Everyone has their favourite scene from a movie and many of them likely involve some kind of movement – whether the camera follows a person or a car or something else. But here’s something you may not know. Some of the best movie scenes ever filmed would not have been possible without casters. In this edition of Wheels Revealed, we look at how casters are used in the motion picture industry.

The most recognizable use of casters in Hollywood comes with what are referred to as tracking shots. A tracking shot is any shot where the camera follows backward, forward or moves alongside the subject being recorded.

This is often accomplished by mounting a camera on a specially constructed dolly that can be rolled on a surface or placed on rails like a railroad track to create smooth horizontal camera movements. Depending on its size, the camera dolly is moved by the camera operator or by a dedicated technician trained to operate the dolly by manually pushing it back and forth.

Camera dollies have several steering mechanisms. The typical mode is rear-wheel steering, where the front wheels remain fixed, while the wheels closest to the operating handle are used to turn. A second mode, round steering, causes the front wheels to turn in the opposite direction from the rear wheels. This mode allows the dolly to move in smooth circles and is frequently used when the dolly is on curved track.

A third mode, called crab steering, is when the front wheels steer in the same direction as the rear wheels. This allows the dolly to move in a direction diagonal to the front end of the dolly.

Casters used on camera dollies most often include pneumatic wheels to allow for a smooth ride. The tread on the wheels also helps grip the surface and eliminate any vibration. As noted above, a combination of rigid and swivel casters provide for different types of movement. The casters are also equipped with foot operated brakes to allow for secure positioning. In some cases the required smooth movement is achieved with casters that feature crowned rubber wheels. Dollies that are used on a track will often be equipped with a grooved wheel.

Behind the scenes, specially equipped studio carts are essential to any production. These carts are designed to hold an incredible array of equipment including stands, telescopic pull out ladder holders, detachable baskets and half milk crates. Carts can handle up to 1,000 lbs. of equipment and need to manoeuvre smoothly. They are equipped with a combination of 10” swivel and rigid casters featuring treaded wheels.

In some cases two additional rigid casters are added to accommodate additional weight. The casters are equipped with foot operated brakes to keep the cart stable when necessary.

So the next time you’re watching a great action scene, you might want to think about the casters that made it possible. But, who are we kidding. No one is ever going to do that. Just enjoy the movie.