New-York tribune., 1907-04-14
SKYSCRAPBR WEIGHTS
THE Heaviest in This City When
COmpEeted viii Be Sc, 1000 Tons.


II one goes through the Offices of one OF thu
big sl1yscraper construction companies one OF
these days one may see roomful OF young
men all figuring away Ike mad on intermlhaOie
sheets of paDer. The Iayuan IS astonished TO
learn that they are weighing skyscTapers anu
that the tallcst and most extensive buildings
UP 10 the thousands Of tons. are careluHy
weighed before they are built The evolution
Of he tan building has brought forth remark
able engineering specialization along many hhsS'
but none more noteworthy than in the case oi
lhe skyscraper weighers
For this weighing Of the skyscrapers Is no
easy job one cannot dump the material. IKE
a pound Of sugar, into pair Of scales and de-
clare there is 50 much weight, because, IN uhe
first place the scale has never been invented
that viii weigh a hundred thousand TONS
and. in the second place. the material is not on
hand a skyscraper must be weighed before II
IS built before the first caisson is sunk for the
foundations or the first steel column is set up
The scales are pencil and paper, balanced by
specially trained brains. And finally the opera
tion OF weighing a modern tall building may
cover, when completed, as many as thfty OF
forty typewriter pages. The weight OF New
Yorll's largest sllyscraper. now building in Cort-
landt street is estimated at $4,000 tons.
what is the most important factor 10 be
reckoned with in this skyscraping weighing:
was asked Of one Of the principal building en-
gineers Of the city.
Wind" was his rather unexpected reply II
there was no such thing wind about New
York the task Of the builder, and particularly
the man who figures on weight. would be great
~ smplihed But we have To figure on wind
up to a hundred miles an hour. If we didn't 4
blow might strike Manhattan some day THAI
would level our tallest buildings like many
dorninos an a row. SO we builders Of tall build
ings are always worrying about the wind, like
so many sailors and I'm all our calculations it
cuts q big figure. If it were not for the wind
New York would have one hundred story Office
buildings To-day"
Having taken D, important element Of wind
infO consideration. the structural engineer he
gins actual weighing operations, and. accord
ing to ground area and height determines the
strength of his steel frame. The nature Of the
! occupations of the tenants has first 10 be taken
into consideration, for if the occupants are to
use heavy machinery in their work il means so
much more strength necessary for the structure
Another thing the Weighers have to figure on
Is elevators. The elevators that hang from
cables require a heavy overhead structure to
sustain them and meet the strain of the heavily
loaded cars. and this is a factor in the weighers
work As he is figuring for cost, he must make
special allowance for this, because half-ton
steel beam on one of the big wheels on which
the elevator cable runs, or in fact. anything
of weight is a much more expensive PROPOSE
ton the thirtieth floor than il would be
the first floor. The growing use of elevators
Of the plunger type for the talleSt buildings.
however. has sinplified this problem, these
elevators not pulled up overhead cables,
but are operated from below by a great steel
column plunger long as the elevators
maximum rise. When the elevator descends this
column sinks into q steel cylinder deep in the
rock foundations OF the earth The fact thay
ms elevator device saves much space in the
building for the of tenants is also a factor
an the weigher's calculations.
The Job of weighing the body of the huildinc
=
pie. He knows how much foot Of wall weighs.
and so figures the whole. But the wall of
thirty story skyscraper is thirty-two inches
thick al the bottom and twelve inches thick al
The top story, with gradually decreasing thick
nesses between as one goes up, this task is also
oAe tiaL Gals Tor ngurlng. In weighing the
steel frame the task is also comparatively sim
pe-for the expert. He finds out how much
steel he VIII require for the whole, and then
10 get the total weight he simply multiplies the
weight Of q known steel unit A similar process
gives him his foundation weight and his weight
Of flooring.
But every bolt and bar and beam and window
sash has 10 be summed up in the reckoning
ana then there Is the problem of live weight, in
Hiudlhg desks, chairs, books. safes. human beings
and the other incidentals in an office The law
however, provides that the engineer shall ALLOW
a fixed figure for every square foot of live
weight, so that here again his task is a matter
OF multiplication. This, however must be fig
ured on floor 10y floor. and in a thirty-tWo story
skyscraper with 100000 square feet Of rentable
area II IS apparent that considerable multplca-
uon can be INDUCED in this matter alone.
me vino pressure, however, is the most diff
cult thing to figure on. and the height of the
Ekyscraper. its shape and the area exposed 10
The wind are all factors in a matter of most
delicate calculation
Even with this the WeiPhers task is not over
IN hguring costs he must ascertain how deep
below the surface Of the ground where the
building is 10 be erected New York's rocky
backbone lies. Borings must be made 10 deter
mine the character of the ground, for an S0Oo0
ton skyscraper cannot rest on loose gravel
Fortunately, New York is built on solid granite
though IN the downtown district this is often
found as far as 100 feet below the surface. If
the granite is too deep for foundations how
ever, the engineer is certain to find hard pan
Of a sufficiently tough quality TO bear up the
enormous weight.
Having determined all these preliminary facts
Involving an inhnity Of details. the skyscraper
Eyeigher is ready TO give his estimates on the
work, and as soon the prospective owner
gives the word an army Of men viii he gath
cred greet cranes and deTr1cks and machines
that would ma Ike the builder of half a century
ago open his eyes I'm amazement viii be brought
upon the ground and the dirt VIII soon begin
20 ny. Passersby viii see first great chaotic
hole, as II one OF the big molars of the world
had been pulled by some titanic dentist, and
then the colossal steel skeleton rising floor by
1lOor amid a pandemOnium Of ear-sTnashing
sounds. But by that time the ickle skyscraper
weigher has cast off his old love. He is figur-
ing away another building that is still i'm the
mysterious and intangible stages Of pen and
pencil.