1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Spaghetti Bridge Design Help?

  1. Nov 14, 2014 #1
    Hey y'all, I am in the 11th grade and have been assigned a spaghetti bridge project. Our teacher taught us nothing about bridges or structures, but only the basic forces. We were instructed to research designs of bridges online but every website or forum that I have found has had a different answer as to what the best bridge design is.

    Here are some of the restrictions and rules we must follow:
    Bridge Length - minimum of 30cm
    Bridge Width - minimum of 5cm
    Bridge Height - no limit
    Roadbed Length - minimum of 30cm
    Roadbed Width - minimum of 5cm
    Total Mass - maximum of 50g
    •A 5cm x 5cm x 1.5cm wood block must be able to be moved along the roadbed across the full length of the bridge
    •No portion of the unloaded bridge shall be at a level below the top level of the testing table
    Basically, we have to be able to load 2.00kg of sand into a bucket that is hanging from the center of our bridge, with a loading time of only 2 minutes allowed.

    Failure is defined as the inability of the bridge to carry additional load and is decided by the judges. The judges will count to 3 seconds after the sand is loaded for the bridge to pass as holding the load.

    Also, we have been given some restrictions for our materials, here are a few:
    Spaghetti must be regular (not tubular, not thin or thick)
    Preferably no hot glue, because it may add extra unnecessary weight to the bridge
    Cannot paint or stain the bridge
    Cannot impregnate the bridge with glue
    Glue must be confined to points of contact between pieces of spaghetti
    Use of glue accelerator is prohibited
    Lamination is Prohibited - Lamination is defined here as any spaghetti-to-spaghetti contact area that exceeds 1.0cm in length
    Multiple contact areas of parallel of near-parallel spaghetti are allowed along the length of the stick as long as each one is at least 3.0cm away from any others on that stick
    Lap Joints are allowed
    Mitering of joints is allowed at any angle as long as the 1cm rule is not violated
    Water and steam to bend spaghetti is allowed

    Anything will help, and thanks in advance!

  2. jcsd
  3. Nov 14, 2014 #2

    Doug Huffman

    User Avatar
    Gold Member

    I would make my own spaghetti! Use lots of egg protein. The usual recipe is of flour and water only. Stir the mixture to develop the flour gluten as much as possible.

    Use the smallest amount of glue at the joints as possible to prevent lozenging, the conversion of a well triangulated joint into a many sided joint.

    Sounds fun!
  4. Nov 14, 2014 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    I don't understand the requirement to be able to move a rather small wooden block across the bridge, which must also be designed to hold a bucket with 2 kg of sand suspended from the middle of the span.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook