China’s leading shipbuilder has begun the construction of a submarine for the Thai navy under a 13.5 billion Thai baht (US$411 million) deal agreed last year that observers say provides clear evidence of Beijing’s growing role as an international arms supplier. Senior officers from the Thai and Chinese militaries attended a steel-cutting ceremony at a shipyard in Wuhan, capital of Hubei province, to mark the start of the project, China Shipbuilding Industry Corporation (CSIC) said late on Tuesday. The Royal Thai Navy signed a contract with CSIC for one S26T diesel-electric submarine – derived from the PLA Navy’s Type 039B, or Yuan-class – in May 2017 and the vessel is expected to be delivered by 2023. Is China’s nuclear attack submarine too easy to detect? Once completed, the boat will have a displacement of 2,600 tonnes, a top speed of 18 knots and be able to remain submerged for up to 20 days. It will also feature the latest acoustics and electronics technologies, and be able to carry 16 torpedoes and missiles, and up to 30 mines. Thailand’s military government had planned to buy three submarines from Beijing, but after coming under strong opposition at home it reduced the number to one. Nevertheless, the deal has been reported as Bangkok’s largest ever defence purchase. Watch: The Liaoning, China’s first aircraft carrier Beijing-based military commentator Zhou Chenming said that as well as building the submarine, China was likely to provide technical know-how to the Thais. “The Royal Thai Navy has no experience of operating submarines so China will certainly provide training,” he said. “The Thai military has been a major buyer of Chinese weapons for decades.” The S26T would be a major enhancement to Thailand’s naval defence capabilities, and the deal came after neighbouring Vietnam last year completed its purchase of six Kilo-class submarines from Russia, and Myanmar stepped up its naval cooperation with India, Zhou said. Why Chinese submarines could soon be quieter than US ones Although Thailand has traditionally been an ally of the United States in the region, since coming to power in a bloodless coup in 2014, the junta government has strengthened its military links with China. Thai Prime Minister Prayuth Chan-ocha, a former army general, ordered 49 VT-4 tanks from China to replace its US-made M41s that have been in service since the second world war. The first 28 of the new vehicles were delivered in 2017 and the rest are expected to be handed over later this year. Despite the deal with China, Bangkok had no plans to shift its military alliance with the US, according to Xu Liping, an expert in Southeast Asian affairs at the Chinese Academy of Social Sciences. “Thailand will maintain its close security ties with the US while buying Chinese arms,” he said. China military develops robotic submarines to launch a new era of sea power While China cannot compete with the US on global arms sales, its hardware and technologies are attractive to many developing countries in terms of price, suitability and support services, Xu said. In 2016, Beijing signed a US$4 billion deal with Pakistan to provide eight S20 submarines – a trimmed down version of the Type 039B – by 2028. It also sold two smaller Type 035G Ming-class submarines to Bangladesh, which entered service last year. A study by the Stockholm International Peace Research Institute showed that China accounted for 5.7 per cent of global arms exports between 2013 and 2017, up from 4.6 per cent in the 2008-12 period.