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-   -   Ballasted deck on railroad trestles (http://www.railpictures.net/forums/showthread.php?t=18337)

John Russell - NZ 05-13-2020 12:44 AM

Ballasted deck on railroad trestles
 
https://www.railpictures.net/photo/735827/

I'm curious about North American railroad trestles with ballasted decks which seems normal practice. Has this always been so? Here in NZ we have many similar trestles but none have a ballasted deck. Sorry if this is off topic for this forum.

jac_murphy 05-13-2020 10:42 PM

Both ballast- and open-deck bridges are common. The trend is moving more and more towards ballast-deck bridges since it's easier to control thermal expansion, they can be surfaced using regular equipment (and are less prone to developing surface deviations at either end where the roadbed meets the bridge,) there's less special hardware (hook bolts, spacers, bridge timbers, etc) involved, and there's reduced wear on the structure itself since the ballast tempers the vibration somewhat (which also makes for a bit of a smoother ride.)

In the photo you linked, I'll bet that bridge started its life as an open-deck bridge and was later retrofitted with a ballast deck.

-Jacques

bigbassloyd 05-14-2020 12:11 AM

A majority of the larger bridges where I live on the old C&O were converted to ballast decks in the early 2000 for the above mentioned reasons.

Loyd L.

John Russell - NZ 05-21-2020 08:31 AM

Thanks guys for the answers.


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