Nucor - Shipping Bay Rail Car Cart
Team: Kelton Christensen, Hannah Maxwell, Cody McBride, Cragun Scott, Ryan Sticht, Tasche Davenport
Sponsor: Nucor
Project Description
- Nucor’s mission is to become the world’s safest steel company in the world.
- Teammates at Nucor Steel Utah regularly need to get in and out of rail cars. Currently, teammates climb ladders attached to the rail cars. Some rail cars have damaged ladders and are difficult to use. Teammates then jump down into the rail car.
- The distance between the top of the rail car and the floor of the car is approximately 5 ft. This poses a significant safety risk to teammates.
- Our goal is to create a system that makes this task safer and more ergonomic.
- The device needed to be motorized so it would be easy for Nucor teammates to transport. It should also be mostly made of steel.
- The device should fit in between the retaining wall and any given rail car that comes into the shipping bay. It must also not exceed 19 ft in height as to not interfere with overhead cranes.
Design Description
The cart (nicknamed "The Pegasus" by us and "The Tower of Babel" by the fabricators) is a 13.5-ft tall steel tower on rails. It will run along docked rail cars and extend a platform and ladder to allow Nucor teammates to lower themselves into the rail cars; no more climbing difficult ladders just to jump down several feet
Performance Review
Safety was the biggest concern. Tipping analyses were conducted to make sure the cart would not tip backwards or sideways during operation. Other calculations were performed to ensure correct motors were chosen to move the Pegasus and the ladder.
| Requirement/Constraint | Target | Threshold | Predicted Performance |
|---|---|---|---|
| Moment required to tip cart in north/south direction (SF) | 3 | 2 | 8.85 |
| Moment required to tip cart in west/east direction (SF) | 3 | 2 | 5.75 |
| Time for deployment/retraction (s) | 15 | 30 | 12 |
| Maximum speed of cart (mph) | 5 | 2 | 5 |
| Height of first step (in) | 10 | 18 | 8 |
| Total width of cart (in) | 30 | 75 | 71 |
| Braking distance of the cart (ft) | 5 | 10 | 19.65 |
Conclusion
- This design includes a motor to move the cart, as well as a motor to lift and lower the ladder. The cart will provide a safer option for Nucor teammates to perform their jobs.
- We learned a lot about collaborative CAD work and OSHA standards. We also learned new skills such as welding, machining, and how to 3d model using OnShape.
- The cart may need fine tuning. Be aware of any rattling that may be an annoyance to be welded or bolted. Ensure that the moving platform has no wiggle room and that it has no chance of sliding off of its designated track.