I’ve heard these terms used somewhat interchangably. Is this like engine and motor where it depends on who you talk to, or is a viaduct a type of bridge, or?
A viaduct is kind of bridge, a viaduct is usualy made from stone or concrete, there are exceptions like park Ave viaduct in NYC.
Hadn’t really thought about it, so I got out the trusty ol’ dictionary and looked them up.
Bridge - A structure spanning and providing passage over a waterway, railroad, or other obstacle.
Viaduct - A series of spans or arches used to carry a road or railroad over a wide valley or over other roads or railroads.
And for good measure:
Trestle - A framework consisting of vertical, slanted supports and horizontal crosspieces supporting a bridge.
To a certain extent, it’s kind of potayto, potahto.
Both viaducts and trestles also fit the definition of bridge. Technically, the trestle supports the bridge (although we rarely differentiate), and a bridge would need to have more than one span to qualify as a viaduct. Chalk it up to life experience - I’ve always considered a railroad overpass that has large steel beams as it’s main structural member (often with a middle support) a viaduct. Probably because there was one in my old hometown. Then there’s things like Starucca Viaduct.
You could argue that a culvert is techically a bridge…
…An example I have been around many times is the Salisbury Viaduct…An abandoned structure of the former WM railroad near Meyersdale, Pa. It was abandoned along with the WM route through there in the '70’s. Now, that route has been turned into part of the Allegheny Trail and the “viaduct” has a new concrete floor and appropiate side rails…[fencing} to make it safe for bikers and walkers that pass over it now. The viaduct is roughly 1500 ft. long and near 90 - 100 ft. high.
It passes over a wide valley containing farm land, a river, a railroad…{Sandpatch area CSX} and a 4 - lane interstate type highway…Rt. 219. The viaduct is a steel structure suported by sections of steel pylons all the way across the valley. By the way, the view from up on it is fantastic…!
Anyone interested in checking the sight from up on this viaduct…go back in the “picture of the day” archive to 8-20-03 to see a photo I took from up on this viaduct.
…It is a telephoto shot.
As an aside, in shop class, they taught us that an engine generates its own energy (coal/oil/wood for steam engines, oil for diesel(electrics), where a motor is supplied energy from another source (electricity for trolleys,Little Joe’s,GG1’s,interurbans,boxcabs).
So is an SD45 locomotive both an engine and a motor?
csx has
the clinton and perry st viaducts are made of steel here in defiance. the wayne jefferson washington riverside and summit st viaducts are made of concrete with steel supports.
the maummee and western on 3rd street is steel.
stay safe
Joe
For some reason, the locals in a town near where I live (Jackson) say “vie-dock” for one bridge in particular- the one carrying the aptly-named “Airline Drive” over the now-abandoned Michigan Air Line right-of-way.
I’m stumped about the odd local pronunciation. First time I heard it, I made the mistake of saying, "You mean “viaduct”? They looked at me like I was from another planet.
Ian Smith
If I remember correctly(don’t quote me on this,I make no claims of expertise), the Park Av Viaduct in NYC is a concrete & stone structure with some iron reinforcement. If you look at it from street level,it is a massively overbuilt of stone & concrete.(early 1900’s ,late 1890’s type)
rgds ign
Yes I was taught the same thing. To make it easier on yourself an engine is strictly mechanical, a motor is strictly electrical.
Actually the real definition of an engine is that it changes chemical energy (when the fuel is atomoized within the combustion chamber it is known as a chemical recation) into mechanical energy for use. From there, an engine can be used to change mechanical energy to electrical energy, back to chemical, or hydraulic energy.
A motor uses electrical energy, which can be changed into mechanical. So the answer to your question as to what a locomotive is or what the SD45 is, um…there really isn’t a definition. It uses chemical energy to mechanical to electrical, and back to mechanical.
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If I remember correctly(don’t quote me on this,I make no claims of expertise), the Park Av Viaduct in NYC is a concrete & stone structure with some iron reinforcement. If you look at it from street level,it is a massively overbuilt of stone & concrete.(early 1900’s ,late 1890’s type)
rgds ign
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The part from mouth of tunnel to about just north of CP3(nick) is not part of viaduct, the viaduct goes from CP3 north enbd to CP4(bridge) and is steel only with a concrete top deck.
so why is detroit known as motor city, shouldnt it be enigne city?
Exceptions also include outboard motor, motorbike, and motorcycle.
The large multi-span railroad bridge in Montreal (Cartier?) would probably qualify under either defintion. A documentary on the construction of the St Lawrence Seaway mentioned jacking it up significantly rather then rebuilding, but didn’t give any details.
Mudchickens were taught from day one that if it carries drainage water or traffic, it’s a bridge! [:D][:D][:D]
(and Santa Fe had several large storm sewers labelled as bridges on its R/W maps & track charts along with an underground culvert with a conveyor system in it in Denver (Gates Rubber at I-25 & Broadway))
…To above post re: Motor City…How about another angle…“Motor” as in “happy motoring”, referring to the fact “Motor City” puts out automobiles for the “motoring” public. “Automobiles” as in the saying “motoring public”…Traveling.
Since it not politically corrrect to say New York City has elevated lines, since they were all supposed to have been torn town, the actual elevated lines, forteen altogether, in all four boroughs that have subways, are all called “subway lines on viaducts!” Officially that is. So a viaduct must be something longer than just a bridge. A bridge I would guess is designed to cover one obstacle, while a viaduct can extend through a whole town or city.
Here are the forteen “subways on viaducts” in New York:
The Bronx: Broadway (1); Jerome Avenue (4); White Plaiins Ave. - Bronx Park East - Boston Rd. - Southern Blvd. - lower Westchester Avenue (2, 5); upper Westchester Avenue (6)
Queens: Roosevelt Avenue (7), Jamaica Avenue (J,Z), Liberty Avenue (A)
Brooklyn: Livonia Avenue (3, 4), Myrtle Avenue (M), Broadway (J, part of “viaduct” to Jamaica Avenue, Queens, not counted), Brighton Beach ara (Q, B), McDonald Avenue (F) and New Utrecht Avenue (D).
Manhattan: Upper Broadway - extension from the Bronx south to Dyckman Street portal. (1) counted. “The Manhattanville Viaduct” Dates from 1904 and is part of the original subway line, spanning the 125th Street valley from about 122nd Street to about 131st. (1)
Bridge is a general term
Viaduct is a specific type of bridge (usually with stone or concrete arch spans), just like trestle, plate girder, suspension or truss, are all bridge, but a Viaduct is not a trestle is not a plate girder bridge is not a suspension bridge is not a truss bridge.
A Viaduct is always a type of bridge but a bridge is not alway a viaduct. So to answer your question there is a difference. There are many types of bridges and a viaduct is one of them. They were originally arched stone structures used by the romans to carry water across valleys. Traditionaly a viaduct would have a series of arched supports.[2c] Aa always ENJOY P.S. Why do we drive on a PARKway but park in our DRIVEway.
" I said we will put a viaduct here and…" I’m a gonna ask you. Why a duck?" “Well, we need to get to the Island, here so, we build this viaduct…” “But why a duck? You haven’t answered my question.” “What question?” “You know.” “No, I don’t.” “Why do we have a duck?”“We don’t have a duck. We have a viaduct to get-” “I’m gonna ask you only once more! Why a duck?” " How do I get into these things?"[:o)][:p]
Ain’t english fun?
viaduct
Etymology: Latin via way, road + English aqueduct
: a long elevated roadway usually consisting of a series of short spans supported on arches, piers, or columns
via
Latin vehere to carry, via way
duct
Etymology: New Latin ductus, from Medieval Latin, aqueduct, from Latin, act of leading, from ducere to lead
bridge
a structure carrying a pathway or roadway over a depression or obstacle
Etymology: Middle English brigge, from Old English brycg; akin to Old High German brucka bridge, Old Church Slavonic bruvuno beam
Only partially true, there are pneumatic motors and hydraulic motors too. An air motor is what makes the wrench work that your mechanic uses to attach the lug nuts on your wheels. Pneumatic sanders, drills, saws are the same, it is a pneumatic motor that makes them work.
Hydraulic motors are common on farm and construction equipment. A hydraulic motor powers the pump a farmer has mounted on the back of his tractor.
There are many applications for hydraulic and pneumatic motors in industry. Sometimes they are used to eliminate the possibility of explosions ignited by the electric motors. And sometimes they are much less expensive because there already is a supply of compressed air available.