Student Worksheet 1: Questions to Excerpt of the Great Bridge

Teacher Guide to Student Worksheet 1-Questions to Excerpt of The Great Bridge

1. What was the Allegheny Portage Railroad? What problem did it solve? The Allegheny Railroad was a series of ten incline planes (make sure your students understand what an inclined plane is) that hauled canal boats over the Alleghenies from Holidaysburg to Johnstown. (Show on a map.) It solved the problem of how to transport people/products over the Alleghenies Mountains.

2. Approximately when did Roebling work there? 1841 or earlier

3. What problem did Roebling observe with the system? The 9-inch hemp hawsers that were being used to haul the canal boats up the mountain were wearing out. This was creating hazardous working conditions as well as being costly to replace.

4. How did Roebling propose to solve this problem? What would be the advantages of Roebling’s solution? He proposed creating a one-inch rope made out of wire. It would be stronger, more durable, and easier to handle.

5. Where did Roebling get the idea? A German periodical. (Roebling was originally from Prussia. Incidently, the first wire ropes were used in the silver mining shafts of Germany from 1834 to 1854.)

6. Because the product did not exist in the United States, what did Roebling have to do? He had to create the product himself. This meant he also had to create the machines needed to create the product.

7. What happened when he went to test the solution? Roebling was sabotaged by someone hired from the hemp rope interests. The person cut the wire at one of the splices, which caused the wire to snap.

8. Why would people with hemp rope interests care how the test of Roebling’s solution went? The hemp rope company was making a lot of money—$3,000 dollars in some cases— each time the railroad needed to replace the ropes. If Roebling’s experiment went well, the hemp rope business would stand to lose a profitable part of its business.

9. There is a method to solving problems of technological design. It is:  Define the problem.  Define all aspects of the problem, necessary information and questions that must be answered.  Propose the best solution.  Design and propose alternative methods to achieve solutions.  Apply a solution.  Explain the results, present improvements, identify and infer the impacts of the solution. From what you can tell, did Roebling follow this method? Give examples of how he did, and/or how he did not. Judging from McCullough’s version, he appeared to follow the technical design process for the most part.

 Define the problem: He did this. He observed that the hemp hawsers were breaking.

 Define all aspects of the problem, necessary information and questions that must be answered. Yes, he most likely did. The excerpt does not lay out this entire process, however. We do know he defined the awkwardness of the heavy hemp ropes, and proposed to make the iron wire only one-inch thick. He most likely calculated the cost to produce the wire rope as well. He purchased the wire from Beaver Falls, northwest of Pittsburgh. He created the “ropewalk system” in the meadow behind a church for production.

 Propose the best solution. Yes, he proposed the best solution. It was not greeted with enthusiasm, but he was given permission to try to design it on his own.

 Design and propose alternative methods to achieve solutions. We don’t know if he did this or not.

 Apply a solution. Yes, he created and tested the 600-foot wire rope in Johnstown.

 Explain the results, present improvements, identify and infer the impacts of the solution. Yes, he published an article in Railroad Journal, and identified other uses for the wire rope (dredging equipment, pile drivers, etc.)