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"Extreme" Heat and Rail Operations

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Hello all,

As I am sure all have seen, heard or experienced yesterday, the O-Train Line 1 was operating at a reduced maximum speed of 50kph due to the heat wave being experienced.

While commentary was plenty online and the media made headlines with the breaking news, the reaction was as expected pretty negative.

However for those who can do some research or know about this stuff, this isn't an isolated incident, and definitely not just an Ottawa thing. 

The tracks are made up of rails (which are steel). Like most metals, steel expands and contracts based on the temperature. Expanding in heat and contracting in cold. At the tension and force the rails are attached to the rail ties, and being bolted or continuously welded together, there is little to no room for expansion or contraction.

Last winter, we all heard about the rail break that occurred, no doubt due to the cold. And now with the heat, slow orders have been given.

With the rail attached with little to no room to expand, should it actually move, it could be outward or up the direction it goes. Either one presents safety issues or could result in damage to the trains and or track. Naturally, to minimize the risk of damage or an incident, it is only prudent to restrict temporarily the speed of passing trains. Even the passage of trains can generate heat, not as much from the friction of the wheels on the rail but from the downward force and flex to the rail as the wheels pass over. If you take a piece of metal and bend it back and forth repeatedly, the bend will heat up in some form.

All this to say, this is normal rail operations. GO Transit in the GTA announced 3 days of slow operations due to the heat (in August 2016). VIA Rail and Amtrak, just to name a few also have similar protocols in this hot times.

What are your thoughts? Clearly my discussion above just scratches the surface of this very interesting topic. 

I will leave you with this... ever seen the ruts in the road left by buses or heavy vehicles on a hot summer day? While train rail may be more sturdy and robust than asphalt, everything has its limits when dealing with the weather.

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I agree that the communication needs to vastly improve. A recent media article suggests this will be the case when the line reopens this Monday, but time will tell. I'm sure the technical issues are o

Due to delays and breakdowns especially during winter operations people in Ottawa have become extremely skeptical, negative, upset and angry towards any announcements of maintenance or normal operations slowdown. 

I can't really blame the average rider but the anger has spread to any announcements. Like you said slowdowns in extreme heat are a normal thing on rail across the world.

What I do think would help is if OC transpo had a much better communication instead of just tweets. (A link to of transpo website explaining would help) The speed restrictions from go trains are very well explained. It would have helped a lot if this would be communicated before hand as well

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I agree that the communication needs to vastly improve. A recent media article suggests this will be the case when the line reopens this Monday, but time will tell. I'm sure the technical issues are one thing but the fail in communication is what really drives people nuts and increases anger.

You could be on a train that is being held, with no idea when it will resume for example. Should I stay on or use surface transit, only to see it leave moments after getting off... or it may stay an hour. There is a reluctance on providing estimates on service restoration but this is essential and most if not all major transit agencies will rail do this. Whether or not it is accurate 100% of the time or not, information is key and helps people make the best decision for them.

The other issue that we saw recently was the news on twitter that one trail broke down or was disabled and system-wide holds were in effect. I can understand they don't want to bunch up the trains behind the disabled one as then getting back to normal spacing and intervals between trains will take longer but still, people need to know what is going on.

Regardless of what is going on, people NEED TO KNOW when a return to NORMAL is expected.

Lets hope that information is much more forthcoming when the line reopens Monday. It's a learning process for all but we need to finally get this right, it's been too long and clearly is one of the major things that is turning people off.

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All great points Shane, one last thing I'd like to add is that rail mass transit is new to Ottawa and it shows. A lot of users get upset or ask questions that are obvious to anyone who's lived in Toronto or Montreal (exemple : why doesn't it run all night?)

This makes it even more important to communicate well with customers.

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Hi Shane, I understand that when Continuous Welded Rail (CWR) is installed, it is done so at what's called a Stress-free Temperature. The rail is thermally or mechanically stressed to a point where it will experience the least stress possible given the hot/cold extremes of the local climate in which it is installed. So, the Stress-free temperature will vary by location. According to Wikipedia, in the USA, this temperature is most often set between 35 ad 43C. It was not this hot in Ottawa last week.

It can happen that even when the appropriate Stress-free temperature for a particular CWR is properly determined, track can still buckle or lose alignment. Perhaps that's what could have happened with the Confederation Line. But I fear we'll never know precisely what's up due to the consortium's ultra secrecy about sharing information (both OC Transpo and RTM are equally in need of upping their games here). It could be that the CWR Stress-free temperature for the Confederation Line has been set a bit low or it could be that Ottawa is just a wild climate to have CWR that both won't crack in the cold and distort/expand too much in the heat.

Nevertheless, while trains running on CWR do slow down during extreme heat, I'm unaware of other systems having to slow down to such creepingly slow speeds. Other factors that affect CWR rail distortion in extreme heat include the ballast (quality and installation), track shoulders, and the sleepers. Somehow I would not be astounded to learn that some of these components are borderline substandard quality and/or incorrectly installed (like the catenary system and overhead wiring infrastructure)

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On 2020-07-01 at 3:04 PM, Gjd353 said:

While the outside temperature did not reach 35C, the temperature of the tracks in the blazing sun will be much higher. I think that's the real reason why we have the slow order

Very good point. I hadn't mentioned it myself but yes it's very true. As another example, it may be 30'c outside but the outside metal of your car is even warmer to the touch, almost burning hot. You can only imagine how hot the polished steel rail is in these conditions.

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