Pratt Truss vs. Deck Girder bridge

The type of construction depends on the distance to be spanned.  A typical truss can span a greater distance than a girder. On my model railroads I have girders that span about 65 feet (full scale between end-supports) and trusses than span 100 and 150 feet.

MELGAR

As Mel has stated it depends on the distance. I know I had spoken to Rich about real railroads and speeds on bridges, whether the type of bridge(wood, stone, steel) played a factor in how fast or slow the train was allowed to go. Thing is that like this, there are a bunch of other factors that go into all that as well. I would say that it is your railroad and put whatever you think is best, but for realism, consult those who have operated trains as well as googling pictures of spans with the types of bridges. Weigh all that and see what you come up with for your preference.

Ben,

I agree that the Atlas Pratt Truss bridge is very nice. I agree with the suggestion above. Ultimately what you like best wins. A few years ago someone was selling two modified single track Atlas Pratt bridges. The bridges were modified to make two smaller bridges but at the time I didn't  have a use for either one. I say this to say that if you wanted you could modify one to make it smaller if the 40" is too long.

Dave

Thank you all!

Not a fan of the Atlas Truss bridge, due to the size. Especially when you compare the openings  to something like the Lionel  lift bridge or bascule bridge. The 20” deck Plate girder bridge is very nice..

Here are a couple ideas for Plate girder bridges. The abutment was made with 1/2 round bullnose/dowels glued to 5/4 stock. The grooves are cut with a table saw.

given the right structural support visually, a series of deck plate or girder bridges has more appeal to me.