Greetings! I am helping to edit a book about the creation and development of the White Mountain Central Railroad in Lincoln, NH. Part of Clark’s Trading Post, a large tourist attraction in the area, the WMCR started on a whim - to save a steam locomotive that was headed for the scrap heap - and grew into a fully operating railroad and a collection area for steam locomotives and other steam machines.
One of the most incredible stories about the WMCR is its covered bridge. The Clark family took apart a covered bridge that had served the granite quarries in Vermont, numbered and labled all the pieces, brought it back to Lincoln and re-built it on land next to the river. Then three teenagers, using the most ancient of vehicles, dragged the multi-ton bridge across the river. There it remains, part of the White Mountain Central, carrying the weight of thousands of tourists and tons of steam engine every summer.
While I have not been able to find any other working covered railroad bridge
Yes, I think Boothbay Village, ME has a covrered bridge over the narrow guage…but it is mostly museum manufactured things along the ROW and not from real railroad operations. As for the real 12 inches to the foot, interstate commerce railroads, I believe the St. Johnsbury and LeMoil trackage hosted the last covered railroad bridge.
Concur with henry6 - there was (may still be ?) 1 or 2 on short lines in Vermont (“Lamoille County”, I think it was). Also, perhaps out west on one of the timber/ paper company logging roads. See Ron Ziel’s Twilight of Steam Locomotives (early-mid-1960’s) as a starting point.
See also the related subjects on this webpage - which references 4 to 6 other covered RR bridges - and also includes a description, history, and photos of the installation of the bridge at Clark’s Trading Post as described by the Original Poster ! http://www.vermontbridges.com/cbmail.bag.htm
There may well be others - I don’t claim that any of this is exhaustive, complete, or correct.
Paul! I can’t believe how close I have been to the C&C bridges and not stopped to see them. The two Newport bridges are actually just of Rt103/11 at Kellyville by about a mile. The third one at Contoocook is virtually right in the middle of twon on rt103! All three are easily seen on sattellite maps. Next trip to or from Bath, ME will include the bridges for sure! (Oh, yeah, they are marked on the NH’s state maps with the covered bridge symbol but not indicated as railroad.)
I lived in Contoocook, NH in 1954 when I was 5 years old. I finally got back in 2001, and was glad to see the covered bridge and station were still there. According to the book The Concord and Claremont Railroad by Edgar Mead (1998), when mainline trains had to detour over the C&C, they would use double headed moguls rather than the mainline pacifics, even though the covered bridges could theoretically hold them.