- In the 1890s, engines failed every 100-200 miles (160-320 km) on average.
- By the early 1900s, engines failed every 500-1,000 miles (800-1,600 km) on average.
- By the 1920s, with improvements in design and materials, engines failed every 5,000-10,000 miles (8,000-16,000 km) on average.
A total of 30 years would pass before people realized this was a transformative shift