Work at height dictionary for facade access equipment

Facade Access Work at Height Dictionary

The world of facade access equipment is full of terms you may not use daily.  We’ve put together the dictionary of facade access equipment to give you a helping hand when you encounter terminology you may not be familiar with.

B is for Building Maintenance Unit

  • ANSI A120.1: The standard in the United States that establishes safety requirements for powered platforms for buildings where window cleaning and related services are accomplished with suspended equipment at heights in excess of 11 m (35 ft) above a safe surface. This standard is set up by the American National Standards Institute.
  • Bosun’s chair: Used to suspend a person from a rope and seat to perform work at height. Also called boatswain’s chair.
  • Building Maintenance Unit (BMU): A type of facade access equipment. The machines are automatic, remote-controlled or mechanical and are most often located on the roof of a structure. Building Maintenance Units come is various shapes and sizes, offering whatever facade access a building needs.
  • Building maintenance: Operations such as window cleaning, caulking, metal polishing, reglazing or other general maintenance on building surfaces/facades.
  • Cradle: See gondola.
  • Davit: A device, a bit like a crane, that is used for supporting, raising and lowering a suspended work platform.
  • EN 1808: This European Standard sets requirements for both permanent and temporary suspended access equipment, such as Building Maintenance Units and suspended platforms. The safety requirements set in the standard include test methods, markings and information that the manufacturer needs to provide for its products.
  • EU Machine Directive 2006/42/CEE: This European regulation sets rules for safety of all machinery placed on the European market. The safety rules apply to all manufacturers who want to sell their product in the European market. The Machine Directive guarantees a high level of safety to workers using the equipment. Building Maintenance Units are governed under this rule.
  • Facade access equipment: A system that allows workers to access the exterior or interior facade of a building for maintenance work, window washing, inspections etc. For example a roof car.
G is for Glass Replacement Unit

  • Gantry: A bridge-like structure with a platform. Can be used for both interior and exterior facade access. Also known as traversing work bridges.
  • Glass Replacement Unit (GRU): A hoisting system integrated in the roof car of a BMU, which suspends a hook between the gondola and the facade. Despite the fact that this extra hook can be used for a variety of purposes, it is mostly used to hoist window panels or other building materials. Read more about <replacing windows with a Glass Replacement Unit in this blog
  • Gondola: The cradle in which workers are lowered along the facade of a building. Building maintenance units and monorail systems can be equipped with a gondola.
  • Jib: The arm of the roof car. The jib can either be a fixed length, or be made to extend.
  • Luffing function: A movement that allows the jib to move up and down, like a hinge.
  • Monorail system: A combined system existing out a rail track with a set of trolleys and a self-hoisting gondola. Monorail systems can be used for interior and exterior facade access.
  • Mullion guide restraint: A system for stabilizing a gondola in which the cradle moves along a rail that is integrated in the building’s facade. The gondola is secured when it moves up and down the facade.
  • OSHA 1910.66: The American regulation regarding “Powered Platforms, Manlifts and Vehicle-Mounted Work Platforms” set by the Occupational Safety and Health Administration (OSHA).

P is for Powered Platform

  • Pantograph gondola: A specially designed cradle that is balanced by a counterweight. These gondolas are designed for buildings with uneven facades or facades with protruding elements.
  • Permanent facade access equipment: A system for accessing a building’s facade that is permanently installed to allow workers to fulfill their day to day tasks. A common example is a roof car.
  • Powered Platforms: Permanently installed equipment, such as a Building Maintenance Unit, dedicated to interior or exterior building maintenance of a specific structure.
  • Programmable Logic Controller (PLC): A computer system that allows BMUs to be monitored and controlled remotely.
R is for rack and pinion

  • Rack and pinion: A circular gear that travels along a straight gear bar to make something move. Generally found in Building Maintenance Units that need to travel along an ascending facade.
  • Rated load: The manufacturer’s recommended maximum load.
  • Restraint systems: A method of stabilization to keep gondolas of a Building Maintenance Unit at a fixed distance to the facade. These systems prevent the gondola from swinging in strong winds. There are three options for gondola restraint: wire rope, mullion guide or soft rope.
  • Roof car: A type of Building Maintenance Unit (BMU) that can position a gondola in front of the facade. The functions of a roof car determine the range of the system. Also called roof trolley.

S is for Suspended platform

  • Scaffolding: A temporary structure used to support a work crew to aid in construction, maintenance and repairs of buildings and structures. Also called staging.
  • Secondary brake: A brake system designed arrest the descent of a work platform or gondola in the event of an overspeed condition.
  • Self-hoisting gondola: Combination of a gondola/cradle with a self-reeving traction hoist.
  • Slewing function: The movement that allows the horizontal rotation of either the jib or the gondola of a Building Maintenance Unit (BMU).
  • Soft rope system: A system of special restraints located in the building’s facade that allow the gondola, or cradle, of a roof car to follow the facade closely. Most often found in inclining facades. Learn more about our soft rope system in our blog about replacing windows in high rise buildings.
  • Spreader bar: The beam via which the gondola, or cradle, is connected to the jib of a roof car. Also called a cross bar.
  • Suspended access equipment: another term for Building Maintenance Units
  • Suspended platform: A (self-hoisting) working platform that can be lowered along the facade.

T is for Traversing

  • Telescopic movement: A movement that extends a certain part of the BMU. The column can be made to raise or lower and the jib can be extended or retracted.
  • Temporary facade access system: A system for accessing a building’s facade that can be removed after the work is done. A common example is a suspended platform.
  • Traction hoist: A wire rope lifting mechanism for suspended work platforms.
  • Traversing: The horizontal movement of a roof car, most commonly along a rail track.
  • Undercarriage: The base frame of a roof car. This is either a fixed base or a base that allows the roof car to move along a rail track.
  • Upperframe: The cranehouse that holds the hoist unit and main slew drive. The upperframe is mounted to the undercarriage.
  • Window washing equipment: Another name for facade access equipment as the machine helps window washers gain access to the facade.
  • Wire rope restraint: A system that helps stabilize the gondola as it moves down the facade. Users attach wire ropes to attachment point on the facade as they work their way down the face of the building.


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