The New York herald., 1870-09-20
The East RIVER BRIDGE.
Progress of The Work Caisson of the
Brooklyn Tower.

| Progress of the Work ON Caisson of the
Brooklyn Tower.
Not boat leaves the Fulton ferry in the daylight
tha, anxious passengers do not crowd the after part
and peer eagerly toward the masonry work studded
with a forest Of derricks, running gear, &C., ana
peopled with busy athletic men, which marks the
first stupendous step of the gigantic East River
Bridge. The caiss0n which is now settling slowly
but surely in It's submarine bed, under the great
pressure OF gray granite and limestone bUulders,
which firmly TERED in adamantIne solidity upon
it, was noated into position the Brooklyn side,
adjoining the Fulton ferry, on the Sd Of May
last. The progress since made under the
immediate supervision OF the engineer Mr..
Roebling and his expert and scientific assistant
and superintendent engineer, c. G. Martin-which
latter gentleman is constantly to be found In his
Office within the enclosure Of the works-has been
most satisfactory. Not single accident or mishap
has thus far been recorded. which Is most sngularly
fortunate In view OF the fact that the material to be
handled is so ponderous and unwieldy
The latest measurement, made on Saturday even
ing, showed tnat the caisson for the tower (Which
viii rise TO height OF 26s feet above high water
mark) had been sunk TO depth of twenty seven
feet six inches below high water level.
The depth assigned for the caisson to be
sunk is oryfour feet, that has yet to be sub
merged seventeen feet more. The higher he tide
the greater the quantity OF air required to be
pumped in the caisson TO relieve The pressure
| From three to FIVE steam engines are Kept con-
/ stantly going in supplying the immense cnamber
| with air, anu hosting the debris sand and broken
rock from the river bottom. There X now egh feet
! OF bJuders In place upon the calssOn, leaving the
top Of the latter about that depth below high wafer
mark. The blocks Of stone which constitute the
mason work weigh from three TO eight tons each.
| There are two pangs of workmen employed
sqw eaGh gang workg axeen egh sour hours
| ont of the twenty-four. The calsson gangs
| number 100 men each. About $50 men are
employed constantly In the yard tending The mason
| work, the st engines, &c. There are also 100
men regularly engaged at the stone yard Of the
Bridge Company, in South Brooklyn. TO this latter
place the stone Is first taken by the vessels which
| bring 1t rom Kingston aud Maine IN large quantl-
| ties Here II Is dressed and assorted prior 10 send
| ing it to lis final destination.
| laborers are readily found by the company who
are willing to work at The prices paid. Most OF the
ask 10 be sent TO work ''in the tank or fin the
pitt as they generally term tie caisson. The wages
paid the "deyers" in the latlerare twenty-five cents
an hour, or two dollars day, whie those employ ed
| IN the yard get 81 - per dem.
The average progress made in sinking the caisson
is about three inches day, though there are many
| very heavy stone bouders, some OF which are ten
| tons weight, encountered In these excavations.
These have TO be blasted and the work is necessarily
tedious. During the blast the men remain IN '';ne
| TANK but withdraw to a separate apartment the
| structure being divided INTO SIX compartments. 1t
| Will be three or four months hence il is beleyed,
| ere the desired depth Will be attained. The average
temperature In the casson varies only from five 10
eight degrees below the atmosphere on the surface,
and no inconvenience Is experienced IN breathing
by the workmen The air being constantly pumped IN
is OF course pure. Work will be continued below the
surface throughout the winter, but the mason work
Will cease before the winter weather sets in. Enough
OF stone will however be placed III position In tnat
time TO set The casson. When this latter labor is
completed the interior of the structure will be filed
up with concrete, thus forming solid foundation
for the great tower Of the East River Bridge. fire
occurred on Saturnay afternoon IN the caisson,
which is the second time within lew weeks that
such an accident has happened. One OF the men held
light to aperture through which the air was es-
Gaping to ascertain the cause OF some slight irlegu-
arlty when the current OF air carried the flame
10 the outside Of the structure, setting it fire.
| hose was introduced through the aperture and a
steady stream OF water had the desired effect, ex-
| iinpulshlng the novel Threatened cOniaglaLlOn.