Attn: Wood workers...

Best I can do for now, haven't been able to get to my desktop so I am posting from my tablet in my hotel room.


Edit: the drawings show single 2"x8" but he doubled them up for strength.

 

Sides and ends 2"x8"s double thickness
Posts are 2"x4" sandwiched

Doubled and sandwiched creates higher strength and resistance to warping because of the opposite grains.


Edit: Posts could be 1"x4"s double-looking at the pics, but the concept is the same

The opposite grains concept is the same thing he did for his old queen and my single bunkbed when I was younger. The bunkbed was probably 5 foot tall to the bottom of the mattress and it supported my dad with no shakes or wobbles. That's 180lbs with 5' stilts, so it appears to work quite well

Both of those beds are still very solid and they are over 18 years old.

 

Should just be a regular queen, quite a bit smaller than the one you are looking at building but I hope it helps!