Labor was conscripted, meaning that the French authorities would set quotas and require area chiefs to supply a certain number of men per year for work on the line. Pay and working conditions were abysmal. In the early years of the project, workers on the Brazzaville line, working between nine and twelve hours a day, six days a week, were paid one French franc per month. Though later, in the early 1930s, pay rose to around one hundred francs per month, this was still a tiny fraction of the pay of the European overseers, who made two or three thousand francs per month plus considerable additional benefits. Beyond the meager pay, the workers on the line were fed poorly and had extremely bleak living and health conditions. Because the Sara people were coming from far away, they were exposed to diseases that they had previously never encountered, which caused significant mortality among the people, adding to the already extremely dangerous work itself. Workers routinely died from industrial accidents with dynamite, landslides, and so on. As knowledge of the dire working conditions reached home, the Sara people's resistance to French recruitment regimes intensified. Chiefs' demands were met with hostility and even violence, and on several occasions a chief or his family was attacked and killed. Though the Sara had been known for being peaceful, the demands of the Brazzaville rail project had pushed them into active opposition to their local leadership and the colonial regime. Resisting recruits would be led to the worksites chained together.
All told, around 120,000 Africans participated in this grueling labor project. While estimates vary, it is clear that tens of thousands of workers died in the course of the railroad’s construction between 1924 and 1934, perhaps up to fifty thousand people.
Could it be said that this tremendous human sacrifice was worth it? No. The Brazzaville line was conceived as a way to more efficiently exploit Congolese natural resources by the colonial power, the French (and to complete with the equally exploitative nearby Belgian railway). Since its completion, the railway has either continued operating for this purpose or has fallen into decay and disuse. Either way, the land and people of the Congo have gained little, unsurprising considering its roots were never planted with an eye toward benefiting the people there. The Brazzaville railroad stands as a shining example of the inherently exploitative nature of Western "investment" and "development" in colonial world, a story which continues today.