Construction Phase Two - Mortise and Tenon
First, a level is used to determine where the bottom beam should connect to the post. Then a 1 5/8" forsner bit was used to create a three inch deep hole at the bottom of the motise, followed by a second at the top of the mortise, and finally a third in the center to remove more of the wood.
First a flat chisel is used to remove the wood between the holes, followed up with a special right angle chisel which squares off the round shoulders left by the drill bit.
Attaching the other end of the 2x6 to the gate wall requires a different technique. First the dimensions of the 2x6 are marked off on the vertical post. Then a saw is used to define the depth of the wood that will need to be removed in order to create a large enough mating surface. Once the top and bottom cuts are done, a few more cuts are made between those two cuts in order to make it easier to chisel out the waste wood.
First, a flat chisel is used to define the vertical edge of the cut out. Then, bit by bit, chunks of wood are pried away until the pocket is defined. Then the chisel is used like a plane to smooth off the mating surface.
The last step is to seat the 2x6 in the mortise socket, and mark the other end for the 45° trim cut. After that, it's just a few screws to join it to the post, and then on up to the next level.
While the lowest three 2x6's are some 18' long, the fourth and fifth are shorter. This wall will form one side of the staircase providing access from the main wall to the high deck. Instead of just being a single flight of stairs, it's actually designed as a combination of three small stair sections broken up by two landings. Each landing will provide a fighting platform from which archers can defend the gate, but they also surve a safety function. If the stairs were one continuous flight, then someone who tripped at the top could fall all the way to the bottom, which is a long way and they would most likely get hurt in the process. Breaking up the steps into three sections insures that when someone trips and fall, at least they won't fall very far.