Bonneville Power Administration Spacer Cart Progress Report #2 Portland State University Spring of 2016 ME CAPSTONE Project Presenters: Austin F. and Carlos J. Team members: Austin F., Joshua P., Mackenzie L., Bao P., Rob L., Sam L. Stephen R.

BACKGROUND INFO Aerial Line Cart [Spacer Cart] Used for repairs of high voltage transmission lines. Created in-house by BPA. Capstone team tasked with redesign to address safety/ergonomic problems.

Product Design Specification Revisited Main Design Criteria [PDS] Redesign of Cart Arms Redesign of Squeeze Wheel Assembly Redesign of Cross Bar FEA Analysis of Cart Determination of Factor of Safety

CART ARMS Current Cart Arm Design

New Cart arm design

SQUEEZE WHEEL ASSEMBLY Current Design

Design A & B

DESIGN C Combines features of A & B for mounting and height adjustment

Final Design

Squeeze Wheel Mounted

Cross Bars BPA has approved the bolt action lock, but they have not made the final decision on whether they will install them yet. We will create drawings and provide them to BPA, who will decide whether to send them for fabrication.

CROSS BARS [cont.]

FEA Analysis – Current Design Analysis performed with a 500 lbf static load on arms. Maximum deflection is 1.26” Horizontal displacement Vertical displacement

FEA Analysis – New Design Analysis performed with a 500 lbf static load on arms. Maximum deflection is 0.16” Horizontal displacement Vertical displacement

FEA Analysis – Dynamic load We are currently conducting a more in-depth FEA analysis to ensure that the cart will not fracture due to any dynamic loading that may be encountered in the field.

FACTOR OF SAFETY BPA currently specifies an 8:1 FoS for the Spacer Cart Capstone team researched using standard: 29 CFR 1926 Sub Part L Based on research done through various standards, specifically, the standard above which defines Safety and Health Regulations for Construction, subsection for Scaffolds, the Capstone team decided that this unit qualifies under the definition of a “scaffold”. The “standard” factor of safety used for scaffolding in industry is 4:1. As a team, we have recommended to BPA to switch to a 5:1 FoS instead of 8:1.

NEXT STEPS… Pinch Wheel Assembly Cart Arms Cross-bar Finalize drawings for fabrication [Tentative 5/20/16] Cart Arms Complete drawings for fabrication. [Tentative 5/20/16] Complete FEA analysis for impact loading on arms. [Tentative 5/27/16] Make a decision on need for Cross-bar based on FEA results. Cross-bar Create drawings for fabrication. [Tentative 5/20/16]

Questions? No? SUCCESS!!