Evening star., 1940-07-07

nearly any kind of surface is held
to be a decisive factC- in the attain
ment of mass production methods in
the making of bcmbardmert air.
planes for France and the United
States Army and giant long-range
patrol airplanes for the United
States Navy. The same method is
expected in the future to find wide
application in many other indus
tries.
The heroic camera, with its lens
In one room and its plate-holder
in another, does its work on plates
averaging 10 by feet in size. The
prints customarily are made on
sheets of aluminium alloy metal with
sensitized surfaces These sheets are
developed in large tanks and the
original drawings appear in exact
size on their surfaces. In special
cases the drawings can also be
reproduced in fractional or multi
pie scales, on paper, cloth, wood or
any other substance.
Using this process, the Martin ex-
perts can produce in an hour or two
any number of drawings which
might have required days in re-
drafting. Drawings can be laid out
directly on metal in a matter of min
utes where formerly days were re-
quired to make layouts on metal
from blueprints.
The Photographic process is esti-
mated to have saved the Martin
company more than $4,000 last year
in drafting costs. More important,
1t has speeded up engineering work
tremendously. Tool designing and
tool making can be gotten under way
more rapidly and more accurately.
Production preparation gets under
way more quickly and changes can
be made more rapidly. Because
there are plenty of exact-scale draw
ings available, greater co-ordina-
ton of the efforts of several vital
departments can be obtained.
Plane Building.
The process can be used in an even
more interesting fashion in the
building of experimental airplanes.
These airplanes can be built up.
where only one or two of a kind
are concerned, directly from photo
graphs. The master drawings, alb
solutely accurate in every detail, can
be photographed directly onto the
metal of which the airplane is to
be constructed and the parts cut
directly from the material.
If a wind-tunnel or water basin
model of a projected airplane is de-
sired, it is only necessary to use the
camera to scale down the lines from
the full-size drawings to an eighth
or a tenth or any other fraction of
the full size. Perhaps weeks of re-
drawing to scale may be saved.
The huge Martin camera is called
upon for yet other duties. Drawings
are projected onto tracing paper,
vellum and wood for various pur-
poses. Typewriter pages of instruc-
tions or design figures, with pictures
in ink, pencil or photographs, can
be reproduced on metal plates which
are treated to become photographic
plates for rapid reproduction by the
multilith method Ordinary photo
graphs can be blown up on paper,
canvas or wood paneling to sizes as
large as 10 by feet for photo
murals.
BY far the greatest use OF the
camera and the greatest economies
from this method, however, are in
the engineering field. Although the
Glenn L. Martin Co. has more than
900 engineers on its pay roll, out OF
a total of more than $4,000 employees,
Its engineering force would have to
be many times larger but for the
camera method. Drafting work
would be multiplied many times.
One of the intresting features OF
the engineering and design depart
ment of the Martin company, which
makes efficient use of the camera
method possible, is a "loft" some
what similar in appearance to a sail
loft, in which original drawings are
made full size, regardless of the
size Of the airplane under develop
ment.
In the basement of the Martin
factory is huge chalk white floor,
raised above the level of the build
ing floor, on which airplanes and
airplane sections are drawn out in
full size by engineers who walk and
crawl over the floor, wearing flannel
window-dressers' slippers over their
shoes.
On this floor the engineers and