US3504464A - Tower structure and method of erecting the same - Google Patents

Description

April'!, 1970 4. 2.34m YET AL 3,504,464

TOWER STRUCTURE AND METHOD OF ERECTING THE SAME Filed March 7, 1966 4 Sheets-Sheet 1 INVENTOR. ROBERT E. BAIR BY HALVOR s. JENSEN A TTORNEY April 7, 1970 I REBMQ ET AL 3,504,464

TOWER STRUCTURE AND METHOD OF ERECTING THE SAME 1 Filed Ma rch 9, 19 6 4 Sheets-Sheet 2 l 8 INVENTOR. ROBERT E. BAIR I BY HALVOR SJENSEN FIG. 3

A TTORNE Y April 1, 1970 I R.,EI.'YBAYIETALI q 3,504,464

TOWER STRUCTURE AND METHOD OF ERECTING THE SAME Filed March 7, 1966 4 4 She'et s-Sheet s INVENTOR. ROBERT E. BA/R HA LVOR 8.JE NSE N kZZ-l TTORNEY R. E. AliQ ET AL 3,504,464 TOWER STRUCTURE AND METHOD OF ERECTING THE SAME Filed March 7, 1966 April 1, 1970 4 Sheets-Sheet L INVENTOR.

ROBERT E. BAIR BY HALVOR s. JENSEN ATTORNEI United States Patent M 3,504,464 TOWER STRUCTURE AND METHOD OF ERECTING THE SAME Robert E. Bair, Fort Worth, Tex., and Halvor S. Jensen,

Concord, Calif., assignors to Kaiser Aluminum &

Chemical Corporation, Oakland, Calif., a corporation of Delaware Filed Mar. 7, 1966, Ser. No. 532,275 Int. Cl. E04h 12/20; E04g 21/00 US. Cl. 52-148 7 Claims ABSTRACT OF THE DISCLOSURE Improved electrical transmission tower and the like comprised of a lower mast secured to the ground by a ball joint means and an upper mast, wherein the lower mast is coupled to the upper mast by a second ball joint means and both masts are guyed to the ground. The guy wires are provided in two sets with the first set of four secured between the top of the lower mast and the ground and the second set of four wires extend from the top of the upper mast to the ground.

The guy wires of each set are paired off with the guy wires of the other set so that one guy wire of one set can be anchored to the same common point on the support surface as a guy wire of the other set. An improved arrangement is provided for assembling the masts at the site of tower installation. The lower mast is tilted into a vertical position and secured by g-uy wires. The upper end of the lower mast and the lower end of the upper mast are temporarily connected by a length of cable loosely threaded through the upper end of the lower mast. The upper mast is raised to a vertical position atop the lower mast and guided by drawing down the cable through the upper end of the lower mast. The upper mast is secured by guy wires. A helicopter may be used to raise the upper mast- This invention relates to a tower for supporting electrical transmission lines and to a method for erecting such a tower. More particularly, it relates to an improved tower for supporting electrical transmission lines comprised of upper and lower mast sections which are coupled together in an improved fashion together with an improved method for assembling and erecting the various sections of the improved tower at a preselected location or erection site.

Accordingly, it is a primary purpose of the instant invention to provide an improved tower for electrical transmission lines and the like made up of uniquely coupled together mast portions as well as an improved method for installing such a tower at a preselected location or site.

This and other purposes and advantages of the instant invention will become more apparent from a review of the following detailed description when taken in conjunction with the appended drawings, wherein:

FIG. 1 is a front elevational and diagrammatic view of a tower assembled and erected in accordance with the instant invention and with certain parts broken away and other parts removed;

FIG. 2 is a top plan view on a reduced scale of the tower of FIG. 1 with certain parts removed;

FIG. 3 is an enlarged broken view taken within the limits of encircling line 3 of FIG. 1 and illustrates details of an improved ball and socket connection between the upper and lower mast portions of the tower;

FIG. 4 is an enlarged broken elevational view taken within the bounds of circumscribing line 4 of FIG. 1 and illustrates various details of the ball and socket connection between the bottom extremity of the tower and the erection site surface;

3,504,464 Patented Apr. 7, 1970 FIG. 5 is a sectional view taken generally along line 55 of FIG. 3 and illustrates details of the socket end of the coupling;

FIG. 6 is a sectional view generally taken along line 6-6 of FIG. 3 and illustrates details of the ball end of the coupling;

FIG. 7 is an enlarged broken frontal view of the upper portion of the tower taken within the bounds of encircling line 7 of FIG. 1, with certain parts removed and other parts broken away and illustrates certain structural elements of the tower;

FIG. 8 is a partial sectional view taken along line 8-8 of FIG. 7 wherein portions have been broken away and other portions removed and illustrates details of an upper section of the upper mast of the tower;

FIG. 9 is a cross-sectional view with parts removed taken along line 99 of FIG. 7;

FIG. 10 is a partial sectional view taken generally along line 10-10 of FIG. 1, with certain parts removed and with other parts broken away and illustrates details at an upper end of the upper mast portion of the tower;

FIGS. 11 to 13 represent three diagrammatic views of the several steps involved in assembling and erecting various components of the tower; and more specifically FIG. 11 is a diagrammatic view of appropriate equipment that can be used during the step of erecting the lower mast from a horizontal position to a raised position;

FIG. 12 is a diagrammatic view of the lower mast when anchored in a raised position; and 1 FIG. 13 is a diagrammatic view illustrating the steps of loosely interconnectingthe upper mast relative to the erected lower mast and thereafter hoisting the upper mast into place relative to the lower mast.

With further reference to the drawings, a preferred form of tower that can be built by following the teachings of the instant invention generally comprises a tower 10 having interconnected upper and lower mast portions 12 and 14 and a set of upper and lower guy wires 16 and 18 respectively connected at their upper ends to the mast portions 12 and 14 and at their lower ends to preselected points P on a support surface generallyv indicated at 20. This connection of guy wires 16 and 18 anchors the masts 12 and 14 relative to the support surface 20 in an improved manner and will be subsequently described in detail. The upper and lower masts 12 and 14 are made up of prefabricated truss members of any suitable configuration wherein the lower mast 14 includes a single vertical.

truss member 22 and the upper mastincludes a series of interconnected truss members 24, 26 and 28. The two truss members 24 of corresponding shape are interconnected at their lower ends and are arranged to diverge in an upward and outward direction relative to each other from their interconnected lower ends. The upper ends of the truss members 24 are interconnected by the span of the truss member 26. The outer ends of the truss member 26 protrude beyond their interconnection with the upper ends of the truss members 24. Two truss members 28, acting as peak towers, are disposed in a raised or elevated position above the bridge member 26 and in spaced relation to each other. Each truss member 28 is preferably connected at a point intermediate the ends of the bridge member 26 and directly above the upper end of one of the members 24 in the manner illustrated in FIGS. 1 and 7. Thus the erected tower 10 when all of its parts are assembled generally approximates the shape of the letter Y, the upper ends of which are divided into segments by the span of the bridge member 26.

As indicated particularly in FIG. 4, one type of ball and socket joint 30 is used to connect the lower end of the mast 14 to an anchor element located on the supporting ground surface. An improved type of ball and socket joint 32, is used to interconnect the upper end of the lower mast 14 to the lower end of the upper mast 12. These joints 30 and 32 in combination with the set of upper and lower guy wires 16 and 18 also provide for an improved method of installation of the double masted tower 10. By virtue of the combined action of the masts 12 and 14 and the set of guy wires 16 and 18, upon the erected tower 10, it is not susceptible to buckling or collapse when unusually high loads such as bending loads are imposed thereon.

Although the tower is preferably used to suspend high tension electrical lines it is to be understood that the tower 10 is not to be limited to such usage.

The single truss member 22 of the lower vertical mast 14 of the tower 10 of the instant invention as best shown in FIGS. 1 and 4 includes correspondingly shaped end portions of pyramidal configuration and an intermediate portion connected to these end portions. Each end portion of the truss member 22 includes three chordal members of equal length, each of which can be an angle member. The intersecting walls of these members define an interior acute angle of approximately 60. It is to be understood that the three chordal members 36 at each end of the member 22 are arranged relative to each other to intersect at a common point to define an apex at each end which serves to mount the ball elements 40 and 40' of the ball and socket joints 30 and 32. The intermediate portion 34 of member 14 includes three chordal members 46, any two of which lie in substantially the same common plane not only in parallel relation to each other, but also in parallel relation to the other chordal member 46 lying outside the common plane.

The chordal members 36 and 46 are positively held in their aforedescribed relation by a suitable arrangement of strut members 48, certain ones of which are generally indicated in the drawings as extending between adjacent chordal members 36 or 46 as the case may be. The ends of the intermediate portion 34 are connected in a known fashion to the associated outer free ends of the chordal members 36 of the end portions by interconnecting coupling members (not shown). Appropriate fasteners not indicated, such as rivets, bolts or the like can be used for rigidly connecting the ball elements 40 and 40 to the apex ends of the end portions, for connecting the strut members 48 to their associated chordal members 36 and 46 and for interconnecting the intermediate portion 34 of mast 1 4 to the pyramidally shaped end portions thereof.

The two truss members 24 of the upper mast section 12 are of corresponding shape and of similar construction as the aforedescribed truss member 22. The lower end 57 of each truss member 24 is of pyramidal shape and includes three convergent chordal members 58, 58 and 60. The chordal member 60 is common to both truss members 24 as best shown in FIGS. 1, 3 and 5. The apex ends of the chordal members 58, 58 and 60 are reinforced by plates 62 extending between adjacent chordal members 58 and 60 and by the plate 64 extending between the adjacent chordal members 58. Each lower end of a truss member 24 includes one reinforcing plate 64 and two reinforcing plates 62 as best shown in FIG. 5. The lower edges of all plates '62 and 64 are welded or otherwise secured at 70, to the back surface 66 of the socket plate 68 for the ball and socket connection 32.

The upper ends 77 of both truss members 24 are also of pyramidal shape and include chordal members 78. These chordal members 78 as illustrated in FIGS. 1 and 7 converge towards each other to define an apex at opposite sides of an upper end 77 ofa truss member 24. These same chordal members 78 as illustrated in FIG. 8

are spaced from each other in divergent relation. The

spaced chordal members 78 on the opposite sides are advantageously interconnected by a channel shaped member 76 extending between the apex ends of the spaced chordal members 7 8.

As in the case of the truss member 22, the end portion elements 57 and 77 of each truss member 24 are interconnected by an intermediate portion including three chordal members disposed in parallel relation to each other. A plurality of strut members generally indicated at 56 maintain the chordal members 58, 60, 78 and 80 in proper spaced relation to each other. Coupling plates, not shown, interconnect the free ends of the end portions 57 and 77 to the associated ends of the intermediate portion of each truss member 24 in a known manner.

The bridge member 26 as viewed in FIGS. 1, 7 and 8 includes an intermediate portion 92 and end portions 94, all of which are of triangular shape in cross-section. The intermediate portion 92 includes three chordal members 96 which are held in parallel spaced relation by obliquely arranged strut members 98 extending between any two adjacent chordal members 96 as is evident upon an inspection of FIGS. 7 and 9. Each end portion 94 includes three chordal members 100 that converge towards each other at their outer end whereby they form an apex 102. The chordal members 100 are held in convergent relation by strut members 104 of diiferent lengths extending between any two adjacent chordal members 100. Although not heretofore mentioned, the end portions 94 are coupled opposite their apex end 102 to the outer ends of the intermediate portion 92 by appropriate coupling plates 106 which are shown in FIG. 7.

Each of the peak towers 28 as viewed in FIGS. 1, 7 and 8 includes three chordal members disposed in convergent relation to each other. Two of these chordal members 108 are of corresponding length and the third chordal member 110 is of relatively shorter length. The three convergent chordal members 110 and 108 are connected at their lower ends to the end portions of the intermediate section 92 of the bridge member 26. Strut members 114 extend in any suitable pattern between adjacent chordal members 108 and 110 or 108 as the case may be in order to maintain the chordal members 108 and 110 in their proper convergent relation.

Although not heretofore mentioned, the outer ends of the two lower chordal members 96 in FIGS. 7 and 8 making up the bridge member 26 at its intermediate portion include a pair of channel shaped members 118 extending transversely between and connected to the ends of the lower chordal members 96. These channel shaped members 118 are afiixed in parallel spaced relation to each other by means of the bracket members 120 extending between the members 118 at their ends. The brackets 120 are inclined in an upwardly and inwardly direction, rela tive to each other. The inclination of each bracket 120 enables the lower end of associated chordal member 108 of the peak tower 28 to be connected, such as by appropriate fastener elements, to the web portion of its associated bracket. The other chordal member 110* of each peak tower 28 is connected at its lower end as indicated in FIG. 7 by an angle bracket 122 which aproximates the letter V in shape to the upper chordal member 96 of the bridge portion 92 at an intermediate point therealong. The apex end 112 of the towers 28 is reinforced by coupling plates 124 and further includes a sheave wheel 126 mounted thereon in a suitable manner.

The connection of the upper end of each truss member 24 to the underneath portion of section 92 of the bridge member 26 will now be described. A pair of T-shaped bracket elements 128 are affixed to the outer ends of the channel shaped member 76. A pair of right angle bracket member 130 are affixed in space relation to each other at either end of the channel members 118 in the manner illustrated in FIG. 8. In other Words, a pair of angle brackets 130 are affixed to extend transversely across the channel members 118 at each end thereof while the downwardly extending, free legs of the aflixed brackets 130 at each end of the members 118 are spaced from each other in such a fashion as to permit insertion of the upstanding stem of the aligned T-shaped bracket 128. The upwardly facing stem of the bracket 128 and the oppositely facing free legs of the angle brackets 130 have transverse openings therethrough that are alignable for the passage of the pin 132 that connects the angle brackets 130' to the aligned and associated T-shaped member 128. Pins 132 once they are inserted can be locked in place in any suitable manner. Thus when the T-shaped brackets 128 at the upper end of each truss member 24 are aligned with 7 their associated pair of brackets 130 the bridge member 26 can be interconnected to the upper ends of the truss members 24.

The aforedescribed ends of the lower vertical mast 14 include the ball shaped ends 40' and 40 of the respective ball and socket joints 30 and 32. The lower ball and socket joint 30 is interconnected to the supporting ground surface 20 or the like by a preformed socket plate 134 which is anchored in the ground. The socket plate 134 includes an upstanding portion 136 having an upwardly facing inner concave surface 138 as indicated by the dotted lines in FIG. 4. This surface 138 provides the mating connection with the ball shaped element 40' in FIG. 4. The upstanding portion 136 can be reinforced relative to the base 140 of the plate 134 by upstanding flange elements 142 extending between the outer ends of the base 140 and the upstanding annular surface of the portion 136. The upper joint 32 is comprised of the aforedescribed socket plate 68 which is disposed in mating connection with the other ball end 40* at the upper end of the mast 14 as best shown in FIG. 3.

Although the back surface 66 of the socket plate 68 is connected to the lower interconnected ends of the truss members 24 it is to be understood that the socket plate generally corresponds to the shape of the lower socket plate 134.

By virtue of the lower ball and socket joint 30 it is possible to raise the lower mast 14 to any position relative to the supporting ground surface 20 even though the lower mast portion 14 is normally anchored in a vertical position relative to the supporting surface 20 by the guy wires 18. The four guy wires 18 are preferably individually connected at their upper ends to the ball element 40 of the upper joint 32 and at their lower ends to the spaced preselected points P on the surface 20 all as indicated in FIGS. 1 and 2.

In other words, each of the connected wires 18 are disposed in divergent relation to each other from the upper end of the raised mast 14 to the lower end thereof. The upper ball 40 preferably has three brackets 144, 144 and 146 affixed thereto. These brackets are connected to the upper ends of the'guy wires 18. Two of the brackets 144 are of a configuration aproximating the shape of the letter Y. As indicated in FIG. 6, the lower outer surface of the ball element 40 includes three intersecting planar surfaces 145. These surfaces define a triangular shaped end opposite the spherically shaped end of the ball element 40. It is to be understood that intermediate the ends of the ball 40, the spherically shaped end smoothly merges with the three intersecting planar shaped surfaces 145. The V-shaped end of each bracket 144 is afiixed to one of the intersecting edge portions defined by the planar portions 145 whereby each bracket is disposed on one of the adjacent edge portions in spaced relation to each other. 7

The other bracket 146 is of a configuration approximately the shape of the letter X wherein the V-shaped end defining the relatively smaller includable angle therebetween is afiixed to the intersecting edge portion defined by the planar side portions 145 of the ball type element 40 of the joint 32. The stem end of the afiixed Y-shaped brackets 144 and the outer V-shapecl end of the affixed X-shaped bracket 146 have transverse openings 148 therethrough that facilitate threadable connection of the upper ends of the guy wires 18 to the aforesaid brackets. As is evident upon an inspection of FIGS. 2 and 7 only one of the four Wires 18 is associated with the stem end of either bracket 144 or only one of the four wires 18 with one of the outwardly projecting legs of the X-shaped bracket 146. It has been found in the use of four lower guy wires 18 for erecting the lower mast 14 at a vertical inclination relative to the supporting surface 20 that a suitable angle between adjacent stem end portions of the brackets 144 and a suitable angle between the outer V- shaped end of the X-shaped bracket 146 is an angle on the order of It is further observed here that the brackets 144 and 146 can be formed from appropriate plate or sheet material. Thus the Y-shaped brackets 144 can consist of two correspondingly formed plate elements welded together at one end to define the stem end of the bracket 144. Similarly, the X-shaped bracket 146 can be made of three V-shaped elements as is evident upon an inspection of FIG. 6.

The upper cables 16 of which there are preferably four in number are connected in separate pairs inwardly of the brackets on the spaced and associated channels 118 at each end of the intermediate portion 92 of the bridge member 26. A pair of channel shaped brackets 150 at each end of the associated and spaced channels 118 extend between the web portions thereof and are disposed inwardly of the channel shaped bracket 120. The flanged ends of each pair of related brackets 150 are affixed to the web portion of their associated channels 118 in the fashion indicated in FIGS. 8 and 10, whereby the web portions of each pair of related brackets 150 are not only disposed in parallel spaced relation to each other, but are also inclined in an upward and inward direction. It is observed here that the upward and inward inclination of each pair of related brackets 150 is for the advantageous purpose of being substantially coincident with the downward and outward direction of the guy wire cable 16 to be connected thereto.

The pairs of parallel and spaced brackets 150 at each end of the spaced and associated channel members 118 include offset openings (not indicated) in their web portions that are alignable for the passage of a self-locking pin 152 therethrough.

In order to effect self-locking of the pin 152, the head end of the pin is disposed to face upwardly in the aligned openings of the spaced pair of brackets 150. In addition, before passage of the self-locking pin 152, the upper and looped end of the associated guy wire 16 is inserted within the space defined by a pair of related brackets 150 and aligned with the alignable openings in the related brackets. After insertion of a guy wrie in a bracket 150 the pin 152 can be passed through the aligned openings and the loop of the guy wire 16 whereby the guy wire 16 will be connected to a pair of related brackets 150. The same procedure can be used for connecting all the guy wires 16 at their upper ends. Thus, a pair of guy wires 16 will be associated with the spaced channel members 118 at each end of the intermediate portion 92 of the bridge member 26.

As the tower 10 is being erected at the selected location and with the upper mast portion 12 being elevated relative to the raised lower mast portion 14 and connected thereto at the joint 32 in the manner illustrated in FIG. 1, the lower ends of certain ones of the upper and lower set of guy wires 16 and 18 will be'connected to common anchor points P on the supporting surface 20. The lower end of one of the lower guy wires 18 as well as the lower end of one of the upper guy wires 16, which extends in the same general downward and outward direction as one of the lower guy wires 18 in FIGS. 1 and 2, can be both connected to the same common anchor point P. By virtue of there being four guy wires in the upper and lower sets, there are four anchor points P disposed in spaced relation to each other. The spaced relation of the points P on the support surface 20 defines as is evident upon aninspection of FIG. 2 the four corners of a geometrical rectangle.

Although not shown in FIGS. 1 and 2, it is to be understood that each connecting point P includes an appropriate anchor arrangement such as an eye-bolt, the eye end of which enables connection of the lower ends of the upper and lower guy wires 16 and 18 associated therewith in a suitable fashion. The opposite and threaded end of the eyebolt can be adjustably fastened to a sunken pier usually consisting of a threaded sleeve encased in concrete.

A system will now be described for carrying out the unique steps of assembling and installing the aforedescribed tower, reference being made particularly to FIGS. 11-13. The first step involves erecting lower mast 14. Next, the lower mast 14 is loosely linked to mast 12. While loosely linked to mast 14, mast 12 is then elevated and firmly afiixed thereto. A power winch mechanism 154 can be used in erecting mast 14. The winch is connected to a cable 158 which extends over an upstanding fulcrum support 156 with the cable being con nected at its free end to the end of mast 14. The lower end of the mast is disposed in alignment with is supporting socket plate 134 of the connection 30. Fulcrum support 156 will, of course, be of the appropriate height. Actuation of the power winch mechanism 154 by the winch operator results in a drawing in or a shortening of the length of cable 158 whereby the lower mast 14 is elevated to a raised vertical position relative to its support surface 20 as shown in FIG. 12. After the mast 14 has been raised to an elevated or raised vertical position, the lower guy wires 18 are connected at their upper ends to brackets 144 and 146 at the upper end of the mast 14 in the manner aforedescribed and at their lower ends to the preselected points P Although not heretofore mentioned, the ball shaped end portion 40 of the mast includes, as indicated in FIG. 6, a recess 160 extending inwardly from the trianglar shaped end of the ball shaped element 40. The recess 160 is defined by the inner planar surfaces of the intersecting side portions 145 of the ball shaped element 40 and the transversely extending substantially fiat surface at the bottom of the recess 160. A longitudinal axial bore 162 extends through the ball element 40 between the spherically shaped surface of ball element 40 and the bottom wall of the recess 160. The socket plate 68 of the upper joint 32 also includes a longitudinal axial bore 164 extending between the back surface 66 at one end to the concave surface 138 at the other end. These bores 162 and 164 advantageously contribute to the next step of locating the upper mast 12 relative to and installing the upper mast 12 on the lower erected mast 14.

Prior to installing the upper mast 12 on the raised mast 14, a length of cable 168 is first loosely threaded through the bore 164 of the plate 68 from the back surface 66 thereof. The threading of the cable 168 is continued until its upper end is locked in a suitable fashion to the back side of the plate 68. The other end of the cable will in the meantime be loocely threaded through the bore 162 in the ball element 40 at the upper end of the mast 14. After being threaded through the bores 164 and 162 of the plates 68 and upper ball 40 the loose end of cable 168 is then threaded through a commercially available block and tackle device 170 which can be anchored if desired to the lower end of the raised mast 14. The aforementioned threading of the cable 168 is preferably done when the upper 12 is lying on the ground 20 and the upper mast 14 is in the raised position of FIG. 12. At this point an appropriate elevating mechanism such as a helicopter H is coupled to the upper mast 12 for elevating same.

As indicated particularly in FIG. 13, the helicopter H has three lengths of cables 172 suspended therefrom. The ends of these cables are coupled to the upper ends of the upper mast 12 at selected points so that when the helicopter lifts off it can elevate the upper mast 12 to the suspended position shown in FIG. 13. During elevation of the upper mast 12 by the helicopter H, an operator draws in the slack of the cable 168 through the block and tackle device 170 in such a fashion as to maintain the portion of the cable 168 between the lower end of the upper mast 12 and the upper end of the lower mast 14 relatively loose. Then as the helicopter H slowly lowers the mast 12 from the position shown in FIG. 13, the operator guides the lower end of the upper mast 12 into a coupled relation with the upper end of the mast 14 by the continued drawing up of the cable 168 through the block and tackle device 170. By virtue of the cable 168 being threaded through the longitudinal - bores 164 and 162 of the plate 68 and the ball 40, a centered connection of the upper mast 12 to the raised mast 14 by the medium of the upper ballsocket joint 32 is assured.

While the helicopter is hovering above mast 14, workmen on the ground 20 will of course have grabbed hold of the trailing ends of guy wires 16 which are connected at their upper ends to mast 12. Then as the upper mast 12 is connected to the lower mast 14, the workmen will promptly lock lower ends of draped guy wires 16 to the preselected points P as illustrated in FIG. 2. Thus upon connection of the gu wires 16 to the points P and release of the cables 172 from the helicopter H the upper mast 12 will be firmly anchored to the ground 20 and to the upper end of the raised mast 14.

Although the upper mast 12 is shown in a position coincident with the raised position of the mast 14, it is obvious that the upper set of guy Wires 16 when adjusted by any suitable winch means can operate in conjunction with the joint 32 to enable a permissive degree of angular adjustment of the upper mast 12 relative to the lower mast 14. Similarly the lower mast 14 by virtue of adjustments to guy wires 18 by any suitable winch means can have a permissive degree of angular adjustment other than the vertical raised position shown relative to the ground surface 20.

Once the tower is erected and anchored by the sets of guy wires 16 and 18 relative to the support surface 20, high voltage lines V can be individually suspended at one of their points relative to the bridge member 26 by means of cables in the manner shown in FIGS. 1 and 2. Inasmuch as in the installation of any high voltage line exposed ground wires are usually required to minimize excessive electrical static charges such as due to local weather conditions the upper ends of the peak towers 28 can carryappropriate ground wires in suspension between successive towers 10.

Although the cable 168 could be left in place after assembly whereby upon securing the bottom free end thereof to a suitable fixture on the mast it can be used to act as a further lock between the masts, it is preferably removed from both masts after final assembly of the tower.

What is claimed is:

1. In a transmission tower and the like, the combination of a foundation mast and an upper mast connected to said foundation mast, said upper mast being comprised of a plurality of interconnected truss-like members arranged in a geometrical pattern, a ball joint means connecting the lower end of said foundation mast with a support surface, a second ball joint means connecting said upper mast to the foundation mast adjacent the connection of certain of said truss-like members on said upper mast, a first set of pairs of mast anchoring guy wires secured to said foundation mast and the support surface, a second set of pairs of anchoring guy wires secured to said upper mast and the support surface, said first and second sets of pairs of guy wires when secured to the support surface and their respective masts all cooperatively acting as the principal means for holding said masts in an assembled and upright relationship, one extremity of each guy wire of said first set of guy wires being attached to the foundation mast adjacent the point of connection of the foundation and upper masts and the other extremity of each guy wire in said first set of guy wires being connected to the support surface at the same common at tachment point as a guy wire of said second set of guy wires and said first and second ball joint means including cooperating arcuate elements on the masts and the support surface whereby said masts can be adjusted one with respect to each other and the foundation rnast to the support surface in a plurality of directions in order for the fully assembled tower to retain an upright position irrespective of the angle of the inclination of the overall assembled tower relative to the support surface.

2. A transmission tower as set forth in claim 1 wherein each of said masts is provided with alignable apertures adjacent their point of assembly through which a common cable can be inserted at least for the purpose of linking the masts together during erection of the tower.

3. A method of erecting an electrical transmission tower and the like at the site of installation, said tower being made up of interconnected lower and upper masts comprising the steps of securing a flexible member to the lower end of the mast constituting the upper mast and slidably threading said flexible member through an aperture in the upper end of the mast constituting the lower mast, raising only the lower mast to a preselected upright position relative to a supporting surface while keeping the lower end of the lower mast in contact with said surface, anchoring the raised lower mast in said preselected upright position, hoisting the upper mast to a position above the lower raised mast, guiding the upper mast into a position atop the lower mast by means of said flexible member, depositing the upper mast on top of the lower mast, engaging the upper mast with the lower mast and thereafter finally locking the upper mast both to the lower mast and to ground anchors.

4. A method as set forth in claim 3 wherein the securing of the masts together is effected by thread ng a cable through openings in both of said masts,

5. A method as set forth in claim 3 wherein the securing of the masts together is effected by threading a cable through an opening in the lower portion of the upper mast and the upper portion of the lower mast, and during the hoisting and lowering of the upper mast into position, drawing up the slack in the cable so as to simultaneously draw said masts together.

6. A method as set forth in claim 3 wherein the upper mast is placed upon said lower mast in such a fashion that the upper mast is in a position of coincidence with said lower mast.

7. A method of erecting a tower and the like as set forth in claim 3 wherein the steps of hoisting and guiding the said upper mast relative to said lower mast and then depositing said upper mast on top of said lower mast are all effected by a helicopter from which said upper mast is suspended.

References Cited UNITED STATES PATENTS 1,026,388 5/1912 Fricke 52--116 1,897,373 2/1933 Gerten et al. 343723 2,213,310 9/1940 Gimenez et al 52108 3,295,699 1/1967 Bauernschub 52-108 3,343,315 9/1967 Marsh 52148 OTHER REFERENCES Editor, Supply Lines, New Y Tower Placed By Copter In Minutes, July 15, 1963 Issue of Electric World p. 79.

Harold Wentzel, Guyed Y Tower Easily Erected, reprint in May 21, 1962 Issue of Electric World p. 81.

ALFRED C. PERHAM, Primary Examiner U.S. Cl. X.R.

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