Possibly, the weather in UK is less extreme than in Ottowa.

Also, Britain does seem get more “Wrong kind of snow” that other countries.

So maybe things balance themselves out in various way?

Howard

I am surprised they have all those breakages in Ottowa.

The railways in Scandinavia, even most of the Trans-Siberian railway, all use overhead electrics and judging by photographs the mechanical designs of those and as used in the UK are very similar. ‘Cos they use simple components and they work.

Fairly elaborate weights-and-pulleys systems at regular intervals maintain an even tension irrespective of weather. (Siberia has the largest annual temperature range of anywhere in the world.)

The one exception on Network Rail is the set of forlorn, empty* davits along the line between Bristol and Gloucester. These massive steel fabrications are clearly made for rapid installation: the arms hook onto the columns rather like book-shelf brackets that clip into slotted bars. Nevertheless whoever designed them instead of specifying the same, tried, tested and proven designs used on the Northern lines and in Norway, must have thought they were building an overhead cable-car system.

[* Still empty? They were a couple of years ago when I last travelled North.)

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I have heard of electricity transmission-lines breaking in cold weather and causing grass-fires, in Norway too! A pen-friend living in the affected area told me of this. After an unusually dry Autumn the weather broke with freezing fog that so iced the line in question that the cables snapped from the weight and I suppose also the added tension due to the contraction. The resulting arcing to ground ignited the grass and heather, still tinder-dry, before the circuit-breakers acted.

(The natural droop for a slack line under its own, evenly-distributed weight is a catenary, but if the line is tensioned the stress in it and on its anchorages increases considerably as it straightens.)

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Howard- we don’t get much snow but the “wrong kind” phrase was by a careless journalist trying to report on an engineering matter, so well out most journalists’ depth. Not a railway official.

Dave – Leaves are a genuine problem, and Network Rail has even built special rail-cleaning machines to deal with them.

I’m surprised to see those two comments on an engineering forum!

Leaves on the track were much less of a problem when we had steam engines because lineside fires got rid of the trees. Just look at old photos from pre 1960, a lot fewer trees. If Netwok Rail started a campaign of tree felling imagine the uproar

Sounds like the wires are not always the best alloys for resisting cold weather, I have no idea whether they are steel or some other metal.