aeroplanes and dirigibles of war-第6章

按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！



represents　the　ultima　Thule　of　aerial　navigation　and　the　means

for　asserting　the　universal　character　of　Pan…Germanism　as　well　as

〃Kultur。〃







CHAPTER　IV

AIRSHIPS　OF　WAR



So　much　has　been　said　and　written　concerning　the　Zeppelin

airship；　particularly　in　its　military　aspect；　that　all　other

developments　in　this　field　have　sunk　into　insignificance　so　far

as　the　general　public　is　concerned。　　The　Zeppelin　dirigible　has

come　to　be　generally　regarded　as　the　one　and　only　form　of

practical　lighter…than…air　type　of　aircraft。　　Moreover；　the　name

has　been　driven　home　with　such　effect　that　it　is　regarded　as　the

generic　term　for　all　German　airships。



These　are　grievous　fallacies。　　The　Zeppelin　is　merely　one　of　a

variety　of　types；　even　in　Germany；　although　at　the　moment　it

probably　ranks　as　the　solitary　survivor　of　the　rigid　system　of

construction。　　At　one　time；　owing　to　the　earnestness　with　which

the　advantages　of　this　form　of　design　were　discussed；　and　in　view

of　the　fact　that　the　Zeppelin　certainly　appeared　to　triumph　when

all　other　designs　failed；　Great　Britain　was　tempted　to　embrace

the　rigid　form　of　construction。　　The　building　of　an　immense

vessel　of　this　class　was　actively　supported　and　it　was　aptly

christened　the　〃May…fly。〃　　Opponents　of　the　movement　tempered

their　emphatic　condemnatory　criticism　so　far　as　to　remark　that　it

MAY　FLY；　but　as　events　proved　it　never　did。　　The　colossal　craft

broke　its　back　before　it　ever　ventured　into　the　air；　and　this

solitary　experience　proving　so　disastrous；　the　rigid　form　of

construction　was　abandoned　once　and　for　all。　　The　venture　was　not

in　vain；　it　brought　home　to　the　British　authorities　more

convincingly　than　anything　else　that　the　Zeppelin　was　a

mechanical　monstrosity。　　The　French　never　even　contemplated　the

construction　of　such　a　craft　at　that　time；　estimating　it　at　its

true　value；　and　the　British　failure　certainly　served　to　support

French　antagonism　to　the　idea。　　Subsequently；　however；　an　attempt

at　rigid　construction　was　made　in　France　with　the　〃Spiess〃

airship；　mainly　as　a　concession　to　public　clamour。



Even　in　Germany　itself　the　defects　of　the　Zeppelin　were

recognised　and　a　decided　effort　to　eliminate　them　was　made　by

Professor　Schutte　in　co…operation　with　a　manufacturer　of

Mannheim　named　Lanz。　　The　joint　product　of　their　ambitions；　the

Schutte…Lanz；　is　declared　to　be　superior　to　the　Zeppelin；　but　so

far　it　has　failed　to　justify　any　of　the　claims　of　its　designers。　

This　vessel；　which　also　favours　the　colossal；　is　likewise　of　the

rigid　type；　but　realising　the　inherent　dangers　accruing　from　the

employment　of　metal　for　the　framework；　its　constructors　have　used

wood；　reinforced　and　strengthened　where　necessary　by　metallic

angle…iron；　plates；　and　bracing；　this　utilisation　of　metal　is；

however；　carried　out　very　sparingly。　　The　first　vessel　of　this

class　was　a　huge　failure；　while　subsequent　craft　have　not　proved

much　more　successful。



In　fact；　one　of　the　largest　German　airships　ever　designed；　L4；

is；　or　rather　was；　a　Schutte…Lanz；　with　a　capacity　of　918；000

cubic　feet；　but　over　6；000　pounds　lighter　than　a　Zeppelin　of

almost　similar　dimensions。　　I　say　〃was〃　since　L4　is　no　more。　　The

pride　of　its　creators　evinced　a　stronger　preference　for　Davy

Jones'　Locker　than　its　designed　realm。　　Yet　several　craft　of　this

type　have　been　built　and　have　been　mistaken　for　Zeppelins　owing

to　the　similarity　of　the　broad　principles　of　design　and　their

huge　dimensions。　　In　one　vital　respect　they　are　decidedly

inferior　to　their　contemporarythey　are　not　so　speedy。



The　most　successful　of　the　German　lighter…than…air　machines　are

those　known　respectively　as　the　semi　rigid　and　non…rigid　types；

the　best　examples　of　which　are　the　Gross　and　Parseval　craft。　

Virtually　they　are　Teutonic　editions　of　the　successful　French

craft　of　identical　design　by　which　they　were　anticipated。　　The

Lebaudy　is　possibly　the　most　famous　of　the　French　efforts　in　this

direction。　　The　gas…bag　has　an　asymmetrical　shape；　and　is　pointed

at　both　ends；　although　the　prow　is　blunter　or　rounder　than　the

stem。　　The　gas…bag　comprises　a　single　chamber　for　the　inflating

agent；　the　distended　shape　of　the　envelope　being　sustained　by

means　of　an　air…ballonet。　　By　varying　the　contents　of　the　latter

through　the　agency　of　a　pump　the　tension　of　the　gas　in　the

lifting　envelope　can　be　maintained；　and　the　shape　of　the　inflated

balloon　preserved　under　all　conditions。



Beneath　the　gas…bag　is　a　long　strengthened　girder；　and　from　this

in　turn　the　car　is　suspended。　　It　is　the　introduction　of　this

rigid　girder　which　is　responsible　for　the　descriptive　generic

term　of　〃semi…rigid。〃　　On　the　other　hand　the　〃non…rigid〃　type　may

be　roughly　described　as　a　pisciform　balloon　fitted　with

propelling　machinery；　inasmuch　as　the　car　containing　the　driving

machinery　is　suspended　from　the　balloon　in　the　manner　of　the　car

in　the　ordinary　drifting　vessel。　　So　far　as　the　French　effort　is

concerned　the　Bayard…Clement　type　is　the　best　example　of　the

non…rigid　system；　it　is　represented　in　Germany　by　the　Parseval

class。



The　Gross　airship　has　been　definitely　adopted　as　a　military

machine　by　the　German　authorities；　and　figures　in　the　〃M〃　class。　

The　〃M…IV〃　completed　in　1913　is　the　largest　of　this　type；　and

differs　from　its　prototypes　in　that　it　carries　two　cars；　each

fitted　with　motors；　whereas　the　earlier　machines　were　equipped

with　a　single　gondola　after　the　French　pattern。　　This　vessel

measures　320　feet　in　length；　has　a　maximum　diameter　of　44　1/2

feet；　displaces　13　tons；　and　is　fitted　with　motors　developing　450

horse…power；　which　is　sufficient　to　give　it　a　speed　of　47　miles

per　hour。　　This　vessel　represents　a　huge　advance　upon　its

predecessors　of　this　design；　inasmuch　as　thelatter　were　about　245

feet　in　length　by　36　1/4　feet　in　diameter；　and　displaced　only　six

tons；　while　the　single　car　was　provided　with　a　motor　developing

only　150　horse…power；　the　speed　being　28　miles　per　hour。　　Thus　it

will　be　seen　that　a　huge　development　has　suddenly　taken　place；　a

result　due　no　doubt　to　the　co…operation　of　the　well…known

engineer　Basenach。　　The　〃M…IV〃　is　essentially　an　experiment　and

great　secrecy　has　been　maintained　in　regard　to　the　trials　which

have　been　carried　out　therewith；　the　authorities　merely

vouchsafing　the　fact　that　the　airship　has　proved　completely

successful　in　every　respect；　conclusive　testimony　of　this　is

offered　by　the　inclusion　of　the　vessel　in　the　active　aerial　fleet

of　Germany。



But　it　is　the　Parseval　which　is　regarded　as　the　finest　type　of

airship　flying　the　German　flag。　　This　vessel　is　the　product　of

slow　evolution；　for　it　is　admitted　to　be　a　power…driven　balloon。　

Even　the　broad　lines　of　the　latter　are　preserved；　the　shape　being

that　of　a　cylinder　with　rounded　ends。　　It　is　the　direct　outcome

of　the　〃Drachen…Balloon；〃　perfected　by　Parseval　and　Siegsfeld；

the　captive　balloon　which　is　an　indispensable　part　of　the　German

military　equipment。



The　complete　success　of　the　suspension　system　in　this　captive

balloon　prompted　Parseval　to　continue　his　researches　and

experiments　in　regard　to　the　application　of　power　to　the　vessel；

so　as　to　induce　it　to　move　independently　of　the　wind。　　The

suspension　system　and　the　car　are　the　outstanding　features　of　the

craft。　　It　is　non…rigid　in　the　strictest　interpretation　of　the

term；　although；　owing　to　the　incorporation　of　the　steadying

hollow　〃mattress〃　（as　it　is　called　by　its　inventor）；　the　strength

of　the　suspension　system；　and　the　substantial　character　of　the

car；　it　conveys　an　impression　of　great　solidity。　　The　thinnest

rope；　both　manilla　and　steel；　in　the　suspension　system　is　as

thick　as　a　man's　finger；　while　the　car；　measuring　30　feet　in

length　by　6　feet　in　width；　carried　out　in　wood；　is　a　striking

example　of　the　maximum　of　strength　with　the　minimum　of　weight；

being　as　steady　and　as　solid　as　a　boat's　deck。　　The　propellers

are　collapsible；　although　in　the　latest　craft　of　this　class　they

are　semi…rigid。



The　mechanical　equipment　is　also　interesting。　　There　are　two

propellers；　and　two　motors；　each　nominally　driving　one　propeller。　

But　should　one　motor　break　down；　or　motives　of　economy；　such　as

husbanding　of　fuel；　render　it　advisable　to　run　upon　one　engine；

then　the　two　propellers　may　be　driven　by　either　of　the　motors。



The　inventor　has　perfected　an　ingenious；　simple；　and　highly

efficient　coupling　device　to　attain　this　end；　but　to　ensure　that

the　propeller　output　is　of　the　maximum　efficiency　in　relation　to

the　engine；　the　pitch　of　the　propellers　may　be　altered　and　even

reversed　while　the　engine　is　running。　　When　one　motor　only　is

being　used；　the　pitch　is　lowered　until　the　propellers　revolve　at

the　speed　which　they　would　attain　if　both　engines　were　in

operation。　　This　adjustment　of　the　propeller　pitch　to　the　most

economical　engine　revolutions　is　a　distinctive　characteristic；

and　contributes　to　the　efficiency　and　reliability　of　the　Parseval

dirigible　to　a　very　pronounced　degree。



Steering　in　the　vertical　plane　is　also　carried　out　upon

distinctive　lines。　　There　are　no　planes　for　vertical　steering；

but　movement　is　accomplished　by　tilting　the　craft　and　thus

driving　the　gas　from　one　end　of　the　balloon　to　the　other。　　This

is　effected　by　the　manipulation　of　the　air…ballonets；　one　of

which　is　placed　at　the　prow　and　stem　of　the　gas　bag　respectively。　

If　it　is　desired　to　descend　the　gas　is　driven　from　the　forward　to

the　after　end　of　the　envelope；　merely　by　inflating　the　bow

ballonet　with　air　by　means　of　a　pump　placed　in　the　car。　　If

ascent　is　required；　the　after…ballonet　is　inflated；　thereby

driving　the　gas　to　the　forward　end　of　the　balloon；　the　buoyancy

of　which　is　thus　increased。　　The　outstanding　feature　of　the

〃Drachen…Balloon〃　is　incorporated　in　the　airship。　　This　is　the

automatic　operation　of　the　safety　valve　on　the　gas…bag　directly

by　the　air　ballonets。　　If　these　ballonets　empty　owing　to　the

pressure　of　the　gas　within　the　envelope；　a　rope　system　disposed

within　the　balloon　and　connecting　the　ballonets　and　the　gas…valve

at　the　top　is　stretched　taut；　thereby　opening　the　gas…valve。　　In

this　manner　the　gas…pressure　becomes　reduced　until　the　ballonets

are　enabled　to　exercise　their　intended　function。　　This　is　a

safety　precaution　of　inestimable　value。



The　Parseval　is　probably　the　easiest　dirigible　to　handle；

inasmuch　as　it　involves　no　more　skill　or　knowledge　than　that

required　for　an　ordinary　free　balloon。　　Its　movements　in　the

vertical　plane　are　not　dissimilar　to　those　of　　the　aeroplane；

inasmuch　as　ascent　and　descent　are　normally　conducted　in　a

〃screwing〃　manner；　the　only　exception　being　of　course　in　abrupt

descent　caused　by　the　ripping　of　the　emergency…valve。　　On　one

occasion；　it　is　stated；　one　of　the　latest　machines　of　this　type；

when　conducting　experimental　flights；　absolutely　refused　to

descend；　producing　infinite