Adjusting a Suspension Bridge Deck

One of the hazards of building a bridge in the woods is that there are trees in the woods. And trees sometimes fall. It was only a couple of weeks after my bridge was completed that a tree fell on it. It bounced off without causing damage other than a dent in a deck board.

A couple of years ago during a flood, a tree next to the bridge came down, and while not actually falling on the bridge, parts leaned heavily on the suspension cable. I cut off the branches that were in our way and let the rest stay for now since I was busy with other projects. This spring I finally cut the rest of the tree that was affecting the bridge cable. I knew that the deck had sagged a bit and would need to be adjusted at some point.

TreeBridge

That’s why I have turnbuckles installed on all the deadman-to-post cable connections as shown in my book, Building a Small Cable Suspension Bridge. I could just turn them to pull the posts back and level out the deck again.

bridgeturnbuckle2

I used  what was handy to provide a resistance (something to work against) to turning the turnbuckle – in this case a big stick and a metal pipe.

bridgeturnbuckle3

WD40 oil worked to loosen up the connections. They weren’t rusty having been protected under the cover of those white tubes all these years, but they didn’t want to break loose easily.

bridgeturnbuckle4

I used a small bar for turning, but a longer one could have made things easier.

bridgeturnbuckle5

I used a pencil mark to verify if I was tightening or loosening.

bridgeturnbuckle6

Once they broke loose, each turnbuckle turned easily.

bridgeturnbuckle7

Jeep seemed amused that one side was now lower than the other. But that’s just part of the process!

bridgeturnbuckle8

I worked on all four turnbuckles, using line of sight to achieve the results I wanted.

bridgeturnbuckle9

All done, until the next tree takes a dive into the creek and the bridge is in its way.

This all only took about 30 minutes. Here’s a movie of the process if you’ve never seen a turnbuckle in action.

Thanks for stopping by! Be sure to check out our suspension bridge book. Here is the link:

Building a Small Cable Suspension Bridge with the Cable Locking System

Images, diagrams, and text copyright 2013-2017 by Marvin Denmark unless otherwise noted. Please do not copy and post my content anywhere without my permission. Thank you.

Advertisements

2 thoughts on “Adjusting a Suspension Bridge Deck

  1. Hi Marvin, Your bridge building video was very good. I have been looking for a replacement bridge, I live in Florida on 7 acres and there is a creek running through it. When I bought this place 12 years ago there was a really nice bridge that spanned the creek. Concrete footers and all. After a few bad storms I could tell that the bridge wasn’t going to last. We had a bad flood through that part of the property and the bridge washed away to the other side of the creek. A couple years later I got 2 guys too retrieve it. They used a come along and ropes and placed it on a different part of the creek. The old spot…banks were too far apart. Fast forward through storms and it again was washed from that spot. It is retrievable but the banks are too far apart now. I think your system would work for me. I was also wondering if you had any easier bridges that could be built? I was wondering about a tree to tree, maybe with a zip line, the grand kids and the guys would love something like that

    Denise Scott

    • Hi Denise, thanks for the compliment! Erosion is always a problem and the big reason to keep bridge footings out of the flood plain, which as you’ve seen is increasing in size. My bridge is anchored about 25 feet from the high-water zone. Even a simple design needs anchoring away from the flood zone but a zip line between two trees sounds fun! We used a zip system of sorts to get buckets of gravel across the creek when we built the foundation. In any case you might want to start planting shrubs and other native plants that will help secure the banks because it sounds like your creek is choosing it’s own path, as they are prone to do. Good thing you own both sides of it!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s