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I have two of these and whilst not the most accurate of bridges they suffice. My question is did these bridges have ballast between the sleepers?
 

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I would think ballast would add a lot of weight to a bridge like that. I remember seeing ballast on concrete viaducts, but not steel bridges.
 

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I've seen ballasted-deck plate girder bridges, but trusses are usually pretty open. I'm not sure about how this old Atlas bridge is modelled though, if it's got a solid bottom and just truss sides it could be convincingly made to look like a ballasted deck bridge. Otherwise the bottom girders/trusswork should be open to below. Nowhere for ballast to be...
 

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There would be no compelling advantage to ballasting a through truss or deck truss bridge. You'd have to close off the gaps between the bridge ties so that the ballast can be supported. That would add several tons of weight. Then, the ballast when tie plates and spikes would do the job in view of the closer proximity of the ties, the spacing, that is typical on bridge decks. Also, when wet, the ballast would still keep the surfaces of the ties moist, which is bad enough on roadbed over ground. It's easier to replace rotten ties over roadbed than it is to replace them on a bridge with metal plates and trusses here and there.
 

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Ballasted deck bridges

I have two of these and whilst not the most accurate of bridges they suffice. My question is did these bridges have ballast between the sleepers?


aquuakiwi;

Ballasted deck railroad bridges exist, but open deck (no ballast) are more common. Regardless of deck type, many railroad bridges may also have two "extra" rails between the normal pair of running rails. These are called "guard rails", and are used to help keep a car on the track, even if a wheel has come off the running rail. Guard rails are often bent inward near their ends, which usually extend beyond the ends of the bridge. This helps the guard rails snag errant wheels and either force them back onto the running rails, or at least help keep the car from falling off the bridge. There may also be "guard timbers" bolted along the outside ends of the bridge ties, and parallel with the rails. These too are intended to prevent a derailed wheel from causing a car to fall off the bridge. Guard rails and guard timbers make nice details on a model bridge.

Ballasted deck bridges are typically, though not always, either deck plate girder bridges, or through plate girder bridges. Sometimes a series of deck plate girder bridges form the top of a steel trestle. They may be either open deck, or ballasted deck.
The Milwaukee Road used ballasted decks on their many tall steel trestles on their pacific coast division. The area traversed by the cost division's track was a rainforest and the ballasted decks helped resist rot and general wear from the soggy environment. On other, drier, areas of their mainline, the same railroad used open deck trestles.

Traction Fan :smilie_daumenpos:

Wye at Black River Junction.jpg

Garrison creek trestle good view.JPG
 
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