Jan 15 (Reuters) - Two of Saddam Hussein's aides were hanged before dawn on Monday, the Iraqi government said, admitting that the head of his half-brother Barzan Ibrahim al-Tikriti was pulled from his body during the execution. Here are some details on how the process should work. * Hanging is the suspension of a person by a cord wrapped around the neck, causing death. Throughout history it has been used as a form of capital punishment in various forms. That used in Iraq is modelled on the 19th-century method of execution used in Britain, which formed the Iraqi state after World War One. * Four types of drop have been used in hanging: the short drop, suspension, standard and long drop. In all but the last, subjects can remain conscious for minutes and eventually die of strangulation and/or loss of blood to the brain. * The 19th-century long drop through a trap door is intended to be more humane, generating enough force from the tightening of the rope and the twisting of the noose knot under the jaw to break the neck. A calculation is made based on the convict's weight, height and build of the drop needed to break the neck. The distance is typically 1.5-2.5 metres (5-9 feet). * When the neck breaks and severs the spine, the subject immediately loses consciousness. Brain death follows in minutes. But if the drop is too short, the subject can be strangled. If it is too long, the subject can be decapitated. Sources: Reuters/people.howstuffworks.com/ emedicine/Capital Punishment U.K.
