Two Decembers ago, a train rolled uncontrolled for 24 kilometres, reaching a speed of 100 kilometres an hour before eventually coming to a stop near the eastern Quebec town of Sept-Iles.

Five months earlier, 33 CN cars escaped from a yard near Edmonton and travelled more than five kilometres onto a line carrying residues of gasoline, diesel fuel and sulphuric acid in their tanks.

Cases like these — referred to technically as runaway rolling stock — happen on average 35 times a year, far more often than previously thought, CBC News has learned after examining a railway database kept by the Transportation Safety Board (TSB).

After this summer’s Lac Megantic tragedy — in which 47 people died when a parked train that was insufficiently secured ran down a hill, derailing and exploding — there have been calls for increased scrutiny of rail safety, including in last week’s auditor general’s report.

Until now, TSB annual reports from 2000 to 2012 only identified 158 runaways, counting an incident as a runaway only when it was the primary issue reported to safety inspectors.

But CBC News analyzed the complete TSB rail database of so-called incidents and accidents obtained through access-to-information and discovered that runaways have been involved in more than 300 other cases.

“This is news to me,” said David Jeanes, head of Transport Action Canada, a rail-safety consultancy, who regularly reads the TSB’s annual reports.

Few runaways investigated

Instead, the majority of runaway train cases remain unreported publicly because they are categorized instead as derailments or collisions — without any indication that the train was rolling away uncontrolled at the time.

"If a runaway causes derailment or collision, it will be reported as this higher consequence occurrence,” said TSB spokesperson Rox-Anne D’Aoust.

For example, the Lac Megantic tragedy, when 74 crude-oil laden cars ran unmanned down the tracks into the community of 6,000, wouldn’t be counted among the publicly reported runaways based on the TSB definitions.

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A look at the unreported runaways reveals that not only are railway cars improperly or inadequately secured in yards, but trains — including those with passengers — have separated while in transit.

Oftentimes, the cars don’t collide with other trains, derail or cause deaths, but they raise questions about the ability to secure railway cars in place.

But only nine of the 459 runaway-related occurrences — or about two per cent — have been fully investigated by the TSB, the independent agency charged with finding ways to make the rail industry safer.

"Looking at incidents is one thing that helps you prevent accidents," said Jeanes, saying more of the smaller issues should be examined.

Jeanes notes that the TSB recently pleaded with Transport Canada, the federal rail regulator, to take faster action to implement their recommendations to help fix some of the issues.

The TSB’s D’Aoust said she couldn’t comment directly on why only nine of the 459 runaways were investigated, but she says they depend on the experience of the TSB’s 18 investigators across the country to determine what type of incident could produce the most worthwhile recommendations.

Flammable, corrosive freight

The database turns up a number of runaway near-misses that haven’t been publicly reported:

A Via Rail engineer had to bring his train to a stop to avoid hitting a runaway gondola car up ahead near Breslau, Ont. (Aug. 16, 2009)

Two CN freight cars, including one containing the highly flammable chemical vinyl acetate, rolled for 10 kilometres along a heavily travelled main track near Longueuil, Que. (Jan. 18, 2005)

A CN freight train lost more than 300 metres of cars that ran uncontrolled before coming to a stop near Huntsville, Ont. (Jan. 29, 2004)

Two CN cars full of corrosive anhydrous ammonia ran uncontrolled onto the main line from Port Robinson near Niagara Falls, Ont. until a citizen spotted the cars and reported them. (Aug. 19, 2001)

Runaways have also led to the deaths of at least five railway workers during the 13-year period — four of which happened in mountainous B.C.

In fact in one area of the Kootenay mountains in Trail, B.C., there have been three runaways from 2002 to 2007 along CP rail lines.

They’ve included unmanned trains careening down the mountains with cars loaded with anhydrous ammonia and sulphur dioxide and travelling through areas at more than double the maximum speed of 30 kilometres an hour.

In a 2007 case in that area where the train was occupied, three crew members tried to control the train but its brakes sent up a cloud of smoke. Two of the employees jumped for their lives, while the third, 51-year-old engineer Lonnie Plasko, was found dead in the derailed locomotive.

The Lac Megantic tragedy, when 74 crude-oil laden cars ran unmanned down the tracks into the community of 6,000, wouldn’t be counted among the publicly reported runaways based on the TSB definitions. (Ryan Remiorz/Canadian Press)

Dieter Bogs, the mayor of Trail, B.C., recalls that 2007 derailment tragedy but was surprised to learn from CBC News about two previous runaways in his community that involved dangerous goods.

“I’m not very happy about that,” Bogs said, adding that both he and emergency responders in the area need to know about runaways, even if the trains don’t derail.

“It’s important because we have to have the systems in place to respond to that,” said Bogs. “It’s absolutely important that we know that the people in our community are not going to be subject to the same incident that took place in Quebec.”

British Columbia ties with Quebec for the third highest number of runaway cases from 2000 through 2012, with 73 incidents each. Ontario leads with 124, followed by Alberta’s 101.

Trains roll across border

Another surprising revelation from the database is that two freight cars have rolled unmanned across the border from U.S. yards into Canada — one from Norton, Vt., in 2010 and another from Niagara Falls, N.Y., last year.

In the 2010 incident, a boxcar full of paper from Vermont travelled 50 kilometres on its own – undetected by Canadian border agents and the railway — coming to rest near Lennoxville, Que.

“The car reached high speeds and crossed several public crossings,” says the TSB database record from the St. Lawrence and Atlantic Railway, though it adds that no dangerous goods were involved, and no injuries or derailment reported.

“That stretch of rail is a dark area [with no electronic monitoring] so we had no way of detecting it,” Mario Brault, president of the small railway that operates between Montreal and Portland, Maine, told CBC News this week.

“The box car rolled through many road level crossings. Some of them had signals and gates, but some of the crossings were ‘unprotected,’” he said, acknowledging the potential of a collision with cars or trucks at the crossing.

Employees of the company were disciplined for not securing the car with enough brakes.

Almost a quarter of the 459 runaway occurrences in the past 12 years involved dangerous goods.

Although many of them are contained to railway yards, the runaways can lead to collisions with other trains, as happened in 2011 in Prince George, B.C., when CN tank cars full of diesel fuel, sodium chlorate and sulphuric acid hit another train in the yard.

Incidents largely minor: CN

Mark Hallman, a spokesmen for CN, said the instances of CN trains and or railcars running uncontrolled “are important leading safety indicators of which CN is cognizant, takes seriously and continually addresses through its safety practices.”

But Hallman added that the vast majority of such incidents are minor, slow speed switching accidents in CN rail yards.

To try to combat the problem, Hallman says train crews are given specific charts on how many handbrakes to use, based on the weight and gradient of an incline.

So-called derails are placed at the edges of yards to stop uncontrolled cars from entering main tracks, noted Hallman.

A CBC News examination of the rail database includes examples where the derails have not worked. Interestingly, railway cars were sometimes moved by high winds.

Ed Greenberg, a spokesman for CP, said they take safety seriously and notes that the company has "changed a lot over the years with proactive steps to enhance safety through the communities in which we operate, including further developing information-sharing with local officials."

Via Rail acknowledges eight cases since 2000 where their passenger cars have run away. Via spokesperson Jacques Gagnon told CBC News each incident was a temporary 'break away' where passenger cars 'uncoupled' from a locomotive triggering, automatic emergency brakes which he says safely stopped the cars.

In five of the cases passengers were on board the trains, some of which were travelling at high rates of speeds, when the emergency brakes kicked in. Three incidents happened in a rail yard.

Gagnon says there was only one minor injury in all of the Via cases.