CE 515 Railroad Engineering Track Source: Armstrong Ch 3, AREMA Ch. 3, REES Module 2 “Transportation exists to conquer space and time -”

Track Alignment • How is Alignment Measured in Tangent Track?

Track Alignment • • How is Alignment Measured in Curved Track?

Mid-Ordinate Offset (in)=Degree of Curvature

Horizontal Curve Elements

Horizontal Curve Elements http://zierke.com/shasta_route/picpages/atsf120williamsjct.html

Horizontal Curve Elements http://thomascranelibrary.org/jpg/legacy/fig50.jpg

• Measuring Gage Gage

Gage • • Max Gage allowance 1-3/4” wider Class 4 Operation, 1” max http://img.photobucket.com/albums/v329/Trainman-2/SCRM%20West%20End/IMGP4575.jpg

• Turnouts 3 Groups of Turnouts – Lateral Turnouts – – Equilateral Turnouts Lap Turnouts http://s145079212.onlinehome.us/rr/howto/faq/faq_turnouts.htm#lapturnout

Bingmaps.com

Turnouts

Turnout Terminology • Also See AREMA pp. 89-90 Fig 3-13 from Armstrong

The Switch • • • Device deflecting wheels of train from track they are running Switch is portion of turnout from Point of Switch (PS) to Heel of Switch (HS) Video (model): http://www.youtube.com/watch?v=FF8YIH160hA

The Switching Mechanism • • Hand operated (switch stand) Power operated (machine)

Frog • Permits flange of wheel to cross the other rail http://static.panoramio.com/photos/original/6940512.jpg

Frog Types • • • • • Rail Bound Manganese (RBM) Spring Frog Solid Manganese Self-guarded Frog Bolted Rigid Frogs Movable Point Frogs

Guard Rails

Railway Crossovers and Crossings • • Crossovers can be considered as two turnouts Crossing consists of 4 frogs (2 intersecting tracks)

Railway Crossovers and Crossings • Slip Switch: combination of small angle crossing with pair of connecting tracks within limits of crossing

Railway Crossovers and Crossings • • • • Information needed to design crossings – See AREMA pp. 105-6 Specialty manufactures design these features Train Crossing Frog: http://www.youtube.com/watch?v=jeWxWkTlsUE How they work: http://video.google.com/videoplay?docid=2853660703765713140&ei=xnFeS 28K5jqqwKsyI3oCg&q=Railroad+Frog&hl=en&client=firefox-a#

Highway Crossings • • Renewal of Crossings are Expensive Public Safety is Serious Concern

Highway Crossings