Abstract:
A below main cable work platform support for hanging a work platform below a main cable of a suspension bridge and a method of installation thereof. A plurality of supports attach to each band on a main cable. Each support has a pair of struts bolted to the band, the top of each strut on each side of the band, the struts extending downward, connecting to the ends of a horizontal bar that sits between a pair of suspender cables hanging from each band. A work platform is suspended from the horizontal bar and tie down cables extend downward from the bar attaching below to stabilize the platform against wind and uplift. The method includes the step of screwing a single bolt into each side of a cable band for supporting the support therebelow.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a nonprovisional utility application of the provisional patent application, Ser. No. 61/869,207 filed in the United States Patent Office on Aug. 23, 2013 and claims the priority thereof and is expressly incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to a platform support and a method of installing said support. More particularly, the present disclosure relates to a below main cable work platform support for hanging a work platform below a main cable of a suspension bridge and a method of installation. 
     BACKGROUND 
     A suspension bridge is a type of bridge in which the load-bearing portion called the deck is hung below main suspension cables on vertical hangers or suspender cables. The main cables are suspended between towers and form a parabola, the suspenders transferring the load to the cables and the cables transferring the load to the towers. 
     The main cables are generally braided steel wire and are over-wrapped to form a circular cross section. At specific points along the main cable, bands are installed to carry the steel wire suspenders. 
     Like any steel that is constantly exposed to the elements, the steel of cables requires periodic maintenance. Generally, maintenance projects require that the bridge be shut down completely or reduced to a minimum number of lanes. Since most bridges carry a significant amount of traffic during most of the day and night, maintenance usually is limited to off-peak traffic times if possible, which extends the duration of the project. 
     When maintenance is performed on the main cables, workers generally must walk on top of the main cable, using a hand rope parallel above the cable to maintain balance. For safety reasons when the workers are working on the main cable, it is generally necessary to shut down several if not all lanes on the bridge to traffic which is not only inconvenient but also has economic consequences. 
     In the present disclosure, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date, publicly available, known to the public, part of common general knowledge or otherwise constitutes prior art under the applicable statutory provisions; or is known to be relevant to an attempt to solve any problem with which the present disclosure is concerned. 
     While certain aspects of conventional technologies have been discussed to facilitate the present disclosure, no technical aspects are disclaimed and it is contemplated that the claims may encompass one or more of the conventional technical aspects discussed herein. 
     BRIEF SUMMARY 
     An aspect of an example embodiment in the present disclosure is to provide a support for a work platform that permits a worker to safely traverse a main cable of a suspension bridge. Accordingly, the present disclosure provides a support for a below main cable work platform that permits a worker to traverse a main cable of a suspension bridge by walking on a flat surface platform situated below the main cable. 
     Another aspect of an example embodiment in the present disclosure is to provide a support for a work platform that allows bridge maintenance to be performed without disrupting traffic. Accordingly, the present disclosure provides a support for a below main cable work platform that allows bridge maintenance to be performed by workers standing on a flat platform, minimizing safety risks while working above traffic, allowing traffic to flow without disruption while maintenance work is performed. 
     A further aspect of an example embodiment in the present disclosure is to provide a work support that fastens to a band on the main bridge cable without disrupting the distribution of a deck load. Accordingly, the present disclosure provides a support that couples to a band on a cable by attaching a plate to the band and coupling a work platform support to the band, further coupling the work platform support to the band with a temporary strap, maintaining tension and load on the cable with the temporary strap. 
     Accordingly, the present disclosure describes a below main cable work platform support for hanging a work platform below a main cable of a suspension bridge and a method of installation thereof. A plurality of supports attach to a plurality of bands on a main cable. Each support has a pair of struts bolted to the band, the top of each strut on each side of the band, the struts extending downward, connecting to the ends of a horizontal bar that sits between a pair of suspender cables hanging from each band. A work platform is suspended from the horizontal bar and tie down cables extend downward from the bar attaching below to stabilize the platform against wind and uplift. The method includes the step of screwing a single bolt into a cable band for supporting a structure therebelow. 
     The present disclosure addresses at least one of the foregoing disadvantages. However, it is contemplated that the present disclosure may prove useful in addressing other problems and deficiencies in a number of technical areas. Therefore, the claims should not necessarily be construed as limited to addressing any of the particular problems or deficiencies discussed hereinabove. To the accomplishment of the above, this disclosure may be embodied in the form illustrated in the accompanying drawings. Attention is called to the fact, however, that the drawings are illustrative only. Variations are contemplated as being part of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, like elements are depicted by like reference numerals. The drawings are briefly described as follows. 
         FIG. 1A  is a dynamic perspective view of an example embodiment of a below main cable work platform support in place on a bridge main cable. 
         FIG. 1B  is a side elevational view in cross section of an example embodiment of the below main cable work platform support in place on a bridge main cable. 
         FIG. 2  is a dynamic perspective view of an example embodiment of the below main cable work platform support in place on a bridge main cable, maintaining the work platform below the cable. 
         FIG. 3  is a dynamic perspective view of a plurality of the below main cable work platform supports in place on the main cable prior to installing the work platform below the cable. 
         FIG. 4  is a perspective view from below of the work platform installed on the example embodiment of the below main cable work platform supports. 
         FIG. 5  is a side elevational view of a strut of the support bolted to a band on the bridge main cable. 
         FIG. 6  is a dynamic perspective view of the platform in place on the example embodiment of the below main cable work platform support with an overlay portion connecting a pair of sections of the deck and covering a horizontal bar of the below main cable work platform support. 
         FIG. 7A  is a dynamic perspective view of a further example embodiment of a below main cable work platform support in place on a bridge main cable, the support having a pair of horizontal bars. 
         FIG. 7B  is a side elevational view in cross section of another example embodiment of the below main cable work platform support in place on a pair of twin bridge main cables. 
     
    
    
     The present disclosure now will be described more fully hereinafter with reference to the accompanying drawings, which show various example embodiments. However, the present disclosure may be embodied in many different forms and should not be construed as limited to the example embodiments set forth herein. Rather, these example embodiments are provided so that the present disclosure is thorough, complete and fully conveys the scope of the present disclosure to those skilled in the art. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1A  illustrates a below main cable work platform support  10 , hereafter referred to as a platform support, in place on a bridge main cable  100 . The bridge main cable is one of several suspension main cables suspended between a plurality of towers. A plurality of vertical suspender cables hang off the main cables, the main cables and suspender cables bearing the load-bearing portion of the bridge called the deck. The below main cable work platform support supports a below main cable work platform when the platform is in a position for performing maintenance work on the main cable of the suspension bridge. The below main cable work platform allows maintenance work on the main cable to occur without shutting a portion of the bridge deck to traffic. 
     In this disclosure, a method of attaching and supporting a particular style of work platform will be discussed. However, it is understood that the method and the support can be applied to many types of platforms and scaffolding for use on a suspension bridge main cable and it not limited to the particular structure or use shown in the illustrations. 
     The support has a pair of struts  14  and a horizontal bar  12  connecting the struts. Each strut has a top end  14 T and a bottom end  14 B. The horizontal bar  12  has a top and a pair of opposing end portions  12 E. The bottom end  14 B of each strut attaches to the horizontal bar  12  substantially towards an opposing end portion  12 E of the bar, a strut coupled to each end forming an isosceles triangle with the main cable at the apex of the triangle. In one embodiment, as shown in  FIG. 1B , the triangle formed by extending imaginary lines from the tops of the struts is an equilateral triangle. 
     The horizontal bar  12  is further stabilized by a pair of tie-downs  22 , the tie downs attaching to the ends of the bar  12 E and extending downward, attaching to the bridge structure below  118 . The tie-downs  22  and bar  12  form a second isosceles triangle. 
     Referring again to  FIG. 1A , the top  14 T of each strut attaches to a plate  16  that fits snugly against the a band on the main cable. The band has a pair of opposing sides, one plate fastening to each opposing side of the band. The strut and plate fasten to the band by a single bolt. 
     The horizontal bar  12  hangs between a pair of suspender cables  102 . A temporary strap  20  straddling the band and attaching to the horizontal bar is in place to stabilize the support during installation. The temporary strap temporarily distributes the decking section load without disrupting the main cable load. Disruption of the load on a suspension bridge can have catastrophic results. The temporary strap helps to prevent the disruption during the installation of the work platform supports and work platform. 
     In the illustration, a plurality of cord guides  18  are on the top of the horizontal bar  12  for placing a plurality of cords of the work platform prior to clamping and installing the work platform. The cord guides  18  govern a plurality of cords  116 . A plurality of clamps  122  fastened to the cord guides, one clamp on each cord guide after one cord of the decking section is placed through the cord guide, the cords operative for hanging a decking section of a below main cable work platform. In one example embodiment, the clamp is a U-clamp. It is understood that substituting other types of fastening systems are possible with this support  10  operative for hanging other structures, scaffolding and platforms from the main cable. 
     As illustrated in  FIG. 3 , a plurality of work platform supports  10  are installed on the bands  104  before a plurality of decking sections are installed, the horizontal bar  12  between each pair of suspender cables  102 . 
     The system for maintaining a main cable on a suspension bridge without shutting a portion of the suspension bridge to traffic is illustrated in  FIG. 3 . A plurality of supports  10  are fastened to a plurality of bands  104  on the main cable, each band having at least one support, the horizontal bar  12  of each support between each pair of suspender cables  102  on each band. 
     Each support has a pair of plates fastened to the each band as explained hereinabove as shown in  FIG. 1A . 
     As shown in  FIG. 4 , a plurality of decking sections  114  hang from cords  116  in the cord guides of the horizontal bars, each decking section having an opposing edge  114 E abutting the opposing edge of an adjacent decking section, forming a continuous platform  120  below the entirety of the main cable. 
     The system has clamps  122  fastened to the cord guides  18 , as shown in  FIG. 1A , one clamp on each cord guide after one cord  116  of the decking section is placed through the cord guide. Note the drawing shows the cords in a slack state for purposes of illustration, but generally are in a taut state resulting from the weight of the decking section. 
     As shown in  FIG. 6 , an overlay decking portion  112  covers each horizontal bar  12 , providing an uninterrupted surface on the continuous platform  120  below the main cable. The overlay decking portion also covers the cord guides and secures the clamped cords of the platform decking sections. 
       FIG. 7A  demonstrates another example embodiment of the work platform support  10 . A pair of supports  10  is fastened to each band  104  through one pair of plates  16 . The support has two pairs of struts  14 , each coupled to one horizontal bar  12  of a pair of horizontal bars  12 , the horizontal bars on the outside of the suspender cables  102 . 
     As shown in  FIG. 7B , in one example embodiment, the bridge has a pair of twin main cables  100  in parallel on each side of the bridge. The below main cable work platform support  10  has the plates  16  and struts  14  coupled to bands  104  on each main cable, the struts  14  on the two cables coupled to one horizontal bar  12 . The below main cable work platform  120  is supported on the work platform support  10  as described hereinabove. 
     The method of attaching the support is described in detail hereinbelow.  FIG. 5  shows a novel step of the method. On each band  104  on the main cable, are a pair of side bolts  106 , one on each side. Coupled to the side bolts are hand rope supports  110  that extending vertically above. Each bolt is temporarily removed and the plate  16  is coupled to the bolt  106  and hand rope support  110  when the bolt is replaced. The top of the strut  14 T is coupled to the plate  16  below the bolt  106 . A temporary strap  20  is placed over the band  104  to stabilize the support during installation. Balancing the load throughout the bridge structure at all times is critical and the method requires temporary stabilization until installation is complete. 
       FIG. 2  shows a hand rope  108  and the hand rope supports  110  extending above each band on the main cable. The hand rope and hand rope supports are pre-existing structures that are present prior to the installation of the below main cable work platform supports  10  and a below main cable work platform  120 . Without the below main cable work platform, workers walk on top of the cable, using the hand rope for support. Without the below main cable work platform, cable maintenance can only be performed when traffic on the deck below is prohibited, either causing tie-ups or having the work performed on off-peak hours. 
     Referring to  FIG. 1  A, the method of installing the below main cable work platform support  10  in place on a bridge main cable comprises removing the bolt  106  coupling the hand rope support  110  to the main cable band  104  and reattaching the bolt with the hand rope and the plate  16  as described hereinabove. The top of a first strut  14 T on the support  10  is coupled to one plate  16  and the top of a second strut us coupled to one plate on an opposing side. In one embodiment, the horizontal bar  12  is coupled to the bottoms  14 B of the first and second strut  14  prior to coupling the struts to the plates  16  and in another embodiment, the bar  12  is coupled to the struts  14  after the struts are in place on the plates on the band. 
     The support  10  is stabilized by at least one temporary strap  20 . Decking portions are coupled to the fastening means on the horizontal bar. In  FIG. 1A , as a non-limiting example, cord guides  18  are on the horizontal bar and cords are placed in the guides and clamped in place. Gaps in the decking are covered by overlay portions  112  as shown in  FIG. 6 . As shown in  FIG. 1B , the horizontal bar  12  is further stabilized by a pair of tie-downs  22 , the tie downs attaching to the ends of the bar  12 E and extending downward, attaching to the bridge structure below  118 . Once the decking section  112  and tie-downs are installed, the temporary strap can be removed. 
     Once the supports  10  are coupled to the each band  104  on the main cable  110 , as shown in  FIG. 3 , the platform deck or other structures can be installed.  FIG. 4  shows a plurality of decking sections  112  having a plurality of planks connected by a plurality of cords  116 . In this embodiment, the cords of the deck  120  are placed in the cord guides  18  and clamped in place. As explained hereinabove, other configurations of decking and scaffolding structures with different fastening means are possible within the inventive concept. 
       FIG. 6  shows an overlay decking portion  112  covering the horizontal bar  12  of the support, to cover a gap for safety reasons and to protect the cords in the cord guides. 
     It is understood that when an element is referred hereinabove as being “on” another element, it can be directly on the other element or intervening elements may be present therebetween. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. 
     Moreover, any components or materials can be formed from a same, structurally continuous piece or separately fabricated and connected. 
     It is further understood that, although ordinal terms, such as, “first,” “second,” “third,” are used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, “a first element,” “component,” “region,” “layer” or “section” discussed below could be termed a second element, component, region, layer or section without departing from the teachings herein. 
     Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, are used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It is understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     Example embodiments are described herein with reference to cross section illustrations that are schematic illustrations of idealized embodiments. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, example embodiments described herein should not be construed as limited to the particular shapes of regions as illustrated herein, but are to include deviations in shapes that result, for example, from manufacturing. For example, a region illustrated or described as flat may, typically, have rough and/or nonlinear features. Moreover, sharp angles that are illustrated may be rounded. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the present claims. 
     In conclusion, herein is presented a below main cable work platform support. The disclosure is illustrated by example in the drawing figures, and throughout the written description. It should be understood that numerous variations are possible, while adhering to the inventive concept. Such variations are contemplated as being a part of the present disclosure.