Section 27-562. Moving loads

Where applicable to the use or occupancy of the
  building, the design shall consider the moving loads described below.
    (a)  General.  The  loads  established  in subdivisions (a) and (b) of
  section 27-557 of this article shall be assumed to include allowance for
  ordinary impact conditions.
    (b) Passenger vehicles. Areas used for,  and  restricted  by  physical
  limitations  of  clearance  to,  the  transit  or  parking  of passenger
  vehicles  shall  be  designed  for   the   uniformly   distributed   and
  concentrated  loads  for  parking areas for such vehicles as provided in
  reference standard RS 9-2, applied without impact. An exception is  made
  for  members  or  constructions  which, because of physical limitations,
  cannot be subjected to direct load from the vehicle or from  a  jack  or
  hoist   used   to   raise  or  suspend  the  vehicle.  Such  members  or
  constructions shall be designed  for  the  loads  corresponding  to  the
  actual usage.
    (c)  Truck  loads.  Minimum  loads  (including  vertical, lateral, and
  longitudinal) and the distribution thereof  shall  meet  the  applicable
  requirements  of  reference standard RS 9-3, except that impact shall be
  taken as ten per cent of the vertical reaction.
    (d) Railroad equipment. Minimum loads  (including  vertical,  lateral,
  longitudinal,  and  impact)  and the distribution thereof shall meet the
  applicable requirements of reference standard RS 9-4.
    (e) Crane runways and supports.
    (1) VERTICAL LOADS. Actual maximum  wheel  loads  occurring  when  the
  crane  is  lifting its capacity load shall be used. To allow for impact,
  the lifted load shall be increased twenty-five per  cent  or  the  wheel
  loads  increased  fifteen  per  cent  whichever  produces greater stress
  condition.
    (2) HORIZONTAL LOADS.
    a. Lateral load (due to crane trolley travel) shall be twenty per cent
  of the sum of the capacity load and the trolley weight, applied one-half
  at the top of each rail and acting in either  direction  normal  to  the
  runway rail.
    b. Longitudinal load (due to crane travel) shall be twenty per cent of
  the  maximum  total  reaction  (not  including impact) on the rail being
  considered, applied at the top of the rail and acting  parallel  to  the
  runway.
    (f) Monorail beams and supports.
    (1)  Vertical  loads shall be the sum of the capacity load and trolley
  weight. To allow for impact, the lifted load shall be increased ten  per
  cent  for  hand-operated  and twenty-five per cent electrically-operated
  trolleys.
    (2) Longitudinal loads shall be twenty per cent  of  the  sum  of  the
  capacity load and the weight of the trolley.
    (3)  Lateral  load shall be twenty per cent of the sum of the capacity
  load and the weight of the trolley.
    (4) Centrifugal forces shall be considered for curved tracks.
    (g) Loads on supports for elevators, dumbwaiters, and escalators.  The
  provisions of subchapter eighteen of this chapter shall apply.
    (h) Loads on machinery supports. Unless machinery is isolated from the
  support  framing,  the  reactions  of reciprocating or heavy powerdriven
  units shall be increased at least fifty per cent and reactions of  light
  shaft- or motor driven units shall be increased at least twenty-five per
  cent to provide for impact.
    (i)  Assembly  structures. Seating areas in grandstands, stadiums, and
  similar assembly structures shall be designed to resist the simultaneous
  application of a horizontal swaying load of at least twenty-four plf  of
  seats applied in a direction parallel to the row of the seats, and of at

  least  ten  plf  of seats in a direction perpendicular to the row of the
  seats. When this load is used  in  combination  with  wind  for  outdoor
  structures, the wind load shall be one-half of the design wind load, and
  the  provisions of subchapter ten of this chapter relating to infrequent
  stress conditions shall apply to this loading condition.
    (j) Heliports and helistops.
    (1) CONCENTRATED LOADS.
    a. Landing area. Helicopter landing areas shall be designed for either
  of the following vertical loads acting at any location:
    1. A single concentrated load equal to three  quarters  of  the  gross
  weight of the helicopter and acting on an area of one square foot.
    2.  Concentrated  loads  representing the gross wheel reactions of the
  helicopter acting simultaneously and increased one-third for impact.
    b. Taxiing  area  Helicopter  taxiing  areas  shall  be  designed  for
  concentrated loads in accordance with clause two of this subparagraph.
    (2)  UNIFORM LIVE LOAD. The landing and taxiing areas shall be capable
  of supporting a uniformly distributed live  load  of  forty  psf  acting
  nonconcurrently with the concentrated loads.