Cable Stayed Bridge, October 2003
Shortly after I built the tree platform I began thinking about the
best way to access it. Some sort of ladder was the obvious choice
but building a bridge seemed like more fun, so that is what I did.
The distance from deck to deck was over 20 feet so I either had to use
deep members or get creative. I chose the latter for aesthetics
and cost, as a low profile bridge would be less obtrusive and the
materials would be much cheaper and easier to handle.
Construction was rather straightforward and started with fixing the
three 2x4's to each deck. At the tree platform the 2x4's are
hanging in 2x10 joist hangers while at the house deck I make a shelf for
them to rest on. Next my father and I jacked up the center of the
2x4's and ran the aircraft cable. The wire is one single strand
that wraps around the 10-inch diameter horizontal log at the
house. Based on my calculations I could have used a smaller
diameter wire but this was all that they had at the lumber yard.
When we released the jack the bridge had a nice camber to it.
Nailing the decking was the last step. To maintain the low profile
I chose 5/8" x 6" redwood which is usually used for fences in
this area. All of the work was done in one day and all in all I am
very pleased with this project.
|Here we see the substructure of the
bridge, three pressure treated 2x4's along with the cable.
To get the camber my Dad and I jacked up the joists before we
ran the wire.
|Pa tests out the completed bridge.
I am very happy with its unobtrusive low profile and the way
that the cable disappears into the background.
|A view from the tree platform showing
the width. Scoobie would not cross the bridge of his own
accord so I had to drag him across. That proved to be a
good load test, 120 pound dog plus 170 pound human (my rough
calculations were based on a 300 pound load).
[ Home ] [ Adventure ] [ Backpacking ] [ Food ] [ Events ] [ Projects ] [ PJ and E-Ling ]