There were around 5000 allied prisoners who worked on the railway, most being captured in Java up to two years before. The nationalities who worked on the railway were:
- New Zealand
The majority of the prisoners were Dutch (around 4000), with about 1000 British prisoners. There were around a further 300 prisoners from the remaining countries.
There was tension between the different groups, with the Australians resenting the British due to their hostory (British convicts were sent to settle Australia in the 1700s). The Dutch were dislike by both the Australians and the Bristish on the grounds that the Dutch had capitulated to the Japanese without a fight. In turn, the Dutch pointed to the British surrender of Singapore.
Many of the European Dutch spoke English, while few of the British and Australian prisoners could speak Dutch. This led to frequent fights within the different groups. The younger Dutch, who hah grown up in the Indonesian environment were able to survive better in the camps due to their knowledge of local languages and local nuts, fruits, grasses, mushrooms etc.
The last rail for the train line was laid the day of the Japanese surrender, 15 August 1945, with a gold coloured spike being used instead of the traditional gold. After the ceremony, it was announced that the prisoners were to have a break, and then would be 'transported to a better place'. Rations were also increased, and leaving the camp was not permitted. During this time, rumors were rife that the war was over, but no official announcement was made. Between August 24 and 30, the majority of prisoners were transported back to Pakan Baroe by train, and on the 31st, one of the Dutch prisoners announced it was the birthday of Queen Wilhelmina, and that the national anthem should be sung. Slowly, everyone joined in, and when the guards started to lay down their weapons the prisoners knew the rumors were indeed true.
Food and other food drops were soon made by the allies, with the first of the sick prisoners finally being evacuated during mid September, after a surprise visit for an inspection of the camps by Lady Mountbatten, in the function of the head of the St John Ambulance Service. Causing more resentment amongst the soldiers, the Dutch were the last to be evacuated from Sumatra, many remaining there months after the war had ended.