US3626534A

US3626534A - Method of erecting parallel wire strands in bridge saddles

Info

Publication number: US3626534A
Application number: US864231*A
Authority: US
Inventors: Joseph R Bell; John E Windsor
Original assignee: Bethlehem Steel Corp
Current assignee: Bethlehem Steel Corp
Priority date: 1969-04-16
Filing date: 1969-04-16
Publication date: 1971-12-14
Anticipated expiration: 1988-12-14

Abstract

PARALLEL WIRE STRANDS ARE POSITIONED IN A BRIDGE SADDLE BY COMPACTING THE STRANDS INTO A RECTANGULAR CROSS SECTION AND APPLYING U-SHAPED FORMS TO THE STRAND AT SPACED LOCATIONS ALONG THE PORTION OF THE STRAND WHICH IS TO BE SUPPORTED IN THE SADDLE. THE SHAPED STRANDS ARE THEN PLACED SIDE BY SIDE IN THE SADDLE IN LAYERS AND AS EACH LAYER IS COMPLETED THE U-SHAPED FORMS ARE REMOVED.

Description

Dec. 14, 1971 J. R. BELL ETAL 3,626,534

METHOD OF ERECTING PARALLEL WIRE STRANDS IN BRIDGE SADDLES Filed April 16, 1969 e R W In 0 w m m J J l N VE N TORS United States Patent Olhce 3,626,534 METHOD OF ERECTING PARALLEL WIRE STRANDS IN BRIDGE SADDLES Joseph R. Bell, Warwick, R.I., and John E. Windsor, Bristol, Md., assignors to Bethlehem Steel Corporation Filed Apr. 16, 1969, Ser. No. 864,231 (Filed under Rule 47(a) and 35 U.S.C. 116) Int. Cl. E01d 11/00 US. Cl. 14-22 3 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION This invention relates to the erection of suspension bridge cables and more particularly to the placement of parallel wire suspension cables in bridge saddles.

The main cables of suspension bridges are usually composed of a large number of steel wires arranged parallel to each other. Traditionally the individual wires have been separately erected by spinning back and forth between the cable anchorages.

The individual wires are laid in the bridge saddles as they are carried across the span during spinning. These wires are then temporarily gathered into strands and then compacted together to form the final bridge cables.

A recent development described in assignees copending application Ser. No. 575,038, filed Aug. 25, 1966 and now Pat. No. 3,526,570, has made possible the shop fabrication of long hexagonal parallel wire strands. These hexagonal parallel wire stands are transported after fabrication to the bridge site and are erected upon the bridge by pulling them across the bridge span. Usually the parallel wire strands are pulled across the bridge on rollers and are then lifted from the rollers by a hoist and deposited in the saddles in a predetermined arrangement.

It is very important that the strands be compactly placed within the saddles with a minimum of voids between the wires. Previous practice with shop fabricated strands has been to place the strands in horizontal layers within the saddle with sheet metal separators between the layers. The hexagonal strands were slid into position across the smooth separators and compacted together into layers of wires by hydraulic or other compression means exerting both horizontal and vertical pressure on the strands. This treatment involved considerable stress upon the hexagonal strands to compress them into uniform layers and the sheet separators added voids to the completed cable within the saddles.

SUMMARY OF THE INVENTION The foregoing difficulties have been obviated by the present invention which compacts each individual hexagonal strand into a rectangular configuration prior to placing it in the saddle. Rectangular or U-shaped forms are placed at intervals over the portion of the strand which is to rest in the saddle to shape and maintain the strand in a regular rectangular shape. Securing means are then placed around the forms to retain the wires temporarily within the forms and the shaped, or formed, strand is placed within the saddle in its final position with the open end of the form facing downwardly. After each layer of strands is placed in the saddle the securing means is re- 3,626,534 Patented Dec. 14, 1971 leased and the forms are withdrawn leaving a uniform layer of compactly arranged rectangular strands within the saddle. A second layer of strands is then placed upon the first in the same manner and this procedure is repeated until all the wires of the suspension cable have been placed in the saddle.

This method of positioning and compacting the strands is much faster and more accurate than previous methods and has the additional advantage that the height of each layer of strands making up the cable can be easily varied by using form members of different dimensions.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic elevation showing a suspension bridge saddle in which shop fabricated parallel wire strands are being placed.

FIG. 2 is a cross-sectional elevation taken along the line 22 of FIG. 1.

FIG. 3 is a schematic plan perspective of parallel wire strands being placed in a brige saddle according to the present invention.

FIG. 4 is a perspective view of form members being applied to a parallel wire strand.

FIG. 5 is a perspective view of a form member.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1, 2 and 3 show shop fabricated parallel wire strand 11 being placed within the trough 13 of a suspension bridge saddle 15. Each originally hexagonal strand 11 is pulled across the bridge span and past saddle 15 on rollers 17. After the strand is correctly positioned longitudinally with respect to the bridge span, the strand in the area of the saddle is compacted to an elongated rectangu-- lar shape by means of the fiat

adjustable jaws

21 and 23 of clamp 25 as seen in FIG. 4. U-shaped form members 19 are then placed over the strand as shown. Other suitable means may be used to compact the strand prior to the application of members 19 and if necessary the form members can be forced over the strand by the use of wooden mallets or the like.

After the strand is shaped and the form members applied as shown in FIG. 4 a strap or band 27 or other suitable securing means is positioned about the form mem bers 19 to temporarily secure the shaped strand within the form member. The shaped strand is then transferred from the rollers 17 by any suitable transfer means such as derrick 29 and placed in the trough 13 of saddle 15 in the position which it is finally to occupy as shown in FIG. 3. The various strands of each layer of strands in the saddle trough 13 are placed tightly together as shown. The shaped strands are placed with the forming members 19 open end downwardly so that all the forming members may be easily removed. After each layer of strands is completed the straps 27 or other securing devices are released and forming members 19 removed. As the forming members 19 are removed, the rectangular bundle of Wires spreads out slightly to take up the space occupied by the forms leaving a compact even layer of wires Within the saddle trough. Subsequent layers of strands are easily erected in the same manner upon the initial layers as shown in FIG. 2 until a predetermined number of layers of wires have been formed in the saddle. After inated when erecting strand according to the present invention.

3 By the present invention the time necessary for the placement of parallel wire strands in bridge saddles is very materially decreased and the compactness and efiiciency of the suspension strand within the saddle is materially increased.

We claim:

1. A method for erecting shop fabricated hexagonal parallel wire strands in a bridge saddle comprising:

(a) shaping a plurality of hexagonal parallel wire strands into individual rectangular configurations of equal height Within strand forming means,

(b) securing said strands with strand retaining means to maintain their rectangular configuration,

(c) closely positioning a plurality of said strands within the trough of a bridge saddle to form a substantially planar layer of said strands,

(d) removing the retaining means from each of said strands within the saddle leaving a uniform planar layer of suspension wires,

(e) repeating steps (a) through ((1) until a predetermined number of layers of wires have been placed in the trough of the saddle.

2. The method for erecting shop fabricated hexagonal parallel wire strands in a bridge saddle according to claim 1 wherein each of the strands is inserted into a U-shaped forming means to form it and is secured therein with a securing means to retain the shape of said strand and wherein the U-shaped forming means are faced downwardly when the strands are placed within the trough of the saddle to facilitate their removal.

3. The method of erecting shop fabricated hexagonal parallel wire strand in a bridge saddle according to claim 2 wherein said strands are compacted into an elongated rectangular form prior to placement in said forming means by the use of clamping means having flat movable jaws adapted to force the wires of said strands into a compact rectangular configuration to facilitate the placement of the forming means over the strand.

References Cited UNITED STATES PATENTS 2,118,187 5/1938 Fine 14-22 JACOB L. NACKENOFF, Primary Examiner