Fort Worth daily gazette. (Fort Worth, Tex.) 1882-1891, 1890-03-15
wAsHrYeToN. d. O.. Feb. 26 !,

WASHINGTON. D. c.. Feb. rs, 1890.
SIR have made careful and detailed esti-
mate of the cost of construction of an outer har-
Dor at Padre Island, based on information given
by you as to the facilities for procuring mate
rial for rip-rap and concrete in the immediate
vicinity.
The work of construction consists of the ap-
proach, the viaduct and the harbor.
APPROACH.
The approach consists of five miles OF double
track railroad, connecting the main land with
the east shore of Padre Island, crossing the
shallow waters of the Laguna de Madre. This
work presents no difficulty, and full estimate
of cost is Sl5o, 600.
THE vIADUCr.
The viaduct connecting the harbor with the
shore at Padre Island VIII be 1000 feet long, and
the cost will depend on the plan of construction
that may be adopted. have made estimate
on iron cylinders filled with concrete and con-
nected by trussed girders of twenty-five feet
span, and the cost, on this plan, will be $780,
Mr.. BenEano, the cost will be SIS per foot, or
$40, 900; difference of $50, COO.
HARBoR.
I propose to construct the harbor by sur
rounding the area with a substantial structure
of trestle-work Carvings double-track railway,
by means of which the material can be carried
in and placed in position with as much IA
cility as if on land.
The structure would consist of a bed of rip
rap surmounted by a solid wall of concrete
The cost OF this portion of the work for length
of 5000 feet, and inclosing an area of $50 acres,
would be 81 200, GOO.
The whole cost Of harbor, viaduct and ap-
proaches, with breakwater to protect the
trance, will not exceed 81, OoG, 600, and can be
extended indefinitely to meet the increasing de-
mands of commerce.
TIME REQUIRED.
Within one year from the time of commencing
operations the viaduct should be completed and
a wharf provided on which vessels could dis
oh in ,u;FI
water, and in two years the harbor should be
completed.
The arrangements would be such with a double
track railroad that the forces at work could be
increased to any desired extent.
wHARvEs AND WAREHOUSES;.
These can be built on screw piles, capped with
timber, but the cut forms no part Of the con-
struction of the harbor proper.
PREcEDENTs.
Outer harbors have not been constructed in
the United States. On the eastern coast there
has apparently been no necessity for them, but
there are numerous precedents in other coun-
tries. have a partial list before me of twenty
two harbors and breakwaters constructed in
open seas and in depths of water varying from
twenty to one hundred and twenty-five feet, SO
that harbor in thirty feet involves no elements
OF uncertainty as to practicability of construc-
ton.
WHY AN OUTER HARBoR Is PREFERABLE ON THE
GULF COAST.
Because all the conditions are favorable for an
outer harbor and very untayorable for an inner
one.
The deep water at Padre Island comes within
1000 feet OF the shore, with q bottom of hard
clay.
At Galveston the deep water, thirty feet, Is
SIX miles from the inner harbor, and the ap-
proach through shifting sand.
Parallel jetties. 1000 feet apart, with maxi
mum tide of fourteen Inches, can neither create
nor maintain navigable channel of thirty feet.
Were 1t possible to create scour between the
1etties on the plans proposed it would lead to
the formation of bars - the entrance and re-
Qulre their continued extension seaward.
There Is no precedent on the face of the globe
where such structures, under similar conditions,
have been successful. The civil engineers Of