- Degree of curvature
-
This article is about the measure of curvature. For other uses, see degree (angle).
Degree of curve or degree of curvature is a measure of curvature of a circular arc used in civil engineering for its easy use in layout surveying.
A n-degree curve turns the forward direction by n degrees over some agreed-upon distance. The usual distance in US road work is 100 ft (30.48 m) of arc[1]. US railroad work traditionally used 100 ft of chord and this may be used in other places for road work. Other lengths may be used—such as 100 metres where SI is favoured, or a shorter length for sharper curves.
Since rail routes have very large radii, they are laid out in chords, as the difference to the arc is inconsequential and this made work easier before electronic calculators.
The 100 ft (30.48 m) is called a station, used to define length along a road or other alignment, annotated as stations plus feet 1+00, 2+00 etc. Metric work may use similar notation, such as kilometers plus meters 1+000.
See also
- Railway systems engineering
- Track transition curve
- Transition curve
References
- ^ Davis, Foote, and Kelly. Surveying Theory and Practice, 1966
External links
Note the variation in usage among these samples.
- http://www.du.edu/~jcalvert/railway/degcurv.htm
- http://www.tpub.com/content/engineering/14071/css/14071_242.htm
- http://www.steamlocomotive.com/model/curve.html
- http://www.cee.mtu.edu/~balkire/ce3401tc/ce3401Lec20.doc
- http://www.trainweb.org/freemoslo/Modules/Tips-and-Techniques/degrees_of_curve.htm
- http://www.fairview-industries.com/standardmodule/circurve.htm *http://ceprofs.tamu.edu/rbruner/curves/circularcrvs.htm
- http://www.memun.org/SchoolsProject/html/Resources/Roads/Fundamentals.htm
- http://www.cityoffrederick.com/departments/Planning/APPENDIX_C_SUBDIVISION_REGULATIONS/Sec__5__Final_subdivision_plat.html
Railway infrastructure Permanent way Permanent way (history) • Permanent way (current) • Railroad tie/Sleeper • Rail fastening system • Track ballast • Rail profile • Fishplate • Breather switch • Datenail • Axe ties • Ladder track • Baulk road • Cant • Minimum radius • Track transition curveTrackwork and track structures Junction • Wye • Railroad switch • Gauntlet track • Railway electrification system • Overhead lines • Track gauge • Railway turntable • Water crane • Track pan • Rail track • Tramway track • Classification yard • Rail yard • Siding • Passing loop • Balloon loopSignalling and safety Railway signalling • Signalling control • Railway signal • Interlocking • Level crossing • Buffer stop • Catch points • Loading gauge • Structure gauge • Block postBuildings Railway track layouts Running lines Rail sidings Junctions Stations Side platform • Island platform • Bay platform • Split platform • Terminal station • Balloon loop • Spanish solution • Cross-platform interchange • Interchange stationHillclimbing Categories:- Railway track layouts
- Surveying
- Transport engineering
- Civil engineering stubs
Wikimedia Foundation. 2010.