GB2308577A - Mooring a balloon - Google Patents

Abstract

The method comprises mooring the balloon casing to the ground through use of guy lines distributed over a circumference of a casing. The balloon is descended into the casing (1) to bring it into contact with the basket (2) of the balloon. The guy lines are then used to fix the casing to the ground whilst keeping it in contact with the basket. The method also incorporates using a number of protective elements for damping a reaction force of the basket and for distributing the reaction force over the casing.

Description

1 2308577 METHOD FOR MOORING A BAL1j00N AND GROUND INFRASTRUCTURE FOR

CARRYING OUT TRE METHOD This 1.r,.vi--ntion relates to a method for mooring a balloon to the ground and to a ground infrastructure for carrving out this mooring method. It can be more particularly applied to the task of keeping a tethered balloon firmly tied to the ground in the presence of strong winds.

Tethered Z balloons, unlike f ree or unrestrained balloons which call Lravel from one geographical point to another. are tied to the ground by means of a cable. it Js currently known to iise:,-,uch tethered balloons for aking passengera up into the air to give them a panoramic view of t:he place where the tethered balloon cz)erates from. A tethered balloon comprises a casing able tn '...)e inflated with a gas that is lighter than air, and at basket or gondola for carrying passengers. The casing providing the lift is linkcd to a load frame by tie lines, the basket being suspended from this load frame. The tethcred balloon is brought back to the ground by mcans of a cable f -ixed to the load Erdme, and which is wound at ground level onto a winch system allowing the rise and descent of the tethered balloon to be controlled.

Once the basket of a teLlicred balloon has landed. on the gro..,nd, it is known to fix the tethered balloon cas-incT - which is subject to a lifting force - to the ground by mearis of guy lines, wir.h r.he te lines I-inking a casing net t-- the load fr-ame 'be.i.n.g tensioned. The guy l-. :ne; fcr e>:a-,..zle consist ef a plurality of cc-,rc;.s or cables permanently fixed r.o the net, tkic free Pand of which is designed to a. anchored to the ground by any;uitable means. In Llic rage of a balloon with a sphezical -shaped casing, the guy lines are preferably distributed uniformiv over the whole circumference of the c-=sing, arcund its equatorial lIne.

BAID ORIG1NAL 03 2 British Patent 21,040 discloses anchoring of an airship having a suspended gondola by means of cloths attached along the median horizontal circumference of the body. The other end of the cloths is secured to the ground or ballasted with stones or other heavy objects, and the cloths can be used to form a tent, once the balloon is tethered, where passengers can shelter- United States patent 3,583,325 discloses a way of raising er lowering a basket or carriage suspended from a balloon, without changing the balloon's position. A hanger or suppurting bracket carrying a puley is fixed to the balluon and the basket is suspended an the hanger v_a the Zulley.

British patent 20,249 discloses another suspended 1-5 gondola airship mooring procedure in which it is proposed to anchor the airship using cables secured at the upper part of the- casing, instead of using a technique cables are secured at the median plane of the balloon. In this document, it is proposed that the basket or gondola 2. suspension cables be stretched or slightly tensionrelieved.

These various mooring procedures have proved satisfactory to date. Theoretical calculation of air resistance of the inflatable portion of balloons and of the forces wind excrcises on such balloons have not brougliL to light any par::i-ular problems with mooring, even in the presence of strong winds -f up to 100 km/hour, ec ruivalent to 62 m.les par hour or 27.7 meters/sec always supposing the mooring cables are su--l-ficieiiL!y strong. Indeed, z.heoretical 3 C cons iderat directed to the case of.;r.'rong winds show Vertical movements of -,he balloon are to be expected: tension in the guy lines increases and when the vert.ical comz)c-,nerit of such tension becomes equal to the u-jward lift provided by the balloon, it is shown that the balloon is free to descend and adopt a new lower positien. For - fixed or susDendeci basket or gondola a j -S'.1ps, rhe conventional soliltion is also completely sa-"isfaczcry, such airships having a wind resistance th SAD ()RIGINAL 0) 1 Z 3 n 5 is generally lower than that of a spherical balloon, if it. is oriented in the direction of the wind.

The invention thus sets out to resolve the new problem of mooring suspended basket balloons for even higher winds. Such a problem had noL been identified to date. Indeed, there was a general prejudice against considering leaving balloons inflated in r_he presence of such high winds: balloons were systemanically de-inflated or put away in hangars, so that the problem the invention resolves was simply nor imaginable. Additionally, the nvention Js based on the surprising fnding that generally accepted theoretical reasoning did not make it possible tn nake account o high amplitude movements due to the balloon being forced downwards as a result of a vertica). component of the wind combined with the balloon's inertial effect, which theoretical considerations had not brought into evidence.

The invention makes it possible to avoid, notably in w-,nter, the lengthy and complicated operations of de- inflating and rc-inflating the balloon, thereby ensuring the balloon is always ready to operate, after completing a few simple and rapid operations. The invention enables the moored balloon to withstand high winds, and notably wind speeds above about 45 miles/hour (20 m/sec.) without any danger of damaging the balloon.

This a.-im ls achieved by the method of the invention w.-iic2.i ri.iake-s it possible to moor a balloon com prising a basket or gond.-!a to the ground, with a step for bringing the basket to the ground, a step in which the,casing is bz-ought inzo contact with the basket, and a step in which Lhe casing is secijr6-d to the ground while still keeping it in contact w.-Lr.h the basket. The step of dcacending the casing and the securing step can be merged into one; however, as explained below, they can also be scparar-c.

Thanks ro the method of the invention, the balloon casing is constantly held against the basket. When the casing is si.,,bjected to a side-wind, the mooring guy lines exercise a -.ract-cnal force on the casing the horizontal BAD ORIGINAL 1.0) 4 1 = component of which opposes the lateral wind pressure, and the vertical component of which accentuates the pressuz-e exercised by the casing on the basket, the latter giving rise: on the part of the basket to an opposing reaction 5 force on the casing. The casing thus rests imittobile.

In a first embodiment of the invention, befort. descending the balloon casing, one or a plurality of protective elements for damping a reaction forr.e of the basket and for distributing said reaction force over said casing are pusitioned on the basket. These are for example inflatable protective members the general shape of which is that of domed blocks or studs.

in a second embodiment of the invention, after having brni.,.ghr the balloon casing into contact with the basket, and prior to the step of f ixing said casing to the ground by means of guy lines, said casing is fixed tc the ground by connecting means exercising a vertical tractional force on said balloon casing opposing a lift force created by said casing make it 11 z These connectincr means possible to advantageously exercise a supplementary tractional force on the casing, which becomes added to the vertical componenL ef the tractional force exercised by the guy lines, Lhereby reinforcing rlie. vertical stability of the casing. moreover, they enGure the casing is constantly held in contact with the basket, during the final stage of fixing the casing no the ground by rneans of the guv lines.

Preferably, with said balloon casing held inside a net, lower meshes of said ner. are fixed to the ground 1 aro,u.,.id a whole periphery of said casing, said net coris--itut--lnq said connecting means.

in one ureferred embodiment, the two particular embodiments stated above are combined, in order to obtain optimum mno7ing of the balloon.

other charac...-.e-r.stics and advantages of the invention will- become more clear rrom the descriDtion that follows of a method for mooring a tethered balloon in a preferred embodiment of the invention, this description being

S ctGxtAA.I-.031 v provided by way of non-limiting example and with reference to the attached drawings.

FIG. 1 is a general view of a tethered balloon the basket of which is resting on the ground, Lhe cas-ing 5 being ready tc be brought down towards Lhe basket, in contacz with r_he inflatable protective stud-like mernbers, mounted at the upper portion of the basket.

PIG. 2 is a diagrammaLical view of the tethered balloon of FIG. 1 once it has been moored, illustrating the various forces exercised on the halloon casing.

The tethered balloon shown in FIG. 1 comprises a spherical- casing L which is inflated with a gas lighter than air, and a basket or gondola 2 able to carry passengers. Casing 1 _Js trapped inside a net 3, which is linked.:.o a load frame 4 by means of a plurality of suspension cords 5. Basket 2 is in -its turn suspended load trame 4. In the example illustrated, basket 2 resting on a landing platform 6 on wheels 7, said landing platform being installed on top of a mound 8.

7.he tethered balloon is brought back to the ground by means of a recall cable 9 one end of which is rigidly fixed to load frame 4, the other being wound around a winch 10 via a return pulley 11, winch 10 and return pullcy 11 being situated below platform g. The oarticular structure of platform 6 and the method for b:-inginq the tethered balloon to land on this platform have already been described in French patent application 2, 714, 019 and will not be described in detail here.

Net 3 of the balloon in FIG. 1 is additionally fitted a Ulural-ity of guy l ines 12, the upper ends of which '2d are permanennly fixed to the mesh of net 3, uniformly around the periphery of casing 1, at Lts equarorial line CE) level, said linc being shown as a dashed lire. in FIG. 1. Only two guy l-nes!2 are -,5 shown Ill.n FIG. 1, for the sake of simplicity.

T.'1.1e lower ends 12b of the two guy lines 12 in FIC-7. 1 are wound around two return winches 13 respectively _fixed BAD ORIGINAL 03 6 to anchor posts 14, permanently set into the ground on the slope 8a of mound 8.

1 In a specific embodiment, alternate guy lines 12 are winched, che other guy lines being fixed to the grni.,,nc,7t by 5 nicans of their ordinary anchoring posts.

A plurality ef inflatable protective stud-like members 1,4 are fixed to the upper portion of basket 2. Th-lese stud-like members 15 for Axample consist of a substantially cylindrical inflatable casing 15a fixed to 10 the surface of a support plare ibb, this support plate n 3 c being releasably fasteried by any suitable means onto basket 2.

in one specific embodiment, zhe basket 2 has an octagonal shape, and is fitted with cight stud-like is ptotection members 15, respectively fitted ar. the corners of the octagonal shaped basket. In FIG. 1, only four of thes-- eight stud-like members, in their inflated state, Can be sel-n. ':venty-four gruy lines 12 are fitted en, sict 2, and zwelve winches 13 are uniformly distributed around C the whoi-c periphery of the landing platform 6.

Tn one preferred embadii.i.tei-iL uf the invention, i--Yie moorinc operations for the balloon of FIG. 1 are carried out in the following order.

Once the ba:keL 2 has landed on planfri.r.-tri 6, the tree ends 12b of altei.i.iaLe guy lines 12 are positioned on the return winches 13; the remaining gtjy lines are anchored at the usual anchor posts; following this, the stud-like protecLive members 15 are inflated. Advantageously, the casings!Sa of stud-like members 15 are linked together pairwise by means of conduits (not shown). Por each vair of protective.5z:iid-like members 15 only one out of two will be fitted with a blower (not shown) making it possible re simultaneously inflate the two casings 15a of two stud-like members.

C1Ince 7-he stud-like members have been inflated, che return winches 1-3 are driven in ror-ation in order zo wind the corresponding guy lines 12, thereby exercising a tractional force on net 3, causing casing i to descend 150) 7 towards basket 2. Simultaneously, the non-winched guy lines are pulled, in order to keep the balloon c-asing constantly guyed during the whole of the descenn. The lines 5 which were initially Lensioned by casing 1 providing the lift, become slackened. Pulling on the non-winched guy lines during the step nf descending the balloon into contact with the basket enables the balloon to be kept centered. In practise, these guy lines can be replaced Ly metal cables tensioned during descent by !G suitable traction devices.

When balloon rasing 1 comes into contact withthe protective member iS, the wincheG!3 are locked to pi-evenz their rotation. Balloon casina 1, now in the posirion shown in dash-dot lincs on FIG. 1, rests agairist basket 2, via the protective stud-like members 15 which have a damping and loaddistributing effect. The balloon casing's device 16 advantageously becomes housed ar. th-- center of the stud-like members 15..1. t should be stressed that, in another alternar.ive embodiment, the protective stud-l-.',ke members is rnuld be inflated not prior to descent of easing 1, but only after the casing has been. brought into contact with the basket.

Once casing 1 has been kept in ronract with the Mrotective stud-like members 15, t, h t-z. lines 5 are completely slack, and the lower meshes of net 3 come close to r_he rncund 8. The.. lower meshes can then be fixed diz.cctly to che grenind, or indirectly using slings, or by dny suitable means known to those skilled in the art. The provision of variable-length slings enables the 5.3 exact posizior ef the casing with respect -.,:) the basket to be adjusted, the points of attacl,-.mcn- being suitably posi-, i.cned. in one specific embodiment, net 3 would have fnrty-e-ight lower meshes; twelve additional concrete a.-ic-hnr r-c.szs Cnor shown) each fitted two iiiocz.irig hooks wnu- -1 be positioned between r-hc anchor costs 14, the lar.rer beina moreover each fitr-ed wich two mocring hooks (nn-,- shown,' In addition to winch!5; the fortyeight lower meshes of net 3 would be -fixed directly to BAD ORIGINAL J10 k 8 forty-cight mooring hooks of the set of concrete anchor posts - Once net 3 is fixed directly to the ground, the direction of rotation of winches 13 is reversed thereby releasing the guy lines 12, until the ends 12a of the guy lines are free. Casing 3 now remains in contact with the prozective sr-,,jd-l-,ke member 15, via its net 3 fixed to the ground. Finally, in a ---,tep, the ends 12b of the set of guy lines 12, including those that were wound round return winches 13, are fixed to the ground, thereby tensioning these guy lines.

In FIG. 2, the balloon of FIG. 1 is shown diagrammatically, once the latter has been moored in acer;rdance with the method juGt described. For the sake the landing platform is nor- 2, shQwn and the ground is indicated by a single horizontal ^,ine 17.

In the moored position of FIG. 2, net 3 c-L- casing -1 o.f the balloon is fixed directly to the ground, at nnint A. The guy lines 12 are fixed to the ground at points B, 2G making a.- angle a with the ho-,-izwntal.

As casing 1 is lighter than air, it has a tendency to rise up, but is kept at a constant height from the ground!7 by its net 3, which is strenched, and exercises vertical rccall forces F on the easing. When:asing 1 is subject co a lateral r-hrijsr: due to wind and shown on FIG. 2 bv arrow D, the casing tends to be brought towards the 91-ound by:he vertical component of the tractional force F', exerc..se.n on the net by the Quy lines 12. This tractional force is balanced by the reaction force R y the protective stud-like exe-cised b_ basket 2 via members 5. An increase in lateral thrust due to wind simply results in an increa3c in the reaction furce R exercised by the stud-like members on casing 1, whereby che la-ter remains stationary. The protective stud-like members i--, enable reaction force R to be damped arid dist---ibuted right. round the periphery of balloon casing 1, ::he,,c.eby also avoiding deterioration of the casing.

c.o ok\ol"g- 0 9 1 In practice, to implemcnt the mooring method of Lhe invention, the same ground anchoring points are used for the guy lines as those which were used until now for guying the casing providing lift. The result of this is, firstly, that the mooring guy lines are shortened compared to guy lines habitually employed, as the casing is at a smaller distance from the ground and, sprondly, that the angle a which the guy lines make with the horizontal is mLich smaller. In one sDecific embodiment, this angle a would be around 250 in the case of the invention, whereas is was ahour. 450 with prior art Lechniques. The decrease in the value of angle a is reflected, for. a given pulling torce exercised on the guy lines, by a tractional force F, having a smallcr vertical component. The degree to which casing 1 is brought closer to the ground by the guy lines under the effect of wind is thus advantageously reduccd.

z Thanks to the invention, the balloon can consequently withstand strong winds, and notably winds having in practice speeds above 45 miles per hour (20 m/sec.) w.':.chou-,- casing 1 starting to move about, thus without any dariger of deteriorating the balloon which remains -Derfectly moored to the ground. A 22 meter diamer. ey. balloon fitted out as pez. the invention withstood winds 2 5 of about 58 miles per hour (26 m/s), and trials using wind machines showed the invention enables a balloon to,,;-.thata:id winds of up to 74 miles per hour (33 m/s) Various particular embodiments improve still further mocrIng c.: the balloon. To further limit movements of jC) Lhe cas-ing ar basker level, means can be provided for r.nocring the nwer part of the casing, or its south polo. This is r-specially advantageous, considering that the balloon carries, critical components, such as valves and a Pressurization blower in this region. This further ensures no damage to the casing can occur resulting from it rubbina aaainst the stud-like members, or even from its roming into contact with the ground or the basket Such moorincj means can take various forms. in one BAD ORIGINAL JO embodiment, these mooring means comprise suspension lines li.nking the lower part of the casing to the basket or to :he ground. At the casing end, these suspension lines can be secured by means of a special reinforcement, taking for example the form of a meLal crown sandwiching part of the casing. The other end of the. suspension lines can be f ixed to the basket or directly to the ground. Tensioning means, for example ratchet tensioners are advantageously provided. Suspension lines fixed in io an oblique direction togerher with suspension lines fixed in a vertical direction can also be provided in order to avold nor- only lateral movements, but also vertical movements of r.he lower of the casing. If the suspension lines are attached to the basket, the basket is iS advantageously also secured to the ground using slings, which for example can be tensioned at a point between the hasket and the stud-like mcmbers 14.

Tc enable the stud-like members disposed between the casing balloon and the basket to withstand higher forces, iO means can be provided for linking the individual stud like members. For example, considering the case of substantially vertical stud-like members uniformly spaced bp.lr 2:; around the periphery of the basket, a can be provided 7.in-ing them at a point not far from their top.

77his avcJ.ds all risks of the stild-like members moving outward--,V and being pushed away from the basket by the forces exe-,c.:.'Lsed by the ballon-n. The lower portion of t'--ie casing can zher. be moored after its descent into contact w-;zh, z.-!e basket, during the securing' staRe or prior zo or after the latter.

The balloon's tesistance can be further increased by oroviding the net with an equatorial belt for preventing deformations of the nec. indeed, ncts that are used generally have. diamond-form meshes, and are closed at their cop or nor7h pole by a crown, and at the bottom or south pole -us'ng e load trame from which the baskec Is suspended. The meshes of the net can then become deformed and, notably when a sideways pull is exercised 11 on the net at equatorial level, the diameter of Lhe net increases and its height decreases. This causes the net to move away from the casing, the latLei. now being free to move sideways inside Lhe net. To limir- such deformations of the net, means limiting deformation of the neL at equatorial level, or mo-re generally at the level where the guy lines are fixed, can advantageously be provided. These can consist of an equatorial belt cons-Jsting of a cord knotted to the meshes of the net at ts -auatc-)r, I'miting its deformations and kee ing it h p around the casing, even in the presence of signi f i cant f neces. Such means are particularly advantageous where the casing is in contact with the basket, as sideways forces e.xercised on the net are 'higher than when the casing is at higher position, the angle the guy lines make with the ground being smaller when the casing is in a lcwa-r position; Additionally, it is increasingly i:n,portan'-, to sidewavs movements as the casing comes closer to the ground.

The invention is not limited to the particular method just described with reference to FIGS. 1 and 2. The protective members are not necessarily inflatable, and do not necessarily have the shape of srilds. They could for exat,.iple be replaced by clongar.t. foarn cylindrical members cf suitable shaDe to allow lateral immobilisation of the bdlloon casing with respect to the basket. rhe for-P exercised on guy lines 12 to bring the ballcon rasing into contact with the basket can be exercised by any suitable means other than winches 13.

Finally, the method of the invention is not limited to the mooring of a tethered balloon, but can also be used wii-) a free balloon able to transport paseengcrs from one geographical point to another. The method of the ..nvention can be applied to all gar., hot air, or rnixed ('.iot air and gas) balloons for which the balloon casing becomes lighter than air, as well as to airships that e-,ip'toy a suspended basket or gondola. The method of the invention can also extend to balloons the casing of which i 11.1 is "1 7..1.1 BAD ORIGINAL 0 J 12 is not. held inside a net. In this case, the operation consisting in fixing the lower meshes of the net to the ground is replaced by fixing this casing using any fixing neans that perform the same function, in other words, by securing the casing to the ground using any suizable connecting means known to those skilled in the art, that allows a vertical recall furce F, opposing the upward force from the casing, to be exercised an the latter. This can for example involve cords or cables one end of io which is directly fixed to the casing close to its lower tropic or elsewhere, and the other end of which is fixed to the 9.c-wu-rld whereby rhese additional cords or cables becc;,:ic stretched, and are substantially vertical. -Z---.ally, the inverition has been described for the case of iS 24 equatorial guy lines, half of them being used to descend the casing, and the remainder being used advantageously for centering the casing during its descent. The number of guy lines can be var--ed, providing for example 16 or 24, a of which are used for descending the balloon.

A common descending and fixing step could also he used, for example by simply blocking the winches and preventing them from rotating after descending the bal-loon, so as tc secure the casing. Alternate quy lines could also be use to descend the balloon, the remaining guy i-ine being used as securing means.

Use of the invention has met with considerable commercial success, making it possible to generali7-e the use cif tethered balloons; Terhered balloons having a hanging baskeL and flItted with mooring systems according to this invention have been sold in Australia, Ccrmany, Chijia and in France. The invention has made it zossible Lc) install tethered balloons, even on extremely windy sites, avoiding the need to systematically dc-inflate the Casing.

The invention makes in Dossible to avoid what would have --aiDpened with prior art mooring systems: when the basket is subjecned to a side wind, the guy line stretch aj,D 0 13 and exercise a tractional force on the casing, thereby preventing sideways movements of the casing. However, when such winds are extremely strong, this being a,ituation which always rcquired the balloon to be deinflated before the invention, the casing undergoes successive vertical up-and-down movements, the ballo-on suspension lines and a part of the guy lines slacken and then bccome tight again, undei. the action of che wind. Under these conditions, the casing could corne dangerously close to the basket or to the ground, or even touch the ground.

BAD ORIGINAL Iv- 3.4

Claims (1)

1. A method fcr mooring a balloon, more particularly a tethered balloon, comprising a basket resting an the 9.-..ound and co a casing providing lift, the method comprising:

   - ninoring the balloon casing to t'.mle ground by means of said mo-oring guy lines distributed over a c.--cu-,iferen--e of the casing; - descending the balloon casing to bring it into io contact with the basket; - fixing the casing to the ground by means of irtuoring guy lines, while kseping said casing in contacL with the basket.

   The method of claim 1, further comurising, be--,'ore descendinc the balloon cas-ing - pos-Jt-loi.,-;ng on the basket one or a plurality of.protective elements for damping a reaction force of the baskeL and for distributing said reaction force over said casing.

   3.- The. method of claim 2, wherein said mrotective element o r plurality of protective clements are -nflazable, the method further comprising inflating said inflatable protcctive elements prior r:.o the step of descending.

   4.- The method according to one of claim 2, whereln said protective element or plurality of proLective elements are inflatable, the method f-urthe: comprising inflating said inflatable protective elements after t--le step of -- escend-.na.

   5. - The method according to one of claims 2 t-.n 4, wherein said n-o:ective elements censist of stud-! 1ke member tha-- are disposed on a periphery of the basket.

   eC - 0) 9PP ' "\" h is 6. - The method according to one of claims 1 or 2, further comprising, after the step of descending and before the step of fixing, - hold-ing the casing to the ground by connect-i..,lcj means exercising a vertical tractional force on sdid balloon casing opposing a lift force -created by said casing.

   7.- The method according to claim 6, wherein said balloon casing is held inside a net having lower meshes, the method further comprising, after nhe step of descending and before the step of fixing, - 1-icldii-jg Lhe casing to the ground around a whole periphery of said casing by said lower meshes.

   8. - The method according to claim 1, wherein said inooring guy lines are permanently f ixed on said balloon casing, and wherein said step of descending comprises exercising a tractional force on said balloon casing by all or a mart of said mooring guy lines.

   g.- The method according to claim 8, wherein a free end of said mooring guy lincs is wound onto retuci.i winches fixed tz, the ground.

   1C.- The according to claim 7 or 8, in which said mooring guy lines are permanently fixed onsaid balloon casing, wherein said step of descendingcomprises excrcising a tractional force on said balloon c:as-'Lng by all or a part c-LE said mooring guy lines; and wherein r he methud further comprises releasing tens-on in said juy lines, after the step ot holding and before the sLep of -fixing, 11. - A device- for mooring a balloon to the ground, gaid ballcon a basker- linked to a cas-.-ig r):-cviding lift and a plurality of mooring guy lines E1A D ORIGINAL jp 16 d4stribuLed over a circumference of said balloon casing, comprising means for mooring and descending said balloon casing to bring it into contact with the basket; and means for fixing the cassing to the ground, while keeping said casing in contact with the basket.

   12.- A device for mooring a balloon according to claim 11, where-in said means for descending the balloon comprise a plurality of winches anchored r-o the ground around a basket landing region for each winding a free end of said guy lines.

   13.- z device foz- mooring a balloo.n according to claim 11 or cia.'Lriz 12, said balloon fur-her comprising a net around said casing, the ner. having lower meshes wherein said means for fixing nhe cas.-m:.ng to the ground comprise a plurality of mooring hooks distributed over all a periphery of the balloon landing region, for fixing said lower meshes of said net to the ground.

   14. A method for mooring a balloon substantially as hereindescribed with reference to the accompanying drawings.

   15. A device for mooring a balloon substantially as hereindescribed with reference to the accompanying drawings.

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