The show south pacific has a very big shower scene where they use a shower cart
Step 1: Make the Base
you will take 4 2 by 4s and cut 2 to 3 ft 1in 3/4 and 2 at 6 ft 1 in and 3/4 then skrew them together into a rectangle and one more 2 by 4 between the base, attach casters to one side of the base on each corner, the cut out around 25 2 by 4s that are between 3 ft 3 in and 3 ft 6 in. take the 2 by 4s to the band saw and cut random patterns in them to give the shower a rugged feel.
Step 2: Make the Shower
You are first going to get 4, 4 by 4s and cut them each to 8 ft you are going to put two on one edge and the other two on the extra supported 2 by 4 you have on the base. Use L brakets to keep the 4 by 4s secure and standing straight then you skrew 2 by 4s on top of the 4 by 4s to make a square and on that you will make the same band saw cuts on 2 by 4s and put them on top. After you make the foundation of the shower and it is sturdy then put sheet good in betweent three of the sides that do not have the rugged look on them. then skrew in hinges and put the other sheet good in the hinges so you have a swinging door.
Step 3: Make the Ladder
Take two 2 by 4s and cut them to 8 ft and on the cut cut them each to 15 degree angle. then for the steps cut as many 2 by 4s as you need and cut them to either 18 or 19 in. put them 12 in apart. then make brakets on your band saw so you are able to hang the ladder on your structure.