Buzzsaw

The answer on the question sheet specifically disallowed "chainsaw" as an answer.

According to Wikipedia, 'buzzsaw' is another name for a cordwood saw, which is a type of circular saw used for cutting across the grain of the wood - as opposed to a sawmill saw, which is also a circular saw but cuts with the grain. ('Cordwood' is a term used to refer to unsplit logs, four feet long.)

Wikipedia goes on to say that cordwood saws have largely been replaced by chainsaws. The main differences between a chainsaw and a circular saw are that on the former, (a) the blade is not circular but elongated, (b) the teeth are attached not directly to the blade but (as the name implies) to a chain around its edge, and (c) it's the chain that moves, not the blade.

So a chainsaw is not a buzzsaw, and the question setter was right not to allow "chainsaw" as an answer.

Please note that I am not an engineer, or even a lumberjack. If I've got any of this wrong, or not explained it correctly, please don't hesitate to let me know.