Howe Truss Loaded

Learn all the main types of trusses used in real bridges, and see how to apply them to model bridges. Learn the history of each common truss design. This page is designed to help you make an educated decision about what truss design you should use on your bridge.

Truss Design

Learn all the main types of trusses used in real bridges, and see how to apply them to model bridges. Learn the history of each common truss design. This page is designed to help you make an educated decision about what truss design you should use on your bridge.

Common trusses used in engineering:

Warren Truss

Warren Truss

Warren Truss


The Warren truss is one of the most simple yet strong designs.  This simple design already existed, but what made the Warren unique is that it uses equilateral triangles. Each side of the triangles are the same length. This marked an improvement over the older Neville truss which did not use equilateral triangles.

Go to a more in depth analysis of the Warren Truss.

Pratt And Howe Truss


The Pratt and Howe trusses are very similar. In fact, the only difference is the direction the slanted members are angled. This changes which members are in compression and tension. On the Pratt truss, the shorter, vertical members are in compression. However, on the Howe truss, the longer, angled members are in compression. Because most materials (especially wood) that model bridge builders use decrease in the ability to resist compression the longer they are, I think the Pratt truss has an advantage.

There are more factors to consider, however. The Pratt and Howe trusses also differ in how they spread the load to the top and bottom chords. The Pratt truss has larger forces on the top and bottom chords than the Howe. Thus. you’d have to use bigger top and bottom chords.

Go to a more in depth analysis of the Pratt Truss.

Go to a more in depth analysis of the Howe Truss.

K Truss

K Truss

K Truss


The K truss looks very good on paper. It shortens the lengths of the compression members compared to the other trusses. However, one must wonder if it adds additional weight simply because of the number of members. It is really interesting to note the two green members on the K truss, in theory those pieces could be taken off. However, I had to include them to make the truss design program work. This shows only one orientation of the K truss. If I reversed the direction of the K’s, I wonder how much it would change the forces.

Go to a more in depth analysis of the K Truss.

The one thing I don’t like about this truss is the long vertical compression member in the middle of the bridge. If that one member could be shortened or even eliminated, I think the bridge would become more efficient.The K truss would be the hardest of these trusses to build. This is something worth considering. Making a strong joint that would make the most of the switch between compression and tension of the vertical members would be difficult.

If you are interested in learning more about trusses and truss design, check out Truss Fun, Second Edition from amazon. It can be purchased online though amazon. This is a comprehensive study on the engineering principles behind the design of bridges. It is easy to understand and to follow, and is a great fit for students who are just learning, but advanced enough to be a great resource to those with more experience. For more great resources, see this list of other great bridge books.

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161 Responses to “Truss Design”

  1. rose - January 30, 2009 at 2:16 pm

    i have to biuld a bridge for science fair do you think that popcile sticks would be the way to go , but i also need the bridge to break at some time with in 5-10 minutes. anyone can answer to this i just need some kind of answer. :)
    i would also like it if you just posted here on the website!!
    please someone respond soon!:D
    thank you
    p.s. i think that this website could use some more information on the different kinds of bridges and not just on your experiments you should have a viriety of appinions so that people will see two or more sides of the story!! OKAY? DO NOT take this as a insult i just think that it would be better that way , i thnk it would guve you more viewers than what you have now !! just my apinoin but i bet other people agree with me on this matter!! *****
    sorry if that sounded wierd :D/:( !!!!

    • Garrett Boon - January 30, 2009 at 10:20 am

      Rose, part of the reason I have the option to leave comments is so people can share their opinions about my bridges or projects they have worked on. I also have an option for people to upload photos of their own bridges, so this site is not just my own work.

      Any bridge can break within 5-10 minutes. It depends on how strong it is and how fast you load the bridge.

    • Kate - April 3, 2013 at 3:45 pm

      Yeah I’m doing the same thing but we have to use toothpicks which is so much hard so yeah if any of you have advice I would like to hear it but it will be hard!

  2. Liam - February 2, 2009 at 8:39 pm

    For a science fair i have recently done, i had the warren, pratt and howe trusses all trusses.
    the efficiencies in weight held over bridge weight were:
    warren – 385.6 reoccurring
    pratt – 425
    howe – 340
    These are not averages of several bridges, and they were only 1 foot long (cause thats what the stores had in stock.)
    In this test, they were weighed by hooking a rope to the bottom beam, putting a bucket on the rope, and adding coins to the bucket (and a ten-pound weight).
    I hope this answers some questions on which is best (the pratt)
    Of course i had 30 pounds of coins.

  3. Liam - February 2, 2009 at 8:41 pm

    p.s. thanks for the info, this is very helpful

  4. Flying Monkey - February 9, 2009 at 4:16 pm

    Has anyone else noticed that the K Truss looks like it has arrows in it as well as Ks? Its like an optical illusion! Great Website, and thanks for the tips!

  5. vinny oddo - February 10, 2009 at 12:41 pm

    . It is the simplest design of the Truss Bridge, with two sides, a bottom, and the railing in simple triangle forms. The bottom of the side of the bridge is 11 inches in length and the top of the side is 10 inches in length. The little rails on the inside of the left and right side of the bridge are 2 inches in length. The bottom of the bridge…… Some of the things I learned in making this bridge were the different jobs involved in the process of actually building a real bridge. You need to have an engineer, an architect, a scientist, and a mathematic. You would need an engineer to help design the bridge. You would need an architect to oversee the construction of the bridge. Also, the architect would prepare information on the structure’s design and specifications, materials and equipment, estimated costs, safety, and construction time. They also make scale drawings and make sure that the bridge meets the building codes and laws. Also, to build a real life bridge, you would need a mathematic. They would make sure that all the little details in the bridge were exact and specific so the bridge was safe, and also look right.

  6. Clarence - March 9, 2009 at 2:58 am

    hi, im in yr 12 and im currently doing an assignment on bridges

    ive built the warren truss bridge with vertical members,
    ive had a look at your diagram with the load factors, but im quite confused, you say that the load factors add up to 100% but i dont see how the numbers come together to make 100%
    i can only see that when 85% + 15% = 100% at the bottom line, but with the 60% lines i cant figure out how they would add up to give 100% please explain to me =]

    • Wraith0127 - June 16, 2009 at 7:06 pm

      Actually, he meant to say that the two black arrows above the bridge represent a single weight, distributed evenly between those two arrows (thus, 2 points at 50% each = 100%), the numbers on the bridge lines are the force amounts(not percentage) most likely, in Newtons. Hope that helps explain things better. There are many free online bridge building games for you to try your own designs and see how they work. I tried a K-truss design in one program from West Point, but the forces were completely reversed. It might have been the program’s physics, but I’m not sure. I had lots of compression at the top and tension at the bottom.

  7. MRs. Goodfellow - April 13, 2009 at 11:18 am

    this is a good webstie for teens and it gives the motives for kids to learn how to build bridges.

  8. E.M.T.A - May 18, 2009 at 2:59 am

    I love this site…it gave me a lot of help for our project. Thanks soo much. I just hope that the bridge that my group makes wins. Um, our bridge is meant to be 40 cm long and we have 150 paddle popsticks to complete it. Anyway, thanks a lot again.

  9. Debby Ade. - May 26, 2009 at 7:20 am

    The school I got to St.Peters grade 6s had to build a bridge for Design+Technology and this website has really helped alot thank you!!!

  10. Bridget - May 26, 2009 at 4:25 pm

    thanks for the tips. i have to make a balsa wood bridge that will support 15 kilos in the center and the truss designs really helped.

  11. nicholas - July 6, 2009 at 12:31 am

    trying to redo the bridge
    –____________
    , /– /— /– /
    /__/__./__/__

    PRESSURE AT THE DOT

    THX, hope it came out

    • nicholas - July 6, 2009 at 12:39 am

      i’m so silly, this is a U.S. site, all the same, i am in AU, so if you can, is it possible to rely to me in metric units? i don’t really know how to convert it. But if you can’t either, I will use a google converter

      please reply 2 me, i need help!!!

    • Garrett Boon - July 6, 2009 at 10:06 am

      Nicholas, the force distribution is the same if the load is on the top or on the bottom of the bridge.

      • nicholas - July 6, 2009 at 11:56 pm

        even though i agree with you, it is the problem of compression VS tension that i am up against.

      • Dave Schwartz - December 14, 2009 at 12:38 pm

        nicolas is correct.

  12. amanda - November 13, 2009 at 12:00 pm

    i love the idiea of the toothpick bridges kids should be able to share their idieas and for this project.

  13. Brandon - December 8, 2009 at 8:43 am

    Great website. it helped me a lot with my bridge structre

  14. Matthew - January 19, 2010 at 3:35 pm

    Hi I have to make a bridge out of straws and masking tape that spans one meter in between two desks plus it has to hold two 5cm cubes full of sand which i calculated and can be no more than 20grams. The most efficient bridge able to hold this weight wins (least amount of straws). Any suggestions on what type of design i should use?

    • Lizzy Bell - January 20, 2010 at 7:16 pm

      I have the same problem. Can SOMEONE please help us?

      • paddingtongreen - January 26, 2010 at 7:02 am

        Where must the cubes be located in the span?

        • jpa - March 22, 2010 at 7:32 am

          In the x and y axis located in the centerfold of the main bridge compartment, DUH!

    • Muutari - March 11, 2010 at 9:08 pm

      im doing a similar project, but with hot glue and popsicle sticks and im having trouble deciding a truss type. it need to support 50 lbs of weight,be at least 18″ long, 4″ wide, and a max of 12″ high. any ideas

      • Wayne - May 13, 2010 at 7:40 pm

        I just built a Warren Vertical Support Truss Bridge out of toothpicks and regular white Elmers glue tha supported 121.7 pounds of sand. This design is typically made for railroad bridges because of the extreme amount of weight a train weighs fully loaded. Good luck.

    • Jerrifus - March 22, 2010 at 7:33 am

      Try using the london crossover?

    • Micaiah - August 29, 2010 at 1:41 am

      one thing you should do to make the joints stronger is cut vertically up the straw and stick it in the end of the other straw and just use a little take to make sure it stays.

  15. thomas betha - January 20, 2010 at 3:12 pm

    im making a warren for my elective with balsa wood.
    what would be better a subdivided warren type or a warren with vertical supports?

    • Garrett Boon - January 20, 2010 at 3:58 pm

      I do not know what you mean by a subdivided Warren truss. What does this look like?

    • Wandahhhh - January 20, 2010 at 10:56 pm

      The vertical supports on the Warren truss allow the bridge to sustain more weight. =) <3

    • Muutari - March 11, 2010 at 9:09 pm

      would that be like the pratt truss?

  16. paddingtongreen - January 21, 2010 at 10:16 pm

    Reference the zero force members. In real life, the loads on bridges are applied at the panel points, so those members would carry a load, even if just a panel load.

    You would make member identification much easier if you were to use Bowe’s Notation. With the external forces shown in place, number all the spaces between the forces. From left to right, label the interior spaces with alpha characters, starting with A. Each force can then be identified by thespace number before and after; each member can be identified either by a number-alpha or an alpha-alpha designation.

    • Garrett Boon - January 22, 2010 at 9:16 am

      Thank you for your comment. Could you explain more about panel load?

      I will look up Bowe’s notation. Do you know offhand where I might find an example (a picture) of it?

      Thanks.

      • paddingtongreen - January 26, 2010 at 7:14 am

        The panel points are the points where the load is applied, usually the joints on the top and bottom chords. For a bridge, beams, carrying the roadway or railroad, would span between two trusses and apply their loads to those points. For a roof truss, the purlins land at the top chord joints.

        I found a site for you that shows Bow’s Notation, slightly different than I described because he needed to number the joints for the graphical solution that he describes. The graphical analysis is very accurate, before computers and calculators came on the scene, I used to check my calculated results that way.

        http://wjesus.org/Frame_3.htm

  17. Falaviena - January 29, 2010 at 3:14 am

    Hello!!! im at school trying to win the bridge building competition !!! you guys really helped me!!!!
    thx thx thx!!!
    your Falaviena

    • brian - April 29, 2010 at 2:18 pm

      I won a competition at my school too! i wouold like to thank My mom, Garrett Boon, and Michael Jackson for support!

  18. aishikimiru - February 11, 2010 at 6:33 am

    I think the pratt truss is better.
    someone told me that the compressional members are more efficient if in an I shape or in a T shape. . .

  19. roy aubertin - February 14, 2010 at 10:46 pm

    hey, love ur work! love ur song! which is the strongest bridge design? i’m a big fan of ur designs,

  20. jake - February 23, 2010 at 7:21 am

    i recently made a k-truss brigde in tech-ed class that held over 350 pounds i used hot glue and wood glue and about 100 or so popsicle sticks it was pretty cool because once it broke i didnt just falter ubder the wait it exploded!

    • Daz - July 18, 2010 at 3:04 am

      Hey Jake,
      How did you make the K for the K truss using the wood? HOw did you make the < stay on the | ? Get what I mean? Please reply quick!

  21. Skipper - April 26, 2010 at 11:50 am

    I think that the strongest one is the Howe. Mine held 150 pounds when it was mad of very thin wood. anyone need help? ask me… Skipper

    • Rico - April 26, 2010 at 11:52 am

      hey can u help me with a project? I think it has to be a specific size but it has to hold more than 150 pounds. help me. please.

      • Skipper - April 26, 2010 at 11:53 am

        I reccomend the howe if u are using stronger wood than mine. mine was thiner and smaller than popcicle stix.

  22. luke - December 26, 2010 at 6:57 pm

    hello i am doing a bridge building contest in illinois at my school, Fenwick High School. The bridge must be able to hold 50 kg if i am to have any chance at winning this contest. What design would you recommend?

    • Garrett Boon - December 27, 2010 at 4:43 am

      Luke, this is the type of question that I just cannot answer. You have to consider what materials you can use, the span of the bridge, and how dedicated you are to winning and learning what it will take to win. The Pratt, Howe, and Warren trusses are great designs. They have been used for real bridges for over 150 years. Choose any of them. But it is not so much what design you pick, but rather how you build it. The care you take in selecting your materials, and the effort you put into the construction are key aspects to the performance of your bridge, just as much so as the actual design.

  23. Caleb - January 5, 2011 at 6:09 am

    Garrett, I have a project in which I have to build a truss bridge with pre-cut wood. They are the really thin but long ones made from basswood. The way the weight is applied is by placing a block inside the structure with a pipe from the bottom to pump more pressure. How would you suggest I build the “floor” of the bridge to support the weight?
    Thanks

    • Garrett Boon - January 5, 2011 at 3:11 pm

      Caleb, my first recommendation is that you make your bridge just wide enough for the block to rest inside. The block should rest directly on the two bottom chords for maximum strength.

  24. maggie - January 11, 2011 at 1:17 am

    which of these designs are best when the weight is loaed by hanging the weights from the botton of the sturcture??

  25. May - January 12, 2011 at 5:58 pm

    Hi, I am doing an extra credit project for my school and I’m am suppose to construct a bridge out of craft sticks and glue. I have been researching for different bridge structures I could try, but I would like to know your opinion in which structures I should try first. Also, this bridge must be able to hold a text book that is about 3kg, this has been a obstacle for my bridge. I would greatly appreciate your input.

  26. P&E - January 15, 2011 at 10:21 pm

    Hello! Our team is making a bridge out of basswood and when we test our bridge, weights will be placed on the bottom floor center. We were going for the Pratt or Howe design but we got confused as to which one is going to be able to support the centered weight the most…or does it not matter?

    Thank you!

  27. N - January 16, 2011 at 5:22 am

    Hey, Garrett. I’m building my first bridge (out of basswood). My design’s really simple; I’m doing a Warren truss with vertical sticks in between the sides of each triangle.

    My question is this: I’m gluing the sides of each triangle to the outside of the bridge. Would it be better to glue the vertical sticks to the inside of the bridge, or on the outside as well?

    Thanks.

    • Garrett Boon - January 18, 2011 at 6:49 pm

      This is a great question. The answer, according to my knowledge, is slightly complicated. When you take a stick of wood and hold it vertically with one end on a table and the other end in the middle of the palm of your hand, you can push straight down on the stick. Because the ends of the stick are “free”, the stick bends in a perfect arc shape. However, if you were to push down while holding the ends of the stick, it would bend in a more complex shape. Perhaps an S shape or something weird. In the second case it would be harder for the stick to begin bending. Thus, by holding the ends of the stick you actually increase it’s strength.

      However, if you glue a piece in compression on the outside as you say (called a Lap joint), the strength of the joint is in the surface face of the wood. And End joint (see my Bridge Joints page for pictures) doesn’t have that issue. The ultimate joint for a member in compression is a Gusseted joint. It combines the value of End and Lap joints. However, it uses more wood and glue, and thus is heavier.

  28. Sarah - January 17, 2011 at 8:02 pm

    If I’m building a warren truss (basswood), does adding verticals in the triangles make much of a difference in the weight it could hold, or is it just adding unneeded weight to the bridge?

    • Garrett Boon - January 18, 2011 at 6:41 pm

      Sarah, the verticals in a Warren truss are quite useful, and can add a lot of strength to your bridge. They break the top (and bottom) chord into smaller sections. This helps because the top chord is in compression. Wood will bend and eventually break (buckle) when under compression. The vertical members help the top chord resist buckling and thus increase the strength of the bridge. Great question.

  29. mitch - March 2, 2011 at 7:19 pm

    i am building a warren truss with vertical supports, made of popsicle sticks, and wood glue. is this good enough to hold 20 lbs.??

    • Garrett Boon - March 3, 2011 at 1:42 am

      Most likely, depending on how well you construct it.

  30. James - March 3, 2011 at 2:23 am

    I know that this page is devoted to Trusses, but what are the advantages/disadvantages of using an Arch as opposed to a truss?

    The bridge must span 20″ and have a maximum hight of 10″, performance is based on weight ratio, however I would love to break the school record. Made of 1/8 x 1/8 x 36″ balsa stringers.

    thanks

    • TIm - March 6, 2011 at 12:04 am

      What truss design do you recommend if there are 5 equal loads placed across the top of the bridge, if the bridge span is 10 inches?

      I was thinking that the warren truss design might be best and that I should double up the thickness of the trusses inside the span. But this is my first time trying this so I don’t know.

  31. zoe - March 4, 2011 at 6:23 pm

    Hello I’m in 6th grade and I am seeing which design of truss bridge is the strongest. I am doing all of the bridges above, but I was wondering which materials would be the best to use… Please don’t say metal or something expensive because im only in 6th grade. Thanks!

  32. allison - March 12, 2011 at 2:35 am

    please help me! it is extremely urgent! i have a blue print due soon and i really need to know how the floor of mt warren bridge should be to make it more supportive! the bridge has to hold at least 1 to 5 kg handing from below it in a cup hanging on ropes from the bridge. i really need fast help, thanks

    • Ryan - March 19, 2011 at 4:04 pm

      Probably dont need to support the floor, all the wieght will be on the sides(because of the ropes).

      I made a bridge that was 496g and 70cm long. It was a combination of a howe and pratt truss(they made Xs like lXlXlXl) with a supporting truss below the stress point(where the ropes will be).
      it hold 200pounds, but we didnt have enough weights to continue, it didnt crack or have any damage on it(other than divets where the ropes rested on).

      You shouldnt have any problem with holding 1 to 5 kgs.

  33. Garrett Boon - March 18, 2011 at 4:39 am

    Austin, I do not understand what you are asking.

    • Tyne97 - May 12, 2011 at 1:44 am

      he means like an s and p in the frame of the bridge or so you cand see the shape of his intials

  34. Pierre - May 20, 2011 at 9:10 pm

    the best way is to put a stick on a stick to make an X figure 

  35. Alex - September 29, 2011 at 4:12 am

    They aren’t equilateral triangles that warren trusses use, They’re isosceles triangles. Equilateral triangles have the length for all three sides, which are not what were used for the example image. I’m not saying they can’t be equilateral, it’s just you make it seem that they can only be made up of equilateral triangles

    • Garrett Boon - November 7, 2011 at 2:08 pm

      Alex, good point. I made a mistake with those example images for the Warren Truss. A true Warren is indeed made from equilateral triangles. I have updated the images in the article. Thanks.

  36. Angie hwawkins - December 4, 2011 at 12:39 am

    Which triangle is the best? equilateral or isoceles? and out of these 4 which bridge is the best?

    • Ciarra - December 19, 2011 at 6:12 pm

      Equaliteral because you want it to be sturdy and strong and in a right angle to hold more efficant, and im an 8th grader.

      • Jerome - January 3, 2012 at 8:16 pm

        You can’t have an equilateral triangle that is right…

      • Laura - February 6, 2012 at 3:42 pm

        Well for it to be a right triangle it must be scalene so but an equilateral triangle would work the best.

    • Richard - February 27, 2012 at 5:16 pm

      Equilateral is always the best. The pressure hits the same on all sides. Good luck!

  37. Alexis freshman - February 14, 2012 at 10:45 am

    thanks for the help(: i got an A woop woop <3

  38. Alexis freshman - February 14, 2012 at 10:47 am

    actually the pratt and how truss is the best

  39. CM - January 28, 2013 at 7:01 pm

    Dear Mr. Boon,
    I am an eleventh grade student and I would like to take this time to thank you for your wonderfully helpful website. My physics class is currently beginning a balsa wood bridge project and your examples of different trusses have been particularly helpful, as well as your tips on types of glue and types of joints. I would also like to take this time to ask a question. For our bridge, we are being given strips of balsa wood that are about a centimeter cubed. Would doubling up the wood be helpful and more supportive to the overall structure, or would it simply make the bridge weigh more and subtract from the bridge’s efficiency? Thank you very much for your time and consideration.

  40. Anthony - January 31, 2013 at 6:38 pm

    Hello,

    I have a question on making an effecient pratt deck truss bridge… except it’s not a real-life model made out of wood, but actually a real-life simulation using the westpoint bridge designer 2011 program. We’re using it in technology, and I have to be able to make one that works and is as cheap as possible. On the westpoint bridge designer the bridge is 44m long and no matter what I do, I just can’t make a bridge that works and is cheap. I know it’s possible… I just don’t know what I should do. Do you have any advice for what would help make it sturdier? I can use 2 different types of bars, hollow and solid(hollow being much cheaper than solid). Idk if you know or even heard of it… thanks for taking the time to read this.

  41. kentaro - February 27, 2013 at 10:51 am

    Hi,
    Im an eleventh grade student,
    My friends and me joined in a bridge competition, but it’s our first time to make a bridge
    In this competition we have to make a bridge from 3mm balsa woods.
    The weight must be less than 25 gram, and the winner ia the one who have the most efficient bridge(the comparison between the weight of the bridge and the maximum load the bridge can hold)
    And we are connecting a 30cm cliff
    The bridge width should less than 8cm and its high less tha 15cm
    And the bridge will be loaded in the centre or 5cm to the left or right from its center
    They will randomize the between that three point

    Since it’s our first time
    Can you give me some tips,about what to concern about.
    And maybe some design sugestion.

    Thanks for your help.
    If i made a lot of language mistake i’m sorry
    English isn’t my mother language

  42. Alson - April 26, 2013 at 9:50 pm

    Hi all.
    Im in engineering but I have to do an individual(!!) bridge project where i have to construct a bridge that must hold a minimum requirement of 25kg. (!!) The efficiency will be tested by hooking a rope and pail to the centre of the bridge and putting weights in the pail.
    I’ll only be given 5 Basswood sticks of 10mm by 2mm x 60cm. I’ve read the comments above and found some inspiration.
    I wanted to do the Pratt or Howe design but is it applicable for my case where i have very little resources thus no chance to test-try my bridge? Because if one stick breaks, i wont get a new one. >< Will appreciate any comments! :)

    • Ethan - October 2, 2013 at 5:37 pm

      Hi I want to know what is better to use in warren subdivided truss bridge; toothpicks or popcicle sticks. I’m in seventh grade.

  43. Madeline & AARYN - May 7, 2013 at 9:08 am

    Hey! :D Im making a bridge out of popsicles for a project in math.We were scteching up some designs for it,and we were wondering what would be the best structure for it? Because it have to last for at least 5 minutes with sand,buckets,and toy cars.! :D Thankssss Byeeee

  44. Bubbles - June 25, 2013 at 12:44 am

    Hi, im entering a bridge building competition at my school and i am on a three week timeline. My team mate and i were given these materials to work with : 8 long wooden sticks, 8 short wooden sticks, a long wooden pipe, two plastic lids that fit on the ends of the wooden pipe, 5m of thinnish rope and 24mls of easy-dry glue. I have a couple of days to come up with a design and so i was wondering what type of bridge would be most suitable to work with those listed materials! Thanks :)

  45. adrian - October 28, 2013 at 1:55 am

    what is the definition of bridge mechanics also what is the strongest bridge design to make out of 200 skewers which will need to have a span of 1 meter.

  46. Ryan Edwards - October 29, 2013 at 12:27 pm

    Hey, im building a truss bridge for my engineering drawing class. i was wondering if i could get some pointers. ive been playing with the bridge designer program but i dont fully understand it. we do have requirements for the brige, although the most important is the under structure must be 8×1″

  47. webb - December 16, 2013 at 4:20 pm

    hi I’m working on a bridge design for my CAD class and we are researching the strongest bridge design out of pratt, parker, K truss, howe, camel back, warren, flink, double intersection pratt, warren (with verticals), bowstring, Baltimore, double intersection warren, waddell “A” truss, Pennsylvania, and lattice which do you think would be best garrett

  48. brian - July 24, 2014 at 11:27 am

    quick question, which is stronger long span top chord spanning whole truss or a segmented top chord(chord is cut into segments pieced together through joints)? truss is inverted pitched pratt so top chord is subject to compression. truss spans 2m.

    Details:
    for our school project we have to make an inverted pitched pratt truss. top chords and verticals are in compression while bottom chord and diagonals are in tension. truss is pin jointed with bolts/screws. we have been provided with long 10*10mm timber sticks. I reckon a segmented top chord is better as forces gets transferred through the joint whereas on long span forces moves around the joints thus joints serves merely as bracing please correct me here?

  49. Sanket - August 30, 2014 at 4:38 am

    Guyz I m participating an event.i.e bridge makingfrom 150 ice cream stick want to build a bridge weight not exceeding 250 gm.load is been applied at midspan through hook attach to rope.size of stick is 11×1.2×0.2cm..plz plz do help me n suggest best design

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