In this video you will learn how to split firewood using only a small folding handsaw. This technique could be useful for backpacking or survival situations. The man in this video claims that he would rather pack a light saw than an ax. An ax is heavy and dangerous but a saw is safer to use and more versatile. He will also show you at the end of the video the proper way to use a hand saw so you can cut for a long time without getting tired.
To split firewood with a handsaw, make a cross cut in the middle of the log about half way through. Then hit the cut area of the log against a hard surface like a tree, rock,stump, log etc. The cut spot makes a weak spot where the log will split down the middle since it is easier for the log to split than break across the grain.
In the video he explains that if you are in a survival situation and you are tired, dehydrated or otherwise not performing at your best, an ax is especially dangerous and difficult to use. In a situation where you were injured and unable to swing an ax, the saw technique would probably be easier if you needed to split your firewood into kindling to get a fire stated.