Pro Tip for Swing Bridges

If you are responsible for maintenance on an older swing bridge with spring grid type couplings, I have an old-timer’s trick that you should keep in your toolbox that just may save the day sometime.

The grids in the main motor coupling on one of my swing bridges broke during an opening stranding the span in the fully open position. The bridge was located about an hour and twenty minutes from our shop and upon arriving and discovering the nature of the problem, I remembered a nugget that an old-timer once shared.

Being 4 a.m. when it happened, the traffic had not been an issue yet but a couple of additional hours to get to our shop and back would have inconvenienced a great many more people. I went to the truck and grabbed a few nylon ratchet straps about one inch in width. I used just the strapping and started wrapping the nylon around one side of the shaft and tied it tightly.

Keeping everything as tight as possible, I then wrapped the strapping over the coupling and looped it around the other side of the shaft. Back and forth until that strap was used up, I then tied it off and repeated these steps with a new strap starting from the other direction.

Once two straps were secure (I used 15 ft straps), I used the slowest creep speed I could and slowly but surely closed the span using the nylon strapping as my coupling material. It worked perfectly.

I was able to close the span within 15 minutes of arriving and looked like a genius to the other maintenance tech in the process. We always kept several 15 ft straps in a toolbox on the bridge from that day on.

You may never run into this situation but if you do, this is one old-timer’s trick that will definitely save the day.