To begin this lesson, I use the Lifter Warm-up PowerPoint to help students begin to envision the important role that cranes play throughout the world. I begin by cycling through the first 4 images and have the students identify all the ways they are similar. I am looking for students to identify primarily 2 features; they are or use cranes and they lift heavy items or are used for rescue. I have found, however, with open-ended questions such as this, the students respond with a wide variety of responses.
After students have identified these points, I ask them to identify the important factors to consider when designing these objects (balance, durability of materials, etc.) and to identify what could happen if these are not properly engineered/used. This leads students into their actual challenge of designing, building, and testing their own crane.
For the next several days students design, test, and improve their prototype. There are many ways to approach the "improve" portion: either being able to lift heavier weights, making the same design smaller and/or with cheaper materials, or adding hand cranks or motors depending on what the students think of or what you want to ultimately get out of the activity.
This image shows students editing their initial desgin idea and the video captures a student explaining how their crane will function (I like how they got their inspiration from the window shades - not something I would have considered!).
To end this lesson, I ask students to critique their design by answering the following questions in their journals: