Before the railway opened, water was the most efficient means of transport. From the time of Livingstone's 1859 expedition, small steamers navigated the Zambezi-Lower Shire river system, and they were later introduced on the Upper Shire and Lake Malawi. The Upper and Lower Shire were separated by about of the Middle Shire, where rapids and shallows made navigation impractical, and both the Upper and Lower Shire were often too shallow for larger vessels, particularly in the dry season. In addition, the main areas of economic activity in the early protectorate were in the Shire Highlands, mainly near Blantyre, which was from Chikwawa, a small Shire River port. Transport of goods to river ports was by inefficient and costly head porterage, as the Shire valley was unsuitable for draught animals.