How to build a raised play fort
Step 12. Making the trapdoor
Make the trapdoor up on a level surface. The trapdoor consists of 150mm x 25mm (1" x 6") floorboards nailed to two 45mm x 45mm (1 1/2" x 1 1/"2) pieces of wood 450mm (18") long. See the 'floor and trapdoor plan' for dimensions.
Next, nail a fillet (an off-cut from a floorboard) to the side of the frame member directly under the hinge side of the trapdoor. This is to give the trapdoor support when people are standing on it. (See side-view picture)
Lay the trapdoor in place, ensuring that the gap is the same on the hinge side and the opposing side. Screw on two 150mm (6") "T" hinges, approx 50mm (2") in from each side.
Drill a 25mm (1") finger hole positioned approximately as shown in the illustration
Step 13. The door, the rope and the tire swing
Almost done. Tie a rope securely to the beam about 100mm (4") in from the end. Nail some type of bracket or saddle clip over the rope to ensure it is not going to slip off the end of the beam (see picture below). Then tie on a tire to the other end of the rope.
Fit the climbing wall door in place as shown in the picture below and you're pretty much done!
Safety concern. If you think the swing could be subject to excessive weight and are concerned about the possibility of the fort tilting, then anchor the opposite end of the fort to the ground. One such method is to concrete a post into the ground at both rear corners and fix the posts to the corner uprights.