DESC:FIELD OF INVENTION:

The present invention is to direct the lightning discharge without air terminal rods for a tall metal statue using the statue body itself as receiving conductor which in turn protecting statue, people and other assets from the lightning hazards complying to International standards.

BACKGROUND OF INVENTION :

Statue of unity depicts the IRON MAN OF INDIA, Shri, Sardar Vallabhai Patel who paved the way for cultural unity and harmony in bringing the 565 self-governing princely states and territories into the Indian federation after independence of India.

Developing design approach/methodology of Lightning protection system for the world’s tallest statue is very important to protect as it will be an iconic monument for the Government of India.

Though various lightning protection schemes are available for tall buildings/structures, metal statue of this magnitude is unique. Hence a fool proof lightning protection design is essential to have a more reliable, less maintenance and without disturbing the aesthetic of the statue.

In tall building, one can avoid lightning strikes using simple rods, and can be achieved by providing a path of low resistance to ground. Copper roofs offer ideal lightning protection where the copper roofing, gutters, rainwater down take pipes are electrically connected and reliably grounded. The specified thickness of materials are calculated to be adequate for lightning protection.

In some cases, lighter gauge copper bonded panels are used, when some of the components of grounding system are made of less conductive materials.

Due to excellent electrical conductivity and resistance to corrosion copper is desired in lightning protection applications.

However in tall structures, one cannot provide copper roof. But with tall structures there is a need for rapid transmission of lightning energy, as lightning takes the path of least resistance so that no damage is done to the structure itself. So the application of lightning arrestors of tall buildings are not suitable for tall structures.

Any conductive structure when erected tall it can become subject to a lightning strike and the main subject is to improve a new lightning arrestor which can capture the lightning strike and divert the current to the ground much faster than conventional simple rod.

The other objective is to have a lightning conductor system with a number of interconnected intercepted conductors along the statue and ground electrodes. Further the interconnected intercepted conductors be bonded properly to ensure all of them remain at equal potential, to reduce side flashing and possible damage to the statue.

In some tall statutes, instead of single top end ‘tip’, multiple ‘tips’ are created as multiple lightning points.

Further rod type lightning system can fail, as lightning current will divide to follow every conductive path to ground and even such divided current can cause immense damage. The secondary ‘side flashes’ ignite fire and cause damage. Hence these has been an attempt to eliminate the air terminals of a typical rod, which air terminals are arranged at or along the upper points of a tall structure. Also there has been an attempt to provide most direct route to one or more grounding /earthing terminals, which connects to the earth electrodes not only have low resistance, but also have low self-inductance.

Hence this invention attempts to create a lightning arrestor system without air terminal rods, which is the most sought-after prior art. Hence there is no need to provide ‘spiked’ extending air terminals rods on the statue head or shoulders.

Further this invention also attempts to eliminate the exposed horizontal and vertical copper strips.

As per invention, in one aspect it is a statue with an integrated lightning arrestor system comprising of

(-) a plurality of bronze micro panels forming a macro panel with equipotential bonding.

(-) a plurality of said bounded macro panels joined together with copper braided flexible to form a statue.

(-) a bimetallic flexible strip is bolted at each end of each of the macro panels to maintain equipotential bonding.

(-) a metal probe is connected to each macro panel through each of the said bimetallic bolts.

(-) a tertiary steel is connected to each macro panel through each of the said bimetallic bolts.

To achieve that, following design methodology have been adopted successfully as detailed above.

1. Eliminated air terminal rods on the statue head / shoulders which stands out as a separate structure

2. Eliminated exposed Horizontal and vertical copper strip by interconnecting all the metal panels of the statue to maintain equipotential bonding and safe lightning discharge to earth.

DESCRIPTION OF THE INVENTION :

To achieve the above objective a detailed study incompliance with IEC 62305 pertaining to lightning protection was carried out and below table 1 is the extract of the code refers to thickness of the metal sheet to be used designing the lightning protection system for statue of unity, General, India

Please refer fig. 1 for illustrates of front view of statue.

Please refer fig. 2 for overall schematic.

Part nos. Part names
201 Statue bronze panel (8mm thick) act as air Terminal to receive the Lighting Strike
202 All statue bronze Macro panels Shall be interconnected together to maintain electrical continuity
203 25x3mm Cu. strip to be connected with statue macro panel for lightning protection (refer Fig. 9)
204 Sadhu Hill
205 Entry pavilion
206 25x3mm Cu. Strip run inside shaft for lightning protection
207 Mechanical trench
208 25X3mm Tinned cu. strip surface mounted on pier for lightning protection
209 25X3mm Cu. Strip immersed in water for earthing of for lightning

Please refer fig. 3 for typical aerial view of statue bronze panel fixing components.

Part nos. Part names
301 Core wall
302 Macro panel refer fig. 4
303 Probe steel refer fig. 6
304 Tertiary steel refer fig. 6
305 Secondary steel refer fig. 7& 8
306 Primary steel refer fig. 8

Table 1: Minimum thickness of air termination system as per IEC 62305-3

As the material of the statue illustrated in fig. 1 is bronze with a thickness of 8 mm( which also takes care of the corrosion factor), the nearest value from the above table 1 is 5mm thick copper material which meets the codal requirement of receiving the lightning strike without damaging the statue bronze panel. To maintain the equipotential bonding statue bronze micro panels are welded to form one macro panels at assembling yard. Further the interconnections to maintain equipotential bonding refer fig 4 & 5.

Fig. 4 illustrates interconnection detail between Macro panels.

Part nos. Part names
401 Macro panel
402 Refer Fig. 5

Fig. 5 illustrates top view interconnection detail between Macro panels.

Part nos. Part names
501 25x3mm Bimetallic flexible strip bolted to facade macro panel maintain continuity for equipotential bonding (typ)
502 Macro panel flange
503 Macro panel

Further all macro panels are interconnected using copper braided flexible, in order to maintain further equipotential bonding, macro panels are connected to metal probe and tertiary steel using bimetallic bolts at both ends as shown in fig 6,7 and 8.

Fig. 6 illustrates interconnection details between macro panels flange and probe.

Part nos. Part names
601 Tertiary steel
602 Bimetallic bolts and nuts
603 Probe
604 Bronze cladding 8thk
605 Probe & bronze flange
606 Connected using cu. Strips

Fig. 7 illustrates typical cast in plate to coupling wall detail.

Part nos. Part names
701 Fin frame stub bracket
702 Cast in plate and anchors
703 CL
704 Torsion slab cast in plate extended to suit connection of fin stub
705 Fabricated fin plates designed for offset moment
706 Torsion Slab
707 SSL
708 Primary fin frame
709 Eccentricity bracing to fin frame stub bracket offset
710 Varies
711 Anchor rods to be tied with rebar to maintain continuity for lightning protection earthing
712 Coupler shown indicatively (typ)
713 75 Dia holes to thread rebar at 150 c/c vertically
714 Alternative stiffener pre-welded to the cast in fin frames
715 In plan bracing / torsion slab support steelwork

Fig. 8 illustrates interconnection between tertiary steel and reinforcement rod.

Part nos. Part names
801 Anchor rods to be tied with rebar to maintain continuity for lightning protection earthing
802 Threaded bar and 70x70x10 washer
803 Full Tension Lap
804 Link bars equal to 1.2 x the area of anchor bars welded to the plate in both directions
805 Cast in plate

Fig. 9 illustrates the earth connection at statue feet level.

Part nos. Part names
901 25x3mm Cu.Strip
902 25X3 mm Cu.Earth strip running in screed
903 25x3 mm Cu.Earth strips for lightning protection (typ)
904 25X3 mm Cu.Earth strips dropped to mechanical trench through shaft (typ)
905 25X3 mm Cu.Earth strips connected to bronze flange (typ)

Fig. 10,11 and 12 are the executed pictures, Fig. 10 illustrates interconnection between macro panels. Fig. 11 illustrates interconnection between macro panels flange and probe. Fig. 12 illustrates interconnection between probe and tertiary steel

The invention essentially discloses a design approach adopted first time for the protection of the world’s tallest statue complying to international standards and tested for the continuity of the equipotential bonding as shown in below test report

The invention has been described with certain examples and embodiments only for the purpose of disclosing the enabling and working of the invention. And variables which are obvious are well within the scope of this invention.

The applicant relies upon the provisional specification and drawings filed in this application and shall be considered as part and parcel of complete specification ,CLAIMS:WE CLAIM :

1. An integrated vertical with bronze status structure with built-in lightning protection system comprising of :-
a. a plurality of bronze micro panels forming a macro panel with equipotential bonding,
b. a plurality of said bounded macro panels jointed together with copper braided flexible to form the statue structure,
c. a bimetallic flexible strip is bolted at each end of each of the said macro panels which maintains equipotential bonding,
d. a metal probe is connected to each macro panel through each of the said bimetallic bolts, and
e. a tertiary steel is connected to each macro panel through each of the said bimetallic bolts,

the said arrangement characterized in providing safe lightning discharge to earth but eliminating air terminal rods of lightning protects on the statue head/shoulder and eliminating the known exposed horizontal and vertical copper strip.