Aerial device:
Device with an extensible (telescoping) or articulated arm, designed and used to elevate workers. The device can also be used to move materials, if it is designed and equipped accordingly.
Aerial ladder:
An aerial device consisting of a ladder (single or multiple sections) that terminates with a work platform.
The American National Standards Institute (ANSI) is a private, non-profit organization that oversees the development of standards for products, services, processes, systems and employees in the United States. These standards are established through a voluntary and consensual process. The organization also coordinates the alignment of American standards with international ones, such that American products can be used abroad.
Device used to align an aerial ladder on a boom rest for storage.
Boom rest:
Platform on which the ladder is secured when not in use. The boom rest is located toward the front of the truck and bolted onto the chassis.
Box truck (cube truck):
Trucks commonly built by bodybuilders for a wide range of functions. They usually consist of incomplete vehicles equipped with components that account for a greater total weight than that of complete models, but offer numerous options.
Cab-to-axle (CA):
Distance from the center of the rear axle to the back of the truck cab. For trucks with a tandem axle at the rear, the measurement is taken from the center of these two axles.
Center of gravity (CG):
The center of gravity is the application point of the resultant of weight or gravitational forces. It is also the point of intersection of all planes that divide a body into two parts of equal weight. It represents the mean position of an object’s mass, or the single point at which an object’s mass is concentrated. CG is used during stability testing or when determining the vertical center of gravity of a vehicle.
In our context, a chassis is the carrying vehicle on which an aerial device is mounted, such as a truck, a trailer or an all-terrain vehicle.
CSA C225-00:
A CSA (Canadian Standards Association) standard in force in Canada since 2000 to regulate the vehicle-mounted aerial device industry. The standard establishes criteria for the design, manufacture, implementation, testing, inspection, installation, maintenance, use and operation of vehicle-mounted aerial devices installed on a chassis and used primarily to move personnel. It also establishes criteria for operator training.
A material is considered dielectric if it contains no electric charge likely to move macroscopically. In other words, it is an environment that does not conduct electricity. It is also referred to as an insulator. An empty space, glass and a number of plastics can function as insulators. For instance, plastic materials are often used to cover electrical cables and thereby contain the electrical current.

D.O.T. (or US DOT):

The United States Department of Transportation (USDOT or DOT) is a federal Cabinet department of the United States government concerned with transportation. It was established by an act of Congress on October 15, 1966, and began operation on April 1, 1967. It is administered by the United States Secretary of Transportation.Its mission is to "Serve the United States by ensuring a fast, safe, efficient, accessible, and convenient transportation system that meets our vital national interests and enhances the quality of life of the American people, today and into the future."Prior to the Department of Transportation, the Under Secretary of Commerce for Transportation administered the functions now associated with the DOT. In 1965, Najeeb Halaby, administrator of the Federal Aviation Administration (FAA), suggested to President Lyndon B. Johnson that transportation be elevated to a cabinet-level post, and that the FAA be folded into the DOT.
Dual hydraulic cylinder:
A dual hydraulic cylinder works in two directions. It has two ports and pressure is applied alternately from each side of the piston, causing it to move in one direction and then the other. By contrast, a single-action cylinder works in one direction only: when an aerial ladder is lowered, for instance, a single-action cylinder simply releases pressure, leaving gravity to do the rest.
Finite element method:
The finite element method (FEM) is a technique used to solve complex problems in physics. It subdivides a complex field into simpler units whose physical behaviour is known, enabling one to deduce the behaviour of the complex field. The FEM is used to ensure that the forces in the parts used in the aerial devices do not exceed the capacity of the materials and that materials serving no function are eliminated wherever possible.
Gross vehicle weight rating (GVWR):
The GVWR is the maximum allowable mass of a road vehicle, including the weight of the payload, the driver and any passengers. The GVWR is set by the vehicle manufacturer or importer and is one of a number of characteristics that must be submitted for official certification to operate the vehicle on roadways. In the case of heavy vehicles, the compliance label is generally placed on the frame of the door on the driver’s side or on the door edge next to the driver. It can also be placed to the left of the instrument panel.
Horizontal reach:
Distance from the central point of the base of a telescoping ladder to the far end of the working platform (e.g., the bucket), when the telescoping ladder is positioned parallel to the ground.
State of a mobile unit when the sum of moments tending to cause overturn are equal to or exceed the sum of moments tending to resist overturning.
The person or company responsible for mounting an aerial device on a carrying vehicle.
Insulated aerial device:
Aerial device equipped with dielectric components that are designed and tested to meet nominal insulation characteristics.
International Organization for Standardization (ISO):
The ISO is an international standard-setting body comprising representatives from the national standards organizations of 158 countries. This organization aims to define worldwide industrial and commercial standards. ISO standards are useful for industrial and economic organizations of all types and function to serve the best interests of the public, namely consumers and users.
ISO 9001:
The ISO 9001 standard belongs to the ISO 9000 series of standards, which pertain to quality management systems. It establishes the organizational requirements for the existence of a quality management system.
Occupational Safety and Health Administration (OSHA):
An American government agency whose mission is to prevent work-related injuries, illnesses and occupational fatality by issuing regulations for workplace safety and health.
A person trained, authorized and employed to operate an aerial device.
Opening the extensible structure of a pivoting ladder moves its center of gravity upward and puts the vehicle at risk of overturning. In some cases, it is therefore essential to stabilize the vehicle when it is positioned for work, prior to operating the aerial device. This is done using telescoping outriggers that extend from the chassis and contact the ground by means of the pads. Neutralizing the suspension reinforces their action.
The payload is the part of what is carried by a given means of transportation that produces revenue or a non-monetary benefit. In the world of transportation (land, maritime or air), the payload is also referred to as freight or cargo.
Platform capacity:
Load capacity of a platform, equivalent to the maximum mass of persons and material that it can carry.
Service body:
A truck body equipped with outside compartments, mounted on an incomplete vehicle.
Snow grooming machine:
A snow grooming machine is a vehicle on tracks designed to groom snow on ski hills and snowmobile trails. It is a specialized over-snow vehicle.
Point of equilibrium in a vehicle. Every truck equipped with an aerial device must undergo a stability test to determine the point at which the vehicle will overturn when the platform is in use. These tests are conducted according to applicable procedures and standards, which provide for a rollover safety factor.
Telescoping device:
The terms telescoping and extensible are synonymous.
Torsion bar:
A torsion bar is a part of the suspension system on certain vehicle models. It compensates for the weight of the car in order to distance the suspension arm from the frame. A torsion bar is a tube that possesses elasticity (spring effect) as a result of thermal treatment during production. It is fastened on both ends.
Total height:
Height of vehicle when in road position. This measure is taken from the highest point of the vehicle (or accessory) to the ground. In the case of RH ladders, the measure is taken from the top of the bucket to the ground. Always be sure to comply with local height requirements.
Transport Canada:
Responsible for the development and application of regulations and policies with regard to inter-provincial and international transportation in Canada. The Department has oversight for navigation and transport, both with regard to infrastructure and the certification of material, and it plays a key role in the area of vehicle safety. The Motor Vehicle Safety Act established in 1971 stipulates that the Department must set safety standards for automobiles, motorcycles, trucks and other vehicles. Transport Canada has test centers that test motor vehicles and recommend improvements. Once a vehicle is built, it must be certified to meet CMVSS standards. As well, a compliance label and the seal of the certified installer must be affixed to the vehicle, consistent with Transport Canada standards (applicable only in Canada.)
A truck is a road vehicle weighing more than 3.5 tons, used to transport merchandise and, in the case that concerns us, an aerial device. Trucks are distinguished from lighter vehicles at the technical level (e.g., greater load on axle, larger dimensions).
Person who controls and is responsible for the aerial device.
A van is a box-shaped vehicle with four wheels that is approximately the same width and length as a large car, but taller and generally higher off the ground (also referred to as a light commercial vehicle). In North America, the term may also be used to designate any truck with a rigid case attached to the cab, including large-sized models.
Vertical center of gravity (VCG):
In a vehicle, the VCG is the average height from the ground of all parts comprising its mass. If the center of gravity is too high, the vehicle will be unstable in corners and the front brakes will be too heavily loaded during braking.
The wheelbase is the distance between a vehicle’s front and rear axles, measured from the center of a car’s front wheel to the center of its back wheel.
Working height:
The working height corresponds to the height of a worker’s chest relative to the ground.
Working platform:
Personnel-carrying component, such as a bucket or a platform, of an aerial device.

Note: We have drawn on a number of resources and Internet dictionaries to provide an overview of some of the terms used by the aerial device industry. This glossary is intended as an aid to understanding our activity sector. Robert Hydraulic Inc. will not be held liable if any information in this glossary is found to be inaccurate, poorly interpreted or legally false. Please note that the standards cited are continuously reviewed and updated, and as such the information presented on this site may not be current.