The "debris" that knocked out transponders and took four trains out service last Friday was actually a part of the train that came loose, the transit commission heard Wednesday.

The city sent a memo last Friday that they had been alerted by Rideau Transit Maintenance (RTM) — the maintenance contractor of the consortium that built the LRT — that the communications system was knocked out temporarily and trains were damaged due to unidentified "debris" on the westbound track.

But it turns out that the "debris" was a speed sensor bracket on the underside of the LRT car that came loose and knocked out four transponders, which communicate the location of trains to the central control system.

"Initial reports were debris — someone threw something on the tracks," RTM CEO Peter Lauch told reporters Wednesday. "That's not really the case … But there's been a fleet-wide check on every single speed sensor, they've all been checked. They've all been tightened. It's not going to happen again."

Few root causes known

The revelation that the cause of last week's service disruption was a falling train part came amid a wide-ranging LRT update to the transit commission, one that revealed RTM still doesn't know the root causes of many of the issues plaguing the $2.1-billion Confederation Line.

For example, RTM isn't sure why the display boards at LRT stations are sometimes wonky, incorrectly showing wait times of more than an hour.

When Ottawa's light rail trains aren't running, passengers on platforms see messages such as this. At times, the display boards have shown erroneous wait times of more than an hour. (Jean-Sébastien Marier/Radio-Canada)

Then there are the various station stenches. While RTM believes it has identified a broken gasket in a sump pump at Rideau station as the cause of the rotten egg smell there, it still doesn't know why Parliament station still stinks intermittently.

Doors still constant cause of delay

Door problems appear to still be a constant cause of delays, but the frequency varies from week to week. Last week, for example, there were six delays caused by door issues, whereas on the week of Feb. 3, there was just a single door problem. There was even one Wednesday morning, before the transit commission meeting.

A software update set for mid-April is expected to improve a number of problems, including door and computer issues, although the update will interrupt service somewhat, Lauch said.

OC Transpo general manager John Manconi and Peter Lauch, CEO of Rideau Transit Maintenance, say two more trains will be brought into service once fixes are in place for current LRT issues, bringing the total number of trains to 15 during peak times. 0:54

Short-term hacks to handle switches, arc flashes

In trying to address switch disturbances — also common causes of delays — RTM has modified part of a switch heater at Blair station, which has been working fairly well, said Lauch. RTM has ordered the material to modify all the switch heaters as he believes "it is a good interim solution" to deal with the switch disturbances, although it's unclear what the permanent fix is. There are also more people out on the line to manually deal with switch problems.

The long-term solution is replacing the inductors. - Peter Lauch, RTM CEO

As for the arc flashes that were causing an issue, especially on New Year's Eve, Lauch said that the issue likely stems from built up carbon and salt on the roof of the trains, coupled with small cracks in the inductors — which filter electrical power from the overhead cable to the train — mixed with water, a combination that was "creating a bit of a battery."

RTM's short-term hacks to address the issue include cleaning the carbon and salt off the roofs, and building a "chimney" around the inductors to protect them from the weather. Lauch confirmed that the insulators used with the Alstom Citadis Spirit trains were unique to this model of train, which Ottawa is the first to use.

"The long term solution is replacing the inductors," said Lauch. "It's a manufacturing process that is underway but that's about 12 months away to start swapping out all the inductors."

Riki Philogene was on an LRT train on Saturday when he heard several loud noises, followed by what he describes as sparks coming from somewhere on the vehicle's exterior. 0:54

14th train could come into service in weeks

Since late last year, Mayor Jim Watson and other officials have been speaking about the possibility of getting a 14th train into rush hour service, a possibly confusing statement considering that the city was supposed to have received 17 working trains when it accepted the Confederation Line on Aug. 30.

But we know now that those trains are not as reliable as the city had expected, and we simply don't have more than 13 available, if that. As well, OC Transpo boss John Manconi said that with the number of customers currently using the Confederation Line, 13 trains should be enough.

Still, Watson and others would like to see another train or two on the track now to help with customer comfort.

To that end, RTM has been testing and commissioned a train from Stage 2, but there are a couple of outstanding technical issues related to rider comfort. Manconi said there's "no firm date" for adding a new train, although Lauch suggested that it could be ready within the next few weeks.