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MILITARY ENGINEERING AND
CONSTRUCTION IN
WORLD WAR II

Thesis for the Degree of B. S.
MICHIGAN STATE COLLEGE

Kenneth A. Clapp
I947

 

 

 

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'Military'nngineering and Construction in World War II

A Thesis Submitted to
The Faculty of
MICHIGAN STATE COLLEGE
of

AGRICULTURE AND.£PPLIED SCIENCE

BY

Kenneth A. Clgpp

Candidate for the Degree of

Bachelor of Science

December 1947

THESIS

"The Engineers -- those un-
sung heroes, have mastered
the trickiest instruments
of modern warfare. "

WIGHT D. EISENHOWER

‘u - .
l)!"r’\.2'_

€V~§¥}I)€J
‘3g/

CONTENTS
Introduction

Part 1
European Theater

Great Britain
Airfields and Roads
Other Structures
0n the Continent
Harbors
Roads
Boat Basins
Piers
Bridges
Airfields

Part 2
Pacific Theater

Unloading Techniques
Pontoons

Bridges

Harbors

Roads

Airfields

Other Structures

Part 3
Zone of the Interior

Construction in the United States

Conclusion

51
31
53
36
38
39
43

46

48

Introduction

In September, 1945, the people of the United States saw a magnifi-
cent war effort consummated in complete victory for the Allied forces.
It was a victory wrought by many diverse functionary groups, both civ-
ilian and.military.

If one had been in a soldier town at the time of the Japanese sur-
render, he would have heard.many good natured arguments concerned with
the relative merit of one branch of service over another.

”If I hadn't gone in and taken the ground", said the infantryman,
”the war wouldn't be over now".

"Without my support", offered the airman, "the infantry wouldn't
have taken any ground”.

"And", argued the sailor, "I transported both men and planes to
battle areas all over the world".

The veracity of these contentions is indisputable. However, the
above accomplishments would have been virtually impossible without the
bridges, roads, airfields, docks, and innumerable other installations
and services, conceived and provided by the engineers and construction
men, who contributed an impressive sum to the total Job of winning a
war.

The conditions under which the overseas projects of the engineers
had to be completed were anything but normal in a majority of cases.
Between the lines of the following description must be read much which
adds to the credit due these men who paved the way to victory.

When raw materials were unavailable from any other source, ade-
quate local substitutes had to be chosen. When shortages of basic equip-

ment hampered progress, improvisations had to serve. When replacement

parts were nonexistent, they had to be manufactured or procured through
means ethical or otherwise.

The following report is intended to present an overall picture of
the activities of the engineering and construction groups of the United

States during the recent conflict.

Part 1
European Theater
The engineering units which operated in the European Theater en-
gaged in the construction of every conceivable type of installation. It
is not the writer's intention to discuss in detail every one of the pro-
Jects undertaken, but to present a comprehensive report on the different
types of problems encountered and the usual.methods used in the solution

of these problems.

Section 1
Great Britain
Before the invasion of the continent by the Allied forces, our en-

gineering units stationed in Great Britain had been at work for two years.
They built airfielde, resurfaced roads for increased military loads,
constructed artificial invasion harbors, and provided beach ramps, water-
proofing tanks, barracks, hospitals, and leave camps. In addition to,the
aforementioned, the engineers engaged in the setting up of emergency
housing and the repair of livable dwellings for the thousands of British

families left homeless by the blitz.

Airfields

Men of the Corps of Engineers started as early as 1942 to build air
bases in the British Isles. Since haste had been the prime factor in con-
struction, the condition of the runway subgrades was usually overlooked,
and little attention was given to drainage. These errors, plus the fact
that the concrete slabs were seldom of sufficient thickness to withstand
heavy bomber loads, resulted in a tedious program of repair. It was found
that the most frequent points of failure were the ends of the runways
where the heavily loaded ships congregated before takeoff, and the taxi-
ways where the planes used the same tracks incessantly because of the
narrowness of the concrete. Factors contributing to these failures, ex-
clusive of enormous loads, were poor subgrades, inadequate slab thick-
nesses, and defective concrete. As repair work progressed, it took on
the aspects of virtual reconstruction in some areas, and when patching;
was practicable, it was found that it interfered too greatly with need-
ed bombing sorties. As a result, the following program of maintenance was
agreed upon.

The runway to be worked on was closed to airplane traffic for a
few days, during which the entire area of concrete was resurfaced by
topping with asphalt mscadam, 3% inches thick at the ends and one inch
elsewhere. While this was being done, the perimeter tracks were covered

with entirely new 6-inch concrete slabs.
Roads

When existing roads were to be resurfaced, the work involved sev-
eral operations. The road was first gone over with a pavement breaker,

followed by a skimmer scoop to remove the broken concrete from the area

-5-

to be patched. Then one a unique, fast-moving paving plant. It consisted

of a water tank and a l4-cubic foot mixer mounted on a trailer and pulled

 

 

Pig. 1. Pavement breaker for use on roads and runways.

by a truck in which were loaded the canent and aggregate. This paving
plant was able to pour quickly and to move out of the way rapidly when

necessary.

 

Pig. 2. Unique portable paving plant.

Beach Ramps

 

For the purpose of facilitating the beach landing of vehicles too
heavy to move on the natural beach terrain without bogging down, the
Engineers developed the "chocolate bar". This was a precast slab of con-
crete with heavy scoring on either side. It measured 2x3 feet in plan,
and had a usual thickness of 10 inches. These slabs were laid on the
beaches and wired together to form a hard and relatively smooth surface
for the landing of vehicles. In some instances, rails were laid on the
bars for the accomodation of freight cars, but for the most part they
were used for highway vehicles only. The heavy scoring provided excel-
lent traction for the vehicle on top and served as a stabilizing fac-

tor on the beach underneath.
Waterproofing’Tanks

The vehicles that landed on the Nbrmandy beaches frequently did so
by breaching considerable expanses of shallow water. For this reason,
it was necessary to waterproof each of these vehicles. To test this water-
proofing, the Engineers provided two types of tanks. The first of these
was made by damming streams so that a depth of 5% feet of water was a-
vailable for the test. In places where streams were not present, tanks of

concrete were erected with a ramp at either end for entrance and exit.
Hospitals and Leave Camps

These buildings were, for the most part, Nissan huts with refine-
ments. These huts were enclosed with brick ends, lined with boards of in-
sulation, and set on concrete floors. A colony of such buildings served
as a leave camp. In constructing hospitals, considerable work had to be
done to provide interior partitioning, as well as enclosed or covered

-7-

corridors running from.building to building. Brick walls and corrugated
asbestos roofing served these functions. After all these extra-Nissan
improvements had been.made, it was difficult to realize that the basic

structure was a simple, 24-foot, corrugated steel arch building.

Section 2
On the Continent

When the Engineers moved to the mainland of Europe after the inva-
sion, it is doubtful that they realized the magnanimosity of the total
work that they were subsequently to perform. For they were destined to
invent, repair, construct, and reconstruct from the beaches to the heart
of Germany. But not only did they build. The writer has seen men of the
Combat Engineers lay down their construction tools, take up their weapons,
and assist the infantry in the repelling of an enemy counter-attack. An
account of the individual accomplishments of these men would require an
historical document of voluminous proportion. Let us now consider some of
the typical installations provided by the engineering units on the Euro-

pean continent.

Harbors

The first great task to be undertaken by our engineering units on
the continent was the repair of Europe's demolished harbors, vital to uhe
maintenance of an expeditionary force in urgent need of a steady flow of
supplies and equipment. Allied bombers and German demolition units had
wrought a tremendous amount of damage to these harbors. Sea walls were
wrecked; power sources were cut off; harbor entrances were choked with
sunken vessels; water supplies were in bad shape; loading spaces and
loading equipnent were useless. An extreme example of the foregoing was
Cherbourg on the coast of Normandy. Let us consider the repair of this
great port as typifying the conditions facing engineers of the Army and
Navy.

Before the actual construction could begin, it was necessary to rid
the harbor and the beach of considerable debris and rubble. The Navy sal-
vage crews moved the sunken craft and swept the harbor of mines, without
which service the port would have remained unusable. The Army Engineers
and men of the Transportation Corps expended.millions of man-hours in
clearing the beaches and docks of the debris that had been reinforced con-
crete buildings and steel port equipment.

It was decided to build over and around the wreckage, using its land-
ing spaces for improvised structures.

An undamaged recreation beach in the center of the harbor coast
provided a good landing space for amphibious craft. The Engineers paved
this beach with 160,000 square yards of 6-inch slabs in roads and turn-
around areas. In order for these roads to go inland, holes had to be cut
in the sea wall behind the beach. In order further to speed up the landing

of cargo, two platforms, 150 feet long and 40 feet wide were built on this

-10-

paved area. These consisted of earth fills dumped between two retaining

 

Fig. 3. Construction of loading platform.

walls and surmounted by reinforced concrete slabs. The amphibious craft
discharged their loads on these platforms while men sorted the cargo and
transferred it to waiting trucks.

where a portion of a retaining wall had not been damaged, 4200 feet
of timber wharf was built to serve barges carrying cargo in fran ships an-

chored in the harbor. The 42-foot deck section of the wharf extended 30

 

 

Fig. 4. Driving piles for wharf decking.

-11-

feet out from the face of the wall to reach deep water, and 12 feet in-

land to be adjacent to a railroad siding. This decking was supported by

wood pile beats and was tied to the shore by digging holes in the wall,

 

Fig. 5. Engineer's pile driver in action.

 

concreting piles in these holes, and securing the piles to the deck sec-

tions. The driving of these piles was done by a drop hammer travelling in

leads suspended from the boom of a crawler crane. Cargo was unloaded by

   

—..—-o.-..~. (an- --- . _‘

 

 

I; . ~....».'._._.‘.~ . ...............

.......

was ..........

Fig. 6. Stiff-legged cranes on wharf.

 

 

means of stiff-legged cranes set on 256-foot centers throughout the en-

tire length of the wharf.

The next project undertaken in the harbor was the providing of
wharf facilities for deep-draft vessels, principally IST's. This was
accanplished by repairing holes in a usable jetty and building sec-

tions of timber wharf to coincide with the hatches of the ships to be

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

:-

served. The huge holes in the jetty I l‘ ---------- fiié.§gg;-jl4 Hacking‘
5,, ”3“” 51 26.2
were patched by filling with earth if ”@109: ,—
Newsfonew 4‘75» ‘- ” IZEIZ'b/ tk
possible. when necessary, the holes facing, Jam 1 '2 17””
somfimes L / . - 72.
were closed by bridging than with tim- 3:353” L/
German
bar trestles. One such gap measured 400 “’35:?" 3-, p,-,e,,,,,;, ,pmd
In." J 4””. a'longifo’IhaI/y
feet in length, 70 feet in width, and r
-/5.0'
was 45 feet in depth. The wharf deck I —
construction was basically the same as I 55: 9

that for shallow-water craft described L u

C. .

 

 

‘-

above. A typical section is shown at ,Fig. 7. Typical section of
deep-water wharf.
the right.

The main source of power for the port of Cherbourg was a transmis-
sion line fraa Caen. This line was, naturally, cut by the retreating Ger-
mans. The city operated two standby stations, but one was destroyed by
Allied bombers. The remaining station was unable to cope with the heavy
emergency load, and one month after it was put into use, its generators
burned out. For a remedy, the city power lines were connected to the pow-
or plant of a Navy destroyer escort, and a captured German diesel-electric
systun was put into operation. The portable units were installed in the
water plant. These emergency measures served adequately until the line
fran Caen was subsequently restored.

later supply is essential to any port before it can operate ef-

ficiently. The Cherbourg plant, like most of those in France, depended

-15-

upon ozone for the treatment of its water. This was found to be inade-
quate because of the many breaks in the
lines and the emergency repairs thereof.
As a result of this, portable chlorinat-
ors were installed in the plant. The op-
eration of these units provided a resid-

ual of 0.4 ppm. in the distribution sys-

 

tam.
When it was discovered that all a-

vailable cold storage space had been

 

bambed out, the Engineers found three

tunnels extending into a nearby hillside. Fig. 8. Portion of Cher-
bourg's ozone water

By equipping these with double doors and treatment plant.

installing sane second-hand refrigeration machinery, many thousands of

cubic feet of cold room were made available.
Roads

In the building of roads in the European theater, it was found con-
venient to restrict the construction to two basic types, although.varia-
tions and combinations were used somewhat.

[here very little or no mud was encountered, roads of pierced steel
plank were constructed. As a base for the steel plank, the Engineers
first placed a layer of burlap. On this was poured a layer of tar fol-
lowed by three layers of open steel mesh. This base provided a stiff,
watertight manbrane upon which the steel planks were laid and welded.

A high crown, usually 16 inches in 14 feet of roadway, assured rapid

drainage.

-14-

luddy ground upon which roads were to be built necessitated a dif-
ferent type of construction lest the entire structure be swallowed up
by the mire. For this reason, timber plank roads were built. The first
step in the construction of these was the laying of 12x12 mudsills,
placed as close together as the mud condition necessitated. In sane

cases this meant a solid platform had to be laid. Next, 8x8 stringers

 

“i "-“k "V“"UULWP’WFFfl'.
»~ 4~ aububa-DM' -

VI! grgwm;j.v_; __

v'a‘iv

 

a , ‘uv ‘:-- ‘

Fig. 9. Timber plank road.

were set on the sills and on the stringers was placed a deck of 4x4
planks spaced for drainage. Finally a running surface consisting of

two rows of longitudinal planking protected on either side by curbs

was set on the decking.

In the building of roads and in.many other phases of engineering

and construction, generous assistance was given to the American units

’0 1
h;
u‘t'

t t f
.;

 

Fig. 10. Corduroying as an alternate method.

by the "Service des Ponts et Chausses”, the French highway and bridge

organization.

Boat Basin Repair

Boat basins, in which ships were protected from the 25-foot tides
prevalent on the European coastline, required a great deal of repair
before they could operate at anything near capacity. These basins were
entered from deep-water anchorage by means of locks. The locks operat-
ed at high tide only, assuring that the basins were always full of wat-
er, and, hence, unaffected by the tides. The Germans again had done an
expert job of demolition on the gates of the locks, and the Engineers
did an expert job of expeditious repair.

A gate consisted of a structural steel framework to which was
riveted or welded a skin of steel plate. Where repair was practicable,
the damaged framework was reinforced with available structural members,

while the layers of plating were patched or Entirely replaced. Where

-15-

the damage was irreparable, entirely new gates were manufactured and

installed by means of heavy floating cranes provided by the Trans-

 

(w‘ n. , , , . , ...-.._ -- v
F:l .r. V. I‘A ' ' ' v.74 7 .
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,‘;-~ , ‘.'. t a . :.. _

I'.‘ ,, -' - tfi‘ ‘_ .‘I
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."‘.',.':" 1“" ‘ ‘.‘ ' :3“:

Fig. 11. Installing a gate strut.

portation Corps. The rapid return of these gates to operation status
meant that the boat basins could be used at full capacity'weeks ahead

of schedule.

2921mm

In.many cases the cargo handling capacity of a port could be in-
creased by the addition of piers to the existing unloading systan. One

of the most popular methods of erecting these piers was through the use

-17-

of pontoons. The completion of these piers exemplified the ever-present
cooperation between units of the army'and Navy. The basic unit for the
piers was the 5x517-foot steel pontoon, which will be described in de-

tail later. A number of these pontoons were fastened together in the de-

 

Eig. 12. Pontoon pier being floated into position.

sired shape at a shore site and floated into position. This work was done
by the navy Construction Battalions. Then the Army's floating drivers sunk
pile dolphins around the perimeter of the pontoon cluster and fastened the
two together, thus forming a floating pier. In order to avoid trouble from
the tide, the pier was connected to the shore with a Bailey bridge span
resting on pivot bearings. L ramp provided the transition from pier to

bridge.

Railroad Bridges

Probably the most important work done by the Engineers in Europe,
and that which was most emphasized, was the task of providing bridges
of all types. Here was needed a railroad bridge; there a pontoon bridge;
somewhere else a single span was required to put a wrecked bridge into

operation. Each bridge that was built or repaired by the Engineers had

-13-

some peculiarity that distinguished it from.all others.

In railroad bridging, the units of construction because of restrict-
ed availability and convenience were few. The following are those which
were used almost exclusively.

The German fimeter beam" became a very popular addition to the stan-
dard units of construction because it was particularly adaptable for use
without pier support for spans up to 95 feet. The specifications of this
beam were a depth of 39.37 inches (hence, fimeter beamfl), flanges 11.81
inches wide and 1.42 inches thick, web thickness of 0.75 inches, a
weight of 210 lbs/ft., and section modulus of 787 inchess. Standard prac-

tice in the use of these beams involved placing one under each rail for

. "'.'""‘"--f z, - "any”...

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Fig. 15. Railroad bridge of meter beams.

 

spans up to 55 feet, a third beam in the center for spans of 60 and 65
fact, two under each rail for 70- and 75-foot spans, a fifth beam in the
center for 80- and 85-foot spans, and three under each rail for spans of
90 and 95 feet. The beams were rolled to a maximum length of 95 feet.

using those meter beams captured at first, the Engineers later received

-19-

than upon order fran a Luxembourg mill.
Another of the units of construction was the UCRB (Unit Construc-

tion Railroad Bridge). This was a parallel-chord, Pratt-type truss span,

‘ - _ . . .Iv . ‘ .‘f-V._‘_

L‘: t?!”
a» ;.'
3’ :5“

 

 

Fig. 14. UCRB units (right).

made up of light individual pieces bolted together. It was installed as
either a through or a deck span.

Light Steel Trestling (LST) and Heavy Steel Trestling (HST) were
prefabricated columns in 3-,4-,8-, and 12-foot lengths, and bracing mem-
bers. These could be assembled into tower piers of varying heights and
plan dimensions. Figures 13 and 14 show bridges supported by this trestl-
ing. Rolled Steel Joist spans (RSJ's) were merely two or more I-beams
welded together side by side.

At Dreux, hence, the Engineers erected a 295-foot railroad bridge
using all of the units mentioned above. It will serve as an excellent
example of railroad bridging in the ETC.

The original bridge spanning the Euro River at ll'eux had been a
high masonry viaduct, but was completely destroyed by the local French
citizens because the frequent attunpts of the Allied banbers to destroy

the span had become an extrune annoyance to the townspeople. The replace-

-20-

ment structure consisted of a UCRB deck span of 70 feet at either and,

two 49-foot spans of 32-inch RSJ's, and a center span of 57 feet made

70mm . ' ‘

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

n, A i49'8pan- 4 1-0me (52”)7 BL Sym- obi ¢,_::..
' a
L . _ . 1 A £415,611 ‘ B 5713'span -4me/sr bee/m"
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., ‘4‘ ’- ‘ . , I, l__L J
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____________________ -.L_ _ _—

 

Fig. 15. Side view of Engineer's replacement bridge at Dreux.

up of two meter beams under each rail. At each point of junction between
the different types of bridge units was a pier of Light Steel Trestling.

Two of the piers were supported on the old footings and the others on

 

Fig. 16. L31? piers.

new footings built over the rubble of the old bridge. Included in the

-21-

 

equipnent available for the job were a 5-ton crawler crane with a 40-foot
boon, one of 30-ton capacity with a 70-foot bean, a truck mounted crane,

a heavy and a light crawler tractor, two arc-welding sets, and a 7-S mix-

 

113. 17. 30-ton crawler crane at work

The UCRB units were installed as deck spans by assembling them on
wheel dollies on the track adjacent to the end abutments, launching
them over the span to cribbing erected on the LST towers (see Fig. 17),
and lowering them into position by means of chain hoists suspended from
gantrys set up also on the LST framing. The chain hoists did away with
the lugubrious lowering with screw jacks.

The center spans of the bridge were installed in a like manner,
with the exception of the final unit which was one of the 49-foot RSJ's.
This was assembled in its place by the 30-ton crane operating from the

ground.

-22-

This construction provided a single track span, but it was found
necessary subsequently to add another track. This was done by widening
the towers sixty percent and duplicating the completed bridge. The e-
rection, however, was done entirely by lifting the units into place
after they had been assembled on the ground. Again the 30-ton crane
was used. Erecting this second unit in the same manner as the first
would have necessitated closing the entire structure to much-needed
traffic. The Engineers completed the first track span in 18 days.

In the construction of long, low bridges, the work was simplified
somewhat by the fact that it was required only to build timber or hollow

steel pile bents to support beam spans. When one or two spans had to be

4 ”tr-'16 7' Z:W.,.:

installed to put a damaged Efiggmaréaag 37 Vfitf’? {Effiftiffigv
, W . ,'-~:'::: “$2.291 _ ._ -' "3 ' “$514

 

bridge into operation, the
usual work involved rein-
forcement of the piers and
abutments and the launch-
ing of UCRB's or beam spans

as described above in the

 

case of the Bronx bridge. H - ? '~~ , , ‘., - . .
Fig. 18. Construction of a low bridge.

BaileygBridges

No account of recent military engineering would be canplete without
some reference to the Bailey bridges; those that use as the basic unit
the Bailey truss panel. Very few of these bridges were built "according
to the books". Let us look at one that was. It was the Bailey bridge e-
rected over the Albert Canal in Belgium by the Ninth Army Engineers.

The construction of this bridge took place at a site where the canal

-23-

flowed through a deep cut. The first step in construction was the build-
ing of piers on either side of the canal. These were supported on timber
cribbing. hob pier was made up of two legs of triple truss construction,
was 52 feet high, six panels (30 feet) wide at the bottom, and two panels
(10 feet) wide at the top. The superstructure was of 3 by 2 construction;
that is, three truss panels wide, and two tiers deep. Each of the piers

contained 45 tons of Bailey truss panels. The west pier was erected in

units by a crane on the ground, and it was planned to set up the east pier

...: , "...-.--- . ._ . . . .
i 2' .p '.:s v

 

Fig. 19. Piers as well as span of Bailey panels.

with the aid of a cableway. Unforeseen difficulties necessitated impeach-
ment of the plan. The superstructure, consisting of three spans of 151,
152, and 121 feet, was assembled on the east bank, and pushed out over
the gap with a bulldozer. Ihen it was launched as far as the uncanplet-
ed east pier, the Engineers took advantage of the cantilever action of
the suspended portion, attaching block and tackle thereto, and hoisted
the remainder of the pier into position. The entire structure was then

pushed the remaining distance, and lowered to the piers by the use of

screw jacks. This formed the largest Bailey bridge in the ETC.

Floating Bridges

Before the fixed bridges could be built, it was necessary to provide
first temporary floating bridges for the infantry and its immediate sup-
port. After a beachhead had been established by the foot soldiers who
crossed the stream in assault hosts, the Combat Engineers moved up to e-

rect the famous pontoon bridges. These consisted of pneumatic pontoons or

,-, L J..." ..
ti)???
2%. a“

 

Fig. 20. Launching the Albert Canal Bailey bridge.

assault boats anchored in the stream.and tied together. If the bridge

were to support only foot traffic, the pontoons or boats were surmounted

 

Fig. 21. Floating foot bridge.

-25-

by a wooden plank catwalk. For heavier traffic, Bailey truss panels were

_..,.. an; .,..L\,,... .--‘,1. . ‘.._ . . ... . . .. a- , - ., .~~--~ .
t . -. . . . _ ....o . H - ..

 

. ."' :24". ‘
m "ft
“.5 WE wail... '
3W “hm

"’ %W&&Lm’

 

Fig. 22. Floating Bailey bridge.

put up on the pontoons and a plank roadway laid between them, thus form-
ing a floating Bailey bridge. Another type of "heavy" pontoon construction
was used employing sections of curbed steel treadway. Each of these sec-

tions was about ten feet in length and consisted of two tracks like those

’. .5. 4 . 4 » _ ’a
a -- . '- 1. -

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:1!“ ‘r-M 34“" “'5‘“

 

Fig. 23. Floating treadway bridge.

of a grease pit, protected on either side by curbing. The sections were
laid longitudinally and bolted together, thus forming a continuous run-
ning surface for trucks and other wheeled vehicles. The author had the
dubious pleasure of crossing the Rhine over such a bridge.

-26-

Airfields

Most of the existing airfields overrun by the Allied armies had
been badly damaged by their own bombers. The concrete runways were pock-
marked with bomb craters of all sizes, and the buildings were all but
obliterated; evidence of the omnipresent German policy of demolition
before retreat.

A large construction job was involved in the repair of these dam-
aged runways. Before work could begin, most of the craters (some 150
feet in diameter) had to be pumped dry. They were then filled with rub-
ble, which.was usually available in the wake of destruction. The cracked
pavement was then cut back to sound concrete, and forms were built to
fit the odd-shaped holes. These forms were of lx6's or 1x8's and were
left in place to provide some protection against the expansion and con-
traction of the concrete. The practice of filling the holes with con-
crete from a portable mixing plant had to be abandoned, since the pro-
cess-was too slow. Instead, batches of ready-mix from a centrally lo-
cated plant were hauled in by dump truck.

Ihen it was necessary to build an airfield where none had been
before, or to add to an existing installation, the employment of the
famous pierced steel plank or Marston mat was almost standard practice.
The laying of the plank did, however, vary with varying conditions of
the soil. Where the ground was relatively dry and stable, the work was
simplified, since it was necessary only to grade, increase the stabil-
ity of the soil with heavy rollers, lay the planks, and weld than to-
gether. In many instances, severe mud conditions prevailed and the tech-
nique had to be modified to an extent in proportion to the depth and

consistency of the mud. In an extreme case, rubble was hauled to the

-27-

site of construction and dumped until it was a foot in depth above the

mud. This required many hauls, since the first two or three layers fre-

quently disappeared entirely in the gummy mass. The rubble was then

~~~~~~~~~~

 

 

I ' ._ . . V; sulxy-Lg}; I .
, ..~~‘.. ,‘ ,_.a ( , J 2. . t
“f",- 51%;“ .1 8‘3"?” .‘r;n. -’5'Yl "'~- '

  

Fig. 24. "Severe" mud.

covered with a layer of smaller stone, after which the steel planks

were laid and welded. Sometimes it was found advisable to top the layer

 

Fig. 25. Laying pierced steel plank.

of rubble with a layer of straw before setting the planking to enhance

-23-

the resistance to.mud seepage. The straw layer was about a foot in depth
when placed, being subsequently compressed to four or five inches. Under
normal conditions, a battalion of the Engineers could lay a 5000-foot

runway of this type in two or three days.

-29-

Part 2
Pacific Theater

The chief purpose of the engineering and construction groups op-
erating in the islands of the Pacific was to take over an island as
soon as possible after its capture (or during its capture) by combat
troops, and to convert the masses of jungle and/or rugged terrain in-
to efficient air bases, from which the Allied air attack could be brought
nearer to the home bases of the Japanese.

At the start, several distressing problems loomed. These were the
vast ocean spaces to be breached by'men and equipment, supply lines
thousands of miles long to be maintained, and a critical shortage of
construction resources necessary for the carrying out of an hmmense
program of providing military installations. The solution of these three
problems did not directly concern conventional engineering techniques
and for that reason they will not be treated here.

The problems that promptlyIQLQ confront the military engineer in
the Pacific islands were those of terrain and climate. With the excep-
tion of arctic, every type of topography and every condition of weather
was encountered. The adeptness and alacrity with which the engineer met
and reduced the importance of these conditions have been described as
"incredible" by even seasoned construction men.

The work in the Pacific islands entailed items such as earth mov-
ing, paving, providing facilities for gasoline storage, refrigeration,
water supply, sewage disposal, and bomb storage, and the construction

of hangars, warehouses, barracks, shops, and power plants.

-30-

UnloadipggTechniques

Unlike the operations in most of Europe's ports, a great deal of the
heavy equipnent and armor used in the Pacific had to be unloaded direct-
ly from the ship to the beaches. Conventional cargo vessels were unsuit-
able for this type of operation for two reasons. The first of these was
the fact that because of the nature of the holds, equipment could not be
loaded in a way such that the items needed first on the beach were the
first to be unloaded. The second reason was that, due to a lack of large
spaces in their holds, equipment such as long-boomed cranes and wide-
bladed bulldozers had to be dismantled for shipment. The solution to
these problems came with the development of new types of cargo vessels;
principally, the Landing Ship Tank (LST), the Landing Craft Tank (LCT),
and the Landing Craft Medium (ISM).

The familiar gaping Tmouth" identified the LST which was capable of
carrying an entire engineering unit with its equipment. Its capacity was
rated at 20,000 tons. This vessel could, in many instances, run in close
enough to the beach so that equipment needed to cross only a short ex-
panse of water, not deep enough to bog down even a jeep. In instances
where the LST could not approach near enough to the beach, the smaller
craft took the cargo in several hauls. The LCT had a capacity of 90
tons, while that of the LCM was 25 tons. None of the long-boomed cranes
or wide-bladed bulldozers had to be dismantled for shipment, and items
that were to go ashore first were not tucked away, inaccessible behind

piles of lumber or sacks of cement.
Steel Pontoons
One of the most useful construction units to be employed in the re-

cent war was the Navy's 5x5x7-foot steel pontoon. This steel building
block, made of 3/16-inch plate and welded throughout, was internally
braced and served many interesting purposes. The single pontoon weighed
about a ton and had a net buoyant capacity of four tons. The pontoon had
self-tightening interlocking bolts and straps - called "jewelry" - which
connected one pontoon to another, for very seldom were they used as in-
dividual units. The most frequent way in which the pontoons were used
was in the form of a string; that is, a series of individual units were
fastened together by means of the ”jewelry" and long steel members a-
long the edges of the pontoons. Thus, a "2x12" unit would consist of
two strings of twelve pontoons each. These strings were used as piers,
barges, or bridges when neces-
sary, and were capable of with-
standing enormous loads be-
cause of the internal bracing.
One of the most interest-
ing uses to which pontoon sec-

tions were put was that of mo-

 

mentlun beaching. This was em-

Fig. 26. 6x18 steel pontoon unit.

ployed when an LST was unable

to reach a shore or beach and the building of a pier became necessary.
The process consisted of carrying strings of pontoons fastened thinly to
the sides of the LST and running in until the ship grounded on the
bottom, at which time the strings were cut loose and allowed to float

to the beach. By means of cables and winches on the ship, the strings
were jockeyed into the desired position where they overlapped one an-

other slide-rule fashion. They were then fastened together and vehicles

-32-

and men sped ashore, frequently without

a test of this process,
an LST grounded 550 feet
from shore, and in just
seven.minutes the pier
was in position and a
heavy vehicle was rol-

ling up the beach.

wetting a tire or a foot. In

 

Fig. 27. LST carrying pontoon string.

Barges made up of

pontoon strings were

fluid,» _ _ 53}- , .
usually standardized as 'eW. m i it.
[:t’i I

new
to dimensions. The most ’

commonly used units
were 3 strings of 7‘
pontoons, 4 strings of
12 pontoons, 6 strings
of 18 pontoons, and 6
strings of 30 pontoons.
The latter unit made a-
vailable a deck space of

43xl75 feet with a car-

 

.wmfikd‘?

Fig. 28. Pier formed by momentum beaching.

rying capacity of 500 tons with a draft of four feet with that load.

Bridges

Bridge building in the islands of the Pacific was not as elaborate

as that practiced in the European theater. Usually, the span to be

bridged was not wide enough.to warrant Whig League" methods, and there

-33-

was practically no call for railroad bridges. For our discussion, there-
fore we shall restrict the construction to the two types which were used
most in the islands. These were the timber bridge and the pontoon string
bridge.

A typical timber bridge can be discussed using one of a number built
on the island of New Britain. All of the timber bridges built on the is-
land were of identical construction, varying only in span and width.
Using native grown logs throughout, stresses were determined by the heav-
iest vehicle in operation in the area, and strength values were arrived
at by comparing the timber with similar hardwoods of the United States.
The first operation was the erection of timber pile bents. Each of these
consisted of five 25-foot piles having 18-inch butts and 10-inch tips.
The piles were driven to refusal and held together as a unit by a cap-
ping log laid across the top of the line of piles and fastened to each
by means of a one-inch pin. The distance between bents was an average
of 20 feet. Retaining walls were formed by logs placed horizontally one
on top of the other against the end bents. These logs extended from the
stream.bed to the underside of the string-
ers. Wing walls were:made in the same fash-
ion as the retaining walls. Stringers were
placed so that they overlapped the support-
ing bents by at least three feet, there be-

ing usually five stringers per bay. Sur-

 

mounting the stringers was a deck of 8-inch ‘ *“* -

Fig. 29. Timber bridge
logs, the crevices between which were filled under construction.
with smaller logs and sticks. Curbs of long, large-diameter logs were

laid along the outside edges of the bridge, after which the decking was

covered with gravel, volcanic slag, or other suitable and available ma-

The constru
ction of a steel pontoon bridge entailed much less lab
or,

  
   

material, and equi
pnent than did the timb
4" . er bridge The first
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g 30. Launching the pontoon string bridge.

in the case of the timber bridge was the erection of timber bents which
was done in the same manner as described above, but only the end bents
were put in. The superstructure of the bridge was a string of pontoons
supported by the bents. The string was frequently installed by pushing
over the gap with a bulldozer. The landward pontoons of the string were
filled with water to provide a counterbalance so that the string could
be pushed as far as possible without needing help from the opposite bank
on which was a crane ready to ease the span into position on the bent. ’
When more heavy equipment was at hand, the pontoon string was lifted
bodily by cranes on either bank and lowered directly to the an t
The methods of bridging herein described.may seam to the engin:por a.
trifle crude, but the structures served a purpose - - speed of :1. a1
cmp>e-

tions

-35-

Harbors

Many of the Pacific islands which were designated as advance bases
of operation were totally without harbor facilities. To the Seabees fell
the task of providing these facilities for the more important bases. The
island of Peleliu was singled out as such a base because of its fine
Japanese airfield. The work involved in.msking a harbor for this island
will serve as an example to illustrate the general problem.

Peleliu, like many Pacific islands was surrounded by a coral reef
which prevented the landing of large vessels. In order to convert the
rock-girdled coastline into a port for the unloading of supplies, the
Seabees decided to construct a boat basin and a number of unloading piers
therein. The approach to the basin was to be a channel cut through the
reef.

The problem of dredging a channel and excavating for a boat basin

was a difficult one because of the hardness of the coral. The solution

 

Fig. 31. Channel leading to boat basin (background).

was blasting. Using forty percent gelatin and TNT, Seabee demolition
squads placed 50- to loo-pound charges at six-foot intervals. The charg-

es were shot at high tide to gain the advantage of the water cushion.

-3e—

These tactics loosened the coral to a depth of approximately two feet,
and it required 100 pounds of explosive to produce about seven yards

of dredgable coral. The approach channel and the basin were excavated
to a depth of ten feet below mean low water by four cranes using drag-
lines and clamehell buckets. Two of these operated from the shore, while
the others were mounted on pontoon barges in order to excavate the chan-
nel and the seaward portion of the boat basin.

When the causeways on either side of the channel were to be built,
the versatile pontoon was again given preference as a basis for the
structures. Strings of pontoons were floated into position to form the
outline of the causeways and then they were filled with coral to sink
them. The entire structure was then covered with the coral from the
dredging operation and smoothed to grade. Protection for the cause-
ways on the sides toward the sea was furnished by riprap of limestone
from a deposit on the island. The limestone was quarried in chunks
weighing as much as ten tone, which provided an adequate breakwater.

On the channel side of each
causeway, the Seabees constructed
unloading piers, or docks. These
were merely pontoon strings set on
piling out over the edge of the cor-
al backfill. The finger piers ex-

tending frun the shore out into the

 

boat basin were also of pontoons,
but were constructed in a different Fig. 32. View of boat basin
- showing one of piers.

manner. The outlines of the piers
were strings of 19 pontoons set 4 pontoons apart. These strings were

filled with coral spoil as was the space between them. Summounting these

two ”stringers" were decks consisting of 14 strings of 7 pontoons each.
Roads

It will be convenient to classify road building in the Pacific ac-
cording to the type of terrain encountered. Usually this terrain was
of two sorts; either swampy Jungle whose soil was difficult to handle,
or an island whose main constituent was coral.

The latter type presented little difficulty because of the very
nature of the coral, which has been described as an ideal road building
material. In many cases, a road in this type of terrain could be built
very rapidly. If the coral was loose, the large chunks were broken up
and bladed into shape. Otherwise, blasting would loosen the material
sufficiently to permit crushing and spreading. Crushed coral, accord-
ing to engineers who served in the Pacific, possesses a high degree
of inherent stability, and when grouted, provides a high-type surface
capable of withstanding heavy traffic.

In the case of the jungle islands, road building took on more for-
midable aspects. The first firoads" were nothing more than one-way trails
pushed by bulldozers, avoiding the largest trees and the worst swamps.
However, when the fighting lines moved many miles inland from the beach-
es, it was necessary to move heavy equipment and armor long distances.
For this reason, the trails had to be converted into highways. The bull-
dozers could no longer avoid trees. If they were unable to push them
down, blasting was employed. Heavy rains often made the trails into
merely series of deep mud holes, which had to be filled four or five
times before the subgrade was stable enough to support traffic; the de-
gree of stability being determined by the weight of the vehicles to be

held. The fill material consisted of beach or stream gravel or volcanic

-08-

slag, when it was at hand. The latter proved to be a very satisfactory
filler, as well as a highly stable surfacing material.

In the swamp areas, the road building problem was solved by cor-
duroying, which proved the most effective means of combatting mud. Cor-
duroying consisted of stringers laid along the road on 10- to 12-foot
centers, and 20- to SO-foot decking logs placed on the stringers at
right angles to the road alignment. The decking was then covered with

gravel or volcanic slag from the nearest deposit.
Airfields

As in the case of roads, the construction of airfields was carried
on either in the Jungle islands or the coral islands. The Corps of En-
gineers and the Seabees performed with such speed in the building of run-
ways, that they could, in coral terrain, have a fighter strip ready for
operation in three days. This greatly increased American air activity in
the Pacific, preparing the way for ultimate Japanese surrender.

For the purpose of illustrating the construction of airfields on
jungle islands, let us use as an example the one built on the island of
Guadalcanal. Work on this airbase was carried on by three different
agencies. The'Marine Corps furnished the engineers; the Seabees did the
actual construction; and the Army was to operate the field after its
completion.

Carney Field, which had been in use for years, was in poor shape
because of consistent Japanese air attack, and because of an inadequate
subbase. The site chosen for the new field was the only piece of level
ground on the island large enough for an air base. This site was a low,

grassy plain at a bend in the Metapona River. The first thing done was

the building of a camp for the working crews. This was erected in a
grove of trees to gain protection from the sun and frem air reconais-
sauce. The airfield was built around this grove of trees. The grass
on the plain was head-high, and when mowing was impossible, it was
burned off. A topographic map had been.made of the area, and while
the grass-clearing was being done, a ditching machine was busy drain-
ing the field.

In order that the work be expedited, a conference was held by the
three groups, and their differences were arbitrated. The final.master
plan called for a longitudinal grade of 1 percent maximum, and a trans-
verse grade of 1.5 percent on either side of center. The runway was to
be 7,000 feet in length, 250 feet between shoulders, with a 500-foot
overrun at each end. In addition, six miles of taxiways were planned,
as well as 101 bomber hardstands spaced at 450 feet. Culverts were made
of empty gasoline drums welded together and encased in concrete.

Excavation proved to be
a problem because of the type
of soil encountered. The tOp-
soil was heavy, slippery when
wet, and impossible to work
for two days after a short rain.
Its depth varied from one to
three feet. The subsoil was
a type of clay, very hard when

dry, and when wet, worse to

 

handle than "had" clay. This

Fig. 33. Campsite hidden in trees.

had to be ripped out and, even

then, it came out in large slabs which were difficult to handle. A sheeps-

foot roller was used to break up the larger chunks, and to compact the
runway subgrade.

While the grading was being done, other crews assisted by native
laborers set about surfacing the finished portions. River gravel, the
only available material was used for the surfacing. Plans called for
two 4-inch layers of compacted and stabilized gravel. Binder for the
gravel had to be obtained locally, and a deposit of a sand, silt, and
clay mixture found along the river bank served the purpose. The binder
was incorporated into the gravel by windrowing with power graders and
the surface was compacted by a multiwheeled rubber-tired trailer weight-
ed down by pierced steel planks.

After the gravel surfac-
ing was in place, it was de-
cided to top this with a lay-
er of pierced steel plank.

First was laid a blanket of
steel mesh, than the plank.
As the latter was placed, the

ends of the steel mesh were

 

bent up and the entire sur-
face was grouted. The bent Fig. 34. Laying pierced steel plank.
up mesh provided a good measure of reinforcement. All of the taxiways and
hardstands were finished in the same manner as described above for the
runway.

Coral island airfields were much less difficult to construct than the
foregoing, in that the native coral proved to be a very desirable surfac-

ing material, while providing at the same time an extremely stable sub-

base. The principal difficulty was the hardness of the substance when it

9» new I . \ " _ all ‘1“; .
'n-- trn«su-a,

  
  
 

Fig. 35. Grouting added the final
touch to the new airbase on
Guadalcanal.

 

was not in the loose state. This, as stated before, called for extens-
ive blasting operations.

One of the most effective units for building this type of airfield
was the Aviation Engineering Battalion of the Corps of Engineers. This
ubiquitous group consisted of 777 men and had an impressive table of
equipment which included 20 bulldozers, 12 carryalls, 3 power shovels,
8 motor graders, 42 dump trucks, and 5 to 10 tournapulls. In addition
to the above, each unit had an asphaltemixing plant with an output cap-
acity of 200 tons per hour, and a rock-crushing plant capable of handl-
ing 150 tons per hour. With 'round-the-clock construction, it is not
difficult to imagine the speed with which one of these units could con-
struct a base. The standard procedure was to land on an island as soon
as possible after the beaches had been cleared, and to go to work as
soon as the equipment could be brought ashore from the landing craft.
Coral was then blasted out or scooped up, brought to the crusher by

truck, returned to the construction site, and spread and graded. After

this had been accomplished, the asphalt plant was ready to deliver coral
asphalt at a rapid rate. Since speed was the essential factor, the nice-
ties of engineering were frequently overlooked. The completed project,

however, served very well the purpose for which it was designed.

mm

In the islands of the Pacific, the problem of securing drinking
water was one of converting the sea water into fresh. This was accomp-
lished through the use of portable distilling units operating on dies-
el fuel. One such still could produce twenty gallons of fresh water
'to one gallon of fuel consumed.

The disposal of sewage was not frequently dealt with, since the
digging of latrines was almost the universal practice, even in hos-
pitals. Shown here is one method of producing a disposal system using

only available items.

Buildings

Practically all of the buildings e-
rected for the housing of troops, for the
hospitalization of the wounded, and for
the storage of supplies, as well as those

serving as hangars, shops, and other ne-

 

cessary structures were of the prefabri-
cated type; and most of them were the Fig. 36. Sewer line of

welded empty gas drums.
familiar Quonset hut. A Quonset con-

sisted merely of a corrugated skin of sheet steel or galvanized iron

fastened to a steel framework. These units were, whenever possible, sat

on concrete floors. Metal construction was used rather than wood, because
of the latter's inability to withstand the rigors of the tropical cli-

mate.
Engineer Depots

Both in the Pacific and in the European theaters of operation, the
setting up of engineer depots for the receiving, storing, and issuing of
engineering equipment and material was a large project in itself. The lay-
out of such a depot had to be such that it could expedite the receipt and
issue of goods with a minimum of confusion and time consumption. Thus,
roads, entrances and exits, and the location of stock piles had to be care-
fully planned. This was evidenced by the fact that an average depot carried
more than 10,000 standard items, as well as about 300,000 spare parts

items.

-44-

Part 3
Zone of the Interior
.Since this report deals primarily with the problems of the overseas
military engineer and construction man, the work of these peOple in the
United States during the war will not be highly emphasized. Although
their contribution to the victory was as tangible as was that of the
units abroad, it was not beset from beginning to end by critical short-

ages of equipment, replacement parts, and raw materials.

-45-

When it became evident that the United States would be required to
build a war machine and to provide training facilities for millions of
troops, the government enlisted the aid of the nations contractors and
construction engineers. The task that they accomplished was not as colorful
as that performed overseas, but the alacrity with which it was done
deserves mention.

The first task undertaken by these men was the construction of
housing and training facilities for the armies. This construction in-
cluded such items as barracks and other buildings, roads, water supply
and sewage disposal, and special installations depending upon the type of
camp to be built. For instance, an air base would require landing strips,
hangers and shops, and gas and bomb storage; camps for heavy vehicles
needed heavy-duty roads; navy installations lacked sufficient dock
facilities; precise surveying was a requisite for the placement of
coast artillery positions.

With the troops taken care of, these men turned to other projects.
Defense plants sprang up almost overnight; the Big Inch pipeline from
Texas northward was begun; the Alcsn highway approximated overseas con-
struction methods; an extra boat lock was installed at Sault Ste. Marie,
Michigan. The list is endless. To give an account of the building of
these would be only to write a library of standard engineering practice
and construction methods.

Perhaps a few statistics would present a clearer picture of the
total amount of work undertaken by the construction men and engineers
in the United States.

Military construction involved the building of 2,973 command in-

stallations, and 300 major industrial plants, at a total cost of al-

-46-

most eleven billion dollars. The acquisition of property found the 0.5.
in possession of an additional 38 million acres. Troop camps provided
facilities for the housing of 5§ million men (and women). Maintenance
was carried on for 13,000 miles of sewers, 4,300 miles of railroads,
13,000 miles of water lines, 63,000 miles of roads, 23,000 miles of
power lines, 3000 miles of gas lines, and 1600 miles of steam lines, to
mention a few. In addition to the above, the Engineers provided 480 mil-

lion.maps of active and potential battle areas.

-47—

Conclusion

The field of engineering and construction in World War II consist-
ed of so many diverse factors, influences, and circumstances, that it is
difficult to think of it as a unit, and even more difficult to tell about
it without consuming more time and effort than is represented here.

Many improvisations which were made by desperate engineers during the
war have definite peacetime values. Many techniques which were used as
last-ditch emergency measures are now rewriting the account of some ac-
cepted standards in the books on engineering and construction.

The agencies which were responsible for the carrying out of the over-
all construction plan for wartime were these: The Corps of Engineers (in-
cluding the Combat Engineers), the Civil Engineer Corps (including the
Seabees), special units of the Marine Corps, and the private contracting
business of the United States under the supervision of men from the
above units.

The countless installations still in use throughout the world stand
silent testimony to American ability to get the job done, and to do it
well. The spirit behind this ability is written in the words "contract
completed" at the end of project reports, and in the blood of the men

who gave their lives that the task could be completed.

 

LY.

whom USE ON

'48- .

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