Evening star. [volume] (Washington, D.C.) 1854-1972, 1906-03-18
DESIGNS COMPLETED
AirShip Being Built for Polar
Expedition.
EXPLAINED BY WELLMAN
Dirigible VIII Be Twice as Large as
Any Ever Constructed.
ANDRES MISTAKES AVOIDED
It is Calculated That the Co-Effcient
of Safety VIII Exceed
Five to One
BY WALTER WELLMAN.

BY WALTER WELLMAN.
Just before 1 left Paris to return to the
United States Engineer GODDARD placed in
my hands the completed designs and
studies OF the huge airship he Is building
Tor the WeIlman Chicago Record-HeraId
polar expedition. To finish work of
such magnitude and so complex and deli
cate I'm the short time at his command
NJ GODDARD was obliged to surround him
self with a staff of engineers and experts
aud TO employ Il force Of twelve draughts-
men and mathematical computers. The
results. I think, speak well for his energy
and skill Inasmuch as he had entered
iato contract to build IN four months
an airshlp more than twice as large as any
that had ever made successful flight above
the earth, NJ. GODDARD found 1t necessary
10 prepare his working drawings at the
same time he was assembling his material
and starting the actual construction.
Accompanying this article the reader will
find "a reproduction of the designs for the
dirigible comprising views IN elevation. in
plan and from one end, together with
drawing showing the method adopted for
calculating the surface, the volume, the IN
terror pressure of the gas and the tensile
strength required in the envelope of the
balloon. Before quoting from the technical
reports of NJ. GODDARD. which accompanied
the designs. it may be well to give some ex-
PLANTATION concerning The details of the
drawings. Not many Americans are ia
miliar with the methods OF airship construc-
ton and operation. 1t is not au art which
has made much progress in this country, al
though KnabcusHue. Baldwin and perhaps
others have done interesting and valuable
work ou a small scale In this country the
prevailing conception of an airship is that
of "a gas bag of small size relatively. COW
cred with a netting of ropes or steel wires,
and with sufficient lifting capacity. when In
fated with hydrogen gas. to carry the bal
loon, light framework of bamboo or wood.
one or two men. and a small motor with
sufficient supply Of fuel to run ii for a few
hours.
Godard's Immense Airship
The dirigible which NJ GODDARD and his
CORPS OF experts have In hand is an entirely
different sort Of affair Its great size en-
abes &c TO lift not only the balloon. but the
car Of steel. The three motors. comprising
total of eighty horsepower. two screws or
prUpulseurs. "a steel boat. moto-sledges, five
men. food for them for seventy-hve days,
Instruments tools. repair materials. lubri-
eating oils and $500 pounds of gasoline for
The motors. 1t will be seen that in its cargo
tons OF carrying power, much more resem-
bles vessel TO navigate the water than the
small contrivaHces used by Santos Dumont.
Knabeushue and Baldwin in aerial experi-
mentatiou.
In this article it IS desired to consider
only the balloon and its materials and con-
struction. leaving the steel-framcd car. the
motors the propulseurs and other impor-
tant features for future explanation.
The instructions given by me 10 NJ
GODDARD. and embodied in the contract. were
L. spare neither weight nor expense in his
efforts TO make a balloon that should give
The maximum Of security and endurance Il
Is commonly believed among the aeronautlc
experts Of France that the unfortunate An
dree met his fate partly through faulty
construction Of his balloon; that il lacked
the gas-tShtDeSs which should have en-
aDlcd IL 10 remain long time IN the air
and that the fabric of which II was COM
posed did not possess sufficient tensile
strength TO enable It TO resist the clements
and give its naylgators a fair chance for
their lives l pass no Judgment as to this
because l believe the builder OF Andree's
balloon. who is now dead. was careful and
conscientious man But. at any rate I
was determined to avoid such mistakes IL
care ana prudence and outlay could SUI
Bc0 TO do IL For In one particular and In
one only, speaking broadly. Is our enter
prise comparable TO that of Andree-the
SpAAAANt anu ti4UeA4 al4tE OF tfEE SAS-DdS Is as
essential 10 us as IL was TO him. despite
the fact that his aerial craft was q mere
toy Of the winds. without motive power or
steerability, while ours is TO have both.
In the past most balloons have been made
OF SILK vanished with from two to five
cOatngs. But in recent constructions of
important character cotton tissues have
been employed, In one or more thicknesses
coated with thin film of pure rubber ap-
piled By means of special machinery similar
to the calendars OF paper mills. The Lee
tsgF al in kad 4lka
ton. both rubbered. After careful con-
sideratiOn and elaborate calculations of
pressures and strains three thicknesses OF
fabric were decided upon for our shp-two
OF cotton material and one OF sllk-with
three cOatings OF rubber All three are
consolidated into one fabric giving great
tensile strength. Counting from the in