NYC DOB Chapter 33 Definitions 2/5/2026
Accident An occurrence directly caused by construction or demolition activity or site
conditions that result in one or more of
the following:
1.) A fatality to a member of the public; or
2.) Any type of injury to a member of the public; or
3.) A fatality to a worker; or
4.) An injury to a worker that requires transport by emergency medical
services or requires immediate emergency care at a hospital or offsite
medical clinic; or
5.) Any complete or partial structural collapse or material failure; or
6.) Any complete or partial collapse or failure of pedestrian protection,
scaffolding, hoisting equipment, or material handling equipment; or
7.) Any material fall exterior to the building or structure
Adjustment (Scaffold) The calibration or modification of a scaffold, including any part or
component, that does not meet the definition of installation, removal, repair,
maintenance, or use, and does not constitute normal use or operation of the
scaffold.
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,NYC DOB Chapter 33 Definitions 2/5/2026
Alteration Any construction, addition, change of use or occupancy, or renovation to a
building or structure in existence.
Architect A person licensed and registered to practice the profession of architecture
under the education law of New York State.
Articulating Boom Crane A power-operated machine for lifting or lowering a load and moving it
horizon tally that utilizes a boom consisting of a series of folding pin
connected structural members, typically manipulated to extend or retrdct by
power from hydraulic cylinders, with or without a hoisting mechanism
integral to the machine.
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,NYC DOB Chapter 33 Definitions 2/5/2026
Axis of Rotation The vertical axis around which the crane superstructure rotates.
Axle The shaft or spindle with which or about which a wheel rotates. On truck and
wheel mounted cranes, it refers to an automotive type of axle assembly,
including housing, gearing, differential, bearings and mounting
appurtenances.
Base (Mounting) The base or carrier on which the rotating superstructure is mounted, such as
a truck, crawler or platform.
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, NYC DOB Chapter 33 Definitions 2/5/2026
Bearer (Putlog) A horizontal transverse scaffold member (which may be supported by legs
or mnners) upon which the scaffold platform rests and joins scaffold
uprights, posts, poles, and similar members.
Boom A section or strut, of which the heel (lower end) is affixed to abase, carriage
or support, and whose upper end supports a cable and sheaves where the
load is lifted by means of wire rope and a hook.
NYC DOB Chapter 33 Definitions Page 4 of 39
Accident An occurrence directly caused by construction or demolition activity or site
conditions that result in one or more of
the following:
1.) A fatality to a member of the public; or
2.) Any type of injury to a member of the public; or
3.) A fatality to a worker; or
4.) An injury to a worker that requires transport by emergency medical
services or requires immediate emergency care at a hospital or offsite
medical clinic; or
5.) Any complete or partial structural collapse or material failure; or
6.) Any complete or partial collapse or failure of pedestrian protection,
scaffolding, hoisting equipment, or material handling equipment; or
7.) Any material fall exterior to the building or structure
Adjustment (Scaffold) The calibration or modification of a scaffold, including any part or
component, that does not meet the definition of installation, removal, repair,
maintenance, or use, and does not constitute normal use or operation of the
scaffold.
NYC DOB Chapter 33 Definitions Page 1 of 39
,NYC DOB Chapter 33 Definitions 2/5/2026
Alteration Any construction, addition, change of use or occupancy, or renovation to a
building or structure in existence.
Architect A person licensed and registered to practice the profession of architecture
under the education law of New York State.
Articulating Boom Crane A power-operated machine for lifting or lowering a load and moving it
horizon tally that utilizes a boom consisting of a series of folding pin
connected structural members, typically manipulated to extend or retrdct by
power from hydraulic cylinders, with or without a hoisting mechanism
integral to the machine.
NYC DOB Chapter 33 Definitions Page 2 of 39
,NYC DOB Chapter 33 Definitions 2/5/2026
Axis of Rotation The vertical axis around which the crane superstructure rotates.
Axle The shaft or spindle with which or about which a wheel rotates. On truck and
wheel mounted cranes, it refers to an automotive type of axle assembly,
including housing, gearing, differential, bearings and mounting
appurtenances.
Base (Mounting) The base or carrier on which the rotating superstructure is mounted, such as
a truck, crawler or platform.
NYC DOB Chapter 33 Definitions Page 3 of 39
, NYC DOB Chapter 33 Definitions 2/5/2026
Bearer (Putlog) A horizontal transverse scaffold member (which may be supported by legs
or mnners) upon which the scaffold platform rests and joins scaffold
uprights, posts, poles, and similar members.
Boom A section or strut, of which the heel (lower end) is affixed to abase, carriage
or support, and whose upper end supports a cable and sheaves where the
load is lifted by means of wire rope and a hook.
NYC DOB Chapter 33 Definitions Page 4 of 39
