Water cannon

A water cannon is a device that shoots a high-velocity stream of water. Typically, a water cannon can deliver a large volume of water, often over dozens of meters. They are used in firefighting, large vehicle washing, riot control and mining. Most water cannons fall under the category of a fire monitor.

Water cannons were first devised for use on fireboats. Extinguishing fires on boats and buildings near the water was much more difficult and dangerous before fireboats were invented. The first fireboat deployed in Los Angeles was commissioned on 1 August 1919. The first fireboat in New York City was Marine 1, deployed 1 February 1891. There may have been other fireboats elsewhere even earlier.

Fire trucks deliver water with much the same force and volume of force as water cannons, and have even been used in riot control situations, but are rarely referred to as water cannons outside this context.

The first truck-mounted water cannon was used for riot control in Germany in the beginning of the 1930s.

The most modern versions do not expose the operator to the riot, and are controlled remotely from within the vehicle by a joystick. The German-built WaWe 10.000 can carry 10,000 litres (2,200 imp gal) of water, which can deploy water in all directions via three cannons, all of which are remotely controlled from inside the vehicle by a joystick. The vehicle has two forward cannons with a delivery rate of 20 litres per second (260 imp gal/min), and one rear cannon with a delivery rate of 15 litres per second (200 imp gal/min)

Water cannons designed for riot control are still made in the United States and the United Kingdom, but most products are exported, particularly to Africa and parts of Asia such as South Korea.

Use of water cannon in riot control contexts can lead to injury or death, with fatalities recorded in Indonesia (in 1996, when the cannon's payload contained ammonia),Zimbabwe (in 2007, when the use of cannons on a peaceful crowd caused panic),Turkey (in 2013, when the payload was laced with "liquid teargas"), and Ukraine (in 2014, with the death of activist and businessman Bogdan Kalynyak, reportedly catching pneumonia after being sprayed by water cannon in freezing temperatures). South Korea used water cannons containing capsaicin and fluorescent dyes for later screening and arrest in recent protests against its citizens.

...
Wikipedia