Daily Kennebec journal., 1901-09-07

used by tie tunnel contractors Tor
transporting rock and dirt from hole
in the ground to wagon at some di5-
tance. First there Is stout wire cable
stretched horizontally. This serves as
q sort sof railway, on which rides
traveller, device no hung on rollers
tLat slight pull will drive It in either
direction. The load liz attached to the
traveller. Finally there Is cord, by
mems cf which the traveller IL moved.
On the bridge there will be four
tramwaya. or. rather. two double ones.
Each will be 80 arranged that a travel
cr wili go across by one route ana
come D2cE by the other. The cord that
does TIE pulling viii also be endless.
and viii follow the same path. Of
course. TO operate these tramway5 a
ca ucrsc power steam engine Will be
called into service on the New York
side Of the river.
When "a alternating begins there VIII
be set UP on each anchorage suitable
frames in which drums holding the ma
te,,al for the ca bles VIII be suspended.
so that they can rotate. The wire !;
wound on a drum as a thread Is on
spool. ard Il Lnwinds when the drum
turns In shape. however. the drum Is
more like n broad wheel than spool
us dia ametcr Is six feet. while IL Is only
II inches thick. There VIII be four
tons Of wire on n drum. and. as II
weighs a pound for every 10 feet. there
, Wi, lie upward Of s0,0C0 feet In each
coil.
on beginning work, the end OF wire
from drum wi. he passed over pIi-
!.y on the traveller and then brought
down to the anchorage chains and fas-
tened. AS soon az the endless rope
starts. the traveller is In the eye of a
loop or blight the halves VI which lead
respectively To the anchorage and the
drum. II all goes well the traveller VIII
have gone clear across the river In about
, ~ minutes and In doing so Will have
stretched two wires not simply one
There the movement II interrupted an
| instant. while the loop is detached from
The traveller hy one gang Of men aud
blight from another drum II caught "vef
th. pJli.y by Il second gang o! mtn.
The first rair OF wires belong 10 one
cable. and the other pair to different
on-. Now. when the Traveller gets back
, tn the starting point IL viii Ire once more
| employed tn p9iI ware from the tirst
| drum. Such connections Win De mad"
| with the anci.or chains by the workmef
| at each end oi the br!d1" that ~ VIII
! not lie necessary Ia rui the Wiz. AT al
! Til. operation ot pulling from eacn drum
| continuously viii H. Kept up until the
! whole S1.v0 feet have been used up
| Stationed ON little baIconiea which
Project from the fo"thridg.s at MINER
| tus points will BE- men known az frgu-
| !.ltors.' They grass and adjust each
pair OF v. res as they are stretched
| There Will be from =, 10 ~ mon iu each
| uf the four gangs employed. IN order
10 prevent tanylsng hF the wind and 10
| iusarc th. wires lying close besid. uii''
| another strings viii he tied temporarily
! lar NJ. m r.- Eb..Tt Intervals and
! each fresh one Is added the old bonds
| viii he removed and new ones substitute
| ed, so as 10 enrircle the whole number.
! In order that each wiT. shall have the
hight strain upon II and take the prop.
1 share in the future work OF the bridge.
I The men sl,e that IL Hes exactly parallel
4 with those which have already been
placed Signals atc given to the en-
sine.r to increase or relax the strain
| hen this adjustment Is mace.
The wires are ot steel and coated with
| OH ben 30 have been atrIng they
I arc, combined into a strand by tying
thcm together q; Intervals OF about
feet with two or three turns of finer
| wire. There will Le s. such strands.
and hence 1896 wires In each cable.
When the whole o. strands are finished
they will be sn' ased In a covering OF
thin sheet steel. Before III" addition Of
the casing the cables will he is1. inches
| In diameter II viii take about a year
10 finish this | art OF the Work.
The trusswork "r frame on which the
|
| So designed to remain rigid when
| heavy loads move over II and to resist
the strongest winds thai strike IL on
the sides The same amount Of steel
gives far greater strength. vertically
and sdewise il put in the form Of open
frame than in oua solid plate or beam.
The land-span trusses of the new bridge
are already finished. While they were
guing up ii was necessary to sustain
| them with temporary wooden frame
built up over the street. There will be
| no suspenders to connect them with the
| main cables. When the main span. over
| IN. river. il being built. work will be
plshed from each tower. and the nee s.
sary support Will be afforded chiefly by
the suspencers. which Will be riygei sim
| ultaEeoisly.
one important difference between the
old bridge and the new will lie in the
provisions made for the expansion of
| the trusswork of the main span. That
OF the old structure is cut in two in the
gap nearly Is inches wide. covered by
metal p.ates Each half expands seven
or eight inc',s IN summer, In conso-
laence the lower ends " the suspend
| crs. which are mere from ~ to 80 inches
ong, are displaced in very hot or very
cold weather In the new bridge the
gaps or slip Joints viii be at the towers.
not in the middle. AT these points the
sLspenders VIII be nearly 1S feet long
and the same displacement OF their
lower ends viii hardly throw them out
of plumb or strain their connections
with the truss. \ new MODE OF attach
ing the suspenders TO the cables will be
iemployed. The wise rope constituting
the suspenders will be doubled and the
main cable will pass through the loop
thus formed The lcop Will rest In a
| sort of saddle placed on tn. en- hia anA
lower ends of the susp.pa.r will be fas-
tened TO the trussWork in mach the sam.
way as on the old hrdse.-New York