The New York herald., 1873-08-31

The recent damage done to our much admired
granite piers have awakened in the pubic mind
Derious thoughts regarding their stability. and like
Ill else that interests the public it has two sides.
which we give In the correspondence below.
It has been stated that the lnman Company have
minated their willingness to pay for the damage
gone to the pier BY their steamer the City or
Unscientihc and Dogmattc.
NEW YonK, August 2s, 1s7&
70 rae EDITOR OF rHR HERALD
do not profess to be scientifically acquainted
with the construction OF granite piers, but must
confess that even with my limited knowledge OF
the subject I am not at all surprised at the scci
dent which befell pier No. l. l think, before
commencing such . vast and expensive work
40 the construction Of o system OF piers
around Manhattan Island, 1t would only have been
common prudence to receive suggestions and take
Of the water, who nave beel In the habit OF build
ing piers for q LIFETIME
Liverpool, 1t is generally admitted has by far the
finest system OF docks In the world. Tney extend
for about ten miles along the River Mersey, with
out single break, and are wholly constructed Of
The stone however, ia not cut into smooth
blocks, but Is what Is known by the name OF rubbe
Maso nrya system under which every fragment
stronger tnan pier made OF smooth blocks.
over dfty years. and have daily received much
harder blows from steamers than the one which
played such havoc with the North River pier, and
erected. Wv '''
Rubbie masonry, IL will be seen at glance, can
be erected at half the cost OF square blocks
First, there is little or no waste OF granite; Sec
pnd the labor OF polishing Is almost entirely dis
servstion, that 1T it Is much stronger. Yours re-
Bpectfully, W. L
Scientific and ApoioEctic-The Damage
60 the New River Wall ut tho Bat
terry.
70 THE EDITOR OF THE HGRALD:-
The Impression that the injuIy to the granite
buykhead wall mot the new pier as enormously re-
ported is due to want OF e0lldity in the masonry
is very far from The truth. The injury was caused
BY the south face OF the wall being rammed by the
bow OF q large iron steamer. The blow was deiiv-
cred at nearly right angles to the face The vessel
was moving, as is proved by competent Observers
who witnessed the ccncussion, at not less than
three knots per hour, or i've feet per second. The
City or Limerick--the vessel that did the damage
It 10 safe to say, on entering port displaces up
wards Of 1000 TONS A weight OF 1000 tons,
moving at the velocity OF five feet per second,
win strike with an energy oil upwards OF S.OOo.OO0
OF foot pounds. The stem OF the steamer
IRON Ii skin Of Ss the Vessel, which for some distance
from the bow runs nearly straight lore and alt
hence this enormous iorce was concentrated over
but nve inches In width; tins explains the damage
done to the massive granite work OF the wall. 1t
will also aford explanation OF the havoc tnat Is
always caused by heavy vessel, with scarcely any
perceptible injury TO herself, striking head on ex-
emples are TOO common 10 need special mention.
IL Is the prnciple as Is well known, on which the
advocates for rams for naval warfare base their
argument.
4 nltecn:Inch cored shot, striking with the ve-
10clty OF loU0 feet per second will deliver q blow
with an energy OF 6,25O,0co foot pounds, or with
put nttle more than twice the force OF the impact
OF this steamer Those who had experienc In the
war unders'an that tho damage which SUCH a
shot would innict on the face OF our most substan
tial granite forts would be very CONSIDERABLE
IL Is quite cIear that neither massive granite ma
sonry any 0Cner construction that il AZ moss bic
to use for a river wall can stand without DAMAGE a
blow from heavy iron steamer striking head on.
The new river wall has larger area of section
and Is of massive character than the walls of
either the London or Liverpool docks. IL, how
ever, NJ high tide at Liverpool the person
In charge OF the movements oil an iron steamer
should manage to run head on into the
outer river wall two thugs would certainly come
to pass-thc masonry would be crushed and dis
lodged, and the plot or o.fcer In charge would be
punished with promptHess that would serve as q
warning. Tie damage 10 the work at the Battery
was the result OF the most wanton recklessness.
And as 10 tho question whether this damage should
cause any hestancy In the work OF giving to New
York decent water Eont--which con only be done
by stone Of some kind--let IL be remembered tnat
fhe short exposed length OF wall at the Battery Is
tne only place along the water front as a 1lance