Since this post things have gotten worse. The narrow LRT platforms are over crowded. The trains break down.
TROY CHARTER, " WE DO NOT KNOW WHY THE TRAIN WHEELS ARE WEARING OUT"
Past candidate for City Councillor in Rideau Rockcliffe Ward. peterkarwacki.overbrook@gmail.com
The city councillor must take an octranspo bus at least once per week...someplace, maybe cross town and back. until satisfaction with service is 90% approval.
ReplyDeleteAnd the trains?
ReplyDeleteThe **premature wear** and failures in the wheel bearings and axles on Ottawa's O-Train (Confederation Line LRT, using Alstom Citadis Spirit vehicles) have been a recurring and significant issue since around 2021, leading to multiple service disruptions, derailments, and fleet reductions.
The core component involved is the **cartridge bearing assembly (CBA)**, which connects the wheels to the axles and supports the train's weight and motion. These are failing or showing excessive wear much earlier than their designed lifespan (intended for around 1.2 million km, but problems appearing well under 100,000–200,000 km in many cases).
### Key Problems and Manifestations
- **Historical issues (2021–2023)**: Catastrophic roller bearing failures led to wheels detaching from axles, causing derailments (e.g., 2021 incident). Root causes included loosening of locking nuts in the assembly, excessive play (e.g., beyond 0.1 mm tolerance), and subsequent overheating/burn-off of axle journals.
- **More recent issue (2025–2026)**: A defect called **spalling** (metal flaking or pitting on bearing surfaces) has been detected on higher-mileage trains (over 100,000 km). This contaminates the grease, inhibits smooth rotation, creates pits/cracks that grow, and risks full bearing failure. As of early 2026 reports, this led to pulling dozens of vehicles (e.g., 41+ out of 60) for inspections and replacements, forcing reduced "single-car" service and overcrowding.
### Root Cause(s)
There is **no single, fully agreed-upon root cause** yet—disagreements persist between the manufacturer (Alstom), the maintainer (Rideau Transit Group/RTG), OC Transpo, and the city. However, sources point to these main contributing factors:
- **Higher-than-expected lateral (side-to-side) loads/forces** on the axles and wheelsets — Alstom's stated root cause in 2023 investigations. This overloads the bearing assemblies during operation.
- **Track/infrastructure-related issues** — Sharp curves, tight radii, rail gauge problems, or wheel-rail interface mismatches on the Confederation Line cause excessive forces, accelerated wear, and stress on the low-floor bogie design (which has limited space for robust components). Alstom has blamed improper track infrastructure/maintenance for accelerated bogie wear, while suggesting fixes like stronger rails on curves, lubrication, and reprofiling.
- **Design/overload factors** — Some experts and reports link it to overloading (e.g., passenger loads or train weight), insufficient bearing robustness for Ottawa's specific conditions, or potential material/maintenance/installation flaws (e.g., bad batches, contamination, or improper assembly). The low-floor Citadis Spirit design may exacerbate this by constraining bogie/axle space compared to traditional setups.
A long-term fix like redesigning/strengthening the axle/wheel hub assembly has been discussed (and partially halted/resumed amid disputes), but short-term measures include mandatory axle replacements at mileage thresholds, inspections, and track tweaks.
OC Transpo and officials emphasize safety first, but the exact "why" remains under investigation with uncertainty about full connections between old and new defects. For the latest updates, check OC Transpo announcements or recent news from sources like CBC or Ottawa Citizen, as this has been an evolving saga. (Grok)
Yes, there are some publicly available illustrations and photos related to the problematic wheel bearings (specifically the cartridge bearing assemblies, or CBAs) on Ottawa's O-Train LRT vehicles.
ReplyDeleteMost detailed images come from official investigations (like the Transportation Safety Board reports on the 2021 derailments), which show damaged components such as overheated/melted roller bearings, failed assemblies after axle separation, or the affected parts post-incident. Recent 2026 spalling issues (metal flaking/pitting inside the bearings) are described in news reports and OC Transpo updates, but close-up photos of the spalled surfaces themselves aren't widely published—likely due to them being internal inspections during maintenance.
Here are relevant visuals I found:
- Photos from the 2021 derailment investigations show the damaged cartridge bearing assembly after failure, including overheated rollers and axle damage (from TSB and CBC/Global News coverage).
(Note: This is a representative example of a damaged bearing assembly from the earlier failures; actual TSB Flickr or report-linked images depict similar melted/overheated rollers and separated components.)
- News articles (e.g., CBC) often include photos of the external wheel/axle area on derailed or inspected trains, or the train itself during service disruptions.
These typically show the wheelset context (e.g., a derailed wheel detached due to bearing failure) rather than microscopic spalling. For spalling specifically, it's internal metal pitting/flaking—think small flakes breaking off the bearing race surfaces, leading to contamination and pits (no direct public photos of the dissected spalled bearings appear in recent coverage, but diagrams in engineering contexts describe it as surface damage resembling craters or flakes on hardened steel).
If you're looking for more technical diagrams (e.g., cross-sections of cartridge bearings or spalling examples from general rail engineering), let me know—I can search further or describe them in detail! The issues remain under ongoing root cause analysis by RTG/Alstom. (GROK)
In the Ottawa LRT context, the detected spalling on higher-mileage cartridge bearings likely stems from a combination of elevated lateral forces (from track curves/gauge issues) overloading the assemblies, leading to accelerated subsurface/surface fatigue beyond design expectations.
ReplyDeleteWe have had our transit committees and experts. We have had elections, democracy and due process.
ReplyDeleteWhat have we got to show for it?
The average voter is driving now, many have given up. They pay the bills resigned to it, white flags raised.
The solution to the LRT woes is pretty well known now.
-New heavier duty design for wheels, bearings and axles.
-better rail bed
-better rails and rail lubrication
Who pays for it? We all will.