This building allows trucks to speed up the movement of containers and make transport times more efficient. Given the size of the post-Panamax container ships that this port serves and the vast number of containers being moved, even a slight increase in speed can make a big increase in efficiency. There are lots of opportunities for students to pose interesting mathematical questions based on the photo above. Below are some of the questions that I thought about.
1. Estimate (similar to http://www.estimation180.com/day-163.html) - I like that the clearance warning sign at the top of the door has both a maximum height and width listed. I removed the numbers for the maximums from the photo (attached below) and projected it for a group of students to look at (this was a combined class of Math at Work 11 and Math Essentials 11). I asked them to estimate how big this door is. The picture above showing the truck entering the door helped students refine their estimate. We also found online that a typical container truck like the one above is around 13.5 ft tall and 8.5 ft wide. They estimated in the range of 15-20 ft for the maximum height. Next I revealed that the height was 16 ft and asked them to then estimate the width given this new information. We measured the projected picture with a ruler and then used a ratio to calculate the width. We had a discussion regarding how close to the actual measurement the clearance might be.
2. Calculate - Lets assume that the clearance sign includes an extra 5% for safety. Given the clearances of 16 x 13 ft what would the actual dimensions and area of the door be? We could also calculate the volume or surface area of this shelter. It is very nearly a cube as can be seen from the image from Google Maps. There is one small door on the side and two large garage doors.
3. Convert - The clearances on the sign above the door are given in Imperial units, indicative of Canada's somewhat stalled process of metrication. What would these clearances be if they were converted to metric units of length. Which unit would be the best? The decimetre (dm) is the closest unit to feet but it is so rarely used Would it be a safety issue to use this measurement unit? If we use metres, how accurate should be make it? To the nearest metre? tenth of a metre? hundreth of a metre? How easy to read are the decimal points?
4. Create - Given a door with dimensions of 16 ft by 13 ft, what is its area? How many other doors could you design that have this same area (if we constrain the dimensions to be whole feet)? Which of those doors could an average car drive through (for example a Chevy Malibu)?
5. Connect - Find a large garage door in your community that doesn't have a clearance indicated (such as at a fire station or service station). What would a clearance sign for this door say? What is the largest door that you can think of in Nova Scotia? Perhaps a hangar door at an airport or perhaps the door on the Ultra Hall of the Irving Shipyard? How big do you think the largest door is?
A nice extension is to explore the dangers of ignoring clearance warnings. There is an article from the Wall Street Journal called The Joys of Watching a Bridge Shave the Tops Off Trucks. The article reports on a bridge with low clearance in Durham, NC. Trucks crash into this bridge so regularly at an employee at a nearby office, Jürgen Henn who runs the website 11foot8.com, with a view of the bridge began to wonder: How often did this occur? “For weeks, you wouldn’t think about it,” Mr. Henn says. “Then there would be another one—and, oh, there’s another one.” An interesting statistics project would be to graph the dates of the crash to see how often they occur or if they are correlated to bad weather or season of the year or some other factor.
Nova Scotia Mathematics Curriculum Outcomes
Mathematics 8 - M03 Students will be expected to determine the surface area of right rectangular prisms, right triangular prisms, and right cylinders to solve problems.
Mathematics 9 - G01 Students will be expected to determine the surface area of composite 3-D objects to solve problems.
Mathematics at Work 10 - M03 Students will be expected to solve and verify problems that involve SI and imperial linear measurements, including decimal and fractional measurements.
Mathematics 10 - M01 Students will be expected to solve problems that involve linear measurement, using SI and imperial units of measure, estimation strategies, and measurement strategies.
Mathematics Essentials 11 - D8 Estimate the volume and surface area using estimation strategies.
Mathematics at Work 11 - M01 Students will be expected to solve problems that involve SI and imperial units in surface area measurements and verify the solutions.