Full report

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N O T I C E THIS DOCUMENT HAS BEEN REPRODUCED FROM MICROFICHE. ALTHOUGH IT IS RECOGNIZED THAT CERTAIN PORTIONS ARE ILLEGIBLE, IT IS BEING RELEASED IN THE INTEREST OF MAKING AVAILABLE AS MUCH INFORMATION AS POSSIBLE

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THX DEVELOFI#Z;j.F OF L?EE XPPEiLIN YIRIGIBLE ?OR LOiTG DISTANCE TRAITSPORTATION Albert Ehrle Translation of In: Dritte Oeffedntliche Siteung der Deutschen Akademie der Luftfahrtforschung am 17 June 1938, zum Gedenken an die hundertste Wiederkehr des Geburtstages des Grafen Zeppelin, Gerlin, 1938, pp 33-47 (NASA-TH-76143) T H E DEVELOPnENT OF T H E N80-27303 Z E P P L I N D I B I G I B L E FOR LONG D I S T A W E T B A l S P O R T A T I O N ( N a t i o n a l Aeronautics and Space Administration) 1 8 p HC A02/flF A0 1 U n c l a s CSCL 0 1 C G3/03 i 8 0 2 3

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. - . -- ST ANOAR0 TITLE PAGE Covatnmm* Accorrion No. 3. Rocipian*'s CooleNo. ''?'%?Y %,1-761 3 3 - 4. Title and Subtitlo 3. Repor Dot. ,ZEPPELIN i1 1980 i)E',.%LO_PIb'L<NT O P T I E WAITS- 6. Perlorming O*#oniaotion C a b ( D I R I G I D I S FOR LOi:3 DISTBI::i3 PORTATIO'T 7. A u t h d s l - Albert 3 h r l e 8. Parformin, Orgonirotion R o w * No. 10. Work Unit No. a11.Controc?or Gront NO. ?. Porfoming Oreoniaotion Nuno m d M d n s s i Redwood C i t y 113. P.TI of ROPO~~a d Period Covond Leo Kanner !Is s oc i a t e s, C a l i f o r n i a - 12. Sponsoring Agmcy Nomo and Address T r a n s l a t i o n and Space Adminis- 14. h s w i n o A p . w C.l. 7Jati o n a l Aeronautics t r x t i o n , Wasilin::ton, i).'Z .. I-10546 15. k p p l o m m t a y Notes . - Translation of In: Dritte Oeffedntliche Sitzung der Deutschen Akademie der Liilftfahrtforschung am 17 Juni 1938, tun Gedenken an die hundertste Wiederkehr des Geburtstages des Grafen Zeppelin, Berlin, 1938, pp 33-47 16. Abstract I n t h e l ~ s tdecade re,ul:ir passeuger t r c m s p o r t a t i o n a c r o s s t h e ocean :as e s t a b l i s ! ~ c d i n 3 c r r n n y with G i r i ~ i b l e s ,f i r s t t o South h n e r i c a a - ~ dthen al:;o t o ';orth -Lieric:i. T h i s was t h e bezinning f o r e x t e ~ s i v ep l a n s n ~ i dt h e devclopncnt i n r e c e i v e d qcv~i n ~ n u l s e s . The explanad i r i ; i b l e c o i ~ s t r u c t i o n t i o n of technic?.l problems t o be solved i s ?receded here 'c:- 2 ::urvey of t3e path t d c e n i n c o n n t r u c t i ~ ~ ;diri;FSles f o r l o n z - d i s t a n c e t r z n s p o r t up t o now. I 19, Socurttv Clorril. [of this report) 20. Socuritp Clorril. (01 this POD*)

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.mE DEVELOPMENT OF THE ZEPPELIN, DIRIGIBLE FOR LONG DISTANCE TRANSPORTATION P Ehr l e - - . The German Academy of A v i a t l o n Researcn zcade rr p a ssenger- t r a ! ross t h e ocean /3" Germa i gible!s, f i ~ n A m e r i c a ar :h d i r - . * " L 2 - - --- LC-. L - - 2 . -La-..: ca. -1 - - - .. i r i g i t n s t r u c ped nei lses. srrrlanativlr VL t e c n n i c a l - . - -2-2 L- S m L v e a w i l l - -- - rvey c~f t h e n s t r u c s t a n c e r L .r- . . . . . 2 . . ..... - - . . . . . . . . -.C a.. . . . . .-- . . . --. . . . * . .r--..:. C --.-. , A,,,. -L. .-I- .--.L* d ~nrt, .- I F i g u r e 1: Zeppelin d i r i g i b l e s r/ 4 g a s content.55,200 to 56,000m 3 i d i a m e t e r . . . . . . . -23.9m l e n g t h . . . . . . . . 196.5m OR@% PAGE IS OF POOR Q U A L ~ I The f i r s t example o f t h e z e p p e l i n d i r i g i b l e s , which c o u l d be conwas t h e 56,000 cbm a i r s h i p . The LZ 6 2 I s i d e r e d a long-distance v e h i c l e , t h i s d e s i g n , By t h e end o f 1917 i n 1916 was t h e f i r s t a i r s h i p of b u i l t a l o n g t h e s e l i n e s . The l a s t examples I t h i r t y - s i x a i r s h i p s had been a t t a i n e d a maximum speed o f 3 2 m/sec and a u s e f u l load o f 39 t - under- I s t o o d f o r a barometer r e a d i n g of 760 mm, O*C a i r and gas t e m p e r a t u r e and , hydrogen g a s f i l l i n g - w i t h a c a l c u l a t e d p o s s i b l e range of 12,000 km. 1 *Numbers i n t h e margin i n d i c a t e p a g i n a t i o n i n t h e f o r e i g n t e x t . i

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t T h i s s h i p t y p e underwent 2 r e m a r k a b l e changes. A t t h e end o f 1917 t h e I A f r i c a s h i p L 59 was c o n s t r u c t e d by i n c r e a s i n g t h e gas c o n t e n t to 68,500 cbm and i n 1918 t h e LZ 112-L 7 0 was b u i l t w i t h a c o n t e n t o f i 62,200 c b m a n d a maximum s p e e d a t normal a l t i t u d e o f more t h a n 3 5 m/sec. by i n c r e a s i n g t h e number o f e n g i n e s and more t h a n 36 m/sec. a t g r e a t e r I a l t i t u d e s by h i g h e r c o m p r e s s i o n i n t h e e n g i n e s . I F i g u r e 2 Key a. g a s c o n t e n t b. d i a m e t e r c. l e n g t h The t r i p o f t h e L 59 to A f r i c a w i l l a l w a y s remain a m i l e s t o n e , s i n c e it was t h e f i r s t lorig-distance t r i p o f a d i r i g i b l e w i t h a c o n s i d e r a b l e c a r g o . The L 59 rose i n t o t h e a i r on November 21, 1917, i n J a m b o l i i n B u l g a r i a . The t r a n s p o r t t a r g e t was t h e Maconde H i g h l a n d s i n German E a s t A f r i c a . Over Khartoum t h e d i r i g i b l e was c a l l e d back by a r a d i o i n J a m b o l i on November 25. The t r i p s i g n a l from Nauen and a q a i n l a n d e d d i s t a n c e t r a v e l l e ? was 6,750 km. The had l a s t e d f o r 95 h o u r s and t h e d i s p o s a b l e l o a d c o n s i s t e d o f a 22 man crew and approx. 23 t g a s o l i n e and was to be d e l i v e r e d a t t h e d e s t i n a t i o n . There were o i l ; a c a r g o o f 14 t s t i l l 9 t o n s o f g a s o l i n e upon l a n d i n g . I n t h e p e r i o d a f t e r t h e war t h e t w o s m a l l t r a n s p o r t d i r i g i b l e s "Bodensee" and " N o r d s t e r n " , o f n o f u r t h e r c o n c e r n h e r e , were f o l l o w e d by t h e r e p a r a t i o n d i r i g i b l e , L Z 1 2 6 , t h e f i r s t G e r m a n d i r i g i b l e t o c r o s s /35 t h e North A t l a n t i c , and LZ 127 "Graf Z e p p e l i n " which became t h e a c t u a l t r a n s a t l a n t i c d i r i g i b l e t r a n ~ ~ p o rt w i t h and w i t h o u t passenpacemaker f o r 2 .'

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g e r s . "Graf Zeppelin" commenced its f i r s t t r i p on September 18, 1928. By May i n 1937 it had covered more t h a n 1.6 m i l l i o n k i l o m e t e r s and had t r a n s p o r t e d a t o t a l of a b o u t 13,000 p a s s e n g e r s . C i r c l i n g t h e g l o b e and t r i p to t h e a r c t i c a r e t h e b e s t known o f its v a r i o u s t r i p s . t h e r e s e a r c h 1i F i g u r e 3: T r i p o f t h e L 59 on November 21-25, 1917 I Key : a . load b. 22 man crew h. c a r g o i. consumption c. s u p p l i e s and d r i n k i n g water j. f u e l replacement p a r t s k . l u b r i c a t i n g o i l d. i n v e n t o r y , e. water f. f u e l g. l u b r i c a t i n g o i l gained w i t h t h e LZ 127 t h e LZ 128 was On t h e b a s i s of knowledge 1. t r i p m. Jamboli-Maconde Highland approx. 6,000 km n. t r a v e l l i n g t i m e - 95 h r s . t ' to f o l l o w w i t h 165,000 cbm g a s c o n t e n t , w i t h l a r g e r passenger accommodat i o n s and with i n c r e a s e d t r a v e l l i n g speed; b u t f o r t h e r e s t , hydrogen /36 was to be r e t a i n e d a s l i f t i n g g a s and normal f u e l f o r engine o p e r a t i o n I a s i n t h e c a s e o f t h e LZ 127. This p r o j e c t was n o t completed, b u t 3

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r "Hindenburg". With a t o t a l g a s cor t h e LZ 129, t h e d i r i g i b l e o ,000 cbm it l e f t open t h e p o s s i b i l i t y f o r employing helium, ar f i t t e d w i t h d i e s e l e n g i n e s . It s e r v e a i n p a c e o f t h e g a s e n g i n e s it was t h e North America r o u t e . On May 6 , 1937, it wz f o r a y e a r mainly o n d e s t r o y e d i n Lakehurst by f i r e . F i g u r e 4 Key: a . g a s c o n t e n t b. diameter c. l e n g t h A t t h a t time a sister s h i p , t h e LZ 130, was being completed. Corresponding t o t h e l i f t i n g c a p a c i t y o f hydrogen g a s it was to c o n t a i n t h e meantime it h a s been c o n v e r t e d to helium; i n 70 passenger beds. I n a d d i t i o n to a s e r i e s o f o t h e r r e d u c t i o n s i n weight it was f i t t e d w i t h new, l i g h t e r passenger accommodations w i t h o n l y 40 beds. s t r u c t u r a l weight is of concern now ir, t h e a i r s h i p , The comparative i . e . t h e weight f o r f u l f i l l i n g e a c h i n d i v i d u a l t r a n s p o r t t a s k . One t h i s purpose, i . e . t h e weights o f t h e s u p p o r t weight c l a s s i f i c a t i o n f o r structure, t h e t h r u s t equipment and t h e o p e r a t i o n a l equipment p r o v i d e i n f o r m a t i o n on t h e s t a t e of development of d e s i g n and a i r s h i p p l a n n i n g and o n t h e i n f l u e n c e o f s h i p s i z e on c o n s t r u c t i o n weight. The weights 4

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of materials f o r o p e r a t i o n form a s e c o n d class w i t h r e f e r e n c e t o t h e w e i g h t o f t h e e n g i n e ; t h i s number s u p p l i e s a measure f o r improvement I i n r e s p e c t to wind r e s i s t a n c e and t o p r o p e l l e r e f f e c t i v i t y and e n g i n e equipment. A t h i r d c l a s s , t h a t o f w e i g h t f o r c a r g o t r a n s p o r t , e.g. f o r t h e accommodation and e n t e r t a i n i n g o f t h e p a s s e n g e r s , is a l r e a d y d e t e r - mined to a g r e a t e x t e n t by o t h e r n o n - t e c h n i c a l a s p e c t s ; it is t h e r e f o r e p r a c t i c a l t o n e g l e c t t h i s w e i g h t i n t h e a i r s h i p weight. The a c t u a l comparison s h o u l d b e l i m i t e d t o t h e f i r s t a n d l a s t a i r - s h i p , t h e 56,000 cbm and t h e 200,000 cbm a i r s h i p f o r r e a s o n s o f b r e v i t y . The g a s c o n t e n t , as a c h a r a c t e r i s t i c r e f e r e n c e q u a n t i t y f o r t h e s h i p , s u p p l i e s a s i m p l e a n d d i s t i n c t common denominator; t h e i n d i v i d u a l w e i g h t s now a p p e a r i n grams p e r c u b i c meter. From t h i s c o m p i l a t i o n it c a n be s e e n t h a t i n t h e p e r i o d from 1917 t o 1937 w i t h i n c r e a s e i n s h i p s i z e from 56,000 to 200.000 sbm, t h e n e t /38 w e i g h t p e r c u b i c meter w i t h o u t u s e f u l equipment i n c r e a s e d by approx. 20%. The s u p p o r t framework c o n t r i b u t e s 8 4 g/cbm t o t h i s i n c r e a s e a n d o p e r a t i o n a l equipment c o n t r i b u t e s 1 9 g/cbm, w h i l e n u l l a n d g a s t h e c o n t a i n e r s remained t h e same a n d t h e machine was reduced by 20 g/cbm. The q u e s t i o n now h a s to be answered t o what d e g r e e r e a s o n s i n c o n n e c t i o n w i t h s h i p s i z e have c a u s e d t h e s e a l t e r a t i o n s , b u t a l s o t o what d e g r e e i n c r e a s e d demands and a l t e r e d v i e w p o i n t s a r e r e s p o n s i b l e . To b e g i n w i t h i n d i v i d u a l p o i n t s , w e f i n d a s u b s t a n t i a l w e i g h t from 43.5 to 9 4 g/cbm i n t h e c a s e o f change i n t h e s u p p o r t s t r u c t u r e t h e main r i n g s . The d i m e n s i o n s are d e t e r m i n e d m a i n l y by t h e f u n c t i o n a s p a r t i t i o n walls, so t h a t t h e f o u r t h power o f t h e d i a m e t e r may be s e l e c t e d a s s p e c i a l r e f e r e n c e q u a n t i t y . Using t h i s a s a r e f e r e n c e , w e f i n d t h a t i n t h e l a r g e s t main r i n g i n e a c h c a s e , t h e s u p p o r t w e i g h t h a s been reduced by 37% and t h e w e i g h t o f r i n g framework w i t h t h e p o r t i o n /39 o f s u p p o r t i n g a x i a l e l e m e n t h a s d e c r e a s e d by 10%. T h i s is a n e x p r e s s i o n o f t h e improvement i n s u p p o r t m a t e r i a l and d e s i g n and i n t h e c i r c u l a r d e s i g n and a whole by means o f s u p p o r t o f t h e framework w i t h a n a x i a l element. For t h e r e l a t e d t o t a l w e i g h t o f a l l main r i n g s , t h e i r number

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Figure 5: Weight in transport ' y: zeppelin.dirig ibles for longdistance transport between 1916 and 1936 weight in kg support structure ribs hull and framework lifting gas equipment machine engines and accessories propellers gondola containers for fuel for water for ballast extraction operational equipment navigational equipment radio equipment electrical devices accommodations for the crew useful equipment useful load passenger accommodations

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• a %c-lrlrr.lin-l.:tft.cl;ifrtfill. I ~ i ~ r r ~ r c ~ r l ~ . t ~ l : r1!)10I ~ i uI!l:lIi 1 f ? i ~ i i . l ~ I I I!:p r ni"~ <;iwisiIal -- ..... ......... g>lncl#inr! ?J:\lnarn,ctncl Xelnlrk .. 1 I ~ t r f ~ r r l ~ r a ~ t l ~ r n........ 1 l(kt,t 9 J (:onrtrln ............. knrtjllrr 1 f i r 1:rtrirOhtoI'r.. ..... I I ? ! 1ft1,l 79,N mfir\'aircr ........... I 2 . 9 lX,#l I ? I(,,fr , f(r,tl fir R ~ l l a r t p i n n r r.... b l ~ e ~ r i r l ~ s a n r r ~ z t t ~ n g k * w r c k a w n r i i . ~ n n ~ Xurlrs.............. b.4 - )iltr~rrl&uma ........ . . - . . fI8f 2 , ?51fl ?fi,!i F i g u r e 6 : Weight and gas c o n t e n t Key : 3 1. w e i g h t i n g/m g a s c o n t e n t ( f o r remainder o f key p l e a s e r e f e r to F i g u r e 5 ) .-*A. P 9 ''k . ----- -- L ---, # 7

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d e t e r m i n e d by t h e d i v i s i o n o f g a s s t o r a g e and t h e s p e c i a l demands f o r s u c h as t h e p l a c e m e n t o f r u d d e r s , would s t r e n g t h o f c e r t a i n main r i n g s also be i n f l u e n t i a l . -6- 0 2 -:p - , A b dJYrJ,'3m F i g u r e 7: Framework of a 56,000 y3 and a 200,000 m d i r i g i b l e c'. The s h e l l c o n s t r u c t i o n o f t h e a u x i l i a r y wings, l o n g i t u d i n a l s u p p o r t s and f i e l d framework, i n c l u d i n g t h e main r i n g s w i t h a w e i g h t o f 110 and 120 g/cbm, is s u b j e c t e d t o stress m a i n l y t h r o u g h t r a n s v e r s e f o r c e s a n d d i s t r i b u t i o n o f l i f t and l o a d and f o r c e s o f bending moments from t h e t h e ambient a i r . The f o r c e s o f t h e a m b i e n t a i r c o n t r i b u t e t h e g r e a t e r d e t e r m i n e d by t r a v e l l i n g s p e e d , i.e. t h e /10 p o r t i o n . These a r e m a i n l y dynamic p r e s s u r e , w i t h a maximum v a l u e t a k e n i n t o a c c o u n t i n a i r s h i p dimensions. For t h e LZ 129 t h i s was approx. 25% g r e a t e r . I f t h e s u r f a c e is s e l e c t e d as a s p e c i a l r e f e r e n c e q u a n t i t y and c a l c u l a t e d on t h e same dynamic p r e s s u r e , t h e l o n g i t u d i n a l s u p p o r t w e i g h t h a s a f a c t o r o f 0.7 a n d t h e framework w e i g h t h a s a f a c t o r o f 1.4 i n t h e m i d s e c t i o n o f t h e LZ 129 d i r i g i b l e . The s t r e n g t h o f wires used i n t h e framework, however, h a s improved o n l y l i t t l e s i n c e t h e war, b u t t h e q u a l i t y v a l u e f o r t h e l o n g i t u d i n a l s u p p o r t s h a s i n c r e a s e d by a f a c t o r o f approx. 1 . 7 5 . When i c o n c l u s i o n s a r e drawn from t h e s e numbers on t h e s t r e n g t h o f t h e s h e l l c o n s t r u c t i o n , it h a s i n c r e a s e d by 30 to 40% i n t h e LZ 129 s i n c e t h e war d i r i g i b l e s , i.e. t h e b a s i s f o r d i m e n s i o n s h a s besn changed. T h i s is a 8

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d e f i n e d p a t t e r n o f a l o a d c a s e ~ ;o u r knowledge o f t h e s e h a s been g r e a t l y i n t e n s i v e measurements o f t h e r e l a t i o n s h i p s between forces expanded by i n t h e a i r . C o n c l u s i o n s on t h e s t r e n g t h r e q u i r e m e n t s of t h e a i r s h i p /41 as s u c h , however, may o n l y be drawn on t h e b a s i s o f e x p e r i e n c e and measurements g a i n e d d u r i n g t r a v e l l i n g . The LZ 120 p r e s e n t e d t h e f i r s t o p p o r t u n i t y f o r s u c h r e s e a r c h w i t h t h e a r r a n g e m e n t o f r e c o r d i n g measuring d e v i c e s a t s u i t a b l e p o i n t s i n t h e a i r s h i p f o r o b t a i n i n g and e v a l u a t i n g t h e stresses. I n t h e LZ 129 t h e s e measurements were c o n t i n u e d and expanded. & ,... .. .\ .* 5 :. ;. t .... ;1* an .. t . . t .....- . . . . I . .'..* .; . . . . . . I..... l.,;!....;. ..:I;. ,,;. *.,.-.; a . . . . . . . . 1 - . . ., d ., . ...... .,- . ..'.4.-- - , . . . . . . . _ . . e . . . . . ' . t. . . i,. :.. ' a , 6 ,, . , * .a' , # . l t . . '.I ..... . -4 F i g u r e 8: Framework of t h e - ' 4 . : LZ 129 . ii *.ti . \ t ,.Q ? -' 1 A long p e r i o d o f o p e r a t i o n w i l l s t i l l be n e c e s s a r y i n o r d e r to d e t e r m i n e a c c u r a t e l y where t h e chosen l o a d cases and s a f e t y f a c t o r s have to be c o r r e c t e d . They are a p p a r e n t l y e v e n too h i g h , f o r t h e r e is n o t h i n g i n t h e e i g h t y e a r s o f LZ 127 o p e r a t i o n to i n d i c a t e i n s u f f i c i e n t s t r e n g t h . S i m i l a r c o n c l u s i o n s c a n be drawn f o r t h e t a i l s e c t i o n . I n t h i s c a s e s p e c i a l s t u d i e s and t r a v e l e x p e r i e n c e is r e q u i r e d i n a d d i t i o n to s u c h s t r e s s m e a s n r c m n t s , i n o r d e r to g a i n f a c t d a t a on t h e demands p l a c e d i n t h e f i n and r u d d e r s e c t i o n s by i n d i v i d u a l c o n d i t i o n s d u r i n g normal t r a v e l l i n g , t r a v e l l i n g w i t h d i s r u p t i o n s i n l i f t and trim system 9

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and approach f o r landing. The t a i l s e c t i o n of t h e LZ 129 weighs a l m o s t LL-cnree times as much a s e a r l i e r a i r s h i p s , s p e c i f i c a l l y 39 a s compared to 13.5 g/cbm, The wing span from one f i n edge t o t h e o t h e r was expanded by a f a c t o r o f 1.8 f o r i n c r e a s e d dynamic p r e s s u r e and proved more than s u f f i c i e nt , F i g u r e 9 Key r a. t a i l s e c t i o n b. rudder u n i t c . e l e v a t o r u n i t The cubis meter weight o f h u l l and l i f t i n g g a s equipment h a s been a l t e r e d o n l y l i t t l e from approx. 50 or 60 g/cbm, i.e. t h e commcrical d i r i g i b l e s weigh more per s q u a r e meter of s u r f a c e . f i e weight i n c r e a s e /42 is shown i n h u l l l i f e expectancy. I n spite o f r e g u l a r t r i p s to t h e t r o p i c s and long docking t h e r e on a mast t h e upper f i e l d s o f t h e LZ 127, s u b j e c t e d to h a i l , d i d n o t have to be recovered u n t i l 530,000 and 740,000 km had been t r a v e l l e d . The lower h u l l f i e l d s were r e p l a c e d o n l y a f t e r 1.5 m i l l i o n km and t h e mid f i e l d s have n o t y e t been r e p l a c e d a t a l l . J u s t ee i n c r e a s e d demands a r e p l a c e c on t h e h u l l f o r long r e s i s t a n c e I I to weather c o n d i t i o n s , t h e g a s b a l l o n e t ~should r e t a i n g a s impermeability. I I The demand i n c r e a s e s c o i n c i d e d i n t h i s c a s e w i t h t h e change i n c e l l u l o s 1 a p p l i c a t i o n . Up to t h e LZ 127 t h e g a s b a l l o n e t s were still produced from s o - c a l l e d f a b r i c s k i n w i t h a c o t t o n m a t e r i a l g e r v i n g a s l i n i n g f o r 10

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t h e f i n e s k i 0 o f t h e o x e n i n t e s t i n e w h i c h was i m p e r v i o u s t o g a s . T h i s was s u b s e q u e n t l y r e p l a c e d by s e a l i n g f i l m s . The amount o f m a t e r i a l for t h e h u l l a n d t h e b a l l o n e t s r e m a i n s c o n s t a n t ; d e v e l o p m e n t a l work m u s t be c o n c e n t r a t e d o n t h e p r a c t i c a l d i s t r ib u t i o n o f m a t e r i a l t y p e s a n d o n i m p r o v i n g t h e m a t e r i a l a i ~ ds u b s t a n c e s f o r o f c o t t o n as l i n i n g m a t e r i a l , s i l k c a n i m p r e g n a t i o n ; f o r e x a m p l e , i n s t e a d meet t o d a y ' s demands p l a c e d o n t h e b a l l o n e t w i t h o u t i n c r e a a i n q w e i g h t . The e n t i r e w e i g h t o f t h e m a c h i n e is d i s t r i b u t e d t o a p p r o x . 46% o n t h e motor, t.o 8% e a c h o n t h e g e a r s w i t h s h a f t a n d b e a r i n g s a n d o n t h e propeller a n d t o 1 9 b e a c h o n t h e a c c e s s o r y d e v i c e s a n d t h e g o n d o l a c a r w i t h s u s p e n s i o n a n d e n t r a n c e . The f u e l s u p p l y f o r a n o c e a n c r o s s i n g r e q u i r e s 24 to 4 times t h e f i x e d w e i g h t o f t h e m a c h i n e . For e s t i m a t i n g n e c e - s a r y t h r u s t 2 v a l u e s a r e r e q u i r e d , w h i c h may n o t be e a s i l y o b t a i n e d e x a c t l y a n d i n t h e same manner - t r a v e l l i n g s p e e d a n d m a c h i n e p e r f o r m a n c e . The m e a s u r e m e n t o f c a r r i e d o u t d u r i n g a s h o r t t r i p i n a s p e c 3 c a n be u n d i s r u p t e d speed o r t h e a v e r a g e v a l u e c a n be s t r a i g h t l i n e a t g o o d , d e t e r m i n e d i n a l o n g e r , s m o o t h , f a i r l y slow t r i p , t a k i n g d i r e c t i o n a l c h a n g e s i n t o c o n s i d e r a t i o n . The m a c h i n e p e r f o r m a n c e m u s t be d e t e r m i n e d v i a c o n s u m p t i o n a s was d o n e i n t h e m e a s u r e m e n t s o f t h e LZ 1 2 7 a n d LZ 1 2 9 . The maximum s p e e d a n d e f f e c t i v e e n g i n e o u t p u t o f e a r l i e r a i ~ s h i p s is known. The c o m p a r i s o n would t h e r e f o r e n o t be s t r i c t l y c o n s i s t e n t , b u t r a t h e r i n f a v o r o f t h e newer d i r i g i b l e s . The maximum v a l u e s d e t e r - mined f o r t h e s e h a v e t h e r e f o r e b e e n i n s e r t e d i n t o t h e t a b l e . The w e i g h t o f t h e c o n t a i n e r s f o r w a t e r a n d f u e l i n c l u d i n g t h e l i n e s , b u t w i t h o u t t h e s p a t i a l i n s t a l l a t i o n s , h a s h a r d l y changed, m e a s u r e d i n c u b i c meters w i t h i n c r e a s i n g a i r s h i p s i z e . O n l y i n t h e LZ 1 2 7 was t h e r e a g r e a t e r w e i g h t , s o l e l y c a u s e d by t h e g a s e o u s f u e l i n t h e c o n t a i n e r w e i g h t w i t h o u t t h e i n d i r e c t w e i g h t r e d u c t i o n s . B a l l a s t e x t r a c t i o n , e v e n when t h i s is a c t u a l l y p a r t o f t h e m a c h i n e r y , w i l l l a t e r be i n c l u d e d i n t h e s e c a l c u l a t i o n s .

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a X ~ ~ ~ ~ l ~ ~ ~ l i ~ ~ - l . t ~ ~ t . t ~ l i i l ' i t liirl : t ~ ~ i i ~ ~ r ! , ~ l ~ rl ! l J Oh i . : l!l;;( l , t b i - I t ~ t ~ g ,I ' t * r l ~ r a t t r I t l~ ~ t - ~ c l ~ ~ v i ~ t t l ~ ~ : h ~ ~ i I .".,.,. . \ v, = (;,,. ?'I.:. b ,r;.lllt:-J .. \ ' : I ,-.'L- e 2 7- ~ , , ~ r ~ ~ t ; , ~ , t ~ Lt ~ a * . , ~ t , t t ~ ~ ~ a t ; ; ~ * . ~ ill111, C r . ~ ~ f ~ i . . l . t ~ ~ ~ l ~ ~ ~ ~ -111111 -( ; r s ; ~ ~ l l * I t ill I I I ~ dli ~ t ~ ~ e l ~ c t t i r L u ~ ~ : ; ~ . : t ~ ~ l-\I ;alt.r*at~~!.llrittc.lt h .;fill[ilb t.x:lb: __-__I--d c r I.III.PIIIIIII..11 \IIAIII a!rr 3 l t l t n r c 1 1.. ..... 11 . n r * a ~ r ~ t l c i \ t t ~ ~ ~ :~ I I1'5 ...... 1 1 11) 1 5 a t :',i,.<:!I*,'! l i r l , . t ; c ~ r l ~ \ t i l ~ , l i > i i t , I I I ~ t),.; L))!;., ?%,(I :;.i,:;(211,2) (.;:,It) m ... .- ;cvic111jl: 1% ill 1:. ... I .I,; .l,5 .IF 4,S .l,:{ I)' n -11.t:,, ... ..c,;,,.,,,,. I,,.!.,I,, , :;,1 I ) I 7r c,,. 3 .~~\IIIII;,~JI,I---....... . . 5 1 111 :t% -4 I. 11.1 11,; .;;!/",I "2 'It-'' : 3 1 ,,,-:: :!I ('9I) UJ!b) F i g u r e 10: Performance v a l u e s Key : a. z e p p e l i n . d i r i g i b l e s f o r longd i s t a n c e t r a v e l from 1916 to 1936 performance, consumption, s p e e d performance e f f e c t i v t t y o f p r o p e l l e r s and g e a r s a i r den.r:+y speed i n m/sec g a s c o n t e n t i n m c o e f f i c i e n t o f r e s i s t a n c e t h e a i r s h i p r e q u i r e s no s u b s t . a n t i a 1 The o p e r a t i o n a l equipment o f i. number o f p r o p e l l e r s j. number o f e n g i n e s k . t o t a l performance i n HP 1. maximum i n m/sec m. w e i g h t p e r HP i n kg n. consumption v a l u e o. performance v a l u e a l t e r a t i o n when t h e t r a n s p o r t t a s k remains t h e same, b u t t h e w e i g h t h a s a c t u a l l y i n c r e a s e d from 1.6 t o o v e r 9 t. Se.vera1 t h i n g s must be mentioned i n c o n n e c t i o n w i t h t h i s . A maiden voyage w i l l always p e r m i t g r e a t e r s a v i n g s , o f t e n even demand them, t h a n t h e a c t u a l t r a n s p o r t s e r v i c e , w i t h r e s p e c t t o t h e amount o f equipment a s w e l l a s t o s t a b i l i t y and d u r a b i l i t y of i n d i v i d u a l p a r t s . The n a v i g a t i o n a l a i d s and i n s t r u m e n t s have a l s o been s u b s t a n t i a l l y improved i n t h e p e r i o d s i n c e t h e war and new a p p l i c a - t i o n s f o r o t h e r d e v i c e s have been found. Such e x p a n s i o n and supplementat i o n may c o n t r i b u t e t o a n i n c r e a s e i n performance and s a f e t y . The l a r g e r v e h i c l e , however, may a l s o l e a d t o some i n c r e a s e d demands, which may n o t I 1 2 I

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b e f u l l y j u s t i f i e d . F i n a l l y a r e a c t i o n o f t h e u s e f u l l o a d o n i n d i v i d u a l /44 p a r t s o f t h e o p e r a t i o n a l e q u i p m e n t c a n n o t b e a v o i d e d . The f o l l o w i n g i m p r o v e m e n t s d e s e r v e i n d i v i d u a l a t t e n t i o n . The d r i v e r g o n d o l a c a r h a s become more s p a c i o u s . S i n c e it is t h e f r o n t l a n d i n g p i e c e , it m u s t a l s o b e b u i l t more s o l i d l y i n t h e l a r g e r a i r s h i p . An e l e c t r i c s e r v o motor is u s e d f o r s t e e r i n g t o d a y i n a d d i t i o n to m a n u a l c o n t r o l s . A c e n t r a l m o n i t o r i n g o f b a l l o n e t p r e s s u r e a n d c o n d i t i o n o f f i l l i n g a p p e a r e d n e c e s s a r y f o r t h e d o u b l e b a l l o n e t s o f t h e h e l i u m - h y d r o g e n g a s d i r i g i b l e ; i t h a s also d e m o n s t r a t e d its w o r t h f o r t h e n o r m a l i n d i v i - c o m p a s s , t h e s o n i c a l t i m e t e r , t h e d u a l b a l l o n e t e q u i p m e n t . The g y r o d r i f t m e t e r , t h e l a r g e h e a d l i g h t etc. were a d d e d to t h e i n s t r u m e n t s . The l a n d i n g d e v i c e s w e r e e x p a n d e d by t h e d e v i c e s f o r p o l e a n d r a i l car m o o r i n g b u f f e r s by b u f f e r w h e e l s . A w e i g h t i n c r e a s e a n d by r e p l a c e m e n t o f t h e t u b e o f s e v e r a l h u n d r e d k i l o g r a m s was a d d e d t o e a c h g r o u p by t h e s e i m p r o v e m e n t s . The i n c r e a s e d w e i g h t o f t h e electrical e q u i p m e n t , c l i m b i n g f r o m 70 t o 1 4 0 kg t o o v e r 3 t, is e s p e c i a l l y n o t i c e a b l e . T h i s d o e s n o t b e l o n g e n t i r e l y t o o p e r a t i o n a l e q u i p m e n t , s i n c e t h e c o n n e c t i o n v a l u e i n t h e LZ 129 f o r s h i p e q u i p m e n t a m o u n t e d to 20 kW,for t h e k i t c h e n s 1 3 kW a n d f o r t h e o t h e r a c c o m m o d a t i o n s 7 kW. wind e n g i n e s d e p e n d e n t o n h e a d w i n d s , w e i g h t a r e o n l y p o s s i b l e by s a v i n g w i t h f u l l r e s e r v e s . R e d u c t i o n s i n The g e n e r a t o r , o r i g i n a l l y d r i v e n by is s u p p l i e d t o d a y by d i e s e l e n g i n e s e l e c t r i c i t y , e . g . by u t i l i z i n g e x h a u s t h e a t f o r t h e k i t c h e n o v e n . t h e crew i n a t r a n s p o r t a i r s h i p a r e o f The a c c o m m o d a t i o n s f o r v e h i c l e , For o f f i c e r s a n d crew t h e r e is c o u r s e l a r g e r t h a n i n a m i l i t a r y o n e mcss e a c h , c o n n e c t e d t o t h e warm h e a t i n g o f t h e p a s s e n g e r rooms. a l o n g t h e walkway. The LZ 1 2 9 had 52 The c r e w s l e e p i n two-bed c a b i n s b e d s . The e n t i r e f i t t e d w e i g h t f o r t h e s e , for t h e messes a n d t h e w a s h i n g a n d a u x i l i a r y rooms amounted to a l m o s t 2 t. Thc u s e f u l l o a d o f t h e m i l i t a r y a i r s h i p c o n t r i b u t e d o n l y a b o u t 150 kg t o t h e n e t w e i g h t . The A f r i c a S h i p r e q u i r e d a l m o s t n o w e i g h t f o r f i t t i n g s f o r t h e 1 4 t c a r g o . The LZ 1 2 6 had 20 seats a n d b e d s of s u f f ic i e n t c o m f o r t f o r its p u r p o s c s , b u t n o t f o r r e g u l a r p a s s e n g e r t r a v e l .

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Figure 11: Crew acconunodations Key: a. restrooms b. bedrooms for the crew c. diningrooms d. bedrooms for the officers The weight for the passenger fittings in the LZ 126 was 1,900 kg. The LZ 127 had a lounge and diningroom with 20 seats and additionally ten cabins with two beds each. which could also be converted for day use, weighing a total of 2,800 kg. The arrangement in a gondola-type construction provides a very good view. At full capacity the accomodations were considered somewhat insufficient. but they were comfortable and sufficient for three-quarter capacity. The possibility for travelling comfort demonstrated in the dirigible gave rise to extensive wishes and demands. In the LZ 129, which was first equipped for 50. but later for made a fulfilling these wishes by means 70 passengers, an attempt was of lounges of large dimensions. The rooms required 400 square meters of floor space, which could now also be arranged in the interior of the ship. Special attention was paid to lovely and expensive decorations. This was good for advertising. but the practical experience was not entirely satisfying. The inside cabins were not popular and the roorniness of the accommodations as such also caused increased weight. In 14

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a d d i t i o n to t h e weight o f f i t t i n g s o f 90 kg-230 kg more t h a n i n t h e LZ 127 t h e r e was per passenger 25 kg i n i n v e n t o r y , 65 kg i n food, d r i n k s and p o t a b l e water and 4 5 kg f o r s e r v i c e p e r s o n n e l i n c l u d i n g accommodat o t a l o f 460 kg, i n c l u d i n g passenger t i o n s and food: t h i s r e s u l t e d i n a weight. I n f u t u r e d i r i g i b l e s weight may be saved i n t h e s u p e r s t r u c t u r e b u t on t h e whole a less e l a b o r a t e s p a t i a l a r r a n g e - /46 and i n d i v i d u a l p a r t s , ment w i l l have to be developed. F i g u r e 12: Passenger accommodations i n t h e "Hindenburg" Key: a . covered walk j. restroom b. diningroom k. passageway c. c a b i n s 1. s t a i r w e l l d. h a l l m. smoking s a l o n e. w r i t i n g and r e a d i n g room n. steward rooms f. o f f i c e r s ' mess o. bar g. k i t c h e n P. gangway h. crews' mess i. bath

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I I n summary it c a n be s e e n t h a t t h e w e i g h t o f i n d i v i d u a l p a r t s o f 1 t h e s u p p o r t s t r u c t u r e i n r e l a t i o n to s h i p c o n t e n t h a s i n c r e a s e d w i t h 1 ! s h i p s i z e , b u t a l l o t h e r p a r t s o f t h e s h i p s h o u l d have been reduced i n Ii order t o a v o i d a w e i g h t g a i n due t o i n c r e a s e d demands or added improvements, I n t h e case o f t h e main r i n g s t h e i n c r e a s e was s o f t e n e d by i 8 improvements i n material and d e s i g n ; i n t h e case o f t h e f u e l t h e reduc- 1 t i o n was i n t e n s i f i e d by t h e p r o g r e s s from a g a s o l i n e e n g i n e t o a g a s i 1 j e n g i n e and t h e n to a d i e s e l e n g i n e . F u r t h e r , t h e c o n s i d e r a b l e w e i g h t . I ' < i n c r e a s e f o r p a s s e n g e r s was d e m o n s t r a t e d . The L 59 employed f o r t h i s /47 , i n n o v a t i o n was d e v e l o p e d from a proven d i r i g i b l e series, w h i l e t h e ! LZ 129 w a s t h e f i r s t model a f t e r t h e l a r g e s t s t e p y e t t a k e n i n t h e 1 s h i p c o n t e n t > 3 : r voyage o f t h e L 59 to t h e s h i p model . . The p a t h from t h a t maiden LZ 129 is now clear a n d looks better t h a n t h e p u r e w e i g h t v a l i l e s would . I f i r s t a l l o w . With t h e knowledge and improvements a v a i l a b l e t o d a y , 200,000 cbm would s u f f i c e f o r 50 p a s s e n g e r s and t h e same s u p p l i e s as i n t h e LZ 129 e v e n w i t h helium a s t h e o n l y l i f t i n g g a s , b u t f o r hydrogen a g a s a s h i p s i z e of 160,000 cbm would a l r e a d y be s u f f i c i e n t .