Project Overview

The Toronto Transit Commission (TTC) required an asset condition assessment of its Line 1 (Yonge-University Line), to establish the condition and associated risks of operating major electrical equipment at substations supplying this line.

The assessment involved five equipment categories at 20 substations and 32 utility chambers supplying Line 1 including:

  • DC Transformers
  • DC Circuit Breakers
  • DC Rectifiers
  • Feeder Cable Chambers
  • Feeder and Track Level Cables

The assessment involved analyzing both available historical data and information, as well as data and information collected from field inspections and equipment testing performed by us. This data and information were then used to establish for each asset unit:

  1. Estimated proximity to the end of useful life, and
  2. Required remedial actions, if any.

How We Helped

We undertook the following activities:

  • Reviewing and analyzing available historical data and information, such as in-service period, corrective maintenance history, inspection records, etc.
  • Performing field testing and inspection of all DC transformers, DC circuit breakers and DC rectifiers at 20 substations supplying Line 1
  • Performing visual inspection of 32 utility chambers
  • Performing testing for cable samples provided by the TTC at our laboratories

We used the TTC's proprietary methodology to determine, two distinct attributes for assessing the condition of the TTC electrical assets:

  • Health Index which is a quantitative measure of the overall condition indicating how far along in their respective useful lives the assets are and when major refurbishment or replacement would be required
  • Action Rating which indicates maintenance action required for the asset to continue functioning properly

At completion we provided the TTC with the following information for each of the asset categories within the project’s scope:

  • Age Distribution
  • Health Index Distribution
  • Action Rating Distribution
  • Condition based Flagged-for-Action Plan (Timing for Replacement/Refurbishment)
  • Degradation and Failure Mechanisms
  • Average Health Index by Substation
  • Comparison of Health Index vs Action Rating
  • Data Analysis

Additionally, we provided to the TTC all the field and laboratory testing and inspection results collected over the course of this project.

Photograph of electrical equipment connected to a substation