Starling (structure): Difference between revisions
m Mzajac moved page Starling (architecture) to Starling (structure): this belongs to engineering, not architecture |
Added info, photos, link; clarified descriptions. |
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{{Short description|Support structure in engineering}} |
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{{About|the architectural term|the bird species|Starling}} |
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| ⚫ | In [[architecture]], a '''starling''' (or '''sterling''') is a defensive [[bastion|bulwark]], usually built with [[deep foundation|pilings]] or [[brick]]s, surrounding the supports (or [[Pier (architecture)|pier]]s) of a [[bridge]] or similar construction. Starlings may be shaped to ease the flow of the water around the bridge, reducing the damage caused by [[erosion]] or collisions with flood-borne debris. They may also form an important part of the structure of the bridge, spreading the weight of the piers. |
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The term ''cutwater'' is used for such a structure shaped with water flow in mind, as a pier or starling with a diamond point.<ref>{{cite web |url=https://www.britannica.com/technology/cutwater |title=cutwater |publisher=Encyclopaedia Britannia |access-date=4 April 2024}}</ref> A ''starkwater'' is a bulwark against ice floes. |
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Depending on their shape and location, some starlings may accumulate river debris, mud and other objects, potentially creating navigational hazards or hindering downstream water flow. |
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| ⚫ | In [[architecture]], a '''starling''' (or '''sterling''') |
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==Shape== |
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One problem caused by starlings is the accumulation of river debris, mud and other objects against the starlings, potentially hindering the flow. The starling has a sharpened upstream edge sometimes called the nose. The cutwater edge may be of concrete or masonry, but is often capped with a steel angle to resist abrasion and focus force at a single point to fracture floating pieces of ice striking the pier. In cold climates the starling is typically sloped at an angle of about 45° so current pushing against the ice tends to lift the downstream edge of the ice translating horizontal force of the current to vertical force against a thinner cross-section of ice until unsupported weight of ice fractures the piece of ice allowing it to pass on either side of the pier.<ref>{{cite book |
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[[File:Chepstow Bridge - geograph.org.uk - 288954.jpg|thumb|[[Old Wye Bridge, Chepstow]], low tide, looking upstream.]] |
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| last =Urquhart |
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Starlings may form part of a [[buttress]] for the vertical load of the bridge piers, so would typically be symmetrical. Other symmetrical starlings may be used on tidal stretches of rivers because of bi-directional flow, requiring dual cutwaters; at low tide, [[Old Wye Bridge, Chepstow]], on the Welsh border, can be seen to have cutwaters on both ends of the piers and their foundations. Cutwaters may also be provided downstream to reduce riverbed [[bridge scour|scour]]. Other starlings may be asymmetrical, with only an upstream cutwater, the downstream end being flat or rounded. |
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| first =Leonard Church |
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| authorlink = |
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The starling has a sharpened or curved extreme, sometimes called the nose. The cutwater may be of concrete or masonry, but is often capped with a steel angle to resist abrasion, focusing force at a single point to fracture floating pieces of ice striking the pier. In cold climates, the starling is typically sloped by about 20 to 45° from vertical, so current pushing against part-submerged ice tends to lift and shear it;<ref>{{cite book |last=Urquhart |first=Leonard Church |title=Civil Engineering Handbook |publisher=McGraw-Hill Book Company |edition=4th |date=1959 |location=New York |pages=8–75}}</ref> this can be known as a ''starkwater''.<ref>{{cite book |last1=Raymond |first1=William G. |last2=Riggs |first2=Henry E. |last3=Sadler |first3=Walter C. |title=The Elements of Railroad Engineering |publisher=John Wiley & Sons |edition=5th |date=1937 |location=New York |pages=163}}</ref><ref>{{cite book |last=Fowler |first=Charles Evan |date=1929 |title=The Ideals of Engineering Architecture |url=https://babel.hathitrust.org/cgi/pt?id=mdp.39015014100849&seq=11 |edition=1st |location=Chicago |publisher=Chicago Gillette Pub. Co. |pages=179–195}}</ref> This is distinct from a sloping top to shed the rain. |
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| title =Civil Engineering Handbook |
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| publisher =McGraw-Hill Book Company |
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On a narrow bridge, a cutwater shape can be carried up to the top of the parapet, to provide a pedestrian refuge. |
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| series = |
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[[File:IMG 4123 Providence and Worcester bridge.jpg|thumb|upright=2.5|left|[[Middletown–Portland railroad bridge]], Connecticut: starlings on the bridge piers and also at each end of the [[swing span]] (the fence-like structures around the piers are pile-supported [[bridge fenders]]).]] |
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| volume = |
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[[File:Baslow_road_bridge_over_river_Derwent_(geograph_3125886).jpg|thumb|Refuges on [[Baslow|Baslow Bridge]], Derbyshire.]] |
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| edition =4th |
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{{clear}} |
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| date =1959 |
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| location =New York |
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| pages =8-75 |
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| isbn =}}</ref> A sloped, ice-cutting starling is known as a '''starkwater'''.<ref>{{cite book |
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| last1 =Raymond |
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| first1 =William G. |
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| last2 =Riggs |
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| first2 =Henry E. |
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| last3 =Sadler |
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| first3 =Walter C. |
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| authorlink = |
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| title =The Elements of Railroad Engineering |
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| publisher =John Wiley & Sons |
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| series = |
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| volume = |
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| edition =5th |
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| date =1937 |
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| location =New York |
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| pages =163 |
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| isbn =}}</ref> |
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== See also == |
== See also == |
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* [[Dolphin_(structure)#To_protect_structures|Dolphin (structure)]] |
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* [[Breakwater (structure)|Breakwater]] |
* [[Breakwater (structure)|Breakwater]] |
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* [[Icebreaker]] |
* [[Icebreaker]] |
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== References == |
== References == |
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{{reflist}} |
{{reflist}} |
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{{DEFAULTSORT:Starling (Architecture)}} |
{{DEFAULTSORT:Starling (Architecture)}} |
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[[Category:Bridge components]] |
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[[Category:Hydraulic engineering]] |
[[Category:Hydraulic engineering]] |
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Revision as of 20:00, 4 April 2024
In architecture, a starling (or sterling) is a defensive bulwark, usually built with pilings or bricks, surrounding the supports (or piers) of a bridge or similar construction. Starlings may be shaped to ease the flow of the water around the bridge, reducing the damage caused by erosion or collisions with flood-borne debris. They may also form an important part of the structure of the bridge, spreading the weight of the piers.
The term cutwater is used for such a structure shaped with water flow in mind, as a pier or starling with a diamond point.[1] A starkwater is a bulwark against ice floes.
Depending on their shape and location, some starlings may accumulate river debris, mud and other objects, potentially creating navigational hazards or hindering downstream water flow.
Shape
Starlings may form part of a buttress for the vertical load of the bridge piers, so would typically be symmetrical. Other symmetrical starlings may be used on tidal stretches of rivers because of bi-directional flow, requiring dual cutwaters; at low tide, Old Wye Bridge, Chepstow, on the Welsh border, can be seen to have cutwaters on both ends of the piers and their foundations. Cutwaters may also be provided downstream to reduce riverbed scour. Other starlings may be asymmetrical, with only an upstream cutwater, the downstream end being flat or rounded.
The starling has a sharpened or curved extreme, sometimes called the nose. The cutwater may be of concrete or masonry, but is often capped with a steel angle to resist abrasion, focusing force at a single point to fracture floating pieces of ice striking the pier. In cold climates, the starling is typically sloped by about 20 to 45° from vertical, so current pushing against part-submerged ice tends to lift and shear it;[2] this can be known as a starkwater.[3][4] This is distinct from a sloping top to shed the rain.
On a narrow bridge, a cutwater shape can be carried up to the top of the parapet, to provide a pedestrian refuge.
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See also
References
- ^ "cutwater". Encyclopaedia Britannia. Retrieved 4 April 2024.
- ^ Urquhart, Leonard Church (1959). Civil Engineering Handbook (4th ed.). New York: McGraw-Hill Book Company. pp. 8–75.
- ^ Raymond, William G.; Riggs, Henry E.; Sadler, Walter C. (1937). The Elements of Railroad Engineering (5th ed.). New York: John Wiley & Sons. p. 163.
- ^ Fowler, Charles Evan (1929). The Ideals of Engineering Architecture (1st ed.). Chicago: Chicago Gillette Pub. Co. pp. 179–195.