The forced construction of the Thai–Burma Railway turned a military supply plan into a vast system of coerced labour. Ordered by the Japanese Empire to serve its wartime ambitions, the railway was built by prisoners and other forced labourers whose bodies and time became substitutes for the machinery, materials, and time the project lacked. Its completion brought neither lasting military purpose nor a complete public record of those who died building it.

Strategic purpose and planned route

The project answered a worsening military predicament. After the fall of Singapore on 15 February 1942, Japan was losing ground and needed a land route to supply its forces in Burma. The Allies were supplying the Chinese Nationalist Army through Burma, while American control of the seas made maritime supply difficult. Japan lacked the money and machinery to build the railway by ordinary means, and its leaders believed they had no time to spare.

In early 1943, Imperial Japanese Army engineers marked the projected route with surveyors’ pegs. The line was planned to run 415 kilometres from north of Bangkok through to Burma. At that point it remained a combination of limited plans, orders, and exhortations: an immense undertaking whose intended military usefulness depended on turning a marked route into track, bridges, and cuttings.

Engineering demands and forced labour

The construction began with the prisoners clearing a kilometre of giant teak trees along the planned route. They were given blunt axes and rotten hemp rope. As work continued, prisoners cleared jungle, broke rock, moved earth, and carried sleepers and rails with basic hand tools and their own strength. The engineering plan repeatedly exceeded the resources available to carry it out.

The shortage was not merely a matter of equipment at the start of the project. After a major cutting was already half-completed, the Railway Command Group altered the plans and ordered it enlarged by a third to address gradient problems in the next sector. The revision added 3,000 cubic metres of rock to the work. The prisoners had to cut rock by hand with hammers and chisels; there were not enough proper chisels, and the camp lacked sufficient coke to sharpen those that blunted. The order increased the work without providing the means to do it.

The Japanese Empire’s faith in victory and in the Emperor’s will was reinforced by the availability of forced labour. Of 22,000 Australian prisoners of war, 9,000 were sent to work on the railway. They formed only part of the workforce: alongside Allied prisoners laboured a much larger population of Asian workers, including Tamils, Chinese, Javanese, Malayans, Thais, and Burmese. The project’s demands were translated into coercion at the work site. As workloads rose and prisoners resisted or weakened, punishment was also used to reassert guards’ authority. In one episode, the punishment of Darky Gardiner was treated by the guards as a means of restoring control and reminding the prisoners of their imposed duty; Dorrigo Evans understood that the railway’s construction was bound up with the violence inflicted on him.

Completion and the human cost

The railway was built under orders that made completion paramount even if most of the workers died. On 25 October 1943, steam locomotive C 5631 travelled the completed route, towing three carriages of Japanese and Thai dignitaries. The milestone marked the railway’s physical completion, but not an agreed accounting of the people who had made it possible.

The Allied prisoners were an estimated 60,000 of those who laboured on the project. Alongside them were about a quarter of a million Asian forced labourers, or more. Estimates of deaths among these workers vary widely, from 50,000 to 200,000, and the total is unknown. The Australian losses were also severe: the account states that one in three of the Australians sent to the railway would die. The difference between the locomotive’s documented journey and the uncertain totals of the dead makes the railway an infrastructure achievement whose human cost resists a definitive count.

Memorials, judgment, and omission

After the war, locomotive C 5631 was displayed in the museum at Yasukuni Shrine in Tokyo. The shrine also holds the Book of Souls, which lists more than two million people who died in service to the Japanese Emperor between 1867 and 1951. Enshrinement there is associated with absolution from wrongdoing; among the listed dead are 1,068 men convicted of war crimes and executed after the war, including men found guilty of mistreating prisoners on the railway.

The plaque before C 5631, however, does not mention the railway’s construction or the people who died doing it. Nor is there a complete, agreed list of the dead. The absence is especially stark beside the record of prosecutions: postwar justice identified some individuals, but could not supply the names of the many labourers whose deaths were never reliably counted. In the case of Choi Sang-min, an Australian military court dismissed the charge that he participated in the murder of Frank Gardiner, upheld charges connected to the killing of Wat Cooney and other mistreatment, and sentenced him to death. The trial material also shows how incomplete camp records and testimony shaped the attribution of responsibility. Such proceedings addressed particular defendants; they did not resolve the larger uncertainty over the railway’s total victims.

Abandonment and the railway’s afterlife

The railway lost its purpose and support with Japan’s defeat. Japanese engineers and guards were imprisoned or repatriated, and the labourers who remained to maintain the line were freed. Within weeks of the war’s end, the railway was being abandoned: the Thais left it, the English dismantled it, and local tribespeople removed and sold its rails.

Over time, its banks and bridges failed, its cuttings filled, and vegetation spread through the abandoned works. Seeds grew in mass graves and among the remains of construction; weeds, termites, rust, and rot overtook the embankments, bridge timbers, and rails. A few short sections were later cleared and turned into tourist, sacred, or national sites, but the railway as a functioning line did not endure. Its physical return to the landscape contrasts with the persistent human desire to preserve memory: the route was broken and its imperial purpose came to nothing, while the names and final number of many of its dead remained lost.