Here is a really nice presentation of building the specific B&O viaduct.
http://basrr.blogspot.com/2013/01/mold-m...aduct.html
Two very interesting things;
a) the manner he included that vertical proud column in with the front facing mold,
b) casting of the curved arch roof
http://basrr.blogspot.com/2013/01/mold-m...aduct.html
Two very interesting things;
a) the manner he included that vertical proud column in with the front facing mold,
b) casting of the curved arch roof