The article documents all the different modes of pulling canal boats along, from horses to electrical or steam towing.
From Low-tech Magazine:"Of course, canal barges are much slower than trucks or trains. But, if they could haul cargo for almost nothing, it would still be an economical choice for many goods. This advantage would grow if oil prices would rise. Many abandoned canals could be put in use again, and even new ones could be built.
Almost all methods above were designed for use on very shallow, trapezoidal "low-tech" canals, which were only 2 metres (6.5 feet) deep at the centre, and much less on the sides (see picture below). These are not public works like the Panama Canal which would take decades and require thousands of workers (or energy-guzzling machines) to build. This is something that might even be done on a community level."