Daily Kennebec journal., 1902-11-20

the mechanical spider that was to spin
the great suspension cables. There
were several such spinning busily all
day long, week in and week out.
The wire of which the four suspen-
sion cables are made is about as small
in circumference as the little toy pen
ellis that come with q silk string and q
tassel. but it is wonderfully strong foI
its weight. One square inch of it-that
is, a bar one inch square made of like
material-would sustain weight OF
one hundred tons. zone hundred tons
of water in a tank would be fifteen
feet square and fourteen feet deep.) II
we attached the end Of this fine wire
to a balloon and released the balloon,
about twelve miles of wire would be
lifted off the ground before it broke
with it's own weight. 1t possesses this
unusual strength, partly from the COM
preston it gets while being drawn and
partly from it very fine temper" But
once heat it red hot, unequally in diff
ferent places and then let it cool in the
November night winds or throw water
on it suddenly, and it might be no bet
ter than SO much uncOOked macarOni
and break into little bits under the
blows of a tack hammer. 't
In the making of the bridge cables
the end Of this fine wire is taken from
the reels on which it is wound in hun
dreds of miles. passed round the grooved
wheel of the mechanical, spider and
brought down TO a temporary fasten-
ing. Then the spider starts across, un-
winding the wire from the reel and
trailing a double part of it behind him
along the footways. When he reaches
the other terminal the loop is taken
from the grOoved wheel and passed
round an ironpin-block with a hole In
it's strand. So back and forth he goes
day after day over the tower tops. leav-
ing the strands behind him to be gath
cred up by the workmen and bound in.
to bundles. Whenever one length o.
wire gives out. tine next is joined to il
by 4 screw coupling, like those used or
small gas pipe. SO that each of the
thrty-seven parallel strands which
make up one cable is virtually a single
wire about one hundred and thirteer
miles long, passing back and fOrtf
around the end blocks. like worsted il
a skein. When all of them are bOunt
into one bundle, making just a com
Portable armful, there are 1890 fibres II
all, each bearing its part-forty-tw(
hundred miles of wire in what look:
from the river like one rope, or enough
to reach from New York to the Sand
/! wich Islands. And there are four sucf
ropes.
So much to give an idea of what the
task would be to merely rehandle tn,
wire in the four cables if, as feared. thu
fire has damaged them. But beside thu
mere tediousness of the spinning pro
cess is the task of lifting the finished
strands bodily into their final place!
and adjusting each Of the thirty-sever
strands--nearly three thousand fee
long-tO an exact length, even to {
tenth Of an inch, so that it bears al
equal load with it's thirty-six fellows
then of fastening them separately t.
| th:rty-seven enormous chains which g.
clear down to the bed of the anchor
piers and take hold in thirty-seven diff
| ferent places. In order to stretch eacl
strand to it's final fastenings, NOR.
| than ordinary mechanical advantages
| must be used. Each is seized in a yer.
powerful clamp attached to 'turi
| buckle" "a screw working in a threaded
| sleeve) and the threaded sleeve is pro
vided with an eight-fOOt lever, and a
the end Of the lever is rope and at tn
| end Of the rope is a steam engine
| When the engine starts, at the end o
this multiplication Of power, some
things got to come.
And, after the cables, comes tn
further difficulty always met with ii
suspension bridges of having to ham,
| from them the main roadway structur
trusses fifty feet deep carrying tw
double carriage ways. four trolley ca
| ways. two elevated railway tracks, tw
bicycle paths and the pedestrians wall
In ordinary bridge construction thes
girders could be placed in Who'll
| lengths. but a suspension bridge. fror
| it's slimness and lack Of any backbone
requires to have its roadways hun
from it almost literally piece by piece
Similarly If. as is feared in the viii
| liamsburg Bridge, they must be take
down. the job is also piece-by-piec
process.
/ Suspension bridges are PARTICULAR
| fortunate in the matter Of sub-struc
lures. Nothing has to be constructe
under them to hold them up till the
j are done. For all that. there is inevit
ably - great amount Of temporar
woodwork Throughout its length an
Eheight. we saw how under each of tn
i four cabless ran a continuous woode
i roadway. So up the tall towers &
4 ladders and galleries and under th
shore spans are props and beams an
all manner OF wreckage in the latticin
OF the girders themselves; SO that al
though we start and end with an entir
i