When once the flying machine had indicated its possibilities in
connection with land operations it was only natural that endeavours
should be made to adapt it to the more rigorous requirements of the
naval service. But the conditions are so vastly dissimilar that only a
meagre measure of success has been recorded. Bomb-throwing from
aloft upon the decks of battleships appeals vividly to the popular
imagination, and the widespread destruction which may be caused by
dropping such an agent down the funnel of a vessel into the boiler-room
is a favourite theme among writers of fiction and artists. But hitting
such an objective while it is tearing at high speed through the water,
from a height of several thousand feet is a vastly different task from
throwing sticks and balls at an Aunt Sally on terra firma: the target is
so small and elusive.
Practically it is impossible to employ the flying machine, whether it
be a dirigible or an aeroplane, in this field. Many factors militate
against such an application. In the first place there is a very wide
difference between dry land and a stretch of water as an area over which
to manoeuvre. So far as the land is concerned descent is practicable at
any time and almost anywhere. But an attempt to descend upon the open
sea even when the latter is as calm as the proverbial mill-pond is
fraught with considerable danger. The air-currents immediately above the
water differ radically from those prevailing above the surface of
the land. Solar radiation also plays a very vital part. In fact the
dirigible dare not venture to make such a landing even if it be provided
with floats. The chances are a thousand to one that the cars will become
water-logged, rendering re-ascent a matter of extreme difficulty, if not
absolutely impossible. On the other hand, the aeroplane when equipped
with floats, is able to alight upon the water, and to rest thereon for
a time. It may even take in a new supply of fuel if the elements be
propitious, and may be able to re-ascend, but the occasions are rare
when such operations can be carried out successfully.
In operations over water the airman is confronted with one serious
danger--the risk of losing his bearings and his way. For instance, many
attempts have been made to cross the North Sea by aeroplane, but only
one has proved successful so far. The intrepid aviator did succeed in
passing from the shore of Britain to the coast of Scandinavia. Many
people suppose that because an airman is equipped with a compass he must
be able to find his way, but this is a fallacy. The aviator is in the
same plight as a mariner who is compelled from circumstances to rely
upon his compass alone, and who is debarred by inclement weather from
deciding his precise position by taking the sun. A ship ploughing the
waters has to contend against the action of cross currents, the speed
of which varies considerably, as well as adverse winds. Unless absolute
correction for these influences can be made the ship will wander
considerably from its course. The airman is placed in a worse position.
He has no means of determining the direction and velocity of the
currents prevailing in the atmosphere, and his compass cannot give him
any help in this connection, because it merely indicates direction.
Unless the airman has some means of determining his position, such as
landmarks, he fails to realise the fact that he is drifting, or, even
if he becomes aware of this fact, it is by no means a simple
straightforward matter for him to make adequate allowance for the
factor. Side-drift is the aviator's greatest enemy. It cannot be
determined with any degree of accuracy. If the compass were an
infallible guide the airman would be able to complete a given journey
in dense fog just as easily as in clear weather. It is the action of the
cross currents and the unconscious drift which render movement in the
air during fog as impracticable with safety as manoeuvring through the
water under similar conditions. More than one bold and skilful aviator
has essayed the crossing of the English Channel and, being overtaken by
fog, has failed to make the opposite coast. His compass has given him
the proper direction, but the side-drift has proved his undoing, with
the result that he has missed his objective.
The fickle character of the winds over the water, especially over such
expanses as the North Sea, constitutes another and seriously adverse
factor. Storms, squalls, gales, and, in winter, blizzards, spring up
with magical suddenness, and are so severe that no aircraft could hope
to live in them. But such visitations are more to be dreaded by the
lighter-than-air than by the heavier-than-air machines. The former
offers a considerable area of resistance to the tempest and is caught up
by the whirlwind before the pilot fully grasps the significant chance
of the natural phenomenon. Once a dirigible is swept out of the hands of
its pilot its doom is sealed.
On the other hand, the speed attainable by the aeroplane constitutes its
safety. It can run before the wind, and meantime can climb steadily and
rapidly to a higher altitude, until at last it enters a contrary wind or
even a tolerably quiescent atmosphere. Even if it encounters the tempest
head on there is no immediate danger if the aviator keep cool. This
fact has been established times out of number and the airman has been
sufficiently skilful and quick-witted to succeed in frustrating the
destructive tactics of his natural enemy.
Only a short while ago in France, British airmen who went aloft in a
gale found the latter too strong for them. Although the machine was
driven full speed ahead it was forced backwards at the rate of 10 miles
per hour because the independent speed of the aeroplane was less
than the velocity of the wind. But a dirigible has never succeeded
in weathering a gale; its bulk, area, and weight, combined with its
relatively slow movement, are against it, with the result that it is
hurled to destruction. All things considered, the dirigible is regarded
as an impracticable acquisition to a fleet, except in the eyes of the
Germans, who have been induced to place implicit reliance upon their
monsters. The gullible Teuton public confidently believes that their
Dreadnoughts of the air will complete the destruction of the British
fleet, but responsible persons know full well that they will not play
such a part, but must be reserved for scouting. Hitherto, in naval
operations, mosquito water-craft, such as torpedo-boats, have been
employed in this service. But these swift vessels suffer from one
serious disability. The range of vision is necessarily limited, and a
slight mist hanging over the water blinds them; the enemy may even pass
within half-a-mile of them and escape detection.
The Zeppelin from its position 1,000 feet or more above the water, in
clear weather, has a tremendous range of vision; the horizon is about 40
miles distant, as compared with approximately 8 miles in the case of the
torpedo-boat. Of course an object, such as a battleship, may be detected
at a far greater range. Consequently the German naval programme is to
send the Zeppelin a certain distance ahead of the battleship squadron.
The dirigible from its coign of vantage would be able to sight a hostile
squadron if it were within visual range and would communicate the fact
to the commander of the fleet below. The latter would decide his course
according to information received; thus he would be enabled to elude
his enemy, or, if the tidings received from the aerial scout should
be favourable, to dispose his vessels in the most favourable array for
attack.
The German code of naval tactics does not foreshadow the use of
dirigible aircraft as vessels of attack. Scouting is the primary and
indeed the only useful duty of the dirigible, although it is quite
possible that the aerial craft might participate in a subsequent naval
engagement, as, indeed, has been the case. Its participation, however,
would be governed entirely by climatic conditions. The fact that
the dirigible is a weak unit of attack in naval operations is fully
appreciated by all the belligerents.
The picture of a sky "black with Zeppelins" may appeal to the popular
imagination, and may induce the uninitiated to cherish the belief that
such an array would strike terror into the hearts of the foe, but the
naval authorities are well aware that no material advantage would accrue
from such a force. In the first place they would constitute an ideal
target for the enemy's vessels. They would be compelled to draw within
range in order to render their own attack effective, and promiscuous
shooting from below would probably achieve the desired end. One or
more of the hostile aircraft would be hit within a short while. Such
disasters would undoubtedly throw the aerial fleet into confusion,
and possibly might interfere with the tactical developments of its own
friends upon the water below.
The shells hurled from the Zeppelins would probably inflict but little
damage upon the warships beneath. Let it be conceded that they weigh
about 500 pounds, which is two-thirds of the weight of the projectile
hurled from the Krupp 128-centimetre howitzer. Such a missile would have
but little destructive effect if dropped from a height of 1,000 feet.
To achieve a result commensurate with that of the 28-centimetre howitzer
the airship would have to launch the missile from a height of about
7,000 feet. To take aim from such an altitude is impossible, especially
at a rapidly moving target such as a battle-cruiser.
The fact must not be forgotten that Count Zeppelin himself has expressed
the opinion, the result of careful and prolonged experiments, that his
craft is practically useless at a height exceeding 5,000 feet. Another
point must not be overlooked. In a spirited naval engagement the
combatants would speedily be obliterated from the view of those aloft by
the thick pall of smoke--the combination of gun-fire and emission from
the furnaces and a blind attack would be just as likely to damage friend
as foe.
Even if the aircraft ventured to descend as low as 5,000 feet it would
be faced with another adverse influence. The discharge of the heavy
battleship guns would bring about such an agitation of the air above as
to imperil the delicate equilibrium of an airship. Nor must one overlook
the circumstance that in such an engagement the Zeppelins would become
the prey of hostile aeroplanes. The latter, being swifter and nimbler,
would harry the cumbersome and slow-moving dirigible in the manner of
a dog baiting a bear to such a degree that the dirigible would be
compelled to sheer off to secure its own safety. Desperate bravery and
grim determination may be magnificent physical attributes, ut they
would have to be superhuman to face the stinging recurrent attacks of
mosquito-aeroplanes.
The limitations of the Zeppelin, and in fact of all dirigible aircraft,
were emphasised upon the occasion of the British aerial raid upon
Cuxhaven. Two Zeppelins bravely put out to overwhelm the cruisers and
torpedo boats which accompanied and supported the British sea-planes,
but when confronted with well-placed firing from the guns of the vessels
below they quickly decided that discretion was the better part of valour
and drew off. In naval operations the aeroplane is a far more formidable
foe, although here again there are many limitations. The first and most
serious is the severely limited radius of action. The aeroplane motor is
a hungry engine, while the fuel capacity of the tank is restricted. The
German military authorities speedily realised the significance of this
factor and its bearing upon useful operations, and forth with carried
out elaborate endurance tests. In numerable flights were made with the
express purpose of determining how long a machine could remain in the
air upon a single fuel supply.
The results of these flights were collated and the achievements of each
machine in this direction carefully analysed, a mean average drawn
up, and then pigeon-holed. The results were kept secret, only the more
sensational records being published to the world. As the policy of
standardisation in the construction of aeroplanes was adopted the radius
of action of each type became established. It is true that variations
of this factor even among vessels exactly similar in every respect are
inevitable, but it was possible to establish a reliable mean average for
general guidance.
The archives of the Berlin military department are crowded with facts
and figures relating to this particular essential, so that the radius of
action, that is the mileage upon a single fuel charge, of any class and
type of machine may be ascertained in a moment. The consequence is that
the military authorities are able to decide the type of aeroplane which
is best suited to a certain projected task. According to the dossier
in the pigeon-hole, wherein the results of the type are filed, the
aeroplane will be able to go so far, and upon arriving at that point
will be able to accomplish so much work, and then be able to return
home. Consequently it is dispatched upon the especial duty without any
feeling of uncertainty.
Unfortunately, these experimental processes were too methodical to prove
reliable. The endurance data were prepared from tests carried out in
the aerodrome and from cross-country trials accomplished under ideal or
fair-weather conditions. The result is that calculations have been often
upset somewhat rudely by weather conditions of a totally unexpected
character, which bring home vividly the striking difference between
theory and practice.
The British and French aviation authorities have not adopted such
methodical standardisation or rule of thumb inferences, but rather
have fostered individual enterprise and initiative. This stimulation of
research has been responsible for the creation of a type of aeroplane
specially adapted to naval service, and generically known as the water
plane, the outstanding point of difference from the aeroplane being the
substitution of canoes or floats for the wheeled chassis peculiar to
the land machine. The flier is sturdily built, while the floats are
sufficiently substantial to support the craft upon the water in calm
weather. Perhaps it was the insular situation of the British nation
which was responsible for this trend of development, because so far as
Britain is concerned the sea-going aeroplane is in dispensable. But the
salient fact remains that to-day the waterplane service of Great Britain
is the most efficient in the world, the craft being speedy, designed and
built to meet the rough weather conditions which are experienced around
these islands, and ideal vessels for patrol and raiding duties.
So far as the British practice is concerned the waterplane is designed
to operate in conjunction with, and not apart from, the Navy. It has
been made the eyes of the Navy in the strictest interpretation of the
term. In any such combination the great difficulty is the establishment
of what may be termed a mobile base, inasmuch as the waterplane must
move with the fleet. This end has been achieved by the evolution of
a means of carrying a waterplane upon, and launching it from, a
battleship, if necessary.
For this purpose a docking cradle or way has been provided aft where
the aeroplane may be housed until the moment arrives for its employment.
Several vessels have been devoted to this nursing duty and are known as
parent ships to the waterplane service. All that is requisite when the
time arrives for the use of the seaplane is to lift it bodily by derrick
or crane from its cradle and to lower it upon the water. It will be
remembered that the American naval authorities made an experiment with a
scheme for directly launching the warplane from the deck of a battleship
in the orthodox, as well as offering it a spot upon which to alight upon
returning from a flight, while Wing-Commander Samson, R.N., D.S.O., the
famous British airman, repeated the experiment by flying from a similar
launching way installed upon H.M.S. Hibernia. But this practice has many
shortcomings. So far as the British and French navies are concerned, the
former process is preferred. Again, when the waterplane returns from a
flight it is admitted that it is simpler, quicker, and safer for it to
settle upon the water near the parent ship and to be lifted on board.
As a sea-scout the waterplane is overwhelmingly superior to the
dirigible as events have conclusively proved. Its greater mobility and
speed stand it in excellent stead because it is able to cover a
larger area within a shorter space of time than its huge and unwieldy
contemporary. Furthermore, it is a difficult target to hit and
accordingly is not so likely to be brought down by hostile fire. There
is another point in its favour. The experience of the war has proved
that the numerically inferior enemy prefers to carry out his naval
operations under the cover of the mist and haze which settle upon the
water, and yet are of sufficient depth to conceal his identity and
composition. Such mists as a rule comprise a relatively thin bank of
low-lying vapour, which while enveloping the surface of the water in an
impenetrable pall, yet permits the mast-heads of the vessels to stand
out clearly, although they cannot be detected from the water-level
or even from the control and fighting tops of a warship. A scouting
waterplane, however, is able to observe them and note their movement,
and accordingly can collect useful information concerning the apparent
composition of the hidden force, the course it is following, its
travelling speed, and so forth, which it can convey immediately to its
friends.
The aeroplane has established its value in another manner. Coal-burning
vessels when moving at any pronounced speed invariably throw off large
quantities of smoke, which may be detected easily from above, even when
the vessels themselves are completely hidden in the mist. It was this
circumstance which revealed the presence of the British squadron in the
affair of the Bight of Heligoland.
The German airman on patrol duty from the adjacent base on the island of
Heligoland detected the presence of this smoke, above the low-lying bank
of fog, although there were no other visible signs of any vessels. Fully
cognisant of the fact that the German Fleet was at anchor in a safe
place he naturally divined that the smoke proceeded from a hostile
squadron, evidently bent upon a raid. He returned to his headquarters,
conveyed the intelligence he had collected to his superior officers,
upon receipt of which a German cruiser squadron was sent out and engaged
the British vessels to its own discomfiture. But for the airman's
vigilance and smartness there is no doubt that the British squadron
would have accomplished a great coup.
This incident, however, served to reveal that the aerial scout is prone
to suffer from over-keenness and to collect only a partial amount
of information. Upon this occasion the German watchman detected the
presence of the British torpedo-boat and light cruiser force. Had
he continued his investigations and made a wider sweep he would have
discovered the proximity of the British battle-cruiser squadron
which routed the German force, the latter having acted on incomplete
information.
While the low-lying sea-fog is the navigator's worst enemy, it is the
airman's greatest friend and protection. It not only preserves him
against visual discovery from below, but is an excellent insulator
of sound, so that his whereabouts is not betrayed by the noise of his
motor. It is of in calculable value in another way. When a fog prevails
the sea is generally as smooth as the pro verbial mirror, enabling the
waterplanes to be brought up under cover to a suitable point from which
they may be dispatched. Upon their release by climbing to a height of a
few hundred feet the airmen are able to reach a clear atmosphere, where
by means of the compass it is possible to advance in approximately the
desired direction, safe from discovery from below owing to the fog.
If they are "spotted" they can dive into its friendly depths, complete
their work, and make for the parent ship.
Low-lying sea-fogs are favourable to aerial raids provided the scout is
able to catch sight of the upper parts of landmarks to enable him to
be sure of the correctness of his line of flight-in cases where
the distance is very short compass direction is sufficiently
reliable-because the bank of vapour not only constitutes a perfect
screen, but serves as a blanket to the motor exhaust, if not completely,
at least sufficiently to mislead those below. Fogs, as every mariner
will testify, play strange tricks with the transmission of sound. Hence,
although those on the vessels below might detect a slight hum, it might
possibly be so faint as to convey the impression that the aviator was
miles away, when, as a matter of fact, he was directly overhead. This
confusion arising from sound aberration is a useful protection in
itself, as it tends to lure a naval force lying in or moving through the
fog into a false sense of security.
The development of the submarine revealed the incontrovertible fact
that this arm would play a prominent part in future operations upon the
water: a presage which has been adequately fulfilled during the
present conflict. The instinct of self-preservation at once provoked
a discussion of the most effective ways and means of disguising its
whereabouts when it travels submerged. To this end the German naval
authorities conducted a series of elaborate and interesting experiments
off the island of Heligoland. As is well known, when one is directly
above a stretch of shallow water, the bottom of the latter can be seen
quite distinctly. Consequently, it was decided to employ aerial craft
as detectives. Both the aeroplane and the dirigible took part in these
experiments, being flown at varying heights, while the submarine was
maneouvred at different depths immediately below. The sum of these
investigations proved conclusively that a submarine may be detected from
aloft when moving at a depth of from 30 to 40 feet. The outline of the
submerged craft is certainly somewhat blurred, but nevertheless it is
sufficiently distinct to enable its identity to be determined really
against the background or bottom of the sea. To combat this detection
from an aerial position it will be necessary inter alia to evolve a
more harmonious or protective colour-scheme for the submarine. Their
investigations were responsible for the inauguration of the elaborate
German aerial patrol of harbours, the base for such aerial operations
being established upon the island of Heligoland.
So far the stern test of war as applied to the science of aeronautics
has emphasised the fact that as a naval unit the dirigible is a complete
failure. Whether experience will bring about a modification of these
views time alone will show, but it is certain that existing principles
of design will have to undergo a radical revision to achieve any notable
results. The aeroplane alone has proved successful in this domain, and
it is upon this type of aerial craft that dependence will have to be
placed.