Fort Worth gazette. [volume] (Fort Worth, Tex.) 1891-1898, 1891-11-07

| tanned in the conclusion of his second ar
| ticle, viz: that he would hardly know
| how to estimate the strains in this pro
| posed bridge. The rules governing calcula
| tons of strength of cables, towers, floors
foundations, anchorage, etc. are the same
| these essentials this bridge is similar
to any other suspension bridge
of the usual types. The addition
of the wind brace cables, and of the auxil
larry device for stiffening and staying the
| bridge, does not alter the rules governing
| the strength of other members, unless it be
to strengthen them.
We think. and the opinion is justified by
his course, that Mr.. Collingwood had some
Interior purpose to serve, and that all that
| deferred him from attacking the vital fea-
lures of the structure was the lack of auda-
city to attempt it in the face of his profess
sion. The only part of the entire structure
which he attempts to attack for lack OF
strength is the single exception OF the brace
rods to the hand-rail
The sum and gist of this remarkable ex-
pert production is advice to build an iron
bridge, which might, and indeed had been,
as urgently given by the avowed repre-
sentatives of that kind CT bridge without
charge. Who was his unnamed friend to
whom he submitted the plans. and whose
opinion he gives US secondhand
Now we will ask your honorable body TO
compare our proposed bridge, to be sup
ported by 2l47 No. galvanized steel wires
Ceaylng out of account the lower half of
the auXiliaries,, with the well-known Waco
bridge, which is supported by about 1850
wires of the same size. The Waco bridge
IS about 800 feet long, and though poorly
stayed, has stood severe tests of traffic and
storm Tor some twenty-three years, and
was pronounced On inspection about two
years ago to be perfectly sound. 1t was
about that time sold to the county for
$4,000, and DIR. Eddy, while in Waco few
days subsequent, offered to duplicate it as
to size, and TO give nearly double guaranteed
strength, for the sumo of $4,000, and was
ready to give sufficient bond for fulfillment
of the offer. We desire to build an unques-
tionably good bridge for the city, and in this
connection will say that DR.. Eddy is now on
his way to this city, and we would prefer
to have him go over our plans before we
begin work, and if ne and his engineers
think any additions should be made, we will
cheerfully make them. We are, however,
firm in the opinion that our plans are more
than sufficient, and will make the best
bridge ever built in the county. We are
respectfully, NEIL P. ANDERSON, & Co.,
For T. j. Matlock.
Specifications for an Eddy steel wire
suspension bride over Trinity river at Fort
Worth, Texas.
The total length of the bridge is to be 23O
feet, consisting of 200 feet of suspended
spar between the towers and fifteen feet OF
an approach at each end. The total width
of the bridge Is to be forty-two feet from
out to out, consisting of two roadways of
sixteen feet each, and two side walks of five
feet each.
The bridge is designed. to carry q load of
100 pounds to each square foot OF clear
available platform space on roadways, and
sixty pounds for each square foot of clear
available space on sidewalks, allowing a
safety factor of five wires. The wire de-
signed for the cables, hangers and stays is
TO be No. 9 Birmingham gauge, galvanized
steel wires. and of an ultimate tensile
strength of 1000 pounds per square inch
net section of metal, allowing tifty-eight Of
such wires to equal one square inch Of
metal area.
The anchorage is made with side and
cross trenches with anchor pipe laid from
side to side behind mass of piling and
concrete as shown on plan. This mass will
be carried down to depth of about sixteen
feet below the surface Of the ground where
the earth is compact and unSielding.
The anchor pipe will be 4 six-inch
wrought iron pipe filled with concrete in
side and entirely surrounded by concrete
when the anchorage is completed so rs to be
protected from rust and decay All cables
and stays are to be surrounded by concrete
wherever penetrating the earth.
Cables-The cables are arranged as
shown on the plan. There are three main
cables assisted by six auxiliary cables. The
mum Der of wires in each of the cables shall
be as follows: