Posted on

Keosauqua Bridge Construction – free ebook

A few years back I created a book detailing my design for the replacement of the historic Keosauqua Truss Bridge with a steel girder bridge. The book has well over a hundred photographs showing the construction timeline and how a bridge gets built.

The pdf file is large (80mb) and is located here (link).

1 (391)

Here is an old video I made a long time ago about the bridge.

Posted on

Retrofit Bridges with Helium Balloons – Bridge Concept

I was looking around the Internet and saw an article on the lifting capacity of helium balloons. Apparently it is about 0.062 lbs/cu. ft. So if you have a balloon 100 feet in diameter it can carry about 33,000 lbs..

You could carry a semi-trailer with two balloons.


So I know there is a small pedestrian bridge that has balloons holding it up but how about using balloons to increase the load capacity of existing bridges? Sure they move around but they would be easy to install! Ten balloons, 5 semi-trailers….


C’mon let me try it.


Posted on

Garden bridge – Bridge Concept

HP has a new post on a proposed garden style bridge.

As HP pointed out, the bridge design is not really responding to the site. Meaning the bridge was designed without the context of the area in mind and you could plop it down anywhere. I always thought context was the mantra of good design?

It is an attractive bridge but is it worth being the most expensive pedestrian bridge ever built. Now that I have joined the party of Yes, of course they should do it! Build two!

Here is my version from two years ago.



Posted on

Baton Bridge Concept

So it has been an odd week and it is only Tuesday! Yesterday I was on the losing side of a debate on the “worth” of a structural design engineer.

I felt that a design engineer is a valuable resource that deserves respect (and money) while the other side essentially saw designers as commodities that should be managed and kept at the lowest possible cost. The engineers who sign the plans should be leading the projects but I see them becoming more like factory workers. Like I said, bad day.

Oh well, I had another goofy idea for a bridge, the Baton bridge. The bridge is a curved cantilevered structure that is balanced with a weight.

The more weight you put on the bridge causes the baton to rotate down, increasing the counter balancing force of the baton weight. Obviously you would need significant weight sensors in the bridge deck plus a computer system to adjust the angle of the baton.

Most importantly, you would require a great deal of liability insurance.

Click on the image to see the slide show.