Pedestrian Bridge Kit Set-up Concept

My name is Jacob Nord, I am 15 years old and I live in Klamath Falls, Oregon. I am in 9th grade and home-schooled.

As you have probably have seen, I have put up several bridge ideas, that could be 3D printed on-site. I wanted to build a different design than what I have built previously. This bridge has the same "concept" in some regards, but keep reading to find out some differences...

For a few weeks I tried working with Fusion 360 on this bridge, and the others, and I have had some problems in several different ways, so I've chosen to work with Tinkercad for all of my demonstrations.

I've read all of the 'official rules' and I've tried to incorporate as many ideas that will go with the rules.

I've always wanted to fly a plane, and flight school is very expensive, so when I saw this contest I got excited and built a bridge hoping there might be a chance of winning so I can pursue my dream of flying.

• I used Tinkercad- for the demonstration

There are several supplies that vary and I don't have listed, so read the whole page to get the needed supplies/info.

Thanks for understanding...

Instead of printing the bridge on-site, this bridge would be made in a factory, in a kit type format. All of the framework underneath would be 3D printed or cast plastic with carbon fiber string in the material to give extra strength. (All of the supporting columns and braces)

This bridge design will take longer time to have completed than the 3D printable bridge design, but will give it a unique look, and unique material/structure to the design.

Most of the framing pieces would be either 3D-printed, or cast into shape (with carbon fiber string all mixed into the material). The plastic will be infused with the oils that are in mosquito repellent. ( See my other bridges to read more about mosquito repellent in the plastics). All of the plastic pieces will have built-in mounting-flanges so everything can be bolted together. The stainless steel bar stock will need to be cut into length of a section length,( this is for bolting the plexiglass down onto the main frame), the holes for the bolts will also need to be pre-drilled before it is a complete kit/setup...

The railing will need to be made ahead of time also. All of the pieces will need to be welded together. It could be done with some type of CNC or a robot welder. The railing lengths will be one section long. The railing could also be pre- painted.

With the picture above, it shows what I call a 'section'. These can be assembled at the manufacturing facility and then trucked in to the site. Then, with a small crane it could be installed into place. Several of these 'sections' would be bolted together. The sections of the bridge could be assembled together on-site also. (Depending on the location, such as; a location where the truck can not bring the individual sections of the bridge, or any other logistical situations that will require building the bridge all by hand at the bridge site. The fact of how it is mostly made of plastic and is a kit, which makes it lighter material, it allows people to build it all by hand without needing heavy equipment to move the materials and/or build it. ) Tight cables could be pulled across and underneath the bridge location, and the bridge could sit on the cables until it is built to the other end...

Once the bridge extends to the other side, a cable would be pushed though the three 'spines' all the way to the other side, (As shown above in the picture) When it is to the other side, it would be bolted down tight to the foundation. This would not only hold the static weight of the bridge but could also hold the weight of a golf cart and more.

The most difficult part of any bridge, is the foundation installation. In my other 3D-printable bridge designs, I came up with the idea of making hollow pre-cast (plastic) foundation blocks, and then filling them with concrete and printing off of that. But with this bridge design that would be a problem because it is a bigger design. It would have to be a pretty big-foundation block to move around.

But I think l have a solution. Manufacture the foundation block into two pieces. When the block is two pieces, it will be half the size, and half the weight. The blocks just need to be made such that they can be bolted together on-site. Once it is bolted together, then it can be filled with concrete.

Paint/dye could be incorporated into the plastic, (such as the main support part) to add a colorful/artsy design, and it would be assembled according to a planned design, (probably made with a computer system) to make a unique design. Themes or crazy colors could be planned out for visual appeal, or make it blend into its surroundings such as, camouflage-type colors and designs...

With the idea of colors printed into the plastic with a wide varieties of colors, and different ways of putting it together, the sky is the limit in terms of the visual appeal!

Once the bottom frame-work is all bolted down, the plexiglass walkway will need to be installed. Stainless steel bar stock would be used to secure the plexiglass decking in place , as shown above...

With the clear blue plexiglass, it allows you to see the unique plastic framing of the bridge structure, and also displays the natural features underneath the bridge as well. Besides, who doesn't like to walk on glass?...

• Railing

The railing will be the same length as individual sections of the bridge, so the railing could be hand assembled onto the bridge, (bolted down). With this design, the whole railing system would basically all be 'snapped' together and be bolted down firmly.

• Lights

Lights would be mounted underneath and on the sides of the bridge to illuminate the vivid-blue-clear plexiglass. The lights will also help people with crossing the bridge when it is dark.

I wanted to incorporate "made with Autodesk Software" on the 'threshold' on both sides of the bridge so everyone knows how the design was made.

There may be some questions/concerns regarding the idea of having a plastic bridge with this type of design such as; Is the plastic strong enough or, is it an efficient enough design (for the building processes)?

1. Is it efficient enough to build?

The idea of having the bridge to be a pre-made kit, makes it an efficient way to build a bridge like this. Picture a bridge identical to this one, but all metal; it is a lot more weight and is more complex (to a certain degree). The idea of making the bridge in a factory setting will enable installing the bridge on-site in a much shorter time frame, especially in a short building season location, or any other conditions that might require a quick build time schedule.

2.Is the plastic strong enough?

The plastic will definitely be strong enough for this bridge, especially when the right type of plastic is used in tandem with the right structure design. We have a greenhouse made from 2'' by 2'' plastic square tubing and it's been holding the roof for a couple seasons now, it also is used and weathered, but is holding up. So with the right plastic and design, plastic will support a medium sized pedestrian bridge. Especially when the plastic is well maintained and taken care of.

Feel free to ask questions about this bridge down below, and I'll try to answer or solve them.

I'm also open to tips and idea's!

Here in southern Oregon there has been a harsh drought, and the farmers, the local Tribal members, and environmentalists, have been fighting over what little water there is in Klamath Lake. This is where farmers get their water. Finally after many years of little rain and water, this year we had lots of rain and the lake is now full and the river and ditches are full also, and everyone has water. Therefore I think this bridge would be a great way to "bridge gaps", even if in the future there is a drought.

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There is a park/recreation area to the south east of town that I think would be a good spot for this bridge kit design. People go out there to go mountain biking, hiking, fishing and picnicking. There would be plenty of people to use the bridge. There is also going to be a new subdivision on the east side of the river. Having a bridge here will allow people to go have fun in this park, on the other side without having to drive around the river to a bridge upstream.

Klamath Falls is not a growing town, but a unique bridge like this one just might put this town on the map, and bring some additional appeal to this town.

I have really enjoyed the building process of this bridge. I began working on this bridge a few weeks after this contest had started, but had suspended this project for a while because as you probably have seen, I've invested a lot of time working on the 3D-printable versions of bridges. But a few days ago I started this bridge concept again. It seemed that it took a long time to build, but I'm glad I have worked on it and have come this far with it!

There have been lots of screenshots, editing screenshots, and writing this Instructable, along with proof-reading and editing. So there was a lot of work put into this.

I hope I have explained this bridge concept well enough to you.

I hope that this bridge will qualify for the contest and I wish good luck to fellow contestants, and happy building ;-)

Please check out my other bridge entries with the link(s) below:

https://www.instructables.com/Dar-Pedestrian-Bridge/

https://www.instructables.com/Double-Arched-DAR-Pedestrian-Bridge/

https://www.instructables.com/Dar-Pedestrian-Bridge-Inverted-Version/