unpublished. When Villa’s raiders were threatening to destroy the
railway-lines paralleling the Mexican border, the Engineer Corps designed
and built a number of self-propelling armored railway-cars armed
with 3-inch rifles, machine-guns, and search-lights. When the German
submarines began their piratical operations along the Atlantic seaboard
in the spring of 1918, these moving fortresses were secretly rushed up
from the Rio Grande in order to afford protection to the undefended
Jersey coast towns. It was well for the U-boat commanders that they
did not attempt to shell Long Branch and Atlantic City as they shelled
Scarborough and Broadstairs. If they had, the Engineers and their armored
cars would have given them the surprise of their lives.
* * * * *
The non-military person does not ordinarily associate with war such
prosaic occupations as lumbering, quarrying, and highway building.
They seem, at least at first thought, to be in character essentially
industrial. But it must be remembered that the workman played fully
as great a part as the soldier in winning the Great War. In fact, the
combat troops could not have held the line for a day had it not been
for the labor battalions, which, without incentive or excitement, glory
or reward, and in most cases without public appreciation, toiled so
faithfully and unceasingly to build the wharves, to unload the ships,
to lay the railways, to construct the roads, and to hurry forward, in
an unending stream, the food for the men and the food for the guns. It
is quite understandable, once you stop to think about it, that in order
to maintain our great armies in the field, there were required immense
quantities of lumber for building wharves, barracks, storehouses,
hangars, and hospitals, and enormous amounts of stone, crushed rock, and
gravel for metalling the roads, ballasting the railways, buttressing the
bridges, and making concrete for the fortifications. When we entered
the war the supply of lumber was not nearly equal to the demands of the
Allied Armies, to say nothing of our own. And, though there was, of
course, plenty of rock and gravel in this country, we could not spare the
tonnage to ship it overseas, even had such a course been practicable.
(Perhaps it has never occurred to you how vitally important an item
gravel is in military operations. Yet at one time the Germans threatened
the Dutch with war if the latter persisted in their refusal to permit
German gravel to be shipped across Holland for the construction of
concrete fortifications in Belgium.) In view of these conditions, it
devolved upon the Engineers to organize and equip special forestry,
quarry, and highway regiments, as well as numerous labor battalions, and
hurry them overseas with orders to obtain the urgently needed materials
from the forests and quarries of France.
Though Engineer officers of the regular establishment were, of course,
given command of these specialist regiments, the other officers as
well as the soldiers themselves were recruited from men trained in the
particular sort of work which each regiment was expected to perform.
How to obtain officers of sufficient experience in these various lines
of industry, and in sufficient numbers, promised at first to be a
serious problem, but it was quickly solved by the Personnel Division of
the Engineers, which had had on file, ever since the war-clouds first
appeared on America’s horizon, tens of thousands of letters from men
trained in every branch of the engineering profession, offering their
services to the government in case of war. Hence, when it was decided to
raise a forestry regiment, it was a simple matter to turn to the files
and find the names of thousands of men—mill-owners, forest-rangers,
lumbermen—with their experience and qualifications carefully listed, who
were intimately familiar with every phase of the industry, from tree
to finished board. The best qualified of these applicants were offered
commissions by telegraph and instructed to go out into the lumber country
and recruit their companies and battalions from men who had worked under
them or whom they knew. Soon the walls of every employment-office,
bunk-house, and cook-shack from the pine woods of Maine to the spruce
forests of Washington blossomed with posters calling for axemen,
sawyers, log-drivers, timber-cruisers, mill-operators, cookees,
teamsters, for immediate service overseas. The response was prompt
and startling. From their camps on the Kennebec and the Androscoggin,
from the Adirondacks, from the pine-clad shores of Superior and Huron,
from the Michigan Peninsula and the North Woods of Minnesota, from the
forested slopes of the Wind River, the Bitter Roots, and the Cascades,
from the big timber of the Far Nor’west the lumbermen came pouring in,
in mackinaws and parkas, in moccasins and shoepacks, in knitted toques
and caps of fur, their scanty belongings wrapped in the blanket-rolls
slung across their backs and often with their axes on their shoulders.
Sinewy-limbed, saddle-colored, horny-handed, tough as the timber of the
forests whence they came, these were the real pioneers, the conquerors
of the wilderness, the last of the frontiersmen, and Europe will, in all
likelihood, never see their picturesque like again.
The first of the forestry regiments, the 10th Engineers, sailed for
Europe five months after the declaration of war, followed at short
intervals by several similar organizations. Immediately upon their
arrival in France lumbering operations were begun in the Vosges and
the Pyrenees (so do not be surprised if the next time you go shooting
in Maine or fishing in Michigan your guide interlards his conversation
with French or Spanish phrases), using French mills at first but later
installing plants of the American type. The enlisted men of the forestry
outfits were, as I have said, for the most part lumbermen by trade,
officered by men familiar with lumbering in all its details. The result
was a striking illustration of what American energy and American methods
can do, for the official reports show that mills which, under French
management, were yielding 500 board feet a day, were made to yield ten
times that quantity when operated by Yankee lumbermen. In the Vosges
this work was carried on so close to the front that the plants were
repeatedly bombed by enemy aircraft and shelled by enemy artillery, the
forestry troops, though listed as non-combatants, frequently suffering
heavy casualties. It took a high order of courage for these men to go
unconcernedly about their business of tree-felling, hauling, and sawing
with German shells yowling through the branches and bursting all about
them. The sawmills were of the portable type, however, and when the
fire of the German guns became too accurate and heavy, the whole plant
was packed up and shifted to a new location. I don’t believe in letting
loose upon my defenseless readers swarms of figures, but it will serve
to give those of them who are familiar with lumbering some idea of what
our forestry regiments accomplished when I mention that during the month
of October, 1918, alone, they produced 50,000,000 board feet of sawed
lumber, 80,000 cords of firewood, and enough standard-gauge ties to build
a single-track railway from the Great Lakes to the Gulf.
In raising the quarry, highway, and inland waterway regiments, the same
method was adopted as in the organization of the forestry battalions.
Enormous quantities of crushed rock were required for concrete and for
the construction and repair of roads, but though numerous quarries were
available in the American areas, experienced quarrymen and quarrying
equipment were lacking. Accordingly a special quarry regiment, the 28th
Engineers, was organized in the United States in November, 1917, with
a strength of 60 officers and some 1,500 men. A skeleton organization
was formed by transferring a few officers and a small detachment of men
from a road regiment, the new unit being raised to strength by giving
commissions to quarry managers and superintendents and filling up the
ranks with drafted quarrymen.
Spreading over almost the whole of France is a veritable network of
navigable rivers and canals, of which the Engineers availed themselves to
the utmost in the transportation of material and supplies. Transportation
by the inland waterways was in charge of the 57th Engineers, this
regiment being largely recruited from men who had had experience on the
canals and rivers of the United States. In the days to come many are the
tales that will be told by skippers of stern-wheelers on the Mississippi
and captains on the Erie Canal of the days when they and their huskies of
the Inland Waterways battalions moved the supplies for Pershing’s men up
the Seine and through the canals of the Marne and the Rhône.
To the dredging, dock construction, and stevedore regiments was assigned
the gigantic task of dredging the channels and harbors of the seaports
which the French placed at our disposal, of building wharves and berths
for the reception of American ships, and of the transferring of the
cargoes from ship to shore. The magnitude of their task is shown by
the fact that cargo shipments grew from 20,000 tons in July, 1917,
to 1,000,000 tons in November of the following year, while the 23
ship-berths which the French Government originally assigned to us had
nearly quadrupled when the Armistice was signed.
* * * * *
Unless you have marched with armies or trekked across hot and arid
lands, you cannot know what it is to be thirsty—really thirsty, I mean;
so thirsty that your tongue swells until it all but chokes you or lolls
from your mouth like that of a panting dog. Water is infinitely more
important to the success of a military operation than arms or ammunition;
to a certain extent it is more important than food; for, though troops
can fight for an amazingly long time on short rations, or even on no
rations at all, they cannot fight without water. The vital importance
of providing an adequate water-supply was learned by the French in
Algeria and Morocco, by the British in India and the Sudan, where the
deserts were strewn for miles with the bodies of soldiers who had died
from thirst. In the Cuban campaign our armies had far more deaths from
impure water than from Spanish bullets. During the Italian offensive on
the Carso, that terrible plateau of sun-scorched rock which lies beyond
the Isonzo, hundreds of men, Italians and Austrians alike, died from
thirst, the Austrians being eventually compelled to retreat because the
Italian artillery had destroyed the pipe-lines which supplied them with
water. During the fighting on the Western Front during the last summer
of the war, when the semitropic sun of eastern France beat down on the
heavy-laden backs of the panting, sweating men, when millions of feet
and hoofs ground the roads to powder and filled eyes, ears, throats, and
nostrils with the yellow, choking dust, when the air reeked with the
mingled stenches of leather, gasoline, sweating horse-flesh, and human
perspiration, and when, as the canteens emptied, the men peered anxiously
over their shoulders for the company water-carts, thousands realized as
never before the truth of Kipling’s words:
“When it comes to slaughter,
You must do your work on water.”
Now, when a hundred thousand men and thirty-five thousand animals are
crowded into a sector perhaps three miles wide and seven miles deep,
the problem of keeping those men and animals supplied with water
becomes tremendous. The responsibility for supplying with water the
troops in the field fell upon the Army Water-Supply Service, which,
as might be expected, was a branch of the Corps of Engineers. The
Water-Supply Service was really a wholesaler of water, delivery being
made at “water-points,” from which water was drawn directly by men and
animals, the largest customers being, however, the ubiquitous two-wheel
water-carts of the infantry and artillery. To supply these “water-points”
every available source was utilized, springs developed, deep wells
bored, village wells and cisterns cleaned out, streams purified and
pumping-stations established, the aim being to provide water within a
mile and a half of every consumer at the front. Ordinarily two gallons
of water per man per day were furnished at the front, this quantity
being sufficient for drinking, cooking, and lavatory purposes, but
during the enormous troop concentrations incident to the St. Mihiel and
Argonne offensives this quantity had to be materially reduced, during
those periods of stress and action the men having scant opportunity for
either cooking or bathing. It was impossible, however, to reduce the
quantity for the animals, for each of which eight to ten gallons had to
be provided daily.
Even under battle conditions the purity of the water was the first
consideration, for impure water can work far more havoc with an army
than enemy shell. In order to provide against this contingency, mobile
laboratories for water-testing purposes moved in the van of the armies,
and during the drives the Water-Supply troops were provided with
poison-testing kits, for, warned by the experiences of the British in
German Southwest Africa, where wells were systematically poisoned by the
enemy, we took no chances. Sources of supply were, wherever possible,
protected, it being considered almost as serious an offense for a soldier
to contaminate a water-supply as for him to sleep on post. Where water
was found to be polluted, the troops, no matter how thirsty, were under
no circumstances permitted to use it until it had been filtered and
sterilized. It is a curious fact that the chlorine used in gas-shell to
kill Germans was used by the Water-Supply Service in minute quantities
to kill an equally dangerous and far more insidious enemy—the microbic
disease-carriers in the water. Special motor-trucks, equipped with
pumping, filtering, sterilizing, and testing apparatus, time after time
demonstrated that they were able to get into action and deliver pure
water from a polluted supply _within thirty minutes_ after their arrival.
In many cases the position of the troops and the nature of the terrain
made it possible to deliver water only by hauling. This was done by means
of trains of motorized water-tanks and by special tank-cars operating
over the narrow-gauge railway systems, the tank trucks and cars being
emptied into reservoirs built in strategic positions near the front. A
common and quickly built reservoir consisted of a hole in the ground,
a waterproof canvas lining, and a camouflaged cover. The lives of the
tank-train truck-drivers were hard and exciting, for though the roads
over which they had to pass in approaching the front were nearly always
subjected to heavy shell-fire, there could be no let-up in supplying
water for the troops on the firing-line. Most of the activities of the
Water-Supply troops were between the locations of the light artillery and
the heavy artillery, the men consequently working almost continuously
within the areas under enemy bombardment. On one occasion, during the
open warfare incident to the St. Mihiel offensive, the driver of a
water-truck ventured so close to a German machine-gun nest that when he
came back his tank was found to be better adapted for road-sprinkling
than for water-transportation purposes.
It is scarcely necessary to remark that enormous quantities of material
were required for the work of the Water-Supply Service, 60 miles of
pipe and 300 gas-driven pumps being used during the St. Mihiel and
Argonne-Meuse operations alone. As there were not enough Water-Supply
troops—the 26th Engineers—for the needs of the army, it was found
necessary to supplement their numbers with other Engineer units,
motor-truck companies, and pioneer infantry, the Water-Supply Service of
the First Army reaching a maximum of 3,500 officers and men.
One does not usually associate intelligence work with water-supply, yet
the American Water-Supply Service had an intelligence section which was
as efficient as that of any branch of the army. Information regarding
the water-supply in the territory behind the enemy lines was gathered
from all available sources, the _Wasserversorgung_ maps captured from
the Germans affording much valuable data, and the information thus
obtained was published at frequent intervals, together with maps. The
production of these water-maps finally became so highly developed that
it was possible for the intelligence section of the Water-Supply Service
to place full information at the disposal of the divisional intelligence
officers within twenty-four hours after it had been received. So rapid
was the American advance in certain sectors that scores of Boche
pumping-plants were captured while still in operation, and turned to the
task of supplying the thirsty Yanks. I might add that German prisoners,
particularly of the corresponding enemy service, frequently were as
successfully pumped for information as the wells sunk by the enemy were
pumped for water.
* * * * *
One of the most picturesque and interesting developments of the war—and,
because of the secrecy which surrounded it, one of the least known—is the
work of the flash and sound ranging section of the Engineer Corps. For
the benefit of the uninitiated—and most people are uninitiated, so far
as this phase of warfare is concerned—I might explain that flash-ranging
means the location of an enemy gun or battery by the detection of the
flash, and sound-ranging by the location of the sound. Flash-reading, as
it is called, is carried on by means of two or more observers provided
with powerful telescopes, who are stationed at known distances apart. By
“spotting” the flashes of an enemy battery and reporting them, together
with the exact direction at which they occur, and by using these readings
as a basis, a simple calculation in triangulation will give the location
of the gun. So highly has this flash-ranging been developed that a gun
can now be located within five yards, when the “core” of the flash can
be seen. In principle the process is extremely simple, but in practice
it is complicated by the fact that the observers may not train their
telescopes on the same flash, in which case the gun position calculated
at headquarters from their telephoned reports will be in error. This
difficulty is met, however, by providing each observer with an outpost
switch-set, by means of which he can flash a miniature light at the
headquarters station at the instant he makes an observation, just as
a light glows on a hotel telephone switchboard when a guest up-stairs
rings for ice-water. When several of the observers flash their light
simultaneously, it is assumed that they all probably caught the same
flash, and their observations are then plotted. In other words, the line
of sight of each observer is prolonged on a map until they intersect, the
point of intersection corresponding with the location of the German gun.
Flash-ranging was also found to be of great value in checking the ranges
of our own guns. If we were firing at a hidden target, a shell was timed
so that it would burst when at the top of its trajectory. Observers would
“spot” this burst, and if it was reported as being at the spot where
calculations showed that it should occur, the gunners knew that they had
the correct range.
Sound-ranging was carried on along much the same lines as flash-ranging,
except that the readings were made by instruments instead of by
observers. Large guns may be camouflaged so that their detection, either
by aerial observation or by the flash of the gun when fired, is extremely
difficult, but there is no known way to conceal the location of the gun
from sound-ranging instruments, suitably placed and properly operated.
This method became so highly developed that it was reported that during
the latter months of the war over 80 per cent of the work of locating gun
positions on the British Front was done by sound-ranging. The instruments
used for this work are of a highly technical nature and for their
successful operation require a skilled personnel. Recording instruments,
so delicate that their use heretofore had not been dreamed of outside of
experimental laboratories and then only in the hands of men carefully
trained in their operation, were set up on the firing-line and operated
successfully under battle conditions, even when the air was quivering
from heavy bombardments and the earth was shaking from the deluge of
steel. The sound-receivers, or detecting instruments, are located well
to the front, whereas the recording instruments are several miles in
the rear. A sound disturbance due to the firing of a gun somewhere
behind the enemy lines is transmitted through several miles of wire to
the recording instrument in the rear, and the sound records received
almost simultaneously from several detecting instruments are traced on
a sensitized ribbon, or tape of photographic paper, or on a ribbon of
smoked paper, depending on the type of instrument used. The intervals of
time elapsing between the arrival of the various sound disturbances is
used as a basis for determining the origin of sound which produced the
records. By this means over 100 new German gun positions were located
in a single day on the British Front. In fact, before the assault on
Messines Ridge the British sound-rangers had located practically every
German battery, so that the British gunners had their exact range when
the attack was launched. When the Armistice put an end to hostilities
there were in operation along the American Front some twelve complete
American sound-ranging sections, each covering a front of approximately
five miles.
A sound-ranging section on an active sector of the American front usually
consisted of four officers and from eighty to a hundred men, one-half of
whom were specially trained in the care of instruments, observation work,
and mathematical computations. On a stable sector the personnel of the
section could, of course, be considerably reduced.
The principles, methods, and instruments employed by the sound-ranging
section of the Engineers for locating active enemy batteries or for
ranging the friendly artillery on any objective whose map-location was
known were of an extremely technical nature and not easy of comprehension
by a lay mind. So for the information of those readers who are
technically inclined I have asked the Engineer officer who was in charge
of sound-ranging in the A. E. F. to explain in the simplest possible
language how the work was done. Here is his explanation. Make the most of
it.
The principle employed by the sound-ranging section of the Engineers for
locating active enemy batteries or for ranging the friendly artillery
on any objective whose map co-ordinates are known is the following:
The time of arrival of the sound from an enemy gun (or from the burst
of the shells from the friendly artillery) at three surveyed stations
inside the friendly lines determines the position of the source of the
sound if simple corrections are applied for the temperature of the air
and the direction and velocity of the wind. For example, if the three
surveyed stations are on an arc of a circle and the sound of the
enemy gun arrives at all three stations at the same time, then the gun
must be at the centre of the circle. If the sound arrives first at the
westernmost station and last at the easternmost, then the gun must lie to
the westward of the centre. If the sound arrives earliest at the middle
station and later at the flank stations, then the gun must lie between
the centre of the circle and the stations. In practice six stations are
used to insure greater accuracy, and graphical methods of computation are
employed to shorten the time of calculation. Accuracies of fifty yards
are regarded as average, and from one to two minutes for calculation are
usually needed.