In a project focusing on the Toronto Rocket Train, I identified a design flaw in the V-shape block used to support the axle during gearbox removal. The original block had developed a crack due to years of cyclic loading, presenting a safety risk to technicians. After a comprehensive diagnostic, I redesigned the TR Axle Block with a rounded V-shape and three contact points for more even stress distribution, resulting in a CAD model approved by TTC's professional engineer. The new design is expected to considerably extend the block's lifespan, with 4 prototypes receiving initial positive feedback during testing.

Background:

• The V-shape block is used to support the axle's weight during the stripping of the gearbox off the axle.

• This block is used especially for the Toronto Rocket Train, the line 1 train.

• I identified that the original design had a high concentration of stress at the trough of the V-shape, which led to the block's failure.

 Problem:

• The original block that holds the axle for the Toronto Rocket train has developed a crack in the middle after years of cyclic loading and repeated usage.

• The crack in the block poses a safety threat to the technicians, and the block can no longer do its intended job.

 Action:

• Conducted thorough diagnostic to identify the root cause of the failure. Found that the original block's V-shape was too sharp, causing a high concentration of stress at the center.

• Leveraged mechanical engineering principles to redesign the TR Axle Block. The new design features a more rounded V-shape and 3 points of contact with the axle, as opposed to the original two, thus distributing the stress more equally.

• Created a CAD model and detailed production drawings using SolidWorks, which were reviewed by a professional engineer at the TTC.

• Oversaw the manufacturing of 4 prototype blocks at the Harvey Shop, which where then delivered to the Greenwood Shop for field testing.

• Inititaed a weekly check-in process with the technicians to gather feedback and monitor the condition of these prototypes.

• Found the function of the original block.

• Measured the original block's dimensions and found the functional distance from the ground to the axle.

 Results:

• The redesigned axle block is expected to increase its lifespan by a substantial amount, therefore reducing long-term maintenance costs.

• Reduce stress concentrations by a factor of 12, effectively mitigating the issue that led to the original block's failure.

• The 4 prototypes are currently in active testing, and initial feedback from technicians has been positive.