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Towers have been a part of developed society for centuries, serving a variety of purposes, from watch towers to modern cell towers. In this activity, student groups design and build three types of towers, engineering them to meet the requirements that they hold an egg one foot high for 15 seconds.

Engineering designs are subject to requirements and constraints, often including limitations on time and budget, and specifications for size, materials, capacity, etc. Engineers design different types of towers to best suit different purposes. engineering design process force structure tower Follow the steps of the engineering design process to create an egg holder at the top of tower. Parts of a structure. Types of towers and comparisons. Safe usage of tools and machines. Forces that must be taken into consideration when building structures. Photographs and drawings of example towers, and/or Internet URLs for tower information (see suggestions under the References section) Cardboard tubes and sheet material (purchase cardboard sheets from local paper suppliers or ask for donations from local printers or find from recycling bins; provide an allotted amount to each team for each tower problem) Materials readily available in the classroom such as straws, tape, hot glue, string, etc. Note: If available, build sturdier towers using small wooden dowels and plastic tubing, which enables students to gain experience with a variety of hand and power tools. Activity Worksheet Towers have been a part of developed society for centuries. Towers serve a variety of purposes. What towers can you think of in your community? What are they used for? What other types of towers can you think of? (Listen to student suggestions and descriptions of their purposes. Examples: fire look-out towers, observation tower, watch tower, prison tower, silo, light house, bell tower, clock tower, minaret, church spire, water tower, oil drilling tower, turret, chimney, skyscraper, rotating restaurant tower, bridge tower [for cable-stayed and suspension bridges], airport control tower, wind turbine tower, radio mast, radar tower, antenna tower, electrical transmission tower, cellular communication tower. How are these towers similar? (Towers are all structures that are taller than they are wide.) How are they different or unique from each other in their designs? (Some are self-supporting and others require external support via wires and cables. This will be researched more in the activity.) Engineering designs (including the design of towers) are subject to requirements and constraints. Can you think of any examples of what these might be? (Listen to student ideas. Examples: time, funding, materials, expected loads, and functionality specifications such as size, height, etc.) Today, your team is going to design, construct and test three types of model towers Just like all engineering projects, it will have some requirements and constraints: Your towers must hold an egg one foot high for 15 seconds. Who remembers the steps of the engineering design process? (Listen to student suggestions. Write on the board: identify the need or problem, research the problem, brainstorm and develop possible solutions, select the best solution, construct a prototype, test and evaluate, communicate the design solution, redesign and improve.) Through these steps, we'll come up with good solutions. Let's get started! The engineering design process has the following steps: Identify the need or problem Research the problem Develop possible solutions (brainstorm!) Select the best possible solution(s) Construct a prototype Test and evaluate Communicate the solution(s) Redesign (and improve!) Three tower types: Towers are usually classified into three categories: guyed or cable supported, free standing or self-standing, and monopole. The self-supporting and monopole towers are similar in that neither requires guy wires or any other support structure. Guyed type toweras are usually the least expensive. As a general rule, three main specifications are needed to choose a tower site: site selection, tower type, and tower specification knowledge (or tower code) within the community. For reference, see Douglas Prime's six-page Fairly Fundamental Facts about Forces & Structures: Word doc version or pdf version Gather materials. Make copies of the Activity Worksheet, which includes student instructions. Find websites; make copies of tower drawings and diagrams, if desired. Introduce the topic of towers. Facilitate a discussion on different types of towers and their uses. Talk about the design process, including a discussion on the benefits of sketches, multiview drawings, and orthographic projections. Organize students into small groups. Hand out the Activity Worksheets. Explain criteria for the tower design and construction. Each group must design and create one of each of the following: a guyed tower (cable supported), a self-standing tower, and a monopole tower. Each tower must be able to support the weight of an egg for 15 seconds. Students test and measure the three types of towers by evaluating height, strength (ability to hold an egg), and the amount of material usage. Students participate in the presentation of the group solutions to the class. Students present comparisons or advantages and disadvantages of the different tower types. Activity Worksheet (doc) Activity Worksheet (pdf) Rubric for Performance Assessment (doc) Rubric for Performance Assessment (pdf) What is the purpose of towers? Why is one type of tower preferable to another? How can an egg be held and supported at the top of a tower? How can we build models to represent the three recognized types of towers? What is meant by tension, compression, torsion and shear in construction? What are the parts of this structure (tower) that are similar to those found in bridge design? Project & Presentation Evaluation: As student teams present to the class their three tower designs, results and conclusions, grade their accomplishments using the attached Rubric for Performance Assessment, which includes criteria for design, construction and presentation. Sturdivant, Peter. So You Want to Build a Tower? Published August 1998. Wireless Network Systems. Accessed August 9, 2001. http://www.angelfire.com/me/blkstrpra/aug98.html Tower Photographs. Pre-Engineering Software Corp. Accessed August 9, 2001. http://www.pre-engineering.com/resources/towers.htm