HO VERING RAFT & HYDROFOIL
THE INTERNATIONAL REVIEW OF AIR CUSHION VEHICLES AND HYDROFOILS The CC-2, first cushion-riding vehicle in the World to be sold (to the UIC Ministry of Aviation), is a 220 hp ten-seat amphibious vehicle capable of cruising at 50 kt, carrying a payload of 1700 lb, and with a range of 500 miles, The CC-2 is also the first cushion-riding vehicle to be put into production, and will be available for delivery toward the end of this year.
CUSHIONCRAFT brMi"914"ED
BEMBRIDGE AIRPORT - ISLE QF WIGHT phone Bembridge 126 cables Britnor Bembr~dge YOLUME I, No. 4 JANUARY '1962 ------HOVERING CRAFT
------& HYDROFOBL ---== ---== -&-=------THE INTERNATIONAL REVIEW OF AIR cUsnlON VEHICLES AND HWDROFO~LS
FIIst Hovo~'tng CtxFt & Hydl.ofo~l Monthly In the World loirzi k,diior.\: JUANITA KAI,EKGIHl THE YEAR AHEAD ROY McL-EAVY Transport's iledgl~ngall-cushion vchrcle Industry may find its ailnus mrrab~l~sIn 1962 wlth the fi~stsubstantial o~deisplaced and product~onl~nes lad down Desplte the fact that the publlc has ro far been treated to little-and that rnnocuous-information as to what has been golng on, no soph~strcatedsense of real~ty1s called for to conclude that w~ththe foundations of the ~ndustryfirmly establishcd, and the fact that the earth's Advcrtisernent Mnnclger : terraln abounds In condlt~onsuntavourable to convent~onalvehlcles yet Ideal for ACV, provlded techn~callysound craft can be produced econom~cally,the market presents a DAVID MONDRY tantallslng challenge to ~~~aglnatlveenterpr~se 1 hree types of consumer s~dewallcraft are expected to be available before the year rr out Saro (Anglerel) has a 19ft long "Sear~der"sealing four, uslng an 80 c c Cllnton cnglne wh~chhas been successfully tested at speeds up to 15 m p h and maintained its curhlon In sharp 3ft waves One of ~tsappl~catlons w~ll be that of tow~ngwater-sk~ers IN TNlS ISSUE Nat~orral Research Assoc~ateshave a t11o of "AquaCems" for high-speed calgo and general ullllty transportat~on,Intercoastal and Ilver travcl, and sport A further small craft IS about to be matketcd by the Anti-F~ict~on Company In the United States In Brltaln, of the four companies asboclated w~thHoverclaft Developmcrlt Ltd , Saunders-Roe has begun waterborne trials w~th~ts 27-ton SR N2, wh~chhas a ctu~sing People and Projects 4 speed of 70 knots and a range of 200 naut~calm11cs Thc SR N7, a craft of 150 tons all-up we~ght,is belng planned, wh~chw~ll be capable of carrylng uo to 110 passengers Letters-Overland Hovercraft 6 at a cruising speed of 80 knots and coplng with 8ft to 12ft seas, and a futther SR.N4 whlch would prove t~ulycompet~tivc with ex~stlngferr~es Over the Hump 8 Vlckers-Armstrong IS about to b~lngout its VA-2, a small vehlcle carrylng four or five passengers w~tha cruislng specd of 40 knots T'h~smay well prove an excellent Japanese Hydrofoils May Relieve demonstrat~oncraft, as 11 IS rmall enough to be a~r-fre~ghtedto any remote part of the world. The VA-3 1s a larger 10-ton vchlcle crulslrrg at about 60 knotr and catiylng Land Transport Problems 11 24 passengers, and a VA-4 of 100 tons and VA-5 of 500,000 Ibb are also bclrlg studled Denny Hovelcraft Ltd havc begun work on therr 80ft long, 25-ton plast~c"Nover- Design and Operating Problems bus," wh~chis expected to be catrylng mole thdn 80 paisengers on rivers, lakes and of Commercial Hydrofoil Boats I2 narrow waterways th~ssummer. Polland Aircraft has been walking on ground cllect rescarch rnachrnes (GERMS) Philosophy of G.E.M. In varlous confiyural~ons. Construction Utilizing Br~tten-Norman,who have becn proczed~s~g~ndependently of Hovercraft Develop- Non-Aircraft Techniques 16 ment Ltd , has successfully bull1 and tested thc Cushioncraft CC-I and CC-2 (bought by the M~nlstryof Av~at~on),and deliveries of production 02-2's wlll begln In the autumn. The Tracked Hovercar 18 Keen lntclest 1s bclng shown in the Un~tedStates, whe~e50 dlffetent films submitted tender.; for a Cove~nrnentGEM development contract Threc a~r-cush~onveh~clcs arc Aquavion'r Waterrnan 26 bcing advertised w~thpayloads between ton and I0 tons and speeds between 50 and 80 m.p h. 'The largest craft has a grade capabrl~tyof 30 per cent All dre h~ghly manoeuvrable and will travel almost anywhe~e,the largei c~aflsk~mming 5ft above the The Military Hydrofoil 29 surface They ale qu~cklyand easily se~v~cedant1 can be operated by anybody capable of driv~nga truck ACV from Sweden 30 In Februaly, the House of Representat~vcs'Sc~ence and Astro~laut~csCommrttee rs planning publ~cheacings for a cr~ticalexamlnatlon and evaluat~onof 11 S effolt In the field Coils~derableInterest In all-cush~onveblcles has beer1 shown rn Norway, Sweden, China and Japan, where sevelal prototypes have been constructed, and Rurr~a1s known to be bulldlng twelve 100-ton craft duc to be In sriv~ccth~s sp~~ng The prog~essivenature of Lh~s industry, whlch IS steadlly seltlng rtself up as an cintlty apart from the sh~p,dvrdt~on and autoniot~vc~ndustries, has beer] matched by the progressive natu~eof 11s construction techmques 'ind the exploltatlon of such newer matcrrals as plastic and glass fibre In dn age wheie secunty is conce~vedof as heaviness NOVERlNG CRAFT & HYDROFOIL is and bulk, 11 1s as well to speculate on the future where 11ght substances will not be produced by Kalerghi-McLcavy Publica- thought of as fraglle, nor thlckncss as strength tions, 18 Barter Street, L.ondon, W.C.I. Telephone : CHAnccry 2413, Cablcs : The Industry 1s reachlng a state of ebullrence Let us hope that ~tsleaders all over Daytonpres, London, W.C.I. Printed in the wolld w~llcreate an atmosphere ot full and flee cxchangc of lechnlcal knowledge, Great Britain by Charles Elphick Ltd., thus best guaranteeing thcir sound determlnat~onto use th~s~evolut~ona~y mode of Uiggleswade, Bedfordshire. Annual sub- transpo~tto serve mankind in the w~destposs~ble sense scription: Five Guineas U.K. and equrva- lent overseas. W.S.A. and Canada $15. There are four main issoes and eight printed news supplen~elrtsannually. COVER PICTURE: Seen flying at CI sustrrined speed of 75 m.p.h. during (I recent test, the El.~erglades Speedster, designed by Carl Weiland, constrllanl to the Reynolds Merctls Contents of this issue are the copyright of Cornpany, is probably the fnstesl ground eflecl inaelzirze built so far. The crtift is built Kalerghi-Mcl,eavy Publications. Per~nis. jrom ulunliniurn sheet clnd weighs nhollt 4,000 1:~s. I1 is 31ft. long, 14ft. wide, and is .on to reproduce pictures and text can DE owere red hy two 150 h.p. Lycoming aircrtrft engrnes. A nzodified single peripheral jet granted only under written agreement. system is employed. Extracts or comrnents may be nrsde with due acknowledgement. Commander L. A. Sweny and Mr. Christopher Cockerell, of Hover- craft Development Ltd., leaving for talks in Paris in January to discuss a London-Paris Hovercar Irnk. A description of the Hover- car starts on page 18 of this issue.
Peopk and
Earlier this month, Commalsiles L. A. Swer~y and Mr. addition, the craft will permit the Navy to explore this concept Christopher Cockerell, directors of Flovercraft Development as a possible military vehicle. I-td., flew to Paris tor cxploratory talks with M. Jules Moch, Bell will design, assemble and test the 62-foot long craft at former French Pren~icr,who is now Cha~rmanof the French its ~~ff~l~,N~~ york, facility. I( will be ready for testing by Society for the stilcly of a Channel bridge. mid-1963. They discussed plans for a Hovercar, operat~ngon the same The vehicle will skim on a, cushion of air over smooth water principle as the tlovercraft and capable of transporting 150 and flat land surfaces at speeds in excess of 70 knots. Test runs passengers at 300 m p h, whrle skimming half an ~nchabove a will be made on the Niagara River and Lake Erie. shallow V-shaped track. One of the possible applrcations for the I-love~carwo~rld be a special track running from London to The aluminium-hulled hydroskimmer will be 62 feet long, 27 I'aris and another from London to Wrussel\, using the proposed feet wide ancl have an overall height of 21 feet. An open cargo Channel br~dge. deck at the aft end of the hydroskimmer will provide space for approximately five tons of payload. It will have endurance fuel for operation at full pwe; for two hours. Work has begun on an 80ft long by 20tt w~dcHoverbus Foilr air cushion fans, mounted horizontally in the hull, will which will weigh 25 tons and have acconlmodation for more provide the lift needed to rise from the surface. It will hover than 80 passengers In ~tsglass-covcred saloon Generally 11 will at a height of slightly more than two feet. opclate on rrvers, lakes and narrow waterways, and is expected Two propellers, mounted in ducts on the after deck, will to be In use this s~intme~The vessel has been developed by supply thrust to drive it over the surface. Aerodynamic rudders, Denny Hovelcraft L~mited,the new subs~diary oi William to be located in the slip stream of the propellers, will provide Denny and Brotl~ers B,tcP., shrpburlders, oC D~~mbarton,in yaw (turning) control. collaboration wlih Hovercraft Developsneelt 1,idi. Four 1,080-horsepower Solar Saturn marine gas turbine Shipwrlghts have been cutllng out thc first shaues of the engines will be mounted in the hull and will power both the sidewall craft, which has two propellers in the water, driven by cushion fans and the drive propellers. ordinary marine dicsel engines of a total output of 800 h p Manipulation of Ihc propeller s w~llcontrol the direction of the * * k * vessel Normal speed wrll be about 25 knots No estimates ot Russia's 92-passenger Stryela [, which has had successful its cost have yet been given trials or1 the Black Sea at a speed of 50 rn.p.h. in a forcc nine * * * * wind, is to be put into regular passenger service from Odessa The Navy's Bureau of Ships has disclosed additional details to Batumi. of plans to bu~lda 22-ton hydroslc~mmerresearch craft. A speed exceeding 70 m.p.h. is promised of the Dolphin, The design and constructron contract to Textron's Bell the new 100-120 passenger hydrofoil due for trials towards the Aerosysterns Co. for $2,040,000 was announced on Nove~nber end of the year. It is equipped with a jet engine identical to that in a 7W.124, the latest addition to the civil aviation Beet. 28th, 1961. 'The company IS a d~vrsionof Bell Aerospace Cor- poration, Suilalo, New York. * * k * This c~aft,of a type .iornctimes called a ground eflects The owners of Norto11 Spit, a 200-yard btretch of beach to machinc or hovercraft, 1s a part of the U S Navy's programme the west of the harbour at Yarmouth, Isle of Wight, have been to dcvelou the technology necessary to deaigrl f~~tureocean- approached by unnamed air-cushion vehicle interests about its going veh~clesof tbls type It w~llbe utllised to develop an use as a base for a shuttle service across the Solent. The railway understanding of rough wenthel control problems and to pio- ferry from Yarmouth to the mainland takes 30 minutes, but an vlde dcs~gncriteria for the construction of futu~evehrcles In air-cushion vehicle would cover the distance in less than five. People and
Projects a
An arrangement has been concludecl between Britten-Nonnan, hovering craft have cnorlnous enterta~nmcntpotential and is desigrkers and builders of the GC-2 Cushioncraft, and J. Samuel trying to arrange a dclnonstrat~or~.The tanrrl~arspced boa1 now White and Co., shipbuilders, to cstablisll a joint subsidiary, has its competilor. Cushioncraft Limited, lo nianufacture air-cushion vehicles and k * * * market them internationally. Martin Marietta Corporation have develoned a new air Cu:,hioncraft Limited will be fully capitalised at &100,000- cushion crall--the Ejectljct -Eor the U S Arllly Il r ansporlatioi-r Bdtten-Norman controlling 60 per cei~tand White's 40 per cent. Corps Expected to be completed shortly, the craft employs a The Board will comprisc two directors from White's and threc rec~rculat~onsystem wh~chre-uses the air drscharged to form from Rritten-Norman. the support~ngcushron. The CC-2 created considerable interest at the Pntcrrsatiorlal * * * * Boat Show, and the prototype has been bought by the Ministry Britlen-Nornnan w~llapply Lo the M~n~stryof Tlansport and of Aviation. A secorrd vehicle will be ready for testing in about the Avration Ministiy COI permsssron to carry passengers on ten weeks. CC-2 Cushioncraft joy-r~desin the shcltcrcd watcrs near Naylsng Design and administratio11 headquarters of the new conlpany Island Warner's )-lollday Camps has offered fac~litlerat its will be at Bembridge, whilst manufacture will be undertaken at Sinah Warren Luxury Camp, prov~declthe plan 1s approved by the Somerton works of J. Samuel White. the autl~o~itics. * * * * * * * * A 300-ton hydrofoil craft of about 200ft. in length, able to According to the spokesman for a leacl~ngcompany In the reach a spced of 80 m.p.h., is to be built for the IJltitod States insurance ma] ket, rate? for ar r-cushion vehrcles operating over Navy by Grummaii. The vessel will be mainly for research and land w~llbc bclwccn 3 and 5 pcr cent pcr annurn of the~rsale more than £3,000,000 is being spent on the project. price--slightly less lhan the 5 to 'I+ per cent per annun1 for * * * * those operat~ngover water These rates may include thud-party 'Tl~emagazine Aviation Week reports from Washington that insurance up to a reasonable figure, but, as In the case of the prospects of an order for a Saunders-Roe SR.N3 Hovercraft motor-ca~s,Ihc owner will have to beat oart of the claim on under nlutual defence agreernents are now bright. The U.S. each claim made dur~r~gthe year I~~abrlltyLo passengers and Navy has asked for a study by Saunders-Roe of the place of freight ale the owner's rcspons~bility hovering crafl in anti-submarine warfare. * * * * The idea of placing long-range weapons and helicopters into One of thc lalcst Bril~shcompanies to lakc an active lnterest hovering craft has been considered and findings submitted to in a~r-cushion crail 1s Ssro (AragBesey) Limited, at one time an Vice-Admiral John Hayward. associate of Saundcts-IBoe on the Isle of Wrght, and now a * 1 1 * member of the tlawkcr-Siddeley Group Britain's holiday beaches may soon offer "hover-rides" to The first type to be ~ntroduced by the company is the passengers wanting to skim dry over wave-tops. Mr. Harry Sear~der,a 19ft. Long srclewall craft, seating four, and using an Porter, spokesman for the Blackpool Corporation, believes that 80 c.c. Clinton englne develop~ng3 h p lo p~ovldethe cushson.
sketch of the Denny Hoverbus by Mr. F. Morris, its designer. A sidewall craft, it w~llcarry more than 80 passengers at 9K !,-..A- 6 Peopie and
Projects .s
tIc,~g~~cil;III~ I, II~\\,hitildi~ig lie protot\pc 01 ;I IIC\\. li!clroto~l cr:ill \\'11Ii ;I crl~i\ingspcctl of 5s Ltloli. ~)o\\.e~c~lb\ \:;tl~.r-lel~~ ill pI:.cc ot the ~)rlhc:~lo\;>ct.c\\z. I'I;iti\ ;ire hr.it~gprc~l.~~ecI 11ict.c' Cot ' ' 4 , ... ..,.,..rc( ' l *."- *. " . ,,. ' .,. > ,,<.. 4 ~ .. - ..... $I"a"",*;:-;2,.,.ILI. , . - , ,<* , :&q;?* , . A"&? ,.; ., -1 Saro (Aiigletey) Searider undergoir~g trials. I LETTERS I An 181n. cllametei ten-hladed I~ftlati IS used, arid this and the Overland Hovercraft power unit are mounted lust aft of the cockptt Propulsion power comes from an 18 11 p Johnson outboard htted w~lha long shaft. 00 olten 11 cnlr be satd of people In tndustry that they arc T so close to the11 subject that they canriot see the wood lor Constructton of the Sea~rdcr1s fiorn wood and wood lam~n- the trees This seems to me to be one of the teasons why top ates, and the all-up weight w~thtbc outboard cngrne, but management irr many ~ndustrresare lukewarm about the tntio- excluding passengers, 1s 820 Ib ductton of new tccllnraues and new tnvcntions 'Their thrnktng The htst prototype, shown publrcly I'or the hlst trmc dl the habits tend to baulk a1 anythtng that cuts too d~asttcallyaclors Dully Enpres~Boat Show tn I,ondon III early Januaiy, is st111 existtrig methods Thrs causes manv sound and potcnt~ally undergo~ngtrials and has several obsc~vatlonports fitted to rtscful rdeas to be erther shelved or else srdctracked tnto paths pernut the study of wavc behavrour Mr Call Butterheld, chief of development wh~chIgnore the11 real potentral Th~sseenls de5rgner of Sa~o(Aoglcsey), who 1s responscble for the develop- to Ire to be happcntng rn the field oi hoverc~afttoday ment of the Searidel, says that the craft in its commerc~ally developed form w~llprobably be avatlable by thls summer As an outstder with l~ttletechnrcal knowledge of Hovelcraft, The sidewall-type ~urtaceeflect niachrne is one ol the srmplest 11 hardly behoves nic to coniment at all. Yet even those ilncon fo~nisof l~overlr~gcraft, and Mr Butterfield 1s confident that nected wtth thc trrdustry cannot fall to riottce p~ctures of these craft have a most plornisrng future, paiticularly rn canal., Hovercraft rn t~ewsreel~and or1 tclevts~on. IJsually they are narrow rivers dnd other part5 where a good spccd is needed, bu~ movrng slowly but surely aclosa a belt 01 watec, whrlc the whcre wash must be kept to a m~nrmuln He polnts out ihat co~nmentator discusses thetr fututc use ;IS a cross-Chatinel theic 1s no wash from the Sedt~ders srdcwalls, which mcasur? vehtcle or Eor travel along rivers Yet who ~eallywants to use 2ft, deep by 15fl long by 4111 wrde At speed the s~de\vnll Hovcrclaft to cross the Channel when aircraft are now cheaper draught is only 2111, although the craft IS actually drawlns 1f1tn arid g11ore convenrent every year? How often, fol that rnattet, if the screw ts included. tlce3 one want to travel along a r~ver" During 114 first selles of t~ialsthe Searider has demonstrated 11s ab111ty to maintain 11s cushcon 111 sharp 3ft waves, an: so The greatest potent~alof the Hovercrdft n1u5t su~elybe for Ear no one has succeeded IJI "knocktng 11 off rts cush~on A land use rhrs new concept~ontn travel has one auality wh~ch loose rubbel-hinged flap lets all rnto the cushion and the all I\ tdr too ltttle constdered--that of needlng no p~eparedsurfacc prcssule at the cear ot the flap tends to flatten rt against the on which to run Thrs stngle aualtty, when its lmplicatrons 'ire waves lo form a seal At lhc real of the nlenum chambel is a cons~derect,could place the Flove~crafton an ent~relydtAerent curved planing surlacc Tests have been made so Ear at speeds level as a practtcal rnvcnt~on up to 1 S m p h , but the craft 1s capable ot a much higher speed, 3nd one of its probable anplicatrons wrll be that of towtng The mtllions wh~chare at p~csentbetrig poured Into load water-skrer s bu~ldingIn thir count~vand elsewhere, the roads whrch cost Plans have already been prepacetl by Snro lo1 a much latgc~ f 1,000,000 per nlrle to hurld and a fortune to ma~ntarn-tbesc srdewall craft-a 4-ton load cdrilei, with a length ot ?Oft, a toads could be drastically cut and alteted tf the motol-car wele 1Sft beam and plopelled by a watel-jet One propo,ed applcca- to be replacecl by a small, manoeuvrable Hovelcraft The toads tron 1s the carrrage of passengers dnd supplies on troptcal Itvers conld rn due course be leplaced by a farlly level, rough track and weedy lakes at speed\ up to 25 Itriots w~thboundary fences only, the cost and matntenanLe of wh~~h * * * * woultl he ~nfinitestmalcol~ipared wrth that of the modern toad Russra's macn l~ydlolorl rnanufact~trcts, the Krabrloye By all means use the Hovercraft's wave-rldlng capabilitres to Sormovo shtpyard, at thz nort of Ciorki, on the river Volga, has d~spensewith bridges, but corlccde that such a land use for lhts Overland Hovercraft , , , rnvcntron opens up a new, Inore attiactive cornrrrercrnl ~U~LIIC rmprovcment on the c'lr would be ~mniense. In AErrcarr and than any rrvcr applrcatron. Asran count1ic5, where the problcnl~of road-build~ngare ri nnytl~~r~gworcc than rn Brltain, the applrcatrons of ~IIL~a An efficrent Hovcrcr'lft can, I understand, travel at eighty flcxxrble vchlcle would be inrrnedrately obvious. n?rles an hour It can negotratc even farrly unevcn ground wrth ease and talie rivelz rn rts sti~de Wear and teal would presum- I belrevc that thc people to develop Hovercraft may not be thc ably bc rmrch lcss than that of the average car ol lor~y,srncc ,rvlat~oi~and slilpbuildrng cornpanrcs, but the motor rndnstry. thc jarring of the road surface would be abscnt I would think, I lie millrons now bclng spent by them In cornpetirrg 111 shrlrrkrng although here I am only guessrng, that a Hover craft rrnged wrth oveise~~srliarkcts, n~arryof whrch rnav never be rcga~ncd,coultl thick rubber bun~perswould tend to bounce off other Hovelcraft well bc devoted to lust such a radrcallv new clepartlrre A rt touched, In the 3ame way as a bu~iiper-car 7h1s could well r wd$ lilst two ycdrs dgo that we bcgdl-~0111 early rrrvestrga I i~onr with Hovercraft and ~n ~etro,pect ~t IS bald to ~rndcrstandwhy we were 50 plcajed with our achrcven~entcat that (rme By thc end of the sumrxlcr of 1959, the SR Nl 'r st111 air spectl wa5 only 25 Itriots, but we had 'ichlevetl n m'ixrn-,um dowti wrnd specd of 45 kcrot?, arlcl we hacl rather niargrnal cross~rlgof tllc Channel to our crcthl I-lowevel, we had gleat d~tficulty In gelhrrg over the hun~p(wl~~ch occura at about 15 Itnots) on '~nythlngother than a pertectly cairn day, and th~srcst~rctetl operat~onsto a la~gccxlcnt. Although these l~gurcs we1 c not pnl t~cularl y rrnpos~rlg they were techr~rcallyclgn~licant, because they t~eclup to the nearest knot wlth our thcoret~cal est~matec From a clcs~gn polnt of vlew 1h1s IS the complete juitthcntron for almost anythrng, ant1 of courye 11 drd show that we had a ~oirghidea how to do or~r su~ns It wac; rmmedr;ltcly aflei the Channel ctosslng In July 1979 that we declded we hacl better get down to dcs~gnrnga real hovercraft We knew eveti a1 that time that the mllilrnuni srze lot a really cfic~entvehtcle was at least 50 tons all-up we~ght, and p~obablymore, but to lurnp iror~a 5-ton expcr~n~entalcrnl't lrkc tire SR.N I with only 25 ltnots to 115 cledrt, to a properly englneerecl f-lovercraft of 50 tons wrth a specd oi 70 knots would have been techn~calfolly, part~c~~larlywhen we were rxot too certain exactly what we were up agalrlst For th~sreasor1 we dcclclcd la concenlratc on the irnallcst vnacb~rxewlilch woultl calry the fan, transrn~ssior~and control syslerl~sthat we woulcl 11ke to use rn a really large Hoverelaft of the older of 125 tons e or lnorc '1111s proposal hati the great advanlage of mltilrlilslng both the fir~anc~aland technical r~sk Although we talk of Hovercraft In term of all-up welght, they ate actually dcslgr~eclin terms of cu.ih~otiarea, 'incl so we chose a cushion area of 800 sq ft because Ih~sIccl lo machine ol 27 tons, whrch 1s a rirce iens~ble7 1 erlglrleerlrrg jump Jrom the SR N1 Wc dcc~dedlo try and hiral~se our proposals by Chrrst~rlas 1959, and so 11 rs not surpllslrlg that th15 rnachrnc wa5 first known as the Chr~~tlnasC~aft There follawccl the usual pel rod of linanc~aldlscu5sron and ~lrlcertarnly w111lc we went ahead with moclels and prclrni~nary deslgn ol the real n~ach~ncSIX months later, in June 1960, negot1atron5 wrth the Nat~olii~lResca~ch Llevclopmcnt Corpolation were n~cely ~esolvedand we were on our way with what 1s now the SR N2 Iri the nieant~mc,the SIX N I had collie to the end of rtr useful tile nnle\\ we cor~lclget more specd out of it Now ihc triost SR.N1 MODES: Top: Mark II version with a Marbore jet englne, in 1960. Speed: 45 knots. Lower: Mark 111, 1961, with a Viper turbojet. Speed: 65 knots. R~ght Mark IV, wrth polnted bow and stern It ytas testcd In late 1961 OVER Tlie SR.NI Mark 1 photographed during trials on the Solent in 1959. THE HUMP . . , eficient way of gett~ngthrust at 9peeds between 40-70 knots rs of pushing the SR Nl at a speed fast enough to carise the undoubtedly Lhe airscrew, and srncc the SR.N2 was gorng to use cusliion to break down, and so whlle we were lounding oiT the gas turbrne engines to drlve 11 we would have liked to have test plogramrne of the Mark 11 verslon w~thits Marbore, plans used a turbsae propeller comblrration for test purposes on the were lard tor a Mark 111 version using a V~perjet englnc w~th SR NJ. It is not that wr: arc worried about the propeller, but about 1,500 Ib thrust, previously used In the SR.53 jet lighter. rather that wc want to know how gar turbrnes would behave in W~ththe Vlper lnslallat~onwt were able to obtalrr lust do~tbllc our salt spray erlvrronment linfo~tunately,prop turblrre englncs the total thrust that had been available on the Mark 11 Marbore are d~fhcultlo acquile and reyulre expensive gearboxes aird a verslon, dnd w~thth~s we managed to ach~evea still ail speed rather werghty rnstallatlon rn order to get the best out of them of 62 knots, and have so tar obta~nedR rriaxlmum recorded So we settled for a Marbore enginc whrch was founcl dlscnidetl water speed of 68 knots and which Blackburns very k~ndlyplrt rnto working order foi It was just over 60 knots thdl we had expected to lose the LlS cushson, but rn the event nothing spectacular occurreti Now- This Mark II vcrslon of the SK.NI wrth its 700 Ib. thrust ever, it was qu~teclear that 60 knots was pushlng the SR.NI Marbore ]el englne put our air speed up to 45 knots and gave almost to ~tsI~mrt, since we knew that the s~rnplechrrrrney us a maximum recorded clown wlnd water speed of about 56 ~ntakefor the l~ftfan is almost completely stalled above 45 knots. 'The modificat~on rnade a great drfkrcnce Lo the craft knots, and it would be surprrslng rt more than half the aniourrt arid operalron in the Solent became almost unrcst~lctcd. 1 he ol all that shoilld be golng Into the system wdr fiirdlrlg its way only adverse eflcct of thrs move was that many pcoplc now to the lrftrrrg jets associated the jet engme as an inevitable part of Hovercraft, Howcve~,th~s 1s st111 not the entl of the SR.NI, for we have but this rs by no means true and we rrlost certainly would not ~ecerrtlystarted a trial5 proglamme on the Mark tV version have used it unless wc had got il free, gratis, and for nothlrrg. Ihe rnarn physical difference to her external appearance is a With the Maik II version we were able to grve very mrrch ~harrgcot shape lrorn a scrn~-clrcula~to a pornted bow and niorc convlncrng dcnionstrations, lncludrng a 60-m~lccsrcuit of stern. the Isle of Wrght whrch was colnpleted in 14 lso~~rs.I1 only we We started the Sli Nl wrth the help of the Natronal Research had left our Cllannel crossrng until after th~sengine had bee11 1)evelopment Corporatron ~nteriton producing ol-ily a quick xn~lallcdwe could have made rt both ways 111 conslder:lbly lc$b 'lasli-up' to prove a plrnc~pleand to demonstiate to the scept~cal t~mcthan it took 11s to cioss 11 once in the summe1 of 19.79 that lrioverciaft welt feasrble We expected to operate for orrly By the crsd ol 1960 we began to be lntriguecl by the possibility SIX months, wh~ch1s about 50 Ilour5 runnlng trme, and Lo get Seen here under construction at Cowes in the summer of 1961, the SR.N2 has an all-up weight of 27 tons, a speed of 70 knots and a disposable load of 12 tons. SR.N2 being wheeled frorn its hangar at Cowes on November 20th, 1941. OVER THE HUMP. . , 25 to 30 kt~otsovc~ the water, but instead this tnach~nehas now largc a. rogue wave at 60 knots, then the SK.Nl should go on clo~ked300 hauls in two yeals of operatlotr, has ach~cvedover opelahtlg, gaining valuable data, for at least another year. 60 knots, and has pushed ~tsway through more than 1,500 m~lesof salt spray. 'rBae SR.N2, SR.N3 and Beyond . . , Over-Wave Performance flowever, llie SR.N2 is now starting its test progtarrrrnc, and it wrll be with this rnachlne that we hope lo makc the 1~1crsf The SR.Nl was clesignet.! to irnpact Zft, waves at 40 knots a[ lapltf clcvelopmenls. an all-up weight of 4 tons, but we have inanagecl lo rn~pioveits X rnent~onedearlier that one of the main alms of the SR NL ovcr-wave performance to a porn1 where 11 coltld ope~alcat was to develop the fan, transmiss~onand control systenrs, for TO-60 knots at 6 torrs over about f+tl. seas. I'tiger and more eficient craft, and so ~t was not long aftel we '~IGtorrgh-water perloin~anccof lhis ctaft, or inileccl of any sl<~rteilwork on the SK.N2 in earnest that we lu~rrcol o~ri hovercraft, rcprc~cntsone ol the inalor dcsigii ploblems and ~t Lhoughls lo the SR.N3. The SR N? uses all the malor com- is Irr this ficlcl that we have a great deal of development bcPo~c ponents of the SR N2 but resorts to the old aircrafl trick ol us. In the early days of the SR.Nl, bow impact accelerations of puttlng an extra loft in the fuselage In fact, the SR.N3 is 1 Ifg could be expectccl in the most lrequently cncoonlcred ~eally111sl a "stretched" SR.N2, but although we have only condrl~onsin the Solent (1.e. a short chop of 9111. 121n. with za rnc~eslscdthe lcnath bv loft.. the odvload has increased from the 12-15 knot wlnd at a water speed of between 25 ancl 30 knots). ortier. of 70 to 1.70 troops, if one thinks In terms of an assault Opeiairons wero lirnlted by 3-4g 1m17acts it the wave l~e~ght landing craft. exceeded 18tn., and this co~~ldbe expected wrth 20 27 knol I~irportanlfrom a naval point of view is Lhal we believe lhat winds. t11e SH.N3 might well be a most s~titableoperational research D~~trngthe COLLJ~~of development we have managed gr<~cIrtally prototype for assessing the potential of hovercraft in the arrli- to rmlxove matleis so that the SR N1 can now reaclr 45 50 subnrarinc rolc. Provicling that an over-wave performance oC krlots rrl 9111. 12111 chops before ieglsterlng I-lfg bow acceleia 3-511, is acceptable for early operational experiments, we may lions, and operations become limited at 25-30 knots rn 2 241'1 reasonably soon be able to develop this to the poirrt where we beas. We know that th~s1s not much of an over-wave pcrlorni- can cope with 8-12ft. seas iii a craft of about 150 tons all-up ancc, but on lhe SRN2 we are liopiiig to be able to rxnprovc weight. 'This of course would be the SR.N4, and apart from its possible military applications, matters 50 that we arc able to cope w~lll7-511 waves, ~vb~cli15 i.t is also the size of hovercmlt eqrrlvillent to a lilnlted fetch sea slate 5 TIl~erers still a great which in its civilian role begins to becoriic really compclilive clcal of uselul ~nto~rnationto be galr-red from ou~first crrrclc with existing ferries. expclrrt~cntalcnach~ne, and ptovrding Lhat we [lo no1 rnect too But tliis is only tlie beginning . , . SR.N3, a "stretched" SK.N2 with the same engines, fans transmis- slon and control system. All-up we~ghtwill be 40-45 tons, the d~sposableload 18 tons. JAPANESE HYDROFOILS MAY RELIEVE LAND TRANSPORT PIXBBLEMS APAN has one of the highert populat~on densities In the J the world, and there 1s a strong tendency for the maloi~tyof the population to concentrate near the newly growing c~tles along the coast. Consequently, transportation around arid between these cltief, by land, espec~allydong the coastl~ne,has become aln-ost full lo capaclty Transpoltation by water could not hope to relieve thrs saturated condit~onuntil au~terecently, slnce the average speed of the nolmal fe~ryboats IS only one-th~rdof that of the road and ra~ltraffic However, hi tach^ $hipbu~ld~ngand Eng~neer~ngCo belleve that hlgh-?peed hydrofo~lscould prove to be cocrrpet~tivew~th cx~strngpubl~c transport and help to overcome the growlng transport problcrns rhey have theretone contracted a techn~cal llcencc agreerrent w~thSupramar to construct craft of the11 design fol use on h~gh-spzedcoastal passenger servlces H~tachl have also obtdlncd the app~ovalof the Japanese M~riist~yof 'Iranspo~tat~onfor the constluctrorl of hydrofoils for such seivlces Meanwhile two tyn~calS~~piama~ craft, a P T-20 and a PT-3, have been ~mpoltedfrom Leopoldo Rodrtqucz to peril-~tpoten- t~alusers to examrne the craft tl~tach~state that people In many helds have shown ~ntcresl 111 the possibllit~esof the craft, and more than twenty prev natties alone have been on trial runs in both Tokvo and O\aka bays. Ser~esproduct~on of the IT-20 has riow been started at the A model of the Cushioncraft Ltmrted CC-2 seen at the Kanagawa Shipyard, near 7 okyo, and the hrst boat, w~thseating lnternat~onalBoat Show, Earls Court, next to the craft itself, for 76, will be put Into servlce In Ap~ll,1962 The first PT-50, with a reat~ng capac~tyfo~ 140, w~llbe completed in the autumn. THE LiGHTES T I050 HP D/ESEL ENGINE EVER 63UIL.7" 2 hs, 8 or, fa MILAN (ITALY) 4 8 Mia Manzoni-Telephone "i'0386/708387-Cable address CREMCME DESlGN AND OPERATING PROBLEMS BIB' GOMMERCIAE, HYDROIF'OBI, BOATS . , , ping company, nanled "Al~scalr,"wns cstablrsliecl in S~cilyar~cl lrlps betwecri Naples and Capr~.PT 50, lrowevcr, nia~ntai~iecl the flrsl sched~rlecl sea servlce inaugurated bctwcerr Srclly and her servlcc Irr an ove~loadeclcond~tion, carrytng 170 passengers the Itallan mainland In August, 1956 Culting the poi t-lo-por t ~nsteadof the regular ~lun~belof 140 On arrolltet occas~ona t~mefroni Mcss~nato Neggro c11 Calnbrra clown to one qua1 let PT 20, passlng th~oughthe Stlaits of Otratlto, was torccd down of thal oC the conventional icrry boat and makrng 22 cldrly trrps, by waves of an estlmaied he~ghtof 13ft., hut sho~llcngth It she thus set a11 example for the onerat~onol' other hydrofo~l way .itill poss~bleto ma~ntainan average speed of 15 knots. In selvices The tesults of 1111s service after Lour yeals ol opera- the Cat~bbcanSea another PT.20 got caught rn the frrrrge of a tion arc noteworthy Wsth a seating capac~ty of 75 p'lssengcls, hu~ricaneand wd!, able to continue he1 loulney in half foil o~icboat alorle has catr~eda tccorci number of some '31,000 borne cond~t~onIn long waves averaging 16ft. In height. people 111 a s~nglcmonth lhe average dally rliimbcr ol As rcga~dsmalntenanee, inspections arc undertaken at regular passcngeir IS today between 800 and 900 To date the bo~lhas rntcrvals oi about 2 3 month?, including clcanlrig of hrrll, cairiecl a total number of appr oxrrnatcl y 1,000,000 paswnger 5 bottonr arid tolls In a trop~calcllmate, where intensrficd growth The boats opera11ng a1 ou~idSrc~ly have covered a cornb~nccl of bdrrraclcs dffeci the dtag of the foils, more frequent rnspec- drstance of apploxlmately 465,000 na~~t~calnrrles, which 1s riiorc t~onand clednrng is lndrcated. If the foils arc not retractable than the d~staiicebetween the eartll and thc tnooi~and back ih~swork 1s usually carried out by aqua-lung dlrvcxs Dl?- agarn. regardrng malo1 machrnety overhaul, whrch 1s no~nially81116 Allcr the establishi-crent of the Mcssina-lieggio line, other after 5,000 operat~nghours, the ~narntenn~iceof the lolls services have been orgariiscd betwcen the followil~glocalities: requries about 25 pet cent of the rna1ntena11ce work of the 1957 Messina---Taorrnina , ...... I'TTO entire boat. 1957 Messina-Liparia11 Islarids--Palerrno , , , Str crlgth arlcl ~el~abllityof the lo11 system wab several tirnes 1959 Vcnice-Triest ...... , clen~onstratedwhen boats ran ag~oundand wese st111 able to 1958 Lalte Garda ...... conti~iueooerat~or~ A boat coll~dir~gw~th a pler cau.ied con- 1960 Naples. -Capri--3schia . , ...... P'?: 50 s~derabledamage lo the latter whllst she suPferccl only minor 1959 Maracaibo-Cabinias (Vcnezttela) ... 3 I'T.20 defoimatroris oi the plating around the for1 suspension point 1960 Slavanger-Be~gcn (No1 way) IT 50 but was not forced to inte~rupthe1 service 1960 Stockholln Marleharnn (Sweden Frrrlnncl) 1)'T 50 In pr eparat~on 6. Problems of Economy 13uenos A~rcsMonlev~deo 2 P'I' 50 Six years of experierice it1 public passetrger service will1 Ihe most pxosnclous iervlccs cxr\l betwecrl Maraca~boanti hydrofoil boats proved that the comruercial application of this C'a b1111as ar~dbctweer~ Naples and Cap1 I On the hi st rnerlt~olrcd type of craft is very profitable in areas with an adequate passen- lrne lwo PT20 carry an average of nearly 1,700 passerigers ger frequency. Sitriilar to air transportation, the comparatively dally and over 600,000 per ycai over a drstancc of approxl- high speed of hydrofoil boats in relation lo other water-borne rnately 20 n111es The shipping company was able to alirostisc craft results in a !~ighcarnuig power. Since the present foil- thc two vessels w~thirione year. 011 the Naplcs C'aptr Jrne, borne craft r~suallyoperate ai speeds up to three times that of operated w~tha PT 50, passenger Lees had to bc ta~setlolr other boats, their potential casuying capacity is up to three accour~tof the high passengel L~ecluency A sccot~cl P'L' 50 ha.; times greater. Zn other words, a hydrofoil boat can be con- been ordered and two P'11'20 have beell sent lo Nanles rn the sjciered to be equal in capacity to a ship up to three times its meanirrr~cto nsslst 111 operahons cl~~r~iigthe season. A sccond size. X"T 50 was also lea uested lo1 the Stavanger- llcr gcn lir~eon1 y Pig. 17 prese~llsan analysis of actual comnrercial experierlce two srronths after ~tsinaugrilat~orr for the type 1"I'.20 (assuming two boals in service) based on 011 many occasions supra ma^ boats hid the oppor t~rnrtyto prevailing European conditions and a price of 6 cts/kg for demonrt~atetheir sea-rld~ngqualrt~es undrt very severc wcathe~ diesel oil and 53 cts/kg for lubricating oil, The graph indicates cond~trons Soon after eslabli.;hrnent oi the 1'1' 50 line at Naples the yearly net return to be expected over ticket price (cls/riaut. a heavy storm caused the 500 le~I yboats to d~s~oiil~nucthe11 mile) mul~iplied by the load factor (number of passengers/ Fig. 16. General 8rrangernen.t sf the PT.50. DESICiN AND OPERATING PROBL,FCMS OF COMMERCIAL HUDWOFOXI, 13OATS , . . available seats). As a runctiorr of tlirec par ametet s Ilie graph lower "i~~rllalcay~rlal expctrdltu~c per pasrcnget nirle" and thus enables to arrticrpate whether comrncrcial applrcation oi operntrorr costr of the tlrsplacet~~enlboat, the attalrrable ~evcnues hydrofoil boats would be profitable uriclcr grvcn local coodr w1t111ur n eel tarii opcrnt~onper rod arc lirghcr for tlic hytl~oloil t~oris.Assirn~rr~g a Pare of 8 cts per nautical rx~ilc,a load factor boat bccrtusc rt havcls three times a\ last It mu~ttdco be taken of 0.7 and 1,500 operatltrg hours per year, thc graph shows a. inlo consrcleratrori that the publrc rs gcncr'~lly wlllrng to jmy yearly net protcl of slightly more than 30 per ccvll ol tlic lr~gherCalcs lor taster tians~oital~orlI lie conipar Iron wrth the Invested cap~tal. cornrncrc~alairplane 1cvcal.i (hat 11s in~tralcost5 ale htglrc~arlcl 'The above dragran, rs bdscti on CL cr~r~riigspeed 01 36 k11ots 115 toLal operat~oncosts very much hrgher rf the cxpcnclituies Irr order to dcterrrr~netlie ~nflucnceof speed on profits and also lor the ground orgnnrsatiori 21rc taken into rcgartl With total tire ccononiical speed of the velscl at whrch the most favourable operatrng cxnenscs estimated lo be at least seven trmcs those ol relation betweerr costs arid revenues 1s obta~ncd,the curve the Ilyd~olorl craft, the helrcopte~ cannot be cons~tlcrccl to depicted In hrg 17 was computed urrder the followrng supposr- repi eseiil arr ecorrornical rnstrunlcut of ti anupor tallon at present trons: In orclei to llncl out the spcetl langes wlthrrr wh~chthe hydro- loll boat ancl 1t5 ~o~npet~lorscan be successfully en~ployetlwe Load Cactor 60/ hdve already shown 111 big I the power cocficrent for the craft Fare 8 cts/naut rlirle. rn question over spced P~rstof all the earnrrlg power lor arrch spccrhc weight w/N 4 '3 kg/h p 'I hydrofoil boat with 550 passengers was calculated as a Ilrerel englne I specrf~cfirel consirrnptlorl II I66 g/h J, /i, Irrnctron of speed rn ordcr to detcrmrne the Irrnrt froni a conr- prrce ol engrrrc - 26 S /h.p nierc~nlpornt ol vrcw In do111g thr~the lollowrrlg roirdrtion\ specrhc wcrglit w/N 1 3 kg/h 17 wcr e assumed 'I ur b~rle I apecrfic fuel coosumptron H - 120 g/h p /h J pr ~ccol erlgrne 44 S 111 p IL,oad factor 60% - 330 passengers. l'icltel pricc/naut, mile 7 cts (in correspondence with tire The errgrnc werght5 rrrcludc gear? nnd all auxilr~riresas well avcrage cconomy class fares for airplanes). as ducts, pipings, etc The hrghest plofit rs obtarricd with crtl~er dresel or Iurbine propr~lsron al a ctulslng spced of 40 knots Operating 11o11rsper year - 2,000. Although the cngrrie oulpul at that spced IS r~early60 per cernt 12angc -- 500 naut, miles. hrgher than 'it 30 krrots, the ienrarltablc profit 1s obtarnetl by 'I'otal weight oC lurbinc including gear and accessories 13 per cent higher revenues 111 accordance wrtb the equal --- 1.55 Ibs/h.p. increase ln 1,assenger rnrlcs. On accounl of the 111gllci grrce of Specific fuel consumption 0.6 Ibs/h.p. the engine and its highet fuel consumptron, the ~ntereston tlic f'urchasing price of tnrbi nc i r~cludinggear and :~cccssorics rnvested capital earned with a turbine-ctrrven boat rs only 87 -- 42 S 1h.p. per cent of that of a diesel-powered vessel However, the fact that the modest space reciuliements for turbines perrnrl thc i*or thc fixed cosls Lhc s~lrr~e~issunipt~ons as rn F1g5 2 ant1 17 accommodatiorr oi add~t~ollalpassenger 5 ha\ not been lalccn viere made ll~espccrhc power rcqurrc~~~er~tsshown ale based rnlo cons~deralron I'lle ctrncli trorrs wrll be charrgetl rf pr Ices or1 m~asiiremenlsin varlorrr bohI5 of tile Schcrtel-Sa~hsenbcrg ax~dco~rrurnpt~on fig111 es Sol tur brnes car1 be Surtl~crreduced in syrt~ni II lii~~~fdOLI~thiit tli~~OWC~ LOCIIICI~~~ N , ,,7l6 gtverl () " (i fullir e. on a loga~itllm~cscdlc ovel t11c F~oudenumber V/ \/I (I for1 We shall now cons~der tlie held 01 applicat~onlor the coni- drstance) l~csfor all hyclroforl boatr conrtructecl or1 a nearly rl~ercialhycltotorl boat witl~inthe Irarnework ol nioclerr~ ltaris ~tralghtI~ne, so that relrablc hgurer, are avarlablc Values of a postatron and wrtlr lega~dto any competrng craft We will also much lower order, grven rn other tl~eoretrcaltieatrws and whrch rnvejtrgate 11s l~mrtalrons as far as technrcal practrcability, lri the firs1 place rregleci the lael that aftel a relalively short speed and cconorny IS concei ired opclatrng time tl~cfo~ls :tie no longc~hyclraulically srnootl~,arc ~iolicallrlrc. Table 18 has been pleoaicd to nicserlt the p~rncipaltldt~. as they afrect the ecorrorny ot the hydrofoil boat ancl 11s three In dragrarn 3 the culves of p~olltablecrcss and of the boat'5 compct~tors the convcntronal clis~,lacerrient boat, the arrpliurc power In consideration of the Increasing drsplacemcnt (turbrne and the helrcopter 'rlrc data are based or1 an assnmed drstance and tuel we~ght)are plotted over speed 7 he number of tu1 bir~cs of 100 nautical n11le.s For an cstlmate of economy the two last to be installed was based on the Hr~stol Srdclcy Olyrnpus columns are the most interesting They rndlcate prrce pel scat tur brne wrth 22,700 11 n maximum and 17,500 11 p contrnuous divrded by block-speed (port-to-port speed) and the drrcct output Uncler the a\sumplror~smade, the best p~ofit1.i obtairictl operatrng costs per missenget rnrle (ex~end~turesless cost ol at about 50 Itnot5 Wrth Incrcaslng rpeed, carnirig power grourld orgao~satron) It apnedrs that the loll-borne craft 17 reduced, and one may consrder 85 Itnots as the utn~osllimit at very economrcal coni~~aredw~tli he other mean? ot trarisporta whrch the boat c'in still rencler a proirt rrrlcier otl~erwisefavour- tlon and urrder the assumed ~onditrons In sp~teol the slrghtly <~-iblecondrl~ons DESIGN AND OVERG'E'ING PROBP,EMS OF COMMERCIAL I-BY DROFOIll, BOATS , . . The liiiiit of techriical practicability, however, car] probably tbat Iiydrolotl boats will ever bc suitable for this task whiel~ be expected at already 75 knots at the present stage of the art, can he IIIIIC~ better accomplished arid wit11 bettci cconornrc when observing the requirements of the classificatiorr companies rcsulls by n~otleirrairplanes. and the regulations of the London Ship Safety Conventiorl, especially with rcfeuesice to electrical installations, ;~uxiliaries and safety installations. Apart from the fact that a larger engine plant can hardly be properly installed, the amourit of fuel necessary for greater speeds, increases at such a rate that the I)cvelopti~crrlof rnodern ineans of trdnspor talion ~rncloublcdly irunibcr of passengers which is necessary for obtaining a profit tiends lowciicls a lxoglcsslve Increase of specd rn con~bsn~tt~on cannot be mairitainecl any longer. w~than rrnprovctl lidrng cornfort Speed on Llic water IS st111 tar behmcl the speed already ach~evedwstli road or ra~lvehtcles Fig. 1 shows that as lower limit ol applicalioii of the cor~1- 'ind allcraft. nicrcial hydrofoil boat of the given size (160fl.), 38 knots were chose11 with regard to the displacement boat and as rrppcr limit Conventional types of watercraft cannot attain the slseec! of 80 knots. Exceeditig this limit under economically acceptable land vchiclcs ~nrcler economically acceptable cor~ditions. Tl-re conclitions seerrls orily possible, for the case in qrtestion, if solution of the problem by nkearis ol the hydrofoil boat is hydrofoil boats with better lift/drag ratios or lighter engines cxan-tir~edand lhe specific qualities are bcing disc~rsscclby which with less fuel corrsumption will be developed in future. In the tllc requirements are S~tllilled. speed range beyond 80 knots the superiority of Lhc airplane--- I he papel then deal5 w~ththe f uirclaineiital physical aspcc ts as i;lr as power reel uirement is concerned----increases con - of the lo11 system as the most impotlant clesigrl problcrn arid tinuously with the speed. conlpa~~sor-r1s made betweerr the surface-p~ercsrrg 1011 dncl the I'hc cl~ag~anialso coritds~~sthe doltecl crtrve of the 'flown" fully-s~rbr~~ergecllot1 sn ~elat~onto dtag-ltfl ratlo and bcliav~our value.; of ground eflcct rnachrnes (Hover elaft) which operate at 111 a sc,lway ('raft ussng the suliacc-picrcsng for1 system ate an altitude of about 5 per cent of the claft's diameter Hecause di~ting~rr~hcdby the11 nalural stabrllly, s~rnpl~cilyof construe- only scar11 results arc ava~lablc,tbts curve docs not pretend to Iron, operatiorial rcllability and ease 01 llandl~ngand md~nlcn- be correct Data of prorects whlch have not yet beerr ieallsed ancc 'They wsll be applsecl wrth preference on inland watcls or powet figures at allstudes of less than 0 05 drarncter are 1101 and rn coastal reglons The fully-submerged for1 system attains represented A Lomparlson between the hydrololl boa1 aiid rhe super lor sea-ridrng clnahtres and oflei.; h~gherridlrrg comfoll to Iloveloaft IS only lustli~edrf the fltght altlt~tdcof the latter the passcngets, but complexity of the herght and stabrllty would be great enough that both types can ri~an~xgcthe same colitrol riecded for this type constllutcs still a sei lous problem height of waves Howevei, 11 car1 be assurned th Designer and Consllallinnt on Ground Effect Machines, Louisville, Kentucky HAVE worideretl for marry years why people lrke to go to arrcraft technrqucs srnce the irnportarrt thrng in an aricraft 1s 1 the movrcs so niuch and why they spend so many hours lo get rt safely to the next airport tio matter how n~uclx11 coqts watchirrg televisron. 1 believe rt IS because the movies and tele- Also, for example, automobrle clesrgrleis are ~rltcrestcdIn Irght- vision show a wonderful world where morrev is no problem welght coristruction, nobody cles~gns a vchlcle hca\icr than The actors wear rnost elegant clothes, they hve 111 first-class absolutely necessary Even a rallroad desrgtlel looks for lrght- hotels, dine In exclus~vcrestaurants and travel the world over in weight dcsrgn how eve^, in many cascs lighlwerght constructron jet planes; and all of this IS free. 'Therr only trouble IS love, but 15 more expensrve than orcllnarv constructron and muqt be never money. just~fied A similarly wondert~rlworld where money IS rlo problem rs The best crrterra lo find out how far one can go In adaptrng that dream wotld so attractrvely portrayed In newspapels arid lrghtwerght corlstructiotr IS to hnd out the amount of mrlcs a maga~rneswhere one zrps around in all sorts ot weather rn a veh~clemakes pet dav The more rnlles a vchrcle covers per ground effect machine. Practically evetvorre has one of these day, the better ~t can drgcst thc h~ghlnrtlal cost of lrghtwerght inexpcnsrve, compact-cat sized vchrcles that is the moderrr constructron A smdll exarciple wtll show what a mean sportsman's answer to the boat, horse, mule, leen or what-have- A cal travels an average of 40 nlrles pel day A rarlroatl you. Most any day now, the press hrnts, these all-purpose fre~ghtergoes about 100 rnrles and an ocean lrrlet averages C;RM's wlll be tumbling ofl assembly lrnes l~lteautoxnobrlcs 400 nrrles per day, but a let plane covels more than 1,000 liealistic Approach Needed ni~les per day The relatrorish~p between car, rarlroad, steamer and let plane rs 1 4 10 100 Thrs riieans thal I belreve thrs dream world could become a real~ty111 a sur- an a~rplanetravels 100 ttrnes mote mrlcs Del day than a prisrngly short 11rne Dolens of workrng GEM'\ have been cal, and th1.s also means that the arrciaft desrgrrer lives In burit In everythrrrg from backyard garages to brg busrrless another world lrorn the aritoniobrlc desrgner The latter experi~neutallaboratories But why aren't thev In pioductron~ lrves only because hrs comnany makes morc cars in a day Slmply because they arerr't crrgrneetecl wrth a dollar srgri on the 111 drde rule Once a reallstrc approach IS taken toward GEM than an a~lciatt cornparry makes a~rplanes a year desrgn, a most rmportant hurdle has beer1 crossed Without the cost-reclucrng advantages ol mass prod~rctron This raises the question, what is a realistic approach'! A and tooling permrtted by thrs quantrty, nobotiy co~rldafford GEM is neither a boat nor an airplarle. 'True, it flies, but it to buy a car. flies so low thal expensive aircraft errgirrcerirrg isn't needed. On the other hand, it uses aeroclynanric principles completely Sllorf Routes at First foreign ro boat construction. Atter thrs excursloti, let ui sec how th~ngsarc In the GEM The answer Ires somewhere strarght down the n~rddleant1 field From the bcgrnnrrig we h'ive to admrt that (?EM'\ wrll offers great rewa~dsfor the rndustry that modrfes 11s desrgn he put ~ntoservrce for relatrvelv short d~rtances,lor example. th~nkrngto take In thrs near-rclat~onof therrs ferry boats, where the trmc lot Joadrng arrd unloadrng IS an The arrcraft tcchnryuc rnearls In the broader sen5c, to burlti as rmportant factor 1n1s k~ri~iot boat w~ll:ivclaRc about 400 lrghl as poysrble, and as safclv as posrlble, wrth cost berng mrles per day, 01 less ln long-drstance scrvrcc, whcre the next secondary In arrcraft aotk vou usuallv have to use the most generation of GEM's rmrght operate, thev wrll be able to cover expensrve matet rals, grv* them the best heat tre'itinent, machrrrc up to 1,600 rnrles dally, or under very favourable cond~tions away every ounce of welght, apply X-lay and all kinds of tests, 2,000 miles per clay The fcrry boat GEM rxakcs one-tenth as load the materral close to the Ilnilt of res~stance,prvc the best many nrrles per day as a let plane and thrs leads to the con- maintenance to the parts, and so on Ihc arrnlane may need clusrorr that GEM's have Lo be burlt cheaper th'in anplanes a S900 gear box where an autonlobrlc docs fine w~th'1 90c rhcre are orrly two ways to nreet Lhrs rea~r~rernent: "V" belt 1. sirnple design. Srr~cenothrng 1s ta~lptoof,the arrctaft desigrrer plays wrth the A nunlber of possrbrlitre~,lncorporatrng for cvely funchon at least 2 Tool un and nroducc '1 greatel nunibel or unrts per year two rndependent devrces If he had to desrgn an autoniobile to l3oth ways have therr lrmrts arrcraft ~equrrementsand standa~ds,it would have erght wheels, two engrnes, each cylrnder two suark nlugs, two rnciepcndent 'The destgn of a GEM 15 tot many reasons much srnlplct than i balterrcs, and so on. the one for a~rc~aftFrr.il ot all, a GFM doe? not rcaurre the safety prccautrons thdt an aircraft does, because In the evcrit Lightweight Cor~ftrirctiol~ trouble rs cxper~cnccdthe craft lands on the water lrke a cal I stops on the road The GEM desrgnel IS also shout~ngfor Irghtwerght piodnc- Another favourable factor that nialte? GEM clesrgns srnlpler lioll, but this doe.; not mean that he can 'idopt uniestr~ctcd and helps to burld GEM'? telat~vel~I~ght 15 the fact that the PHILOSOPHY OF G.E.M. COIVSTRUCTIBN UTlLlSlNG NON-AIRCRAFT TECHNIQUES . . . weight of the craft is supported directly by tile cushion, which is underneath the whole craft. By distributing the weight equally over the bottom of the craft, the hull itself could be made from The fan which creates the air cushion is 60 inches in diameter. thin, stretch-formed aluminiurn. Tho entire craft, built from aluminium sheet for strength, light weight and corrosion resistance, weighs only 4,000 pounds. Difference in GEM Construction Steering is controlled by the rudder on the tail, much like an airplane. But while it has advantages of an airborne vehicle, it In an ailciait th~ngsare much d~fte~entThe weight of the has simple one-dimensional controls. fuselage concentlates at the loot of the wrng and froin there it has to be spread out to the Iiftrng area of the w~rig Or In other While the craft is designed to operate either on land or water, it is built primarily for use on water. It is completely floatable. words, the welght of the cockpit 17 supported by the wing t~p, The interior of the hull is lined with six inches of polyurethane th~shappens In flight condrtlons, but the full weight of an air- plane has also lo be sunportcd by the landmg gear and is foam with a buoyance double the weight of the craft. Thus, it therefole concentrated on three vomts. Thrs means that the could be sliced into sections and each still would float. structure ol an ailplane has to resist 111gher folces than the hull The "Everglades Speedster" also has distinct advantages over of a GEM 7b1s expla~nswhy alrcraft have to ur;e h~ghstress boats using hydrofoils, iricluding better visibility, ability to materrals, whrch 111 turn are expellsrve operate over ice, snow, swamps and sllallows, and freedom from damage from logs and other debris frequently encountered on Another s~mplrficatronIn GEM design IS the absence of a rivers and lakes. thrcc-d~mensronalcontrol system A one-drmerisional control 19 suffic~ent Fu~thermore, there arc no land~nggears and no It is appropriate for a designer to give an evaluatio~iof his brakes, both heavy and exnenslve devrces with the11 hydraulrc craft after a sufficient period of testing has occurred. It is my pumps and instpllat~onn conclusion that we have in the "Everglades Speedster" a success- ful prototype of a practical operational craft. Here I stress the The hull of the GbM has to be watert~ght,this d~fierslittle word prototype, because I consider it the successful first step from the wrng tanks in a~rplanes In the first place water wants in a series of design and construction stages which eventually to penetrate rnto the hull, in the second place gas wants to leak will result in practical, high-speed, low cost, operational GEM's out of the wlng, f~oma iechn~cal standpo~nt there is no of sufficient size and versatility to accomplish many missions. d~fiercncebetween the two cond~t~ons The~e1s one b~gdiftcrence, however, in the phrlosophy of 20-ion GEM Proposed constructron between GEM's and allplanes GEM's have to be deslgned to bc Ilomogenously elastic GEM'S ale bound to I believe the next stage in the developmerital programme operalc close to the water surf,lce arid can, therefore, hit the should be the construction of a 20-ton craft capable of trans- c~estsof waven, (h~nImpact hdr to be absorbed elastlcallv arid porting 20 people, flying three feet above the water and making d~st~~butedto the rest of the craft A rig~dhull would be very a speed of 100 knots. dangerous There should not be any so-called hard spots in the This large craft would give us the required criteria for design structures If ~t were feasible, a hull made out of lubber would and construction of large air-cushion vehicles suitable for many be ideal because of the great elast~c~tyAlumlniuni rncets the purposes, including: requirements best because of the low module of elast~cityand, the good strength to we~ghl~at~o 1. Anti-submarine warfare. The GEM float~ngIn the water 1s no st evenly supported, 2. Rescue operations. 5inl1lar to the flight conditions 3. Fire-fighting. 4. Assault landing craft. Everglades Speedster 5. Torpedo boats. Reynolds Metals Companv hired me to design and construct 6. Cargo craft. a GEM that could be fabricated exclusivelv with ordinarv boat 7. Passenger vessels. fabricating fac~lities. This craft, which we named the "Ever- glades Speedster," went on the drawing boards in July, 1960, From the 20-ton craft we should progless to 100-to11 vessels. and was completed in May, 1961. Kussian Progreris To date it has accumulated more than 150 hours of service and more than 100 people have ridden on it. It holds sustained We should not forget (hat we are not alone in our interest speeds of 75 m.p.h., making it the fastest air-cushion machine in air-cushion vehicles. Russia is known to be building 12 we know of in the free world. We belleve it could be modified identical GEM'S for test purposes, each with a gross weight of for Inass production at something like $12,000 a unit. 100 tons. They will be completed in the spring of 1962. Six will be launched on Siberian rivers and six will be placed under The design details of the "Everglades Speedster" will be command of the Caspian Sea fleet. These craft will be given significant to you. thorough tcsts as torpedo boats, minesweepers, amphibious The craft 1s 31 feet long and 14 feet wide. The maill hull is landing craft and other applications. We must assume that by two feet deep. The blister-like mounting on the front can the Fall of 1962 the Russians will have accumulated rr~uch accommodate the operator and three passengers. valuable experience in the opelation of large GEM'S. The power plant is a pair of Lvcoming aircraft engines In conclusion, it can be seen that the design of a GEM is produc~ng150 h.p. each. One engine drives a fan which blows basically simple ;md, therefore, the first requisite for cheaper alr through a modified single perinheral let underneath the flat construction is met, and GEM's should not cost as much as bottom, creating a cushion of air on which the boat rides. The aircraft. When the market becomes such that mass production other engine powers a propeller mou~ltedor1 the tail fin which can be used-this is the second reauisile-a really economical propcls thc craft forward at high speeds. machine can be made. PREFACE togetller witis (he usc of Jight alloys and methods of cnnbtruction HE Flovcrcat 1s a new ccrnception of unlace tiamspot( 5imilar to those eniploycd iix tlne rnanul'actrrre of aircraft opelatrng at 5pceds between those of prorent day tia~ils fuselages, wrll result ira a vehicle with a low weight per T passenger carried. arrd a~tcr'ift It IS a vehicle travellrrig ovel a metal oi concretc track i~on~which rt 1s separated by a layer of prcssrrrised air. Normally the 1f;ovcrcar operates con~pletely clear of the While, for ccrtarn appl~cat~ons,the Hoverca~ offers somc cle- track, therefore neither are subject to wear. Stopping in ail firiite atlvanlagcs over other Cotnx of transport, if could be eincrgericy is an rmportarlt exception when braking forces regarded as supplcmentrrig existing forrns of transport rather would be provided by contact between specially designed parts than as arr attempt to completely replace any exrstirrg system of the vehicle and the track. 'The held5 of applrcatiorl of the Hovcrcar can be bloadly High-speed inter-city Hovercars hold out the possibility of classrfied as follows.-- shorter journey times than at present acl~ievet~with aircraft Class 1. Past passenger services between city centres at speeds operating from airports outside the citye centre. Idondon to between 200 and 400 cn.p.h. or faster without inter- Edinburgh rnay take about 19 hours by Ilovercar. If, in the mcdialc stops. At these speeds single ~rricouplcdunits future, a bridge is built across the Eilglish Chanirel, a non-stop will be ireccssary. The larger vehicles in this class may Hovercar service should be capable of bringing Paris within also carry cars and urgent freight. about an hour's travelling time of L.ondon. Present estiniates THE TRACKED HOVERCAR Chsr 2. Frerghter setvrces between crt~esoperatrng non-stop rndtcdte that the fares on these Fervrccs should be sltnllar to at ~pecclsoi over 100 m p 11. l'hcse vehrcles will use ra~lfares the ';anie t~aclcas the passengel servrces but at trlrres Futule vcrtrcal take-olf and landrrrg arrcraft operat~ngdsrect when the demand for passenger tiavel IS not so great, from the crty centre, wh~leachlev~rig journey times comparable yay between nirdnrght arld 6 a.m rll~cywill trot wrth the Hovercar, wrll be relat~vel~complex and expensive to normally calry bulk Crerght such as coal operate Fulthermore, arrcraft are small trarlsport unrts and not ('la99 3. Shorter drsta~lcccornmutot services w~thI-lovcicat~ ~deallysurted to large scale travel. ope~atrngat slower speeds than the intel-crty passen- A comparison ot some of the characterrstrcs of thiee types of ger servlces vehicle, an express tram, a picsent day asrc~aitand a Floveicas, Clars 4. Short, slow specd scrvlces, using hrgh densrty seatrng operatrng an inter-crty rervrce arc shown In Table I. Novcicars operat~ngon say, the undesglound system The srrlall Hovelcar IS about the same p~rccas the ttalri whrlc 'Th~s c~rtrcleis concerned wrth some aspects of Class I, the the rrl~tralcost of the arrcraft is much higher To some extent, hrgh speed inter-c~tyHovercar t~ansportsystem. the highei riiitral cost of thc arrclaft IS ofIset by the fact lliat 11 Such a ~ystenicalls for cornplete te-thlnkrng of alrlicrst all the does not need a tlack rn older to operate. It does, howevei, need cxtenslve ground and air traffic control facrlrlre5 and a13 iam~lraiand accepted plact~ccsot the rnrlway of today such auxilra~ytransport system between thc crty tcrrnrnal and the as - airport. (a) Staliclarclisatioi~ betweerr routes. It is seen that even the small Tiovercar can tvas~sportmore (b) 'The use of poinls. passengers in a typrcal working day than the train. 'This is a (c) The use of couplet1 units. direct result of the greatly increased operating speed and (d) 'The sigrlalling and cor~trolsystems. (e) Terniinal lacilities. absence of Intermediate stops. (f) Cuttirigs anti tunnels. Over the relatrvely short distances envrsaged fos I3ovcrcal' (g) Type of construction of the vehicles. operatron, the aircraft carries about the same nurnber of passen- gers durrng tlic workirrg day as the train and small FIovercar. A transport ~ystemusrng the t-loveicar should be deslgned io The inrtral cost of the vehicle per passenger carrred is of tlie tit the ~outeundes consrcleratron, the sue of the ~rilstsernployed same order for the small EIovercar and train but rr~uchhigher belng detelmrned by the tlalfic available Any grven route may for the arrcraft. The larger Novercar has clear cut advantages lequrle niole tharr one we of Elovercar but these can be oper- over both the train and aircraft In all of these aspects. ated oil the same track As a sesult of the basic conceptroll of the inter-crty I-lovc~car system there IS little pornt in trans- Both Wovercar and train however, need a fixed track to fer~r~~ga vehrclc fiom one ioute to another Plon~thcse corr- achieve their low figures. The aircraft is a nlore flexible form s~dcratroiisthere is no need for standardrsatlon of vehicle and of transport in this respect. track betwccrl the diflerenl routes. At any grven trale, however, Thc introduction of the high speed, long distance Hovercar all the veli~cleson a route must be opeiatrng at the same speed servrce must be a gradual process. 'The first stage woulcl have Couplirlg of the uriits, as with conventional trans is cor-isidered rxot to bc practical at the high speeds under co~rsideraliot~for this application. Again, at these speeds, visual signal systenrs arc inadequate, and completely automatic vehicle control shoultl be designed into the system from the outset. Furthermore, only gradual chairges of course are acceptable iron1 cor~sicleratioslsof passenger comfort. Terminal systems will have to be designed lo facililate a quick turn rourrd of thc vehicle. This is esse~itialiri order to achieve the rrlaximum utilization and hence work capacity of the vehicle. llovelcal tcim~nali could be built oves cxistrng rallway tcimrnals, the I-lovelcas tiavcllrrrg in and, out or1 its own elevated tracks, abovc the exrst~ngrarlway Sines Whrle rrl the burlt up a1 ca srrr I ound~llgthe tclniinal the Hovercar wrll travel relatively slowly In ordct to mrrlrniise rrorse and because tu~ris ale ~nevrtablc Once char ol the built up area ri ulill acccleiate to its I-rrgh ci~~rs~iigspeed A useful characterrst~cof such a high speed vehicle rs that, with some ieductron in specd, rt can rlegotratc relalrvely steep gradrents 'n-~rs car] be ut~lr/eil to I educe lhc necessrty 1 or cuttirlgs and tirnnels Typica/ Section of Smo/l [)ire to the basic conceptiorl of the systeni, the Ilovercar will Hovercor not have to be des~glled to wrthstand shunting loails. This,