Fenland Double Lock Bridge
We built this bridge inside our HQ by standing the four vertical posts in buckets packed with sand and used sand bags to secure the butt of the sloping spars.
Equipment
- 2 x 4m (12 ft) spars
- 4 x stout pickets approx 1.8m (6ft) long
- 4 x 2.4m (8ft) spars
- 4 x 1.8m (6ft) spars
- 1 maul (or sledge hammer)
Method
Drive the stout pickets vertically into the ground approx. 1.0m (3ft) apart, 2 on each side of the ditch or stream.
Hold a 2.4m (8ft) spar on the outside of each picket at approx 45o to the ground.
Rest a 1.8m(6ft) spar horizontally on the 2.4m spars against the stakes.
Lay the 2 x 4m (12ft) spars across the stream between the horizontal spars.
Place the final 1.8m (6ft) spars across the 4m spars and push them firmly into place under the sloping spars.
As Scouts walk across with one foot on each cross spar the bridge structure will automatically tighten.
Note: Since the design of the project the principles of Health and Safety have changed dramatically.
Caution should be exercised to assess the risks associated with this build and especially regarding possible falls from height, so handrails or belays and harnesses may be required.
To download the complete plan and design document please Click Here
