Don't know how much it weighs, about 100lbs without the counterweights, and stands at just under 16 feet tall with the boom standing up, and around 8 feet tall when it's locked.
Right now we're in the tweeking stages and throwing 10lb rocks about 200 feet with 90lbs of counterweight. My long run goal is to throw a bike. Best thing thrown so far, a rock with some fireworks taped on.
No clue why we built it, we were sitting around when I asked if anybody wanted to build a trebuchet. 20 minutes later we were on our way to the lumber yard (it would have been sooner but my friend's truck sucks). Took about 15 hours to plan and get working, and alot of that was us goofing off, drinking and drawing penis's on my friends truck and workshop. Cost was $38.42CDN.