The Birmingham age-herald. [volume] (Birmingham, Ala.) 1902-1950, 1918-04-21

withstand the submarine warfare, and
that we must have them at the earliest
possible moment"
Throughout our conversation about
concrete ships, Mr.. Wig was very con-
sentative He evidently believes that the
new vessels will do all that is expected
of them, but says that the government
expects to test them out thoroughly be-
fore entering into any large shipbuild-
ing programme. Many of the problems
of the concrete ship are being carefully
studied, and experiments are made to
remedy the difficulties which arise. A
very important matter is the durability
of the ship and whether its life may not
be heightened. Mr.. Wig thinks it can
and his Judgment on such matters is
worthy of great consideration. In con-
nection with the bureau of standards
here at Washington. he has been engaged
for long time investigating all mat
tiers relating to concrete and its dura-
bility 1t was not long ago that he was
sent by the navy department to inspect
the concrete construction along the At
lantic and Pacific coasts of the country
and Canada He also visited all the
ports and examined the concrete har-
bors of the West India Islands.
! During this work he found that the
| concrete was greatly affected by the salt
| in sea water, matter which is inn
portant in making these ships to sail over
the oceans He found that wherever
| the concrete came in contact with the
/ salt air it was deteriorating and dis
integrating, and that the deterioration
was much greater in some places than
| in others For instance. he examined
! series of concrete platforms erected on
concrete piles in the Cape Fear river
from Wilmington, N. c., to the sea-
/ The platforms were built by the light
house service to hold the beacon lights
outlining the channel At wilmington
where the water was fresh, it was found
4 that the concrete was almost as good
as when it was made, and that the steel
used to reinforce it was clean and free
from rust A little further down stream,
where the tide came up and the water
was brackish, the salt water mad eaten
Into the iron. forming rust, While at the
mouth of the river so much rust had
formed upon the iron that 1t had swelled
and caused the stone posts and platforms
to crumble to pieces.
From these and other observations Mr
wig reported that sea water has bad
effect upon concrete. He believes, now
ever. that certain methods OF treatment
may be used which will prevent the salt
water from reaching the iron. THIS may
be done by galvanizing or painting the
rods before they are put in. This Is
.
struction. -
II NAV be possible also to paint the
bulls of the ships so that the sea water
or moisture cannot go through the con,
crete. AS it Is now. when the vesse
lis completed. it is practically lmperVi-
Gus to sea water, because the cement
when it sets, covers the outside with
s,.ir ~ limestone which sea water does
. not nenetrate This protects the hui
until II is abraided or broken, at whicf
time the salt moisture comes in
The nroblems that enter into the de-
signing and building of ship OF tnis
, kind are puzzling. The man wat
: knows nothing of concrete ana .h'
, action of metal upon 1T would nat
urally suppose that If the steel rods y
The concrete rusted holes might bt
/ created through which the moisture
) could seep. The fact Is, the rods swell
) with the rust and break the artificia
{ stone in lust the same way that IN
+ old Egyptians used to break grca
4 blocks of granite by drilling holes am
driving in wooden pegs. which they
then soaked with water. The water
v caused the wood to swell and thi'
t broke the granite. In the same way tn
e particles of rust take more room thai
: the solid rod and break the concrete
$ In fact, everything connected with
! vessel Of this kind Is a matter OF sci
e entific study and experiment. IL
building must be carefully watched
e for any flaws that may occur DURING
! the construction are hidden in the con
. crete after the ship has been poured
: This is not the case with ships o
p wood or steel, where the construc
o ton can be examined when the shil
!, is completed For this reason the in
. spectors and superintendent must b.
4 men Of more than ordinary ability
and they will probably command a