Every evening, Wilmington daily commercial., 1906-01-25

SlS Z.zs.s
are used they shall fully make good the
members in either tension or compression.
Stiiieners shall be provided ON both
sides % the web over supports and under
concentrated loads. They shall be of suf
ieient strength to carry the loads and
shall be connected with n sufficient NUM-
ber OF riyets to transmit the stresses into
the web plate. Stiileners shall fit SO as 10
support the flangos of the girders. Stiff
feners shall be used whenever the total
shear at any section of the girder divided
by the clear distance between the hanues
in feet
All rolled steel and wrought iron floor
and roof beams used in buildings shall
be Of full weight, straight and free from
injurious defects.
When rolled steel or wrought iron
beams are used in pairs 10 form a girder.
they shall be connected together bv bolts
and iron separators at the ends over sup
ports and under concentrated loads. OF at
intervals of not more than five feet for
uniformity distributed loads. All beams
twelve inches and over in depth shall
have at least two bolts TO each separa-
tor.
Tie rods shall be proportioned 10 re-
sist their respective stresses and have
nuts or turn buckles according TO the
duty 70 be performed. Holes for tie rods
in beams and channels shall be placed as
near the thrust of the arch as practicable.
Channels and other shapes where used as
skew backs, shall have a sufficient resist
iufr runr1anf frt 90 La sr.. tl,. AI....aA
arch. Tie rods entering walls shall be
thoroughly anchored therein.
All framing OF an iron or steel frame
proporiioned according 20 these provis-
ions shall have the shop and field connec-
tions made by riyeting, if possible, and
the corrections between cast iron and
wrought iron or steel members made
with the straps and bolts as rigid as pos
sible
When beams are Joined on the top Of
girders they shall be tied together with
the straps and to- the girders with bolts.
When riveting is not possible or manda-
tory, connection may be effected with
bolts. Beveled washers shall be used
whenever necessary TO fit the pitch lines
of members.
The distance from the centre of a rivet
hole to edge of material shall not be less
than one and one-half times the diameter
of the riyet Wherever possible, how
ever. the distance shall be equal to two
diameters. An rivets wherever practica-
BILE shall be machine driven. The rivets
in connection shall be proportioned and
placed 20 suit the stresses. The pitch of
rivets shall never be less than three di-
ameters Of the rivet nor more than six
inches. Gussets shall be provided wher-
ever required of sufficient thickness and
size to accommodate the number of rivets
necessary to make the connection.
Trusses shall be of such design that
the stresses in each member can be cal
/ culated. All trusses shall be held rigidly
in position by efficient systems of lateral
and sway bracing. Any member of a
truss subjected to transverse stress, in
addition to direct tension or compression
/ shall have the stresses causing such
stress added 10 the direct stresses coming
ON the member, and the total stresses
thus formed shall in no case exceed the
maximum allowable working stresses.
Bearing plates of stone or metal shall
be used to reduce the pressure on the
wall ends of all beams, girders, lintels
and trusses Wall plates under beams
and channels may be used as per regular
standards when little span openings not
over six feet in the clear or the floor
beams do not exceed six inches in depth
and are spaced not more than thirty
inches on centres, templates may be
omitted
Anchors shall be provided at the ends
of all beams, channels, girders or trusses
bearing on walls.
The iron or steel frame Of any build
ing shall be carried up true and plumb
and be rigidly braced from the beams OF
every story and left until the building is
! enclosed No more than three stories
shah be riveted up in advance Of the
others without completely plumbing
braeing, connecting and riveting up the
work in the stories below.
All cast iron or other metal fronts shall
be designed to allow for expansion and
contraction, backed up and made weather
tight and protected from corrosion by
being filed in solid with masonry, stone
or cinder concrete not less than eight
inches thick in front of the skeleton
frame.
All structural metal work shall b'
cleaned of all scale, dirt and rust and bs
thoroughly coated with one coat Of non
oxidizing or red lead paint before leaving
the shop or before erection. Cast iron
columns shall not be painted until after
the approval of their inspection by Chg
| inspector. Where services in riveted WORK
come in contact. they shall be painted
before assembling. After erection AL
spaces left for shop marks, all abrasions
and an rivet heads and bolts are 10 hs
gone over with coat Of paint after
which the whole frame shall be painted
with at least one additional coat Of dif
ferent tint from the first or coat Of
rattan cement may be applied.
All iron OF steel used below water leve
shall be enclosed with Portland concrete
to exclude the air and water.
AN metal fire escapes, balconies
bridges. ladders, chains, scuttles, brackets
tanks and piping exposed TO The outei
air or subject TO couosion shall be pro
portioned with a factor of safety pre-
scrihed for exposed work, and all sucl
work shall be painted as prescribed unde
the previous section. All brackets an'
cantilevcrs for bays, balconies and fir
/ -...... ehau ha nlaoad at or as near Z