Part 4 (2/2)
That in itself was a remarkable achievement which could have been accomplished only by possessing the scientific knowledge borne of experience. But it is not all.
One Hundred and Fifteen Zeppelins Built and Operated
From the day Count Zeppelin built his first s.h.i.+p until the last in 1919, a total of 115 Zeppelins were built and operated. The first three were experimental. Nine Zeppelins were successfully operated commercially in the transportation of pa.s.sengers. Forty were delivered to the German army and 63 to the navy.
Scientific Comparison
There exists in the field of engineering an impartial, positive and unswerving means of determining the relative merits of things; and that is by a technical a.n.a.lysis of their success. By it one may recognize the values of the principles and construction methods involved. It is commonly said that nothing succeeds like success; and this is virtually true of the Zeppelins. Their record for efficiency remains unsurpa.s.sed, as a matter of fact, unequalled. It has never been denied that they were superior to contemporary craft or that they failed to maintain an increasing advantage over them.
This comparison is justified by the following figures which we will first attempt to explain.
It will be noted that there are three kinds of efficiency, (1) Speed (the aerodynamical figure), (2) Lift (the constructional figure) and (3) All-around efficiency (the combined quality figure).
The first relates to the efficiency of airs.h.i.+p propulsion as effected by degrees of refinement in form, lessening of resistance, conservation of power, etc. It is simply the relation between the speed and engine power. Inasmuch as higher speed with the same power or the same speed with less power means economy of operation; therefore, the higher figure indicates superior quality.
[PLATE 26: Zeppelin-Dornier ”Dolphin” Monoplane All Metal Flying Boat Type DoCsII, 1920 Model.
Zeppelin-Dornier ”Dolphin” Monoplane All Metal Flying Boat Type DoCsII, 1921 Model.
Carries six pa.s.sengers besides pilot and mechanician. Speed 93 miles per hour, 185 horsepower motor. Gasoline consumption 11.9 gallons per hour. Weight empty 3200 pounds.]
Secondly, referring to the lift, this constructional figure indicates the relative useful or pay loads carried with the smallest amount of material used in the s.h.i.+p itself, because the s.h.i.+p, which must also be carried is ”dead weight.” As we must consider all s.h.i.+ps equal as far as structural safety is concerned, the technical performance is determined by judging the relative performance in carrying useful loads (for s.h.i.+ps of similar size), or equal loads with smaller s.h.i.+ps, which means economy of operation. The higher figure indicates superior quality. It should be noted that this constructional figure is applicable only to comparison of airs.h.i.+ps of similar size, speed and service requirements. For general comparison, however, s.h.i.+ps of approximately the same size may be considered.
Thirdly, all-around efficiency (the combined quality figure) is somewhat arbitrarily chosen by considering both the speed and carrying qualities together. It is not based on scientific deduction, but rather is a practical means of estimating general worth, as speed and carrying capacity are the main requirements of an airs.h.i.+p.
[PLATE 27: Zeppelin-Dornier ”Komet” All Metal Monoplane, Type DoCIII, 1920 Model.
Zeppelin-Dornier ”Komet” All Metal Monoplane.
Carries six pa.s.sengers besides pilot and mechanician. One motor of 185 horsepower.]
Efficiency Characteristics of Some of the Latest and Best Airs.h.i.+ps of All Nations
===========+=======================+========+========+======+======+===== | | | | Efficiency | |Capacity|Maximum +------+------+----- Nationality| Type and Name | Cubic | Speed, | | | | | Meters | Miles |Speed | Lift |All- | | | per | | |round | | | Hour | (1) | (2) |(3) -----------+-----------------------+--------+--------+------+------+----- Non-Rigid Airs.h.i.+ps -----------+-----------------------+--------+--------+------+------+----- American | Goodyear Pony Blimp | 990 | 40 | 24.2 | 0.60 | 15 French | Caussin T 2 | 9120 | 57.5 | 28.0 | 0.85 | 24 British | NS | 10200 | 57.2 | 25.6 | 0.65 | 17 German | PL27 | 31300 | 55.7 | 27.0 | 0.98 | 26 Italian | T 34 (Roma) | 34000 | 74.2 | 21.5 | 0.68 | 15 -----------+-----------------------+--------+--------+------+------+----- Rigid Airs.h.i.+ps -----------+-----------------------+--------+--------+------+------+----- British | R 80 | 34000 | 59.7 | 36.6 | 0.80 | 29 British | R 33-R 34 | 55500 | 59.7 | 37.3 | 0.75 | 28 British | R 36-R 37 | 59500 | 65.0 | 40.0 | 0.80 | 32 German | Schutte-Lanz SL22 | 56000 | 62.5 | 45.2 | 1.36 | 61 -----------+-----------------------+--------+--------+------+------+----- German | Zeppelin LZ 120 | | | | | | (Bodensee) | 20000 | 82 | 63.7 | 0.76 | 48 German | Zeppelin LZ 121 | | | | | | (Nordstern) | 22500 | 78.8 | 61.4 | 0.78 | 48 German | Zeppelin LZ 100 | 56000 | 67.2 | 56.0 | 1.59 | 89 German | Zeppelin LZ 113 | 62200 | 81 | 62.2 | 1.60 | 100 German | Zeppelin LZ 102 | 68500 | 63.7 | 54.4 | 1.90 | 103 -----------+-----------------------+--------+--------+------+------+------
Scientific deductions and formulae to be found in ”Zeitschrift fur Flugtechnik und Motorluftschiffahrt,” June 15th and June 30th, 1920, issues. Article by P. Jaray.
[PLATE 28: Dr. Max Freiherr von Gemmingen.
Dr. Hugo Eckener
Kommerzienrat Alfred Colsman
Dr. Ing. Ludwig Durr
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