Cranes—the heavy-lifting kind—are all around us, and they perform vital roles in a variety of industries. They can lift or lower tremendous amounts of weight, move loads into position, and enable construction companies to ascend their buildings into the skies. An opportunity to explore the mechanical principles of these fascinating machines was presented to Clairbourn students during their annual Engineering Week Design Challenge in January of 2020.
CHALLENGE TOPIC – FIRST DAY OF BUILDING:
The challenge to build cranes was revealed to students in Grades 1-8 at a Tuesday Morning Assembly, and their first attempt to build cranes took place during their science block later that day. To ensure creativity would be unimpeded, students were asked to attempt the build without any prior knowledge of crane components or mechanical principles. They were encouraged to experiment and explore solutions. A kit of craft supplies, including paper cups, popsicle sticks, tape, straws, skewers, string, a binder clip, rubber bands, spools, a cardboard base, and more, was issued to each team. The students had only one hour to work on their first project, with an additional half hour provided for testing. During this first build, which was designed to be a warm-up, students met their assigned team members, focused on the challenge requirements, explored the possibilities for using the building materials, and constructed prototypes. Afterwards, Middle School Science Teacher Mary Wright, who coordinated entire the cross-grade Design Challenge, visited each classroom to test the designs and to help teams identify weak spots or elements that needed to meet the requirements.
VISITING ENGINEERS SHARE EXPERT ADVICE:
On second day of the crane-building challenge during the Morning Assembly, students were introduced to three Skanska engineers who work on the Los Angeles Sixth Street Bridge & Viaduct as well as the Los Angeles Purple Line Extension (Westside Subway). In their Presentation to Clairbourn Students, they explained crane technology and how they use it in their building projects to safely move materials and accomplish construction tasks. The engineers were Chief Bridge Engineer John Schroerlucke, Structures Field Engineer Shannon Tynan, and Project Engineer Edward Ma. Three key elements they stressed in their talk were safety, counterweights/stability, and compound pulleys to reduce the amount of force needed to lift weight.
THE SECOND CRANE BUILD:
After the talk, the students were instructed to build a second crane using a fresh kit of craft supplies. The engineers toured the classrooms as students were building and helped each team to apply the knowledge gained from their presentation. It comes as no surprise that having access to new information from experts can result in dramatic improvements with student designs—and that is what occurred. But it is important to note that for the second crane build, some of the younger grades were given a revised set of requirements or a new goal to achieve.
Revisions are typically necessary for Clairbourn Design Challenges because the item selected for students to build each year is always new, so there is no pre-tested precedent. This situation leaves some unknown factors in the project planning regarding what is achievable for students. Following the first build, Middle School Science Teacher Mary Wright was able to gather enough feedback to determine what grade-level modifications were needed to ensure younger students were still highly challenged but were not set up to strive for an unobtainable goal.
GRADE LEVEL MODIFICATIONS FOR THE SECOND BUILD:
- First-graders, in the second build, were only required to make a crane tower that could suspend a weight for 3 seconds, but they were released from the need to have a pulley or crank mechanism to lift a weight.
- Second and third-graders still needed to build cranes that raised and suspended a weight, but they could use a simple hand-operated pulley system and did not have to add a crank. Plus, they only needed the top of their weight-bearing cup to reach 12 inches in height.
- Fourth-graders retained the original requirements to have a crank, but they did not need to attach the crank or include a lock to stop the crank from unwinding. Like the third-graders, the top of their weight-bearing cup only needed to reach 12” high.
- Fifth-graders needed to have a crank, but they did not need to attach the crank to the cardboard base or include a lock to stop it from unwinding. However, they did have to meet the full lifting-height requirement where the bottom of the weight-bearing cup had to be suspended at a full 12 inches above the table.
- Middle School students in Grades 6-8 received no modifications to the original challenge. Their crane projects needed a locking crank mechanism (operable by only one person) which had to be attached to the cardboard base, it needed to lift the entire weight-bearing cup up to a 12 inch height, and the weight had to be held steady by the locked crank for three seconds.
DAY THREE – CRANE TESTING:
The third day of the challenge, each grade brought their new crane projects to the Middle School Science Room for testing. In order to qualify for the finals, the teams faced an initial project review to see if the cranes were in compliance with the grade-level requirements. Next, each crane was tested to see if it met the minimum weight-holding threshold (comprised of loose pennies or penny rolls). The remaining cranes then went head-to-head to hold increasing amounts of pennies until the top three projects per grade were identified as finalists. There was no full-capacity testing, at this stage, because finalist cranes needed to remain in operational shape for the final event.
THE FINAL COMPETITION:
On last day of the Engineering Challenge, the excitement in the air was palpable! Parents, students, teachers, and Skanksa engineer John Schroerlucke were all in attendance to see which projects would come out on top and who would win the coveted title of Overall Winner for the 2020 Engineering Design Challenge. The finals started with first-grade cranes competing against one another to hold the most weight. All three teams met the basic requirement to hold 10 pennies and, after adding more in increments, the top project held 185 pennies before the crane failed. The winning team from second grade had similar results with a crane that maxed-out at 175 pennies. Third grade’s top-performing crane held an astounding 950 pennies, but they did not tie for the Overall Winner of the Design Challenge because only Grade 4-8 students have eligibility.
For the older students, the tougher build requirements took their toll on crane performance. The fourth grade students, who needed to add a crank to lift the weight, had their best project max-out at 200 pennies. Fifth-graders found the crank requirement combined with a higher lifting threshold daunting. Their best project held 100 pennies. Sixth grade could only show exhibition cranes in the final event because their projects had minor issues that kept them from qualifying—they either did not meet the lifting height requirement or did not have an attached crank.
When the seventh-grade class put their projects to the test, however, things were back on track. Their top crane lifted and held in place 650 pennies. But in the end, the project that surpassed all others was an simple, unique, and effective design put forth by an eighth-grade team. Their easy-to-operate, strong crane held 950 pennies before failing under too much weight. The Overall Winners of Clairbourn’s 2020 Engineering Design Challenge were eighth-graders Matthew R. and Austin H.
COMPETITION RESULTS:
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Grade Level
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Finals – First Place Team Members
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Pennies Held
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First Grade
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Atticus, Ayden, Zoey,
Porsche, Amberly, & Xenia
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185
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|
Second Grade
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Tied: Bella &
Aaron and Keira & Alan
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175
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Third Grade
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Matthew & Sima
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950*
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Fourth Grade
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Matteo, Ruby, Heath, &
Marc
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200
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Fifth Grade
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Hannah, Anderson, Naomi,
Mauricio, & Kelson
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100
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Sixth Grade
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Exhibition only: Yuqi &
Winter and Joshua & Zachary
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100
|
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Seventh Grade
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Faith, Emma, & Madeline
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650
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|
Eighth Grade
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Matthew & Austin
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950
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*Only Grades 4-8 are eligible for Overall Design Challenge Winner status due to more challenging requirements. | ||
STUDENT REFLECTIONS ON THE CHALLENGE:
Following the finals, students were asked to reflect on what they learned about teamwork, time management, design strategy, project requirements, and mechanical principles so they can apply that wisdom to next year’s design challenge. Some of their comments are included below:
Mechanical Principles:
- Third-grader Matthew noticed, “The cranes needed a counterweight.”
- Shalom in fifth grade shared, “Another principle was gravity and mass since it made our arm on our crane bend and made the crank hard to turn. Because of the gravity pulling down on our cup, which had a lot of mass, [it] put pressure on our string and crane.”
- Sixth-grader Melanie noticed, “The more loops you make with a [compound pulley] string, the stronger it will be.”
- Seventh-grader Yu-Hong said, “I think the designs with extra support beams made the structure be able to hold more weight.”
- Eighth-grader William shared, “Overall, the mechanical/engineering principles that stood out to me were probably the mechanics of using different pulley systems and also building a structured crank.” Classmate Cyanne noted, “Triangles really helped because they are the strongest geometric shape and are used for most builds.”
Meeting Requirements:
- Seventh-grader Kelly shared, “If you didn’t follow instructions you get disqualified, and we didn’t, but we learned our lesson.”
- Fourth-grader Asal remarked, “I learned that I had to reread the instructions to understand what I had to do.”
- Fifth-grader Karissa said, “I learned that it’s very important, because for example if your crane didn’t match all of the requirements, you would be disqualified.”
Designs Strategy:
- Third-grader Kaitlyn noticed, “You should add more support for the arm.”
- Fourth-grader Jerry shared, “We noticed that the higher it is without stabilization it is going to fall. So we made it lower.”
- Sixth-grader Cole realized, “In the eighth grade, the water bottle was being used as a crank, and it looked like it was doing well because the water bottle had a lot of space to wrap the string.”
- Eighth-grader Sophia noticed, “Designs that worked well were not overly complex and were simplistic but still got the job done.” Classmate Leah shared, “I think the ones that worked well were the ones that had a water bottle as its crank because it was a better way to grip and stabilize the foundation of the crane.” William, another eighth-grader said, “With strong infrastructure, it helped out a lot with the different issues that we encountered and helped us control our weight.”
Teamwork Reflections:
- Second-grader Gwen said “I learned that it is important to help your partner because it is more likely to succeed,” and her classmate Isabel said “Never refuse help.”
- Fourth-grader Matteo commented, “We were able to hear everyone tell their ideas and that really helped.”
- Fifth-grader Sabryna shared, “Even though we had our ups and downs, we still worked together and helped each other on things we needed help on.”
- Cole in sixth grade shared, “My partner and I agreed to make me the brain-stormer and him the builder, so we worked well [together].”
- Eighth-grader Emily shared, “We were able to figure out a system that split the process in half.”
Time-Management Importance:
- Third-grader Fiona shared, “If you think you’re done, see if you can make it better,” classmate Bella commented, “It was important that everyone on the team helped,” and classmate Malena noted, “You have to keep working and not stop or you won’t have enough time to finish building.”
- Fourth-grader Ruby said, “I definitely needed to manage my time well by not arguing with my teammates and by working fast but carefully.”
- Fifth-grader Karissa shared, “I think that our team should have planned out the crane beforehand so that people weren’t working on whatever, they actually had an assigned job.”
- Seventh-grader Marcos realized, “If you spend too much time on one thing you will never finish.”
- Eighth-grader Madison shared, “By managing your time you can reserve certain time for improving your design.”
FINAL THOUGHTS:
In reviewing the event, Skanska Engineer John Schroerlucke, was thrilled by the students’ creative projects, mutual support during the competition, and enthusiasm for engineering. But, his main take-away was the “can-do attitude” he witnessed across the grade-levels. He remarked, “I can’t say enough how much of a privilege it is to be invited here to help the students with these engineering projects, and hopefully be able to inspire some of you to pursue engineering. In my office, we’re talking a lot about having a can-do attitude. Even in your professional lives, as you get older, you are going to have a lot of challenges. It is important to hold on to that can-do attitude—a positive attitude towards problems. It is going to carry you a very long way in life.”
MORE GRADE LEVEL VIDEOS:
Watch videos of Grade 5-8 students as they conceptualized, tested, and rebuilt their cranes over three days in order to compete in the final design challenge.
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