MIT students build a roller coaster in one week
Did anybody else laugh at the idea of using 2 grade 5 1" bolts per 2x4?  I know wood is strong and all, but it's not that strong!  They could have held it all together quite successfully with some 3" deck screws or 3/8" lag bolts.By using such big bolts they actually made the structure less safe because they had to drill very large holes; those holes made the wood weaker than it otherwise would have been.  I don't know who at MIT insisted that they use 1" bolts but that person had no business sticking their nose in.