"The reason the british did not build the railway when they first surveyed it was because of the predicted cost, not in money, but in human lives. The report stated that too many workers would die."

That sort of thing never stopped the British government on civil engineering projects in Britain. It certainly didn't stop them in other foreign countries. The loss of life on these projects was seen largely as a financial impediment. It matters not whether you are talking about native labourers in foreign countries or Irish navvies in Britain itself, the attitude to their loss was only concern as to the impact on the project.