Alrighty, here is my first entry for the Speed Modeling Contest #34, also did a second modern/futuristic one... This is a "wall scaler" called the Armored Turtle... Basically, those huge harpoon hooks is shot over the wall, then the turtle reverses to pull the rope tight because only the first five meters are 'armored' so the enemy can't cut the ropes. Then the crew starts reeling in the rope, pulling the turtle to the wall and then up the side [didn't have time to do the gears and pulleys inside that will accomplish this but I have it all worked out ;D ]. Once they reach the top, the crossbows are used to clear any soldiers directly next to the exit which is now the bellow of the turtle standing on its read [ will do reference pics to illustrate and post it in the comments thread ]