Illness and death were constants on the Burma-Thailand railway. Approximately 12 800 of more than 60 000 Allied prisoners of war, and up to 90 000 rǒmusha, died between 1942 and 1945. Malnutrition, disease and overwork—mostly attributable to the brutality, neglect and indifference of the Japanese—all contributed to this death toll.
Many prisoners were in poor physical condition even before they reached the railway. The forces leaving Changi included many prisoners who were ill, since the Japanese assured the Allied officers that conditions at their destinations would be easy. The long and arduous journeys to Thailand and Burma (now Myanmar)—by train, ship, truck and foot—further undermined the health of many prisoners.
Survival rates differed significantly along the railway, depending on the location of the camps, the time of year, the availability of food and medicines, the resilience of the prisoners and the calibre of their leaders. Camps next to running water had reasonable water supplies and sanitation. Those close to population centres and transport routes had better access to additional food and medicines and could trade with the local population.
In more remote camps prisoners often lived in filthy conditions on a starvation diet. In many cases they were expected to construct their camps while working on the railway, a situation that exacerbated their health problems.
The attitudes of the Japanese particularly influenced the rates of survival. Since prisoners of war were considered to be the lowest in the military hierarchy, they were given little priority in Japanese logistics. Despite repeated requests by Allied doctors essential medicines were not supplied. Prisoners who fell sick were denied rations and often forced to work.
Leadership and organisation within the prisoner-of-war groups were also important. Outbreaks of cholera had to be fought with preventative measures such as isolating the infected, boiling drinking water and sterilising eating utensils. The equitable distribution of food, the pooling of money and the allocation of any extra rations to the sick also relied on strong leadership.
The lack of leadership and organisation contributed to the high death rate of the rǒmusha. As civilians they lacked the military discipline and organisational structures of the Allied prisoners. They had few, if any, trained medical personnel and little knowledge of the causes of illness and the ways to prevent it. They would fail to bury their dead properly increasing the risk of disease to themselves and the prisoners-of-war.
Survival rates seem not to have been influenced by nationality or culture, though it is sometimes suggested that they were. Instead the rates of illness and death were dependent on the specific circumstances of each work group.
F Force, for example, had one of the highest death rates (44 per cent) of any group of prisoners on the railway—some 3096 of the 7000 of the Australian and British prisoners. This force included a considerable number of men who were sick when they left Changi. After arriving in Thailand they were forced to march up to 300 kilometres from Ban Pong to their work site near the Thai–Burma border. Supplies during the march were poor and little attention was paid to staging posts. With no chance to rest and recover, the prisoners' health was fragile even before they started work on the railway.
Then the area in which F Force worked was remote and well beyond villages and the Kwae Noi. The only road from the south became a quagmire in the monsoon. F Force therefore was particularly vulnerable to starvation, dysentery, cholera and other illnesses.
Yet even within F Force, death rates could differ. At Shimo Songkurai camp, Major Bruce Hunt, the senior medical officer, exercised strong leadership and tight control over the food and preventative health measures. Only 151 men from a camp of 1800 (8 per cent) died. In contrast, the nearby camp of Songkurai had a much higher death rate as a result of ineffective camp leadership, harsher treatment at the hands of the Japanese and a larger proportion of prisoners from Changi hospitals. Over 600 from 1600 (37 per cent) died there.