Railway engineers such as Sandford Fleming had a crucial responsibility in plotting a railway’s route. Any time there was a pronounced curve, the train would have to slow down, losing precious minutes. Curves also meant an increase in fuel consumption because of friction, and friction also increased the wear on wheels and rails.
A slight upward slope, even if it was only 0.5%, meant that a steam locomotive would not be able to haul as heavy a load, would burn more fuel and would need more water – hence extra costs and the need for more stops along the way.
Calling on his experience, knowledge and ability to observe and make deductions, the engineer was required to anticipate the railway’s route, assess all of its implications and make the best, safest, cheapest and most profitable choice.