The Aviation Historian — January 2018

128 THE AVIATION HISTORIAN Issue No 22

type, instead of the more orthodox biplane
arrangement, are partly explained by the
foregoing. By using three planes, the overall
span is reduced to a minimum and the spars,
being shorter, are obviously much stronger.
The length of the half wing being only 10ft 3in
[3·1m], storage conditions are ideal. The total
weight is extremely low [he puts the total weight
of the glider, minus pilot, at 54lb 8oz/24·7kg],
and probably constitutes a record for this type.
“The construction and subsequent flying of this
machine should prove of absorbing interest to
those with skill in the use of woodworking and
metalworking tools, and to whom the making
of, say, a model aeroplane does not appeal. To
work on a glider, through all the varying stages
of construction, and then to experience in a small
way the exhilaration of flying, is a scientific
sport of no mean order. The writer wishes it
to be clearly understood that the appended
description makes no pretence of teaching the
rudiments of simple carpentry, it being taken for
granted that this has previously been acquired
by the reader or intending builder.”

THE TRIPLANE DESCRIBED
The detailed description of the glider’s cons-
truction specifies the gauge of the mild steel
used for the fittings and the diameter of the
bolts, eyebolts and cotter pins. To facilitate quick
erection and dismantling, bolts were replaced by
cotter pins and split pins wherever possible. The
wing ribs were to be steamed and bent to the
correct section and dried over a gas flame, then
screwed and glued to the main spars. Camm
points out that “the curvature of the wing tip
diminishes or is ‘washed out’”.
The control wires were guided to the elevators
and ailerons through short pieces of copper
tube clipped to the spars, and Camm states that,
although steel wire could be used for the straight
lengths, at these points stranded Bowden wire
was to be used. “The control lever, or to use its
aviatic name, ‘joy stick’” was attached to the
cross-bar by a universal joint, the movements
being instinctive. “... thus, to increase the angle

of descent the lever is pushed forward and

pulled back for rising, while to raise the left-

hand side of the planes the stick is moved to the

right, and vice versa”.

He also states that the fin is fixed, “and cannot

be moved by the pilot, its use being to assist the

machine in keeping head to wind”. “Making

the rudder movable,” he adds, “imposes

unnecessary complication, and really the only

directions in which control is needed is laterally,

to counteract side gusts, and longitudinally for

getting off and landing”.

Camm dismisses a wheeled undercarriage

because, “when wheels have been used to

facilitate launching, they have rarely survived

the first few shocks. In addition, they add

considerably to the cost, weight, and resistance

of the machine. Conversely, a strong, low-built

skid will stand up to the roughest landing”.

Regarding the necessity of giving the

interplane struts a streamline cross-section,

Camm gives them squared-off trailing edges,

stating: “The section does not taper to the sharp

edge usually associated with streamline, a small

flat of about^111 ⁄⁄⁄⁄ 88 in [3·2mm] being left. In this

case the designer has taken advantage of a fact

adduced from some experiments carried out a

while back, which proved that no appreciable

difference exists in the resistance of a strut

worked to a fine edge and one left with a flat of

about^3 3 3 ⁄⁄⁄⁄ 1616 in [4·8mm], this, of course, varying with

the size of strut employed.”

Camm’s design is primitive, even for 1919, and

it could well have been draughted a few years

before publication of the drawings. Moreover,

it seems that in his efforts to pare the weight to

the absolute minimum he might have made the

glider a bit too flimsy, especially regarding the

structure supporting the tail surfaces.

One wonders whether anyone actually built

Sydney’s triplane glider and tried to fly it, but

that remains unknown. It is stunning to think

that, only ten years later, the Hawker Hornet —

prototype of the beautiful Fury biplane fighter

— appeared, to be followed after another six

years by the Hurricane.

TAH

LEFT Structural

details of the Camm

triplane glider as

published in the

second half of the

two-part series

published in two

issues of Work

during March

1919. This panel
      shows illustrations
      of fittings for the
      various components
      required to
      complete Sydney
      Camm’s previously
      unknown design.