DIY Suspension Bridge - 54' Span

How to build a suspension bridge. Cost: approx. $500. Time to complete: 40 hours. Built across a creek in the woods by one person.
Download the free Quick Start Guide that I made. DIYSuspensionBridge.com - Everything you need to get started on making a backyard suspension bridge. The guide includes:
- a complete Materials List for a 54' DIY Suspension Bridge with quantities and image references,
- How To Determine If Your Location Will Work,
- and a BONUS section on how I spent only $500 building my own 54' suspension bridge.
Update 11/2020: This suspension bridge is an older video, but if you want to see more DIY projects and things related to real estate investing and construction, watch the our entire farmhouse remodel YT series: buildistics.com/farmhouse-rem...
OUR CAMERA: amzn.to/36CgvtJ
OUR DRONE: amzn.to/2CfYhQH
IG stories & behind-the-scenes: / buildistics
The music we use: buildistics.com/music
DISCLAIMER: This video and description contains affiliate links, which means that if you click on one of the product links, we’ll receive a small commission WITH NO ADDITIONAL CHARGE TO YOU. This helps support our channel and allows us to continue making awesome videos like this. Thank you for the support!

[@WVmedic511]

Yes sir, very creative. I'm not writing this to criticize, but to inform. I am not an engineer and I'm sure some will read this and could offer more specific suggestions for the next one. I lived in the country in West Virginia and 'swinging bridges' were common. I concur as Ted mentioned about the I-bolts...not passing through the pipe. This reminds me of the skywalk collapsed in KC. (I'm an old firefighter/paramedic). I also was trained in high-angle rope rescue, so was familiar with the tension put on static lines and anchors (bottom cable, I-bolts, pipes). It will probably do you fine in your garden, but I wouldn't allow more than one person on it at a time. I'll share why. Your bridge, not counting the cable, has a standing load of about 460 pounds (wood). Add two 150 lb. adults brings load to 760 lbs. The tension placed on the anchors would be calculated based on the angle created by the load on the cable(s). If your cables are so tight there is very little deflection when the additional load is applied, the force on the anchor (and cables) can be estimated as follows: 170 degree vector angle increases tension force 574% on each anchor, or an adjusted load of 5144 lbs. 140 degree internal angle increases tension by 145%. Take that into account when chosing your support cables and calculating the 'sag'. The recommended safe working load on 1/4 inch steel cable 1100 lbs. static, while 3/8 is 2440, and 1/2 inch is 4280 lbs. The in-line working load limit on a split eye I-bolt (wire turned)...for 3/8 inch is 125 lbs, for 1/2 is 200 lbs. (4:1 safety factor...should NEVER be used). In contrast, forged I-bolts are 1200 and 2200 lbs. respectively (5:1 safety factor). These numbers are just some examples I learned dealing with rope rescue and safety considerations and don't include force changes with acceleration (bouncing). Again, your bridge is really cool, and will likely serve you well, but I just wanted to mention these things so others may want to go 'heavier' to increase their safety margins. It is just important to calculate these forces and assure your 'weakest link' will meet the test. Sorry for rambling....

[@Itismeonhere]

yes, thank you both!! I need a bridge about the same length to cross my creek especially during the winter. in Summer it gets low enough to cross through the water, but it stays full all winter too deep to cross. My main concern has been what kind of rope to use for weight and wear and tear durability so it could last for a while. I have been considering the 1/4" cables like yours, but I wasn't sure how strong it needed to be.

[@archaris8124]

mechanical engineer here, not professionally licensed for civil engineering or anything in particular, but the anchor points for the bridge were definitely too close to the pivot "tower". it's easy to pull a concrete plug out of the ground, it's MUCH more difficult to bend a rebar-reinforced "anchorage" out of the ground from far away; especially if it was poured in a special shape to use concrete's compressive strength at an advantage (for example: a triangular anchor point placed farther away will weigh more, use the soil as resistance, and reduce upward tension that could extract it from the ground. I didn't check any of the math above, but a 100lb force at 45° angle is about 70lb force vertical and 70lb horizontal (via trigonometry). Bridges are symmetrical, so if it is 100ft long; the center is at 50ft. You place a 150lb person there you get a moment around the pivot point (fulcrum, tower) at 150lb*50ft=7500ft-lb. If the anchor is at a 45degree angle to the pivot tower, then it needs 7500*70%*(1/100%)=5250lbs to prevent simple pull out sans frictional forces. tl;dr: it might work well for the occasional person but I'd add a second anchor point farther away, maybe half the bridge span and in a smart 'triangular lug' shape. when in doubt, it's worth paying a LOCAL civil engineer one or two hundred bucks to do a calculation based on soil quality than to repay the insurance company after an accident!

[@mahatmakain]

Funny you mentioned the KC disaster at the Hyatt, back in 1981. When I saw the phrase 'swinging bridge' that incident immediately came to mind. If I recall, the contractor suspended one walkway from another above it, rather than each walkway having its own independent suspension rods, so the rods holding the upper level were also supporting the weight of the lower level. I think they had several "flying" walkovers arranged one above the other in different directions and the upper one broke free and brought down the rest of them. We studied it in civil engineering classes as a classic example of what can happen when a contractor takes a short cut rather than following the plans exactly. You all make some great points about safety in these comments. It's a cool idea, but even with my engineering background, if I designed this, I'd have another engineer review it for me.

[@johnlangaker9098]

I lived in KC for 15 yrs and am an license mech engineer for a large firm there. The Crown Center collapse was actually caused by an un-approved contractor field change to the vertical cable connections between levels. Instead of a 3-plate sandwich joint they actually made a single lap joint between the joining plates. Instead of the bolts being sheared in two places for 50% sharing it became 100% in one place. The result: collapse and fatalities.

[@cindymeyerson2099]

I ❤️ it but I am taking your knowledge into consideration when I make my bridge. Thank you for your knowledge.

[@tompate5874]

Watched this video cause I need to build one very similar length but over a deeper ravine. Can't lie, some the components and practices used gave me heartburn, there's just no way I'd get on that bridge. I just hope everything has worked out ok so far and nobody has gotten hurt on it.

[@aliastagami2346]

This video is 10 yrs old now. I'm curious if you've updated the bridge or if it is still functional/standing. I won't repeat the engineering comments previously made, but I see many design choices that might not last over time.

[@skyelinepark1]

Thank you very much for sharing. Good on you for starting it and putting it out there to share and also to allow others to make suggestions to improve it. I love people giving stuff a go. I have been putting shade sails up around my place using similar steel rope on a mountain top where the winds are crazy. The shades over lap and are in uneven places so it is quite the adventure with improvements happening every time. I trust my brain is gaining much from the exercise as yours must too from the bridge. One day I will give the suspension bridge a go having learnt from here. When people mention problems with hardware I am wondering if Stainless steel is a must. Thank you again.

[@cadavatar]

I think this is awesome, I'll just say that outright, it is. I do, however have an important critique with safety in mind. Where your eye bolts are installed, you should always use an eye bolt that goes through the pipe entirely, 2 holes not just one, and there should be two, thick galvanized washers, one on each side of the pipe. This only increases the build cost very slightly, but it increases the structural integrity of the bridge significantly. Installing a nut inside of a pipe and using one hole means the force exerted on the cable is creating the pull on the inside of the pipe against a small concave steel surface area. Since the shape is concave, it invites deformation of the hole under load and the nut can possibly pull through. Installing an eye without using washers means the nut, even if it is on the opposite side of the pipe, can possibly deform the hole and if it pulls through the first side, there may be enough energy for it to pull through the other in the event of a failure. I'm just putting this out there, of course do as you like but you may want to do a little research on how to improve your already impressive design.

[@brentderksen]

Thats awesome! At least there are still some people out there who like to try cool stuff.

[@hogwilder2198]

Amazing! Great Craftsmanship, you do neat work. It's so cool to see someone do great work and also figure out how to save some $$$. Great Video and Great Bridge!

[@kayakerodie]

there is no redundant (backup) safety system on the support cables at the ends of the bridge in case of a cable break due to the clamps slipping or turnbuckle failure. The free end of the cable should have been turned back and reclamped at the source before the turnbucke.

[@matthewdavis1752]

That's tight, thanks for sharing, totally going to implement this design thank you!

[@zoelo01]

Good job for one-man work like this. For the bridge to last longer, I would use PT#2 deck boards and 6x6 PT timber. The galvanized conduits will rust after a couple of year.

[@BadUncleIke]

I like the minimalism. Good job!

[@VaranusVideos]

Talk about creativity love it man im building a bridge accros my 14 foot stream, might do something similar

[@foodieants7878]

Love the design! Looks amazing!

[@niftyflip]

Wow, Awesome Bridge!!!

[@DandyDi1]

I really like your bridge and my husband and I are thinking about building something very much like it. Is there another video that completes the process, since this one just gets as far as the attachment of the planks to the cable and then ends? Thanks for posting such a helpful video.

[@DoubleDHomestead]

That looks great!

[@franksnb]

a rough calc. assuming a 5ft sag in the middle, a load of 185lbs in the middle and the load is divide over 2 bolts the maximum tension will be 250lbs on each bolts. if the sag is less the force goes up! whats the shear strength of the thread/bolt? btw thats static, jump up and down and expect a large increase.

[@AAGWproductions]

Great work!

[@contactdk]

dude your shop is a kitchen.. awesome

[@ronaldj1781]

I googled for a suspension bridge and came across your video. You've done a fantastic job and the result is impressive. Some folks have a good eyeball for what's good some folks don't. Obviously you have the touch!

[@shanepemberton354]

Excellent job.

[@stllbrown]

Brilliant!

[@blindbox99]

cool! I need about 3 of these for my property. :-)

[@belliappasabusabu7549]

very good work, keep it up...

[@PeterRatsch]

Question, wondering if the screwed in metal strapping under the boards securing the cable slips at all? Considering the same for a treehouse but mine will be more sloped so worried they might slide?

[@williamblacksmith6692]

Great bridge. You did a very nice job of constructing it. It would be interesting to have James Crane expand on his comments that you should have your home owners insurance up to date and you should expect to have a lot of problems with your hardware. Anyway, I hope to begin construction on my own suspension bridge soon. Essentially I will be using your basic design premise to build my bridge. It may be a little longer span. Between 50 to 60 ft. Thanks again for sharing the video. I have watched it many times as I think it is probably the best DIY suspension bridge on you tube. Also, I am curious how your bridge is performing. Do you suggest any changes or modifications? Thanks again.

[@jamieshotter9762]

Good bit of simple engineering. For securing the deck to the support cables, I would recommend u-bolts through deck or passing two bolts right through the deck with plates top and bottom. Bottom plate holding cable to deck on underside and the top plate to stop bolts pulling through timber deck.

[@MichaelBrown-zn6fc]

how deep did you make the post holes for the concrete? What diameter was the concrete? And how has the bridge held up so far? Thx.

[@Abdulbhaighansar]

how do u conect upper cable(suspended cable) to lower cable.?plz reply me.wanna construct this type of bridge.

[@jeanavelinovlog663]

Wow nice bridge

[@peckerwood780]

Impressive

[@flyingjoed]

What are the 1"x1" (approx) brackets that you used to attach the planks to the cable? Are those sold as something else or for this type of use? Where did you get them? Thanks! Great back yard btw! People pay lots of money for manmade versions of what you have naturally! :-)

[@s.porter8646]

How far did you haul materials? I'll be building one it's 3 miles in

[@fdm9282]

Very cool I'm looking for something similar

[@teamhowardoutdoorst.v.6695]

kzbin.infok3xo82BJ

[@landyboy7]

Hi I need to build one of these to cross my creek but it needs to be 140 feet long. Do you think this design would be effective at this length? And would 8mm cable be suitable? Many thanks

[@wadenshell211]

awesome job brother!

[@ovniproject]

how to tension the steel cable?

[@specopdoc]

How much would you charge to do it to an inept person like me to do it?

[@marconorbert6946]

cool

[@sourabiesoura6804]

very nice your bridge is very beautiful. are you ingenieur?

[@sourabiesoura6804]

oh okay i wanted to make my own bridge but i can't

[@bhelmore1]

I'm curious to why the upper cables are attached at such a high height rather than lower where they would be at arms length (4 feet or so). Is there a particular reason for this? Could the cables be attached lower and shorter poles by used? Many thanks!

[@BrianPTATC]

Could this bridge be built using wooden posts rather than the steel posts? The bridge I need to build will be about 40 feet.

[@BrianPTATC]

Thank you for the response.

[@paulavery366]

Looks nice but probably not very safe. Most of the hardware looks way too flimsy and the design has several single point failures that could bring it down (zero redundancy of elements in tension).

[@emersonbigguns5196]

You have a planer but don't own a $35 pair of bolt cutters. Lol

[@Amanotesgamer2024]

YES I GOING PICNIC SEE THE BRIDGE

[@michaeljwildner8153]

I have seen many sites, but one thing I have not seen How do we get the rope from one side to the other, if we can not just walk the rope across. If I was hiking in an uncharted area, I came to a cliff with a height of 300 feet down, about the same across. I can cut vines and trees for wood planks and such but how do I get the vine ropes about 300 ft across that valley?

[@alabastardmasterson]

Magic

[@dmpmasters3353]

"Not for supporting human weight" haha

[@Maverick8175]

This bridge scares me.

[@akilichev]

Beautiful bridge. Obviosly this bridge isn't for heavy duty stuff. So critics, go ahead post your own videos so we can how well can you do! lol

[@brettmcdonnell4430]

Is this bridge still standing? Just curious if it lasted this long?

[@Buildistics]

No, apparently about 10 of my nieces and nephews went on it, jumped up and down and it broke. They fell in the creek.

[@davedoesthings]

@@Buildistics Is this a joke? I'd like to build a bridge exactly the same and roughly the same size.

[@Buildistics]

Not a joke. I would build it differently if I were to do it again.

[@davedoesthings]

​@Buildistics thank you for the reply on a 10 year old video. Very cool. What was the weak point?

[@Buildistics]

Good question. I don't know for sure, but I suspect it was one of the cable clamps.

[@mcrane2653]

I have trust issues, I would have dumped a pallet of concrete on each side for footings

[@Buildistics]

That would probably not go anywhere! 👍

[@jamescrane289]

Good luck with your bridge, make sure your home owners insurance is current. Expect to have a lot of problems with both your design and choice of hardware. Looks nice though!

[@I-Love-Taylor-Swift]

You've got a creek in your garden? What the hell! Our gardens are the size of a car!

[@thesockthatcan]

Then get the hell out of the suburbs!

[@akilichev]

+I Love Taylor Swift Hah! I don't even have a garden ! lol

[@Icix1]

Huh, so the safe working limit of 2" eyebolts are somewhere around 20k lbs...calculate the load on the bridge from the stress of the entire structure plus human weight and you would have you answer as to whether it was safe or not. My guess is it is because of such a short span ie little stress on the entire bridge.

[@Abdulbhaighansar]

how do u conect upper cable(suspended cable) to lower cable.?plz reply me.wanna construct this type of bridge.