Internal Pipe Climber

Overview

As part of the IMechE Design Challenge 2022, designed and fabricated an internal pipe climber built to ascend a 2 m vertical pipe, lift an attached 0.265 kg chain load, and return to the start point as quickly as possible.

The challenge simulated real-world pipeline pigging operations used for inspection and cleaning. The design had to meet strict constraints:

• Budget: ≤ £30 for all manufactured and purchased parts
• Size: Must fit within a 105.6 mm diameter, 300 mm length
• Power: Maximum 6 V, 2 W motor
• No control electronics (ie: Arduinos or speed controllers)

Design

Several concepts were explored before arriving at the final rectangular chassis.

• Tripod concept: Lightweight, but aligning wheels and axles was impractical within the given dimensions.
• Quadrant concept: Allowed for efficient free-fall return, but the spring-loaded wheel mechanism introduced instability and safety risks.
• Final rectangular chassis: Provided a robust frame to house the motor, battery pack, and gear system. Triangular cut-outs reduced weight while maintaining rigidity.

Failure Mode & Effects Analysis (FMEA)

FMEA was carried out twice (before and after testing) to ensure reliability:

• Risk of insufficient spring tension → failure to grip pipe walls
• Risk of low friction tyres → slipping during ascent
• Risk of excess weight → inability to reach pipe top

These risks were addressed through spring rate adjustments, tyre selection, and chassis weight optimisation.

Results

• Performance: The device successfully ascended the 2 m pipe while carrying the chain load and returned under gravity in 21 seconds.
• Testing observations:
  • Early prototypes struggled with grip and friction, causing slips.
  • Improvements included selecting tyres with higher tread and reducing overall chassis weight.
• Competition outcome: The climber performed consistently within the competition constraints and passed scrutineering checks.