CE 515 Railroad Engineering Turnouts, Yard Design, & Clearances Arema Ch. 6 “Transportation exists to conquer space and time -”

Turnouts Turns one track into two Three basic components Switch Closure Curve Frog Are designated by their frog number Replace rail when worn out or has defects. Ties replaced when they fail or can’t support the track. http://enwikipedia.or/wiki/Railroad_switch

Turnout Design PI Method Equivalent Curve Method Requivalent= 2(Gage)(Frog Number)2 Rounded to the nearest 15 Turnout is place with its beginning/end at the PC/PT of the Equivalent Curve

Turnout Construction Provide the PS and PF for construction One of three methods Built in place Panelization Hybridization http://www.oerm.org/pages/Turnout_construction_5_27_07_sm.JPG

Turnout Speed Determined by points and closure curve For curved points, must also consider the point of radius Self –guarded frogs are usually 15mph limit Maintenance can cause track disturbance. Try to keep in equilibrium to prevent buckling. Lay rail at elevated temperature and then lock in place with anchors. Dynamic stabilizers apply controlled, accurate stabilizing forces into the track structure at continuous speeds of up to 3/4 mph. Combination of horizontal vibration and a vertical load. Arema p. 249

What Does Underbalance Mean? Underbalance is a measure of an adequate level of superelevation for optimal conditions. Because passenger and freight trains have different optimal levels, less than optimal levels are permitted by regulatory agencies, which limits passenger trains from traveling their maximum speed. https://www.nysdot.gov/regional-offices/region1/project-repository/i87MultiModalStudy/documents/draftfinal-highspeedrailsummary-may04.pdf

Frog Number Generally available from No. 6-24+ Frog angle decreases as turnout number increases Turnout minimum on most mainline tracks are No. 10 Flange of the wheel tends to crowd the outer rail – results in abrasions which lead to wide gage and formation of defects. Locomotive on-board lubrication, wayside lubricators, high rail equipped lubricant pump and nozzle system, hand application Only apply to gage corner of rail – low rail should be lubricated Other friction modifiers applied to the tread of the rail to optimize coefficient of friction on the running surface of the rail. Arema p. 250

Turnout Location Tandem Leads have a second Turnout immediately after the first Arema p. 252 Multiple turnouts in a series are called a ladder Maximum Ladder Angle ∂=Sin-1(S/L) Used to remove surface imperfections on the rail ∂: Deflection angle S: Yard track spacing L: Length of turnout http://www.building-your-model-railroad.com/images/railyard1.jpg

Design of Yards Storage Yard Local Yards Flat Switching Classification Yards Torino, Italy Pueblo, Colorado Blocks drainage, decreases visibility, fire hazards Some is desirable for wind breaks, prevent erosion Herbicide or mechanical cutting for removal http://z.about.com/d/goeurope/1/0/a/Y/torino-railroad.jpg http://www.airphotona.com/stockimg/images/00200.jpg

Flat Switching Classification Yards Receiving Yard Classification Yard (Hump, Gravity, or Flat) Departure Yard Rip Track Many of the commonly applied hwy stabilization methods are applicable to RR. Talk more about this in drainage portion of class. Flash butt welding: A technique for joining segments of metal rail or pipe in which segments aligned end to end are electronically charged, producing an electric arc that melts and welds the ends of the segments, yielding an exceptionally strong and smooth joint. Also called flash welding. http://www.youtube.com/watch?v=XuOZfYMTcx8

Passenger Car Storage Yard Should be near the terminal Willowbrook Yard, Toronto Production gangs include: Rail, Tie, Undercutting, Surfacing, Road Crossing Renewal, Turnout http://jeffwilk.com/granduncle.php?big=13 Recruiter http://transit.toronto.on.ca/gotransit/2304.shtml

Other Design Considerations Administrative buildings Lockers and toilets Equipment storage Fueling and servicing Minor repair facilities Turntables Air compressors Floodlighting Roads Jacking Pads Cleaning stations Wastewater and oil treatment facilities http://www.flickr.com/photos/grundlepuck/151676388/

Clearance The space required between the track and other fixed obstructions, including other track Determined by Type and Size of locomotive Type and size of cars Dimensions of oversize loads Lists and calculation procedures can be found in Arema Chapter 28 Inspect for internal flaws within the rail. http://www.panoramio.com/photo/6355575

Clearance Side clearance is measured from the center of the track Must be increased on Curves Overhead clearance is measured from the above top running rail. Geometry cars check basic track geometry and gage compliance. Indicates the problem areas. Can leave paint mark on track. FRA operates one to determine compliance. GRMS – finds wide gage under loading conditions. FRA permits the data in determining gage compliance in lieu of the required number of non-defective ties for a given class or track per 39-foot segment (Track and Safety Standards). http://gritton.org/greg/rail/docs/clearance/AAR_plates_with_UIC.gif

Swingout Clearance Maximum swingout occurs at the mid point of two cars Over hang distance, s, from centerline S=m + w/2 Where, m=R-(2*R-(t/2)*2)1/2 R=Radius of track curve t= truck centers w=railcar width Arema p. 259

Superelevation Clearance e=E*t/G Where, E=superelevation t= height of car G= Gauge distance So e+m is the additional clearance needed http://zierke.com/shasta_route/picpages/rb22994.html

Overhead Clearance Telltales used to be used to warn trainmen on top of the train of an upcoming tunnel http://www.irritatedvowel.com/Railroad/WMRY/JacksMountain/pmb_jacks_mountain_tunnel_telltale_1.jpg

Clearances in Iowa Effective as of last November, close-clearance warning signs must be places where obstructions might impede a person who is lawfully riding on the side of the train. Dimensions

Questions?