A basic tunnel structure:

NOTICE

Tunnel Building Stabilization

To keep a tunnel structure stabilized, start the building procedure from a constructed frame, such as a room structure or one of the tunnel cross sections.

Procedure

1. Build a 50 wall x2 on top of a 100 wall. These walls function as the tunnel walls.
2. To measure a distance of 70 cm between the two tunnel walls – place a 100 wall at the end of the walls, verify that the tunnel walls are parallel.
3. Assembler 1, place tunnel cover so that the key holes of the tunnel walls and the tunnel cover are aligned.
4. Assembler two, place four keys in key holes.

1. Assembler 2, insert two keys on the exterior key holes of both tunnel walls through the tunnel cover, make sure to properly strengthen the keys.
2. Insert bottom clamp while it parallel to the ground to the middle key holes.
3. Lift bottom clamp up so it is vertical to the ground. The lifting up process locks the bow in its place.
4. Place top clamp on top and in the middle of the tunnel cover.
5. Use the force of hand to insert it. It functions as Klamra Coupler.
6. Strengthen the tunnel walls by adding a Klamra Coupler.