New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1899-11-29
DANGERS OF WOODEN DOCKS.
In comparing wooden and stone structures the
Chief OF Yards and Docks says in part:

Chief Of Yards and Docks says in part;
The conditions affecting the stability Of the Two
classes OF dock are pracHcay me yesse is the
same in the two generally speaking, though ne
masonry dock distributes the weight upon 's
superior in this respect, The condltoh lnVol'Ins
the greatest danger for drydock bnf the
pressure of the water contained IN the sou peiVm
the level Of high tide, which acts n4rmaly 10 ,ne
force in the sides. II needs little explanation 10
show that the dock which Is Gapaee tS Se oHe Of
masonry. The timber drydock Is built OF a com
Of stability, and its integrity depends upon the
measure OF success with which the access OF water
vented and with which the wood, which constli;
the interior lining OF the excavation Is P pinned
by driving piles into the soil, to which the interior
woodwork is secured by bolts. It will be seen that
the hydrostatic pressure. and in all timber dry,
docks is the practice partlculary IN InoSe 4
through which the water in the soil may ma &C
cess 70 the interior of the dock suGienty 10
through the cuyerts to the pump well ana thence
discharged into the harbor. -.,.. .,. % nre.
serve the stability Of timber drydock Is to let the
into and then pump it out The press 6
the timber drydock, which. being near the harooT,
a as beeH equeny found that
and in many instances the affairs have been FORCED
on the sides of the entrance works have been
forced inward, the bottom OF the dock mas n peeh
upfted, and, where defects in the WORK nave e1
listed. an nhood of water once set up has resulted
very dsastrously and endangered the entre s.ru'i
much less, but In those Of great depth, wnich are
necessary for the 0f Sse o5e and
is ever present; Leaks in timber drydo ,,ii
grave suspicion and require constant watching and
prompt remedy. because once started t tney SI
may be carried in undermining parts OF the struct-
ure and loosening its hold upon the soil to such an
ence in the case Of Drydock No. at the New-York
Navy Yard. This dock had only just been accepted
from the contractor when leaks developed In the
entrance works. undermining a portion OF the
abptment and threatening the collapse OF tim, the
but fortunately she was about ready to come out
voived the loss of the use Of this dock a period
Of eighteen months during Its repairs and an e~
4 somewhat similar accident occurred in the case
Of timber dryd9c No Ss a. the same SNayy Yard
storm, the west abument angle gave way. and
bulged in for distance OF about ffty feet l9ngI,
the coping to the floor, A number. of the braces
| and altar timbers were broken. In addition to
| inward and forward
safe for use until rebuilt or extensively repaired.
This failure was undoubtedly due to the rain
| water finding its way in large volume down be-
tween the altar timbers and the earth back Of
great head was aided by the decayed condition OF
! the timber end the washing away of the earth
| This illustrates how in very few years timber
| drydock may be in condition to be practically
| wrecked from slight a cause as heavy rain
| storm.
The drydock was pronounced unsafe for further
| use without very extensive repairs. which have
been undertaken. This failure was anticipated by
the report Of board OF engineers; who made an
| examination OF the dock on May 49, 1885, and esti-
mated $500 900 for its repair, which to include
concrete entrance: Here is an instance where
sgnally in nine years from the time of its com
petion as 10 require extensive rebuilding, amount
Ing 60 per cent OF its first cost 1t has been con-
cuded wise TO entirely renew the side structure In
! concrete and 100000 additional is asked In this
report for this purpose.
THE DANGER AT LEAGUE ISLAND.
| In the course of describing similarly danger
Gus state Of affairs at League Island. Philadelphia
! where the dock completed in 1884, Admiral En-
dicott quotes the civil engineer in charge before
repairs commenced few months ago. In an official
| report. thus:
The dock is IN state OF decreptude that
| causes anxiety and constant watchfulness. Shores
| of timber have been placed at threatening points
| to prevent disturbance.
! Subsequently, when the repairs had made some
| progress. the engineer reported as follows:
The uncoverng OF the dock has shown very