Both are vehicle bridges. The first Center Street Bridge was a wooden structure that was replaced five or six times. One of these was the. The present bridge, a steel truss with unequal arms, was built in This example of the center-pier, swing type, is fast disappearing from the American scene [Figure XVI].
This rim-bearing swing span is feet; 8 inches; minimum channel clearance is feet. The bridge turns horizontally about a vertical axis, like a railroad turntable. The two projecting arms act as cantilevers when the bridge is open. When closed the bridge becomes a truss. Since the two arms are unequal, a balancing counter-weight is required on the shorter arm.
This is accomplished by a solid deck of concrete on the short span and a open mesh deck on the long span. Contractors for the substructure were L. Smith Company.
The King Bridge Company built the superstructure. This structure has the pivot pier on the north bank, similar to that of the old Superior Viaduct. When this type of bridge was first used, the pivot pier was placed in the middle of the channel. When the bridge was open, the free end of the bridge was protected by long fenders built of timber piles and walers. Little wonder that this type was replaced with longer — and more expensive — spans.
Its history dates back to the very earliest days of Cleveland and Ohio City, as we have seen in Chapter 1. Its superstructure was of wood and covered — probably the only covered bridge Cleveland ever had. By transportation demands had outgrown this bridge, and agitation for a new structure began.
However, the city of Cleveland and Ohio City could not agree as to who should build it, whereupon the county settled the dispute and assumed the responsibility. In and iron bridge was built, but this, too, soon had to be replaced. In a new bridge, designed by city engineer Walter F. Rice, was built. It was an extraordinary structure — a double-swing span — the first of its kind in the world. Each leaf was mounted on a separate pier and turntable.
The clear opening between fenders was feet. Each river arm was 65 feet; the short spans over the piers was 15 feet. The combined length of the two leaves was feet. At present it needs repairs. The Columbus Street crossing exemplifies the life-history of the low — level bridge over navigable waters.
First came the crude and narrow structure, with a center leaf to open the channel to river traffic. By the middle of the nineteenth century, the timber bridge was followed by a light iron bridge with a wider roadway; it generally was a swing bridge. Near the end of the century, came a still heavier structure, generally of steel, to carry increased loads.
Finally an entirely different bridge type emerged, designed to accommodate modern transportation needs; the vertical lift. This bridge serves the team tracks of the oldest railroads in Cleveland, dating from Founded by Alfred Kelley, mayor, canal commissioner and promoter, it was originally called the Cleveland, Columbus and Cincinnati Railroad.
When extended to St. The present bridge, erected in , replace an older Scherzer Rolling Lift Bridge, built in , with a clear channel opening of feet. The new bridge was designed by Howard, Needles, Tammen and Bergendoff, and received the American Institute of Steel Construction Award of Merit for the most beautiful bridge in its class.
It has a vertical lift span of feet, with a clear channel of feet. The two hp motors are located at the top of the two girders. Massive balance chains adjust the changing load. Normal lift is about 90 feet. The present Carter Road Bridge, a vertical lift, designed in by Wilbur Watson and Associates, replace the two older structures.
Carter Road, appropriately named after Lorenzo Carter, the first permanent settler, has long been the site of an important vehicle crossing.
There was a bridge at this general location as early as This was followed in by an iron swing bridge with one pivot span of feet and one fixed span of feet. The fourth bridge on this site was a Scherzer Rolling Lift Bridge, built in , and the first of its kind in the city.
It had a double-leaf drawspan feet long. The roadway was 23 feet wide with two 6-foot sidewalks. The lift span is feet long; the clear channel opening between fenders is feet.
Total length of the bridge is feet. The concrete piers support the superstructure. And each pier foundation comprises six inch steel cylinders about feet in length, supplemented by steel batter piles and a steel pile enclosure.
The normal lift of the bride is a about 75 feet, with a clearance of a little over 97 feet for a large lake freighters. Overall width of the bridge is 58 feet, 6 inches. The roadway has four vehicle lanes and is 46 feet, 6 inches wide, with two 5-foot sidewalks. The superstructure was fabricated by Mt. The contractor cantilevered the center span out from each tower in a raised position. The foundations were built by the Western Foundation Company of Chicago. Built in , it had a channel opening of The present viaduct has an overall length of 1, feet from Scranton Road to Ontario Street.
The ramp includes the vertical lift span over the Cuyahoga River, built on the same grad as the viaduct. This lift span has the distinction of being the first vertical lift in Cleveland, having been built in , and the sixth such structure in the United States. The span is feet, with a clear channel opening of feet, and is 52 feet wide. Designing engineer was F. Gorman, and the engineer in charge of construction was Noah H. The resident engineer was G. The bridge has been recently remodeled with new electrical controls, but the original hp motors were retained in service.
As the motors turn to lift or lower the bridge, the drums haul in and feed out the cable that are connected to the top and bottom of the towers, thus pulling the bride up and down. The bridge has free-standing towers, a design no longer used because the alignment shifts, and then the bridge binds.
Under the Lorain-Carnegie High Level Bridge, there is another type of movable bridge-a trunnion bascule with a single leaf. This replaced a Scherzer type of draw that had a span length of feet and was built in In the Cleveland, Columbus, Cincinnati and St. Louis Railway erected the present structure. It has a clear channel length of feet and opens to a full angle of A single track runs through a riveted truss with a length of feet and a width of 18 feet. In addition to the lift span, the bridge consists of a foot tower span and a foot deck plate girder approach.
The three piers are of concrete. It is worth more than a casual glance, for the concept is old. The prototype of the bascule bridge is the drawbridge across the moat of a medieval castle. The modern prototype is the Tower Bridge over the Thames in London, built in The present-day trunnion bascule bridge comes with one leaf or two. The leaf or leaves is supported at the shore and on a trunnion or shaft. In opening, the bridge rotates about this shaft and raises its leaves to a nearly vertical position; in the opening position the trunnion supports the entire dead weight of the structure.
The river arm is longer, of course, than that part of the bridge extending to the rear of the trunnion. This makes necessary the use of counterweights at the rear of the bridge. Joseph Strauss was the famous American engineer who designed the Golden Gate Bridge, and he held numerous patents on bascule bridges. He designed many of the lift bridges in Chicago, where one can see excellent examples of both the single-leaf and the double-leaf bascule.
It consists of a plate girder viaduct and six deck and through riveted truss spans of moderate length. A double-track viaduct, the total length is 3, feet.
Bridges come in many shapes and sizes. When you consider the types of materials used, the style of construction and the main use of the crossing, you find that bridges can take many forms. Bridges can be simple wooden beams over small streams or massive steel and concrete suspension structures crossing miles of open water and shipping channels.
The best-known bridges in the Portland area span the Willamette and Columbia rivers, but there are also smaller structures that cross the Sandy River, Johnson Creek, Beaver Creek and other waterways, as well as roads, highways and railroads. View of Morrison Bridge from SW. Bridges are of two general types: fixed and movable. Fixed bridges are usually classified by their basic geometry such as arches, trusses, beams, girder, suspension and cable stayed.
Steel has been used in the construction of bridges for many years. Many small bridges today are constructed using concrete beams. Suspension bridges, whose decks are suspended from cables and towers, are used in locations where it is difficult to place piers. Snowbird, Utah, USA. April 9—12, Movable railroad bridges, consisting of lift, bascule, or swing bridges have been used by American rail tracks that cross usable waterways for over a century.
Although custom made, movable bridges share many common components and designs. Automated locks hold the bridge in place as soon as the movement stops. The bridge operation, train and ship signaling systems work in synchrony for trains and waterway traffic to be granted safe passage with minimal delay.
The primary objective of this paper is to develop a framework to analyze the safety and security of the bridge operating systems and their synchronous operations with railway and waterway systems. We do so by modeling the movable physical components and their control system with the interconnected network system and determine the faults and attacks that may affect their operations.
Given the prevalence of attacks against PLCs, FPGAs and controllers, we show a generic way to determine the effect of what if scenarios that may arise due to attacks combined with failures using a case study of a swing bridge. Sign In or Create an Account. Sign In. Advanced Search. Skip Nav Destination Proceeding Navigation.
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