, the CDA5B1 locomotives are equipped with modern safety features, including an Automatic Train Protection (ATP) system and Closed-Circuit Television (CCTV) cameras that also produce low emissions and are fully compatible with the European Train Control System (ETCS) level 1. The first 20 units were delivered on 4 February 2022, and another 30 units delivered in February 2023. They will be allocated for use in towing convoys of passenger and freight trains throughout the country., which will increase the efficiency of train operations and support the opening of the double-track railway during 2023–2024, replacing the aging engines that have been in service for almost half a century.

In December 2021, the SRT received 17 air-conditioned KiHa 183 series diesel multiple unit trains from JR Hokkaido, paying only for shipping. These trains, consisting of four sets with four vans and a backup car each, offer a total of 216 seats per train and can travel up to 110 kilometers per hour. They feature facilities for tourists, including air conditioning, reclining seats, and closed-system bathrooms. Currently, the trains are utilized for one-day travel routes, and all 17 units are expected to be operational by the end of 2023.

The SRT has collaborated with King Mongkut's Institute of Technology Ladkrabang (KMITL) and Energy Absolute (EA) to develop a locally made battery-electric locomotive prototype under the "EV on Train" project. The prototype was finalized in 2022, and the SRT plans to produce three more battery locomotives and procure another 50 from other sources this year to replace its aging fleet of diesel engines. By the end of 2023, Thailand is expected to have around 54 battery-powered trains, with four of them being domestically produced. This effort aligns with the government's commitment to reduce greenhouse gas emissions by 25% by 2030.

Electric multiple units
Electric multiple units (EMUs) are the primary type of rolling stock used in Bangkok's rapid transit systems due to their environmental sustainability and efficiency. These trains can draw power from both overhead wires and third rails, allowing them to provide rapid and reliable service to passengers. EMUs are used by different rapid transit systems in Bangkok, each with its unique features.

The BTS Skytrain uses a variety of electric multiple units (EMUs) including the Siemens Modular Metro, Siemens Bozankaya, and CRRC Changchun. The Siemens Modular Metro, which operates on the Silom and Sukhumvit Lines, was first introduced in 1999. The newer Siemens Bozankaya model, introduced in 2018, features advanced safety and energy-saving features such as regenerative braking and a lightweight design. Both models have an air-conditioning system that responds to weather conditions, high temperatures, and humidity levels. They also utilize interior and exterior LED lights to reduce maintenance costs and energy consumption.

The MRT system uses Siemens Modular Metro and Siemens Bozankaya EMUs on its Blue Line. Meanwhile, the J-TREC Sustina S24 EMUs are used exclusively on the Purple Line and feature a lightweight stainless steel design, making them more energy-efficient and reducing maintenance costs.

The Red Lines commuter rail employs the Hitachi AT100, which is capable of reaching a maximum speed of 160 km/h. The train's electric car design incorporates Aluminum Plate and Aluminum Extrusion materials. The State Railway of Thailand awarded the Red Line Project contract to Hitachi, Mitsubishi Heavy Industries, and Sumitomo Corporation on 30 March 2016. The first and second completed rolling stocks for the project were shipped out from Hitachi Kasado Works in Kudamatsu, Yamaguchi Prefecture in September 2019. Hitachi was contracted to ship a total of 25 train sets, comprising 130 rolling stock units, by the end of June 2020.

Siemens Desiro EMUs are utilized by the Airport Rail Link. A total of nine Siemens Desiro sets were purchased, with five three-car trains operating the city services and four trainsets with a fourth car designated for check-in baggage handling the express services. The first trains were shipped from Germany in September 2007, and testing was initiated in Bangkok in March 2008.

Monorail
Monorail will be used for a secondary mass transit system in Bangkok, designed to feed passengers into the main line. The Pink Line and Yellow Line are two such systems, with a total of 42 Innovia Monorail 300 model trains. The first branch of trains arrived in Thailand on 28 September 2020, and the second branch arrived in November 2020. The trains are controlled by an unmanned CITYFLO 650 signaling system, and inside the cabin of the train, there are safety equipment such as CCTV cameras, smoke detectors, and communication buttons for passengers to interact with car operators.

People mover
The Innovia APM 300 is the only people mover currently in operation on Bangkok's Gold Line, introduced in June 2020. It uses a central rail-guided system and rubber tires, offering passengers a smooth and noiseless ride. This unmanned electric vehicle can reach speeds of up to 80 km/h. On the other hand, the Siemens AirVal model arrived in Thailand in July 2020 and is set to commence operations on the Suvarnabhumi Airport Automated People Mover at Suvarnabhumi Airport's terminals in September 2023. This model has the capacity to transport up to 3,590 passengers per hour and direction during peak periods, operating 24/7 to accommodate varying demand. It also features spacious aisles and large doors, making it easy for passengers to board and disembark, and providing ample room for luggage.

High-speed trains
Thailand's first high-speed train service on the Northeastern Line, connecting Bangkok to Nong Khai, will be powered by the Fuxing Hao CR300, which is expected to arrive in 2024. The service will operate on a double-track designed for high-speed travel, with an operating speed of 250 km/h. Each of the six trains will feature eight passenger cars, offering a total of 594 seats, including 96 first-class seats and 498 standard-class seats. Meanwhile, on the Northern Line connecting Bangkok to Chiang Mai, Japan has suggested employing Shinkansen trains, which can reach a maximum speed of 300 km/h.

Tracks
Thailand's railway tracks come in two types: metre gauge and standard gauge. The majority of railway tracks in the country use metre gauge, but in Bangkok, the Mass Rapid Transit System operates on standard gauge tracks, with the exception of the Red Lines, which are electrified and run on metre gauge tracks. As of 2020, the total length of metre gauge tracks in Thailand, excluding the Red Lines, is 4,814.862 km. This includes 3,326.230 km of single tracks, 1,103.192 km of double tracks, 320.157 km of triple tracks, and 65.283 km of separated tracks on the Maeklong Railway.

The Mass Rapid Transit System in Bangkok consists of several lines, with most of the tracks being standard gauge. As of 2022, the total length of standard gauge tracks in the system, excluding the Red Line, is 170.438 km. The Red Lines include the Dark Red Line, which is 26.30 km long, and the Light Red Line, which is 15.26 km long, and both are electrified and run on metre gauge tracks.

Railway stations


There are approximately 650 open railway stations and halts in Thailand, with the Krung Thep Aphiwat Central Terminal being the largest in both Thailand and Southeast Asia. The terminal covers an area over 270,000 square meters and has three floors, as well as a mezzanine and an underground level. It serves up to 800,000 passengers per day and has replaced the Bangkok (Hua Lamphong) railway station, as the primary rail transportation hub. The name Krung Thep Aphiwat Central Terminal was bestowed by King Rama X, signifying the prosperity of Krung Thep, which is the official name of Bangkok. The station has 24 platforms, including 10 for high-speed rail, 2 for the Airport Rail Link, 8 for inter-city rail, and 4 for Red Lines. It is also linked to the Blue Line

To further improve the station's accessibility and convenience for all passengers, including those with disabilities and the elderly, a double-track railway project is currently underway. The project will apply universal design principles, making the station more user-friendly and accommodating to everyone.

Bridges
Thailand's railway system features approximately 1,000 bridges, varying in size from small overpasses to large viaducts. One noteworthy construction is the railway bridge over the Mae Klong River, which runs parallel to the Chulalongkorn Bridge in Ratchaburi Province. The former railway bridge over the Mae Klong River has been replaced by this extradosed railway bridge, the first of its kind in Thailand. Spanning 340 meters, the bridge includes a 160-meter-long cable-stayed section with a height of 16 meters from the rail ridge to the top of the cable-stayed pole. Another remarkable project is the Lopburi-Pak Nam Pho double-track railway, featuring a 19-kilometer-long elevated railway that bypasses Lopburi city, making it Thailand's longest elevated railway.

Tunnels


There are currently 8 railway tunnels in Thailand. The Khun Tan Railway Tunnel, measuring 1,352.10 meters, located between Hang Chat District, Lampang Province and Mae Tha District, Lamphun Province, held the title of Thailand's longest railway tunnel for several decades, from 1925 to 2021.

In 2021, the record for the longest railway tunnel in Thailand was surpassed by the construction of the Dong Phaya Yen Railway Tunnel, which spans a distance of 5.85 kilometers between Map Kabao Station, Pha Sadet Station, and Hin Lap Station in Saraburi Province. The Dong Phaya Yen Railway Tunnel is part of the Map Kabao–Thanon Chira Junction double-track railway project and runs through the Dong Phaya Yen mountain range.

Level crossings
As of 2022, there are 2,630 level crossings across the country. These crossings are categorized into 195 overpasses, 215 underpasses, 1,409 level crossings with rail barriers, 5 private level crossings, 186 crossings with traffic signs, and 620 illegal crossings. The lack of proper safety features, such as crossing barriers, has resulted in frequent accidents, particularly at the unauthorized crossings created by villagers without authorization from the railway authority. To address this issue, the State Railway of Thailand has implemented a policy to close unauthorized crossings, established 122 safety passages, and constructed overpasses and underpasses in double-track railway project to prevent accidents.

Signalling
The State Railway of Thailand (SRT) has been pushing upgrades to the signalling system. The new signalling mandate being adopted is the European Train Control System (ETCS), a standard that boosts capacity and increases the reliability of rail networks. Thales, has been supporting SRT's efforts by introducing its ETCS technology since 2017, and has designed, delivered, and installed the ETCS Level 1 Automatic Train Protection (ATP) system covering a total of 48 stations across four sections of track in the Bangkok area. The Cityflo 650 Communications-based train control (CBTC) system, developed by Alstom, has been in use on the Purple and Gold Line, and will be used on the Pink Line and Yellow Line. Meanwhile, the older signalling system in use on most parts of the rail network, relying on colour light signals, semaphore signals and token signalling.