Water cannon vehicle used in riot control

 The first truck-mounted water cannon were used for riot control in Germany in the beginning of the 1930s.
Truck-based water cannon were used widely in the United States during the 1960s for riot control. Although they were safer than a combination of firearms, tear gas, and batons, their use as a non-lethal riot control mechanism has fallen out of favor in the United States.
Since then, other higher-tech non-lethal weapons have been developed for domestic use. Whether these newer weapons are more effective and safer than water cannon remains controversial. Their competing vendors disagree as to which is more effective and safer.
Water cannon 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. In the case of the UK there are only 6 water cannons, all held by the Police Service of Northern Ireland, their use in England and Wales would require the authorisation of Parliament (or in the case of Scotland, the Scottish Parliament). The most modern versions do not expose the operator to the riot, and are controlled remotely from within the vehicle by a joystick. These vehicles can carry 8,000 litres (1,800 imp gal) of water, and have a delivery rate of 15 litres per second (200 imp gal/min). The water can be delivered as a continuous stream, or in pulses; as a hard jet or as a spray.
The State of New South Wales in Australia purchased a water cannon in 2007, with a view to using it during an APEC meeting in Sydney that year. It was not used. It was the first purchase of a water cannon in Australia.
Water cannons are still in use on a large scale in Germany, Northern Ireland, Belgium and other parts of Europe. The annual riots on May 1 in Berlin, the Schanzenfest fair in Hamburg, which regularly ends in riots, or other demonstrations, are usually accompanied by water cannon, which support riot police. German communities use their water cannon in hot summers to water public parks.
The pictures are two kinds of water cannon vehicle manufactured by Haomiao company. One is 4X2 drive, tank capacity is 6,000-8,000 liters. The other one is 6X4 drive, tank capacity is 10,000-12,000 liters.
http://www.hmfiretruck.com/pid11316559/HOWO+10+ton+ANTI-RIOT+WATER+CANNON+VEHICLE.htm