The CN continuous welded rail work train.

Trains of Canada HD Video #204 www LanceCampeau com

Its that time of year! The continuous welded rail is on the move...

Welded rail joint
Most modern railways use continuous welded rail (CWR), sometimes referred to as ribbon rails. In this form of track, the rails are welded together by utilising flash butt welding to form one continuous rail that may be several kilometres long, or thermite welding to repair or splice together existing CWR segments. Because there are few joints, this form of track is very strong, gives a smooth ride, and needs less maintenance; trains can travel on it at higher speeds and with less friction. Welded rails are more expensive to lay than jointed tracks, but have much lower maintenance costs. The first welded track was used in Germany in 1924 and the US in 1930[2] and has become common on main lines since the 1950s.

Flash butt welding is the preferred process which involves an automated track-laying machine running a strong electrical current through the touching ends of two unjoined pieces of rail. The ends become white hot due to electrical resistance and are then pressed together forming a strong weld. Thermite welding is a manual process requiring a reaction crucible and form to contain the molten iron. Thermite-bonded joints are also seen as less reliable and more prone to fracture or break.

If not restrained, rails would lengthen in hot weather and shrink in cold weather. To provide this restraint, the rail is prevented from moving in relation to the sleeper by use of clips or anchors. Anchors are more common for wooden sleepers, whereas most concrete or steel sleepers are fastened to the rail by special clips which resist longitudinal movement of the rail. There is no theoretical limit to how long a welded rail can be. However, if longitudinal and lateral restraint are insufficient, the track could become distorted in hot weather and cause a derailment. Distortion due to heat expansion is known in North America as sun kink, and elsewhere as buckling. In North America a rail broken due to cold-related contraction is known as a pull-apart. Attention needs to be paid to compacting the ballast effectively, including under, between, and at the ends of the sleepers, to prevent the sleepers from moving. In extreme hot weather special inspections are required to monitor sections of track known to be problematic.

After new segments of rail are laid, or defective rails replaced (welded-in), the rails are artificially stressed. The stressing process involves either heating the rails causing them to expand,[3] or stretching the rails with hydraulic equipment. They are then fastened (clipped) to the sleepers in their expanded form. This process ensures that the rail will not expand much further in subsequent hot weather. In cold weather the rails try to contract, but because they are firmly fastened, cannot do so. In effect, stressed rails are a bit like a piece of stretched elastic firmly fastened down.

CWR rail is laid (including fastening) at a temperature roughly midway between the extremes experienced at that location (this is known as the 'rail neutral temperature'). This installation procedure, along with normal track structure strength, is intended to prevent tracks from buckling in summer heat or pulling apart in winter cold. In North America, because broken rails are typically detected by the signaling system; they are seen as less of a problem than heat kinks which are not detected.

Joints are used in continuous welded rail when necessary, usually for signal circuit gaps. Instead of a joint that passes straight across the rail, the two rail ends are sometimes cut at an angle to give a smoother transition. In extreme cases, such as at the end of long bridges, a breather switch (referred to in North America and Britain as an expansion joint) can gives a smooth path for the wheel while allowing the end of one rail to expand in relation to the next rail.

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• ribbon
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[vacuumtube56]

Hello Lance

Just curious !

Is this Ile Perrot ?

[LanceCampeau]

@vacuumtube56

Yes, this is Ile Perrot!

[khroe]

One word: lawyers.

[WelcomeToZomboCom]

if we have welded tracks, how come our trains are still not high speed :(

[tehatemachine]

@TechnologicsCo taht's how it used to be. Trains are cheaper for hauling bulk goods a long distance. But check this out, before the box car was the main method used to haul goods in, Now a container with a well car is WAY quicker. we use both. Trains for long haul with many different items. and trucks for local.

[ChachaChapati]

Heh, "En Tout Temps." Sure sign you're in Quebec.

[CSXer]

Nice catch! That's HUGE compared to the NS rail train I caught in Alabama USA.

[witchcraftlord]

@TechnologicsCo Canada became a nation offically in 1867, .... small buisnesses use trucks, and thats ok, but it is more efficiant and makes for a wonderfull jounry to transport a classy nice train of people from montreal to vancouver compared to if all of them drove a silly car or truck, if there were more trains I wouldnt  have to waste a bunch of money on filling up my car,

[TechnologicsCo]

@witchcraftlord how far back in history?

[witchcraftlord]

@TechnologicsCo ya go call Canadian National Railway and tell them what you think. Trains in Canada are still active and in use. The train has left a bigger mark in our history then the 18 wheeler. It wasnt a transport truck that saved the day. If it werent for the train , British Colombia may not have joined confederation and they may be part of the USA. Still trains kick ass, its a great way to ship goods, and great for tourist travel long distance, heard of via rail Canada?

[TechnologicsCo]

@witchcraftlord i did. the reason trains are inconvenient is because small businesses cant afford nor need them, which is most of the us economy

most companies dont have the need to carry 20 cars of goods when they dont even buy or make that much

the only industry that needs trains around here is the coal industry shipping coal from here to the docks to be then shipped to the rest of the world and that's because they are mining enough coal to fill dozens of cars a day.