Although Acts of Parliament allowed railway companies compulsory purchase of wayleave, some powerful landowners objected to railways being built across their land and raised objections in Parliament to prevent the bill from being passed. Some landowners charged excessive amounts, so these early lines did not always follow the optimal route. In addition, steep gradients were to be avoided as they would require more powerful locomotives, while since speeds were expected to be less than about 30 mph, curves were considered less of a problem. It was the curves on these early lines that, a century later, would lead to British Railways' experimentation with, and later introduction of, tilting trains.