Everest Weather Station
Team: Tanner Maingot, Kari Taylor, Wyatt Theurer, Luke Watkins, and Kent Willmore
Sponsor: Campbell Scientific
Project Description
Campbell Scientific Built a weather station that was placed near the top of Mount Everest. During the first year after installment it fell over. We took 3 of the possible weak points in the design and sought to make them better.
Requirements and Constraints:
- Needs to be able to withstand wind speeds around 180 mph, which equals a loading force of 1000N
- Needs to hold up in temperatures down to -60 degrees Celsius
- Should be able to last up to 2 years on Mt. Everest
- Guy wires need to be stronger than they are on the current model
- Leg clamp could lock in up and down position
- Guy wire should be resistant to slipping at a destructive frequency
- 2 hour max install time
- Parts must be operable by hand strength alone (Tooless assembly)
Made changes to legs (1), leg clamps (2), and guy wire tensioners (3)
Tripod legs
1: Carbon fiber leg
2: Carbon fiber insert
Requirements for the leg design:
- Lightweight
- Able to withstand wind and other forces it will be subjected to
- Meets strength requirements in cold temperatures on Mount Everest
Final design description:
- Use carbon fiber
- Increase the strength of the ends of the tubes where the most stress was noticed. This is done by attaching an insert or sleeve to the ends of the tubes using an adhesive
Tension and compression tests setup
Three point bend test setup
Tests performed and results:
- Tensile test up to 1000N force. No failure
- Compression test up to 1000N force. No failure
- 3 point bend test up to 1000N force. No failure
The design meets all of the requirements.
Lessons learned:
- Communicate well with sponsors and others involved with the project to gather as much relevant information as possible. Miscommunication could lead to missed opportunities to create the highest quality product possible
Recommended future work:
- Determine the minimum length and diameter the tubes could have. This would reduce the cost and weight even more
- Perform all tests at -60 degrees Celsius to confirm our findings from research that the carbon fiber and adhesive are still strong enough at this temperature
Guy Wire and Tensioner
The goal of the tensioner and guy wire assembly is to act as a secondary measure to prevent the structure from toppling under severe load. The mast is supported by 3 guy wire assemblies spaced 120 degrees apart and fixed to the ground with individual anchors.
The guy wire is firmly secured by a tensioner, employing a cam for primary rope retention, complemented by a clamping feature integrated into the securing arm, serving as secondary rope retention.
Material Selection
-
Guy Wire-Mastrant Premium 5mm Synthetic rope
- 800 lbf Safe Working Load
- Low Elongation (1.2%)
- UV Resistant
-
Tensioner -6061 T6 Aluminum Alloy
- Meets Strength requirements (yield = 40,000 psi)
The design meets all requirements and constraints applying to this design
Lessons Learned:
- With initial prototypes focus on DFM.
- Create prototypes quickly so that testing can get started sooner
Recommended Future Work:
- Optimize design for manufacturability
- Perform testing on complete tripod assembly in simulated environment
Guy Wire and Tensioner Assembly
| Requirements | Tests Performed | Results |
|---|---|---|
| Vibration Resistance | Tensioner subject to a destructive frequency for a minimum of 2 hours with less than or equal to ½” of slip | Four hours at 12 hz with ⅛” Slip |
| Rope Grip Strength in tension | 225 lbf as calculated worst case load with less than or equal to ½” of slip | 225 lbf with .5” slip (given a 40 lbf preload condition) |
| Clamping Force | Under average grip strength with SF = 2 (50 lbf) | 22.5 lbf |
Clamping Force Test
Rope Grip Strength in Tension (With Varying Preload Conditions)
Leg Clamp
Original Clamp
Objectives:
- Increase adjustability of clamping force
- Clamp while tripod is disassembled.
- Perform similar or better to current model.
New Clamp Design
Tension Test was performed (as shown above) and the new clamps performed ~40 lbs better than the original clamps.
The clamps are fully adjustable and can clamp while the tripod is disassembled.