Of the many types of bridges, the simplest is the beam bridge, which can be as simple as a log placed over a creek.
You will need
- 4 concrete pier blocks
- A level
- A shovel
- Hand tools
- Two support beams
- Four metal straps
- Nails or bolts
- The load for the bridge
- dry ground (optional)
Step 1 Study the location Decide where to put the bridge. Measure the space and assemble your materials, keeping in mind the carrying capacity of the materials you select.
If you are building your bridge over a creek or stream, consider the maximum water level. The bridge’s foundation should rest on firm, dry ground.
Step 2 Position two pier blocks Place two concrete pier blocks in the ground at one end of the bridge site. The blocks will support the beams. Use a shovel and hand tools to level the blocks.
Step 3 Attach the beams first set of blocks Rest the beams on the two blocks so that they extend across the bridge’s span. Attach the beams to the blocks with metal straps.
Make sure the two beams are parallel to each other.
Step 4 Add planking Cover the two beams crosswise with wooden planks and nail or bolt the planks to the beams.
Step 5 Test the carrying capacity Test the bridge’s carrying capacity using an appropriate load.
Work on the original London Bridge began in 1176.