On my Pennsy HO layout I have four bridges crossing a 200-foot scale river. The first double track truss bridge is approximately 47 feet above the water. In order to meet track on the other side I reduced the grade 1” from one side of the bridge to the other. My wife said all bridges are always built level and never have a grade. Can anyone settle this argument?
I agree with wife [:D]
See this thread
http://www.trains.com/community/forum/topic.asp?page=-1&TOPIC_ID=31352&REPLY_ID=312132#312132
Tell wife that out here in the Sierra Nevada, the bridges conform to whatever grade the track is on. There’s a viaduct on the Siskiyou line in southern Oregon (just over the california border) that is on a 3.5% grade! Most of the bridges on the ex-SP Donner Pass line over the Sierras are on about a 2-2.4% grade, and the west approach to the Carquinez Straits Bridge near Oakland, CA, is on about a 1.5%. The bridges on the ex WP Feather River route are all on a 1% grade. You don’t halt a grade just to cross a river, otherwise you’re going to have Hell to pay trying to make up that grade on the other side. I’ve got four bridges on my Yuba Pass Sub that are on a 2.4% grade, and my projected large curve viaduct is going to be on a 2.2%. It happens all the time, both in models and certainly in real life. At least out here in the mountains.
Tom
[:D][:D]
Lots of graded bridges in BC. Both the CPR and CNR (heck, even the Esquimalt & Nanaimo and the BC Railroad) had few clean lines across rivers in the various mountain ranges. When you think about it, rivers wouldn’t flow if THEY didn’t have a grade!
Thanks a lot for all the information showing that bridges can have a grade and proving my wife was wrong. It has been quite a learning experience for both of us. My wife learned a whole lot of details about bridges and I learned how uncomfortable the couch is.
Drainage is better with a slight grade; wouldn’t want too much snow and ice on a bridge.
Can’t say I’ve ever been sent to the couch over something like that! [(-D]
So what happens when you start talking about ballast color? [:P][;)]