Water cannon

The water cannon picture shows a spray of liquid water, but this would result from the sudden depressurisation of steam immediately upon escaping the muzzle. Since there is a relationship between pressure, temperature time, I m not convinced that these two processes don t explain the s1 r9 power stroke. 

Figure 4.7. Elevated water cannon for use in HF release mitigation.

On Brent Spar we were bounced. This matters - we all took great pains to represent Shell s side of the argument. By the time the broadcasters had tried to intervene on the scientific analysis, the story had been spun, far, far into Greenpeace s direction [... ] When we attempted to pull the story back, the pictures provided to us showed plucky helicopters riding a fusillade of water cannons. Try and write the analytical science into that to the advantage of the words. (Cited in Rose 1998 158)... 

CR (dibenzoxazepine) was put into production in 1973 after testing on army volunteers. In addition to the usual properties (above) it may induce a transient rise in intraocular pressure. Its solubility allows use in water cannons. ... 

Full-Scale Civil Disturbances. In the control of full-scale riots (e.g., for politically motivated reasons) or clashes between rival groups (e.g., at sporting events, a variety of procedures may be used for dispersion and control purposes). These include truncheons, nightsticks, projectiles (e.g., bean bags, plastic bullets), water cannon, PCSIs dispersed as pyrotechnically generated smokes or in liquid spray devices. 

Provide water-spray cooling of fire-exposed containers either by remote-operated monitors or water cannons or by mobile water cannons placed near the fire-exposed containers early in the fire, with fire-lighters then retreating to a safe distance. The time available to set up and aim mobile water cannons would depend on the size of the container, its design pressure, the size of relieving devices, and the volatihty of the contents. 

Firefighting should be accomplished with remote appliances such as the water cannon (also called deck gun) of the fire truck. If there are no fires to fight, the fire service should remain out of the blast zone. Treat all explosions as a criminal act until proven otherwise. All bomb scenes are crime scenes and should be treated as such (see Chapter 1). 

The unit 3 hydrogen explosion caused damage to the integrity of the fuel storage ponds on units 3 and 4, with the risk of spent fuel becoming uncooled and uncontained, so water cannons were aimed at the fuel ponds on March 17. Helicopters were also seen trying to dump water onto the reactor buildings. 

Large-scale methanol storage usually uses cylindrical tanks similar to those used for petroleum products. A floating-roof design is usually the choice. If a fixed-roof tank is used, an inert gas pad must be used to prevent the possible formation of an c q)losive mixture above the liquid. Tanks in a tank farm are usually enclosed by dikes and protected by water cannons and fire-extinguishing systems. 

The use of all of these weapons is inevitably controversial and subject to intense press and scientific scrutiny. The debate about their use is often clouded by misconceptions and strongly held political and moral views. Although the use of baton rounds and water cannon is very unusual in the UK, chemical incapacitating sprays and TASER are now relatively common. 

Water cannons are designed to shoot a high-pressure water stream similar to a fire tender device. They can be used to control or disperse crowds during public disorder incidents. They cannot be used to target specific individuals, and have therefore been criticised as being indiscriminate and less useful at riot control than some other measures, such as baton rounds. Most of the advantage of such systems is that they are believed to act as a visible deterrent. 

Some modern water cannon systems are also capable of adding tear gas mixtures to the stream in order to increase their effectiveness. Some manufacturers have considered the addition of salts in order to enable electrical charge to be passed through the streams, although such systems are still experimental. 

One of the main difficulties with water cannon systems is that the behaviour of free water jets is very complex. Bulk properties of a water jet could potentially be calculated by examining mass flow rate and average jet velocity. However, it is extremely imlikely that the effective load on a particular individual could be calculated from first principles due to minor fluctuations in pump or nozzle characteristics. This makes water cannons unpredictable as a weapon and also has consequences due to the significant safety and training implications implied. 

TLiere is an extremely low worldwide incidence of life-threatening injuries as a result of water cannon use. However, it is well known that it is very difficult to differentiate injuries caused by water cannon from those caused by other potential sources of trauma such as baton rounds, hand-thrown projectiles or chemical incapacitating agents during public disorder incidents. 

Severe eye injuries caused by the direct force of police water cannon on the face have been reported in the medical literature but are fortunately rare. 

Casualties with injuries from water cannon use should be assessed and investigated as for other conventional injuries. Particular attention should be paid to the potential for significant eye injuries or blunt abdominal injury. 

There is no evidence of any fatality resulting from the operational use of a water cannon. Casualties should be allowed home, or admitted for further treatment or observation, as per routine injury guidelines, such as in the case of head injury. 

Defence Scientific Advisory Committee (DSAC) Sub-committee on the Medical Implications of Less Lethal Weapons (DOMILL) Interim statement on the medical implications of the use of vehicle-mounted water cannon in a public order role, Available at www.nio.gov.uk/... 

Nonlethal means for dealing with violent situations constitute a problem for law enforcement officials worldwide. Water cannons and rubber bullets are two examples of nonfatal methods used for dealing with mob action. Now there is another way— sticky foam. 

---