Friday 13 January 2023

A(nother) Shot At Power: Thailand’s DTI-1 Rocket Launchers

By Stijn Mitzer and Joost Oliemans
The mid-to-late 1990s was shaping up to become the Royal Thai Armed Forces' golden decade. The acquisition of 18 F-16As propelled the Royal Thai Air Force to the forefront of military aviation in the region, while the Royal Thai Army was reinforced through the addition of M60A3 MBTs and 155mm M109A5 SPGs. The Royal Thai Navy was to benefit from this period of prominence the most, becoming the recipient of Southeast Asia's first and only aircraft carrier, the HTMS Chakri Narubet. Equipped with six AV-8S Matadors and four S-70B Seahawks, this ship, along with 18 A-7E Corsair ground-attack aircraft, three P-3T ASW aircraft and a brand-new replenishment ship and six frigates acquired from China, was set to transform the Royal Thai Navy into the most powerful naval force in the region for years to come.

A dearth of funding as a result of the 1997 Asian financial crisis however meant that neighbouring countries were ill-positioned to challenge Thailand's newly-acquired capabilities anyway, and the lack of financial means of its own meant that Thailand was soon struggling to maintain or replace all of this equipment. Already two years after their delivery just one out of the nine AV-8S' could be kept operational. The type soon had to be retired without a replacement, leaving the Chakri Narubet without any aircraft (a situation that continues to today). The same fate was bestowed on the A-7Es and P-3Ts, making Thailand's bid for becoming the undisputed regional superpower rather short-lived.

Only in recent years has Thailand found the necessary funding to make another attempt at expanding its capabilities beyond those of its neighbouring countries, while in other areas it is finding itself merely catching up with regional rivals. After being the first country in Southeast Asia to operate submarines in the 1930s, it is now one of the last nations to (re-)acquire this capability in the form of one S26T attack submarine from China. [1] One capability Thailand did make substantial strides in are in its long-range fire capabilities thanks to a 2011 deal between Thailand's Defense Technology Institute (DTI) and China to research and eventually license-produce large-calibre rocket launchers. [2]

These consist of the WS-1B and WS-32 that boast a maximum range of 180km and 140km respectively. The WS-1B received the Thai designation of DTI-1 while the WS-32 is designated as the DTI-1G (G standing for guided). DTI also struck a license to produce and further develop Chinese 122mm rockets, which Thailand installed on trucks and even on the Type 85 APC. Together with the purchase of French 155mm Caesar SPGs, the local integration of ATMOS 2000 SPGs (known as the M758 ATMG in Thailand) and PULS MLRS (designated as the D-11A) and 120mm Spear mortars from Israel, and the introduction of Chinese BL904A artillery locating radars, Thailand should have secured its regional artillery supremacy for years to come. [3] [4] [5]

The DTI-1 on a 6x6 Volvo chassis with an armoured cabin to protect the crew against small arms fire and shrapnel.

The DTI-1 (or WS-1B) is a 302mm artillery rocket system developed on the basis of the WS-1 in the early 1990s. Each rocket has four fixed fins and can lob a 150kg warhead out to a range of up to 180km. The WS-1B was first demonstrated to the Chinese People's Liberation Army Ground Force (PLAGF), which however showed no interest in the system. Its first success came in 1996 when Türkiye struck a deal to license produce the WS-1B as the TRG-300 Kasirga, after the U.S. refused to grant the country a license to produce the MGM-140 ATACMS. The WS-1B was also exported to Sudan in the 2000s along with the more capable WS-2. Roketsan of Türkiye has further developed the WS-1B (Block II and Block III) to incorporate GPS/INS guidance at the cost of a reduced range and warhead (for the Block III). [6]

Thailand's 150km-ranged DTI-1G integrates a guidance suite that is connected to China's BeiDou Navigation Satellite System. This enables the DTI-1G to attain a circular error probable (CEP) of less than 40 metres at a maximum range of 140km. [8] The launcher of the DTI-1G consists of four canisters in a 2x2 configuration externally similar to the American MIM-104 Patriot SAM launcher. In contrast, the rockets of the DTI-1 are housed in four large open-ended tubes. Thailand originally planned to assemble six DTI-1Gs (enough for one battalion) and two DTI-1s, though delays meant that DTI ultimately constructed just three DTI-1Gs awaiting the development of a new modular launcher that will presumably see the Royal Thai Army fnally acquiring the systems in meaningful quantities. [8]

The original configuration of Thailand's DTI-1 launcher.

The proposed full complement of a (Thai) DTI-1G battery.

Both the DTI-1's and DTI-1G's launchers are installed on commercially available trucks. The DTI-1 and the associated transloading system were initially based on an unarmoured Volvo 6x6 chassis, though the former has since received an armoured cabin to protects its occupants against small arms fire and shrapnel. The DTI-1G is based on the Iveco Trakker 440 8x8 heavy-duty truck, which received an armoured cabin from the get go. The reloading vehicles of both the DTI-1 and DTI-1G lack an armoured cabin however. In 2022, the Defense Technology Institute showcased a new 6x6 launcher based on the Tatra 815-7 chassis that can be used to launch both unguided 122mm rockets and the DTI-1(G)s. [9]


Thailand knows no perpetual enemies among the countries it borders. The last time the country took up arms was during the 2008 Cambodian-Thai border skirmish that has since been resolved through the International Court of Justice. Several border disputes with Cambodia remain outstanding however, and a full border demarcation satisfactory to both countries is yet to be made. Highly unlikely as it is, renewed conflict with Cambodia is the most plausible scenario where these arms will be put to use. Cambodia fields large numbers of 122mm MRLs and has in recent years acquired six 300mm AR2 MRLs from China. [12] Boasting a range in excess of 130km, the AR2 can fire 16 300mm rockets out to a similar range to Thailand's DTI-1s whilst carrying a significantly heavier warhead (280kg vs 150kg). These escalations in capabilities are illustrative of the type of advancements in rocket artillery that have changed the military landscape of the new millenium.

A Cambodian 300mm AR2 MRL.

Despite being a legacy customer of American weapons systems, Thailand is increasingly turning to China for its defence needs. This has included VT4 MBTs, VN16 Amphibious Assault Vehicles, VN1 IFVs, a S-26T attack submarine, a Type 071E and the CY9 and BZK005 MALE U(C)AVs. Cooperation with China has so far allowed Thailand to license produce a number of advanced weapon systems at the same time, including the Thai Army's DTI-1/1G guided MRLs, in deals that would otherwise be unattainable from other countries. This leniency has allowed Thailand to revive at least some of its former ambitions of becoming a South East Asian Tiger, with a more realistic perspective of maintaining that status this time round.

[1] History of Royal Thai Submarines in World War Two
[4] Thailand Unveils New 155 mm Truck Mounted Howitzer
[8] สทป. ดำเนินการทดสอบสมรรถนะและทดสอบทางยุทธวิธีต้นแบบรถฐานยิงจรวดหลายลำกล้องอเนกประสงค์ ณ สนามทดสอบ ศป. จ.ลพบุรี