We carry a similar manual chain saw and have used it to clear pine trunks fallen across various tracks over the last 5 years. In some conditions it is my favorite cutting tool. While we have used it with a person on each end, I find it most effective when I initially pass the chain under the trunk, staddle the log and saw with alternate pulls of my arms. While the initial length of ours was sufficient to get a good stroke, it was too short to stand up straight. After two 10" pine trunks and an aching back I girth hitched a 20 or 30 cm climbing sling to each handle. Now I can stand straight while sawing with the same stroke. If a log is 12" diameter or less and lying flat on the ground the manual chain saw is faster than either my Silky Katanaboy or Zubat. If the log leans or is more than 12" off the ground I use one of the Silkys. For clearing limbs growing over the track but still attached to trunks I use the Zubat for stuff within easy reach or the Katanaboy for higher pieces. For firewood at camp I use the Katanaboy. We don't carry a bow saw nor do we carry a motorized chainsaw (but it's sure nice to travel with someone who has a motorized saw!).
Howard Snell