Counterweight in the context of "Garage door"

A fly system, or theatrical rigging system, is a system of ropes, pulleys, counterweights and related devices within a theater that enables a stage crew to quickly, quietly and safely fly (hoist) components such as curtains, lights, scenery, stage effects and, sometimes, people. Systems are typically designed to fly components between clear view of the audience and out of view, into the large space, the fly loft, above the stage.

Fly systems are often used in conjunction with other theatre systems, such as scenery wagons, stage lifts and stage turntables, to physically manipulate the mise en scène.

An elevator (North American English) or lift (Commonwealth English except Canada) is a machine that vertically transports people or freight between levels. They are typically powered by electric motors that drive traction cables and counterweight systems such as a hoist, although some pump hydraulic fluid to raise a cylindrical piston like a jack.

Elevators are used in agriculture and manufacturing to lift materials. There are various types, like chain and bucket elevators, grain augers, and hay elevators. Modern buildings often have elevators to ensure accessibility, especially where ramps aren't feasible. High-speed elevators are common in skyscrapers. Some elevators can even move horizontally. Smart elevators enable multi-elevator coordination, enhancing the riding experience while reducing costs.

A sandbag or dirtbag is a bag or sack made of hessian (burlap), polypropylene or other sturdy materials that is filled with sand or soil and used for such purposes as flood control, military fortification in trenches and bunkers, shielding glass windows in war zones, ballast, counterweight, and in other applications requiring mobile fortification, such as adding improvised additional protection to armored vehicles or tanks.

The advantages are that the bags and sand are inexpensive. When empty, the bags are compact and lightweight for easy storage and transportation. They can be brought to a site empty and filled with local sand or soil. Disadvantages are that filling bags is labor-intensive. Without proper training, sandbag walls can be constructed improperly causing them to fail at a lower height than expected, when used in flood-control purposes. They can degrade prematurely in the sun and elements once deployed. They can also become contaminated by sewage in flood waters making them difficult to deal with after flood waters recede. In a military context, improvised up-armouring of tanks or armored personnel carriers with sandbags is not effective against cannons (though it may offer protection against some small arms).

A weight (also known as a mass) is an object, normally with high density, whose chief task is to have mass and exert weight (through gravity). It is used for different purposes, such as in:

• Anchor
• Balance weight
• Ballast
• Bob
• Counterweight
• Fishing sinker
• Paperweight
• Plumb bob
• Tuned mass damper
• Weight training equipment

The Gerald Ratner Athletics Center (colloquially, the Rat) is a $51 million athletics facility within the University of Chicago campus in the Hyde Park community area on the South Side of Chicago, Illinois in the United States. The building was named after University of Chicago alumnus, Gerald Ratner. The architect of this suspension structure that is supported by masts, cables and counterweights was César Pelli, who is best known as the architect of the Petronas Towers.

The Ratner Athletics Center was approved for use in September 2003. The facility includes, among other things: a competition gymnasium, a multilevel fitness facility, an Olympic-sized swimming pool, a multipurpose dance studio, meeting room space, and athletic department offices. It serves as home to several of the university's athletic teams and has hosted numerous National Collegiate Athletic Association Division III regional and University Athletic Association conference championship events.