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483

 

 

ENGINEERING FEATURES
OF
SEA COAST FORTIFICATIONS

ASN aia

GLENN A. BARCROFT
side
THESIS
 
Thesis

Wor Desree of C. E.

SKE EEKES

Pniineerini features
of tne

Construction of iwiodern Cea Coast Fortifications

KKK EK EK EK

by

Glenn A. Bargroft

RRR EE

Michisan 3

»
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— —

ut
c
ro

 
Engineering Features
of the

Construction of Modern Sea Coast Fortifications.

The emplacements of modern forts are located at stratlegic points in
the most commanding positions. Their exact location is also affected by
the ease with which construction can be carried on and by the facility
with which their position can be hidden from view. If not inconsistent
with the before mentioned requirements their location should be such that
the fort and vicinity may be a desirable place for the. permanent residence
of officers and men. Mottar batteries are of course located behind nat-
ural embankment where horizontal fire can not reach them.

For. protecting guns the Grusen Turret of specially chilled steel of
great thickness and weight has been extensively used in Europe.- Exper-
ience has proved it to be inferior to the fort with disappearing suns
which are. protected by embankment and reinforced concrete walls except
for a fraction of a minute at the time of firing. The latest and enora-
ously expensive Grusen Turrets have been easily battered down by the
heavy artillery used during the present Furopean war. The United States
forts with disappearing guns while much cheaper to construct are greatly
superior to the Grusen Turret fort in this respect; with modern smokeless
powder they are hidden from view of the enemy except at the time of fir-
ing,while the turret is always above its surroundings,a visible target
' for the enemy's guns.

Disappearing guns are mounted over wells in which is the recoil cylinder
and other mechanism. In front of these wells are parapet or protection
walls of concrete ani from fifteen to twenty feet in thickness. The walls
are behind thirty feet or more of sand or clay,sand being preferable as
it will absorb without harm a shell designed to explode by concussion.

Many times ,the battery,or at least the front of it is sunk to below the
natural ground surface thus not only affording protection from hostile fire
but effectually hiding the location of the battery. Behind this same pro-
tection of embankment and walls ani also protected above by from eight to
ten feet of reinforced concrete are the shell rooms, powder magazines, plot-
ting room,officers room,power room,store rooms etc.

Plate No. 1 sketches a typical arrangement of the lower rooms of a batter:
for a large rifle. At the rear and above the rooms shown may be an officer's

93843
 

m iy
Pe ee eee

room and above it yet a battery commander's station affording. protection
to a man below the shoulders and giving the officer a commanding view of
the surrounjings. The shell rooms and powder magazines are connec¥ed with
each other and with the loading platform around the gun well by passage
ways or corridors. Means of communication between the gun platform and
the various rooms and between the rooms themselves is provided by speak-
ing tubes. Openings for electric wiring,water pipe,ventilation etc.must
be provided. ‘A tunnel from the plotting room to the gun platform is nec-
essary for the installation. of the mechanical range indicator. An over-
head trolley system with chain shot hoists provides a means for the rapid
transference of shells. All of the rooms of the battery must be water
proof. ‘An emergency water reservoir andj a defense wall on the land side
of the fort are usually provided.

‘An important part of a modern sea coast fort are the mining structures
ani equipment. In the mining casemate the submarine cables from the mine
fields terminate. The contact of a ship with a mine is made known at the
mining casemate by an electric current thru the cable andj the mine can be
explodei from the casemate. A large store house for mines is essential;
also a seperate loadins room for filling the mine cases. The reels of
surplus submarine cable should be stored in cable tanks which are housed
in and it is necessary to provide a suitable dock for loading and unload-
ing mines on the mine tender andj a boat house in which to keep the.launches
and small boats. All of these buildings should be fire proof and of a very
substantial construction. While rather expensive at some locations re-
inforced concrete is best adapted to this work altho frame buildings cov-
ered with asbestos siding and roofing are sometimes used for the less im-
portant buildings.

The range of a ship is quickly and accurately determined by the modern
range finding system. Locations for the primary range finding stations
are selected so that the base line between, measures from one to two miles
ani so that the range finding instruments have an unobstructed view of the
water approaches. Secondary ani tertiary stations are also located by

- triangulation where needed and the data made available for use on the plot-

ting boards of the various batteries.

The working of the system is as follows: The lookout reports to the
battle commander the appearance of ships. The battle commander notifies
the fire commanders of the approach of a hostile fleet. The first ship is
picked up by the range finding stations as soon as any part of it is above
the horizon. The distance is of course a function of the elevation of

the stations. The vertical and horizontal angles to the ship from each

end of the base line are telephoned to the plotting rooms of the batteries.
On the plotting boards which are semi-circular and graduated into hundredths
of degrees the ansles from the range finding stations are set off on the
board by straight ejises from their respective plotted positions. The inter-
section of the straisht edges is the position of the ship at the time of
observation. The location must be corrected for several things before

being given to the gunner. Mechanical deviges compute changes of data

due to; 1st,wini,2ni,chnange of ship's position between time of observation
and firing of gun,3rd,enersy of powder for the temperature,4th,density of
the air,5th,tide elevation. Readings af the stations taken every fifteen
seconds determine the speed of the ship. Computations in the plotting

room are maje fifteen or twenty seconds ahead of the time of the firing

so the gunner sets his azimuth and elevation ani shoots at the proper in-
stant.

In case of accident to the triangulation range finding system a sinsle
Lewis alt-azimuth instrument can determine less accurately the position
of a ship. Knowing its elevation above sea level tne vertical ansle
gives a right angle triangle of one known side and with one angle read-
able. Because of the flatness of the triangle the jata is not so accurate
as<-that given by the preceding method. The instrument is arranged to read
directly the range of the ship without computation and is therefore sin-
pler to use tnan the plotting boari system. At present both systems are
combinei.

The mechanical range iniicators installed in the latest United States
forts are set from the plotting room where the jata is recieved and work-
ed out, ani read at the gun pit by the gunner himself; a system which does
away with the necessity of hearings verbal orders and the corresponding
liability of error.

Flectrical energy is required for lighting the batteries, firing the
guns and mines,operating the search lights etc. Besides the general pow-
er plant for the fort and barracks,each battery,search light andj the min-
ing casemate must have an emergency outfit. These usually are gasoline |
motor generator sets of from twenty-five to fifty kilowatt capacity each
located in rooms constructed for the purpose.

The heaviest guns are desisned to destroy hostile vessels before they
have any chance at all to reach the land batteries with their ordnance.
This ought to be possible with guns of the same weight and muzzle veloc-
ity as those of the enemy,due to the greater accuracy of range finding
from shore ani to the greater stability of land ordnance. Small calibre
cannon are also needed to take care of small craft that might slip by the
big guns ani to cover the mie fields. 7

The fourteen inch rifles now used by the United States in the import-
ant forts throw a projectile weighing 1€60 pounds with a muzzle velocity
of 2250 feet per second making their range effective at about eleven ani
a half miles. This is a disappearing gun which rises above the parapet
wall,fires ani recoils to the loading platform level out of danger and
in position to be gjuickly reloaded. The barrel abome of this gun weighs
nearly seventy tons anj is forty-eizht feet long.

The sixteen inch rifle,the largest in the world has also been perfect-
ed by the Unitei States. It is nearly fifty feet long,weighs one hund-
red ani thirty tons and fires a twenty-four hunired pound projectile. two
thousand three hunired and six feet per second with a charge of six hun-
dred ani forty pounds of powder. One is now being mounted at the Pacific
entrance to the Panama Canal and another is in process of manufacture.
The twelve inch mortars having approximately the. same range as the four-
teen inch rifles are just as accurate and probably more effective as the
shells drop on the most vulnerable part of the ship, the deck. They are
usually mounted two in a pit ani from four to sixteen in a battery.

The. preliminary engineering work for fortification construction is
just as important or perhaps nore important than the engineering work on
actual construction. It bears the same relation to the eucceeding engin-
eering work that the founjation bears to the superstructure. Experience
shows that neatness ani system are absolutely essential in the keeping
of engineering jJata. During the construction of a fort many plans will
be made; preliminary, seneral,jietailed and revised. One of the best sys-
tems of keeping plans is to fasten them between light wooden clamps at
one end and hans them in racks where they will be convenient ani acces-
ible. They should be numbered and indexed. The number,ytitle ani date
of each plan should be a part of the index. Charts of progress of the
work are convenient for reference ani recori ani may form a part of in-
dexei plans. There is a chance along this line for the engineer to show
much originality and his value as an engineer depends to a large extent
on his ability to show costs ani juantities in a way most suitable to
determine best methods of economic construction. Field note books should
always be carefully kept,iniexed,and when full filed away as permanent
references. Unforseen problems arising during construction can often be
solvei from data in a carefully kept field book. Fach bit of information
should have the date when obtained,the name of the party performing the
work and other information which may possibly be useful such as degree
of accuracy striven for,local conditions affecting the jata etc.

As soon as the general location of tne fort has been decided upon,
an accurate topographical survey of the site should be made. The differ-
ent emplacements are usually located accorijing to the contours on the topo-
graphical map and their geodetic positions determined afterwards. If care-
fully made a topographical map showing two and one half or five foot con-
tours will give information sufficiently close that much field engineer-
ing work in cross eectioning will be saved.

While the closest setting on the azimuth circle of an ordnance piece
is only to one one hundredth of a jesree,yet the triangulation system
should be developed with a high degree of accuracy so that no appreciable
error or combination of errors can creep in due to poor triangulation.
Only experienced men should be employed and their independent determinat-
ions made to check closely. .

In determining the length of base line,tape measurements should.if
possible be taken with all points of support in a straight line in both
grade ani alignment. Invar steel tapes should be stanjiardized and one
used only as a comparator. Tested spring balances should be used in ap-
plying tension to the tapes. A record of the temperatures gives data
for expansion corrections. Leai or zinc strips may be used at the stat-
ions for marking and lines made on them by a knife blade. Two pulls
should be made for each measurement ani the measurements made forward and
backward with different tapes. For the second measurement the front andj
rear chainnen should change places to eliminate personal ejuations.
Levels on the stations sive data for reduction to sea level.
 

-.' With care but without excessive work the triangles may be made to
close with an average error of but three or four seconds and a maximum
error of six or eight seconds. At Fort Sherman,Canal Zone the author
used an ordinary Keuffel ani Esser engineer's transit in determining the
geodetic positions of the several batteries and had a maximum error in
closing triangles of five seconds.

It is readily seen that a gun or a range finding station with an un-
stable base is not only useless for the purpose designed but actually a
menace. If the gun base settles unevenly (ani it usually does) the az-
imuth circle will not be level nor properly oriented and at.a time of
emergency this may cause the downfall of the fort. At a distance of
twelve miles one one hundredth of a jesree error in gun pointing amounts
to eleven feet. This is not a great amount but no error of any magnitude
that can possibly be eliminated is allowable in firing,for a few apparent-.
lyinsidnificant mistakes may combine to make a serious error as noted
in consideringaccuracy of triangulation work. Wnen it is considered that
the firing of a large rifle generates some 25,000, 000 horse power the
necessity for a perfect founiation is apparent. The stability of strata
should be carefully verified before any construction work is begun and
care must be taken that boulders are not mistaken.for rock strata. Much
information can be gained from wash borings but diamond drill borings are
more certain and.can be continued into rock until it is certain that bed
rock has been found.

_ At Fort Sherman we located a six inch rifle battery with the mining
casemate in a tidal swamp of quick sani,finger coral ani ocean ooze. At
a depth of approximately fifteen feet was an unreliable stratum of coral
rock ani ten or fifteen feet deeper yet a bed of coral as shown by wash
borings. A test pile was driven and found refusal at elevation—30 feet.
On this was loadei steel rails,a few tons at a time and readings taken
to determine settlement. As no appreciable settlement was detected with
fifteen and then twenty tons the load was increased to thirty tons when
it was founi necessary to greatly increase the lateral support of the
-pile to keep it from bending ani spoiling the test. With a load of thirty-
five tons,failure occured not due to faulty bearing but to the fact that
the pile had settled away from the vertical and therefore snapped where
a platform bolt passed thru it. Seven hundred fir’piles were then driven
to refusal so that the maximum load for each did not exceed twenty tons.
At the gun wells extra piles were battered out to give also lateral sup-
port. Care was taken to see that they were driven to refusal and the pile
hammer stopped before brooming took place. Cut off was given on the
piles at—2' and the concrete footing of the battery carried down a foot
below cut off. After the battery was complete no settlement was ever
detected,but a lateral movement of the parapet wall in front of the min-
ing casemate was visible at the planes of weakness. This movement was
unjoubteily the result of pumping sand backfill which caused hydraulic
pressure adainst the front of the wall to a depth of over twenty feet.

One heavy battery of another fort in the Canal Zone with which the
writer had no connection was built on an apparently stable coral found-
ation without piling. This battery designei for two fourteen inch rifles
contained about twenty thousand cu. yds. of concrete. Within less than
a year after completion settlewent occured to such an extent that the wat-
er in the gutters ran the wrong way,that is to say away from the sumps. _
In fact levels on the gun platform showed a maximum sinking of eight in-
ches and,worst of all,a tilting of the gun wells ani platform. It is
possible that in the future,settlement will cease so that use may be
made of the battery but when the guns are mounted the recoil of the fir-
ing may. augment the trouble.

After having this experience ani also a settlement of the rooms on
one flank of a Fort Sherman battery the officer in charge proposed the
following method of providing a foundation for a six hunired anj fifty
cu. yi. range finding station on the worst flank of the Fort Sherman
swamp battery. He ordered old seventy 1b. steel rails to be laid trans-
versely with the wall,one end resting on the ye footing of a
previously constructed retaining wall supportedi”’part of the pile foundat-
ion for the battery as before described. The other end of the rails was
to be laii on old pile butts thrown on the swamp muck in the manner of
a corduroy road. The vigorous protests of the Superintenjent of Con-
struction and of the author as S3eneral Foreman haji no effect on his de-
cision and the foundation was prepared accorijing to his instructions.
Before the concrete placing was started anotherman was appointed officer
in charge ani by taking him to the site and thrusting a section of water
pipe twelve or more feet into the slime I convinced him that a pile founi-
ation was necessary ani he save authority for the change.

In the pile foundations mentioned the piles were not subject either

——_
 

to rot or to teredo action because they were cut off below low tide and
because they were not exposed anywhere to the action of sea water except
thru the soil where the teredo can not work. In the case of the boat house
the piles,driven in from five to ten feet of water had to be protected

from the teredo and,cut:off +5 feet had to be protected from weathering.
Wood forms were first tried for encasing in reinforced concrete but later
old worn out eighteen inch dredge pipe was found very convenient and in-
expensive for forms. These when driven over the pile four feet into the
sand were washed out with a water jet. The reinforcing for the concrete
around the piles was heavy woven wire mesh.

For a reinforced concrete jock foundation the opposite extreme from
the range finding station was taken. The design called for twenty-two
reinforced concrete columns four feet in diameter sunk to bed rock under
a dock one hunired and eighty-four feet by 40 feet with no superstructure.
Steel cylinders were driven to an average depth of 55 feet below sea lev-
el,passing thru several strata of coral,soft rock etc. and. penetrating —
solid rock eighteen inches to two feet. Because of logs and other debris
much time was consumed in driving,it being necessary several times to put
the steam hammer on again ani drive after excavation had been almost com-
pleted to bed rock,jue t@ leakage under the cutting edge of the cylinder.
Of course a. piece of-scrap iron or a tough stick of wood carried down with
the cylinder andi hammered against bed rock made a weak place for the en-
trance of water. The cost of this dock of approximately one thousand cu.
yds. of concrete was $40,000. Over most of the site as shown by diamond
drill borings and by cylinder excavation,after passing thru the loose up-

.per strata a thick layer of reasonably clean compact sani was found be-
tween which and bed rock no treacherous material was interlaid. The crit-
icism of the author is this; it was unnecessary to go deeper than the

sand as it furnished a foundation sufficient for any practicable load.

There is no possihle chance of the sand washirg away as the ocean itself
is not so deep for several miles. The saving by this method would have
been a very significant per cent of what the entire dock cost.

Local conditions may in a general way determine the location of con-
struction plants, yet the unit costs will depend on the detailed working —
out of the track and plant location by the superintendent of construction
and the field engineer. It is absolutely essential that these men work
in conjunction and with complete harmony. Most of the constructiom track
can be so located that by slight realignment and ajustment it will become
part of the permanent track layout.

There is no standard concrete handling plant that will suit every
job. The ease with which ejuipment and materials can be obtained and
the natural feature of the site may limit to a few designs or even deter-
mine exactly the most suitable plant. An elevating tower of sufficient
height to chute the wet concrete to every part of the battery is used in
most cases. This can be erected by an ordinary carpenter in a short time
from rough lunber,or it may be ome:of the patent knock down steel elevat-
ors put out by several companies in tne United States. The accompaning
plate shows one of the form@rthat was used at Fort Sherman,Canal Zone.
This tower is wide enough to include two runways for buckets of one half
yard capacity each. The buckets shown were reconstructed from the Bod-
ies of Decauville push cars. They are connected by a five-eights ‘inch
steel cable so that when one is at the top of the elevator dumping, the
other is under the mixer spout recieving its load. A cable runs from each
bucket to a two drum hoist engine. A tower with an extreme height of 85
feet will chute wet concrete to every vart of a large gun battery. Us-
ually a half yari mixer will mix enough concrete to fill the forms behind
as many carpenters as can conveniently be used on such a job. Various
methods of charging the mixer are used. Fast work has been accomplished
by charging with wheel barrows. In the case mentioned a hopper construct
ed above the mixer heli rock on one side ani gand on the other ani a lab-
orer chargei the mixer by opening ani closing gates which emptied into
a measuring box just above the mixer, There was room below the rock and
sani hoppers for two hunired barrels of cement where it was most conven-
ient for dumping into the batch. Three men worked here; one controled the
water and charged the measuring hopper with sand and rock,another dumped
the cement into the batch and the third charged and discharged the mixer.
It was found that an experienced man'could better regulate the amount of
water rejuirei in the mixture by observation (the mixer being below him
he could always see into it) than by a measuring devise. Ten inch riveted
steel pipe was first used to carry the wet concrete from the tower but
because of unusually large rock ani the excessive friction in the pipe
much trouble was experienced in keeping the concrete flowing. & simple
wooden trough fourteen inches and eighteen inches wide and twelve inches
deep lined with sheet iron and braced with U brackets of one ani one
half by three eights inches iron every three feet proved very satisfactory.
This chute will enable concrete to flow at a flatter angle than any other
chute the author has ever seen and if the movement is augmented by a man

with a shovel an astonishingly flat angle may be used. For reaching the

distant parts of the battery a guyed 30 foot mast was used to sppport the
lowest section of chute. As shown on the plan the booms were built of 6

x €'s because this size was available,a deeper dimension would have been

more suitable. i

A stiff legged derrick rigged with a clam shell bucket and operated
by a two drum hoist engine filled the hopper with rock and sand as fast
as they were needed. The adsregates were brought in by trains of dump
cars and dumped within reach of the clam shell. A maximum of two hund-
red and twentfive cubit yards of concrete has been placed by this out-
fit in a nine hour working day which is as fast as a one half yard mix-
er can thoroughly mix it and faster then the carpenters can ordinarily
get forms ready to pour into.

In some cases and especially with mortar batteries the storage piles
of aggregates and the mixer can be put high enough so that a gravity sys-
tem of distribution can be used without an elevating tower. This is an
economical system even though the track to the plant is so steep as to
rejuire a hoist engine and cable to pull loaded cars up. Also if necess-
ary the slope of the distributing chutes may be made so flat that a man
with a shovel is reyjuired to assist the flow.

A shorter distributing tower might be mounted on a flat car so that
it could be moved along the job as the forms are prepared. This of course
would necessitate other means of charging the mixer than a derrick clam
shell and in many cases its use would be out of the juestion because of
the room required. Again locomotive cranes of suitable type might be used
to.place concrete and deliver aggregates to good advantage.

It has. previously been noted that it is necessary to have the rooms
of the batteries waterproof. This is especially true of powder magazines
and shell rooms. A drain with open joints is laid just outside the footing
of the wall all the way around the battery. Where a battery is located
in seepy or continually wet ground an air space two feet wide is often
built in the wall around the entire battery and what moisture comes thru
the outside wall is carried away by a gutter and drains. In otherplaces
it may be unnecessary to build the air space if the concrete is made as
nearly waterproof as possible by using a liberal amount of cement and_pro-
 
 

portioning the aggregates carefully. For reservoirs anj cable tanks this
concrete is treated with the following waterproof method: Heat four gal-
lons of water to a temperature of from 150 to 175 degrees F. then add 2
pounds concentrated lye and 10 pounds alum. Stir constantly until thor-
oughly mixed and disolved. To one pint of the above stock add 10 pounds
cement ani thin with water until it will spread readily. Apply with white
wash brush to surface while concrete is as green as possible--i.e. first
coat should be applied within 48 hours after concrete is placei. Make

a total of three applications of the wash at intervals of not less than

24 hours.

A very troublesome problem is sometimes encountered in the seepage
of water thru the floors of the rooms. This usually requires that part
of the floor be dug up and a combination of under floor drains and dense
concrete usei.

Roofs are waterproofed by covering with sheet copper and then several
alternate layers of tar compounj and felt. The whole is anchored down
by several inches of porous concrete.

Some of the excavations and backfill around the batteries must be done
by hand. Usually the most satisfactory way is to put the work on a unit
cost basis payin3 the men a certain amount per car or yard of material
moved. One foreman at Fort Shernan however obtained good results in hand-
ling sand backfill by working his men on the hourly basis. Part of the
Sang he gave shovels and lined them up along the sani to be moved,the rest
ani by far the greater number were formed in a circle,each man with a wheel
barrow. This circle when started to rotatimp never stopped during work-
ing hours. As the barrows passed the shovelers they were gradually filled
ani the faster the men walked the less load they had to push. The barrows
were dumped from both sides of the trestle so that the line was not halted
anywhere. New men who were unfit for the work when put in the circle and
forced to keep the pace soon playei out and lost their jobs. Of course
the pace was regulated by varying the ratio of shovelers to wheel barrow
mens This same system under different conjitions and with different men
might not be a suecess but a good foreman will introduce some efficiency
system whatever the conditions.

Steam shovel excavation is so common ani the methods of haniling the
spoil sowell known that space is not considerei to warrant a detailed
discussion here. Steam shovel work is nearly always required in excavat-
ing for the batteries,making railway cuts and obtaining spoil for fills.

In many cases the steam shovel furnishes the best available method of fill-
ing around the batteries.

Unjer favorable conditions the suction dreise is the most economical
way of handling large quantities of backfill. It may be found necessary
to deeped and enlarge the harbor of the fort and unless the material is
solid rock a suction dreige will excavate it and pump it several thousand
feet to a maximum elevation of forty or forty-five feet for 8 or:10 cents
a cubic yard. Above an elevation of forty-five or fifty feet the wear
on the. pump,troubles with the pipe line,decreased efficiency etc.rapidly
increase the unit cost. For a battery rejuiring several thousand cubi¢
yaris of backfill a dreige with a 20 inch suction and about 700 boiler
horse power will do the work easily.

Probably the most trouble in hydraulic backfilling is to héld ani sep-
erate the sand anj water after delivery. Anji on this work the difference —
between experienced ani unexperienced carpenter foremen or backfill fore-
men as they might be called is the difference between almost certain fail-
ure ani probable success. It is comparatively easy to hold backfill from
a dredge where a large area is to be covered ani a basin of considerable
extent is to be used but orly first class men who have studied the action
of hydraulic force operating thru loose sand on a board bulkhead can hope
to take care of such treacherous material in a small basin built up to
a considerable height.

At Fort Sherman one: carpenter foreman:with .a-gang of 25-or. 30. Jam-
aican negro carpenters with only board bulkheads brought sand backfill
from elevation +5 feet up to elevation +57 when the area at the top of the
mass was scarcely 100 feet sguare. . He had but one serious breakdown dur-
ing the filling while another carpenter on the opposite side of the same
battery and with slightly better conditions had continual trouble. When
at elevation +50 a small break started under the latter's upper fence
and ending by washing out an enormous quantity of backfill and all of the
dozen bulkheads below. So suddenly did this occur that several of the
negroes working near barely escaped from the treacherous mess with their
lives. A repair job like this is very expensive because of the special
manipulation and frejuent halts of the dredge output in filling again.
The chagrined foreman decided that eternal vigilance andj an almost super-
natural sense of solidity are reguired on such work. |
 

 

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By having the. pipe line from the dredge fitted with wyes,branches
can be run to several basins at the same time,giving the carpenters a chance
to construct bulkheads and bank them where necessary without working in
the water.

Two successful systems of carrying away the water have been used.
In one, wooden,water tight flumes running thru the fences at the edge of
the fill and low ehough to rest in the sand are provided. The amount of
water taken by each is regulated by the height to which the entrance at
the top is boarded up. By using narrow strips the flow can be regulated
so that undesirable currents along the bulkheads can be controlled and
only the water free of sand allowed to escape. The other method is to
have the outlets near the center of the basin,being rectangular box flumes
located on the origiaal ground and built vertically as the basin fills.
This system gives better control of the water currents but is likely to
leave the lighter part of the fill at the bulkheads where it should be
heavy ani solid. The accompanying sketch shows the details of building
and bracing the bulkheads.

Development of efficiency in fortification construction depends not
only on obtaining good men but on keeping the same good men. There are
none who are supreme in the art of construction and every new man on fort-
ification work finds unfamiliar problems even tho he be ever so efficient
along other lines. While some of the army engineering corps seem to be
placed on this work for the purpose of rounding out their education and
developing them into engineers,most of the construction work is accomp-
lished by civilians with the object of getting results. This is. not in-
tended to mean that the engineering corps has not capable efficient men
in it. Fortifications should certainly be designed by and the construct-
ion thereof supervised by the army engineering corps. Nevertheless the
government surely would get better work and at less cost by transferring
these civilians including not only engineers but all classes of skilled
labor of proven worth to the next work on fortifications instead of
starting a new organization for each job with all of the attendant adjust-
ments and costly mistakes.

Special tact and ability to handle men are necessary for those in
authority on government work. In private practice an employe may be dis-
charged simply because his superior does not like the man and though his
work be good,bad or indifferent he has small chance of retaliation.
But on government work there must be a clear case of incompetency or in-
subordination for the removal of an euploye. In many cases the dis-
charged man can convince those atove his immediate superior that in-
justice has been done. At any rate he can and will throw muck so that
only superintendents and generai forenen of charity ani fitness to con-
mand make a success of government work.
MICHIGAN STATE UNIVERSITY LIBRARIES

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