After passing the fortress, Zhang Tie found that the terrain in front suddenly became open. There were many well-paved broad roads leading to all directions. However, those broad roads were covered with black-green military vehicles and soldiers at this moment.
Fiery oil was an important strategical material, which could only be used at critical moments. In order to relieve stress facing fiery-oil supply, many military vehicles being responsible for communicating and freight were driven by steam engines like before. These steam engines were not picky. They could run with burning coal or firewoods and some water. They had very high adaptability and were convenient for maintenance. They were still useful on the battlefields.
