The "Long drop" or measured drop method.
In
1872, William Marwood introduced the concept of an accurately
calculated drop for the execution of Frederick Horry
at Lincoln
prison, as a scientifically worked out way of giving the prisoner a humane
death. This concept had been developed by doctors in Ireland and was in use there by the
mid 1850s. Longer drops were in use elsewhere by this time, e.g. in America, but the short drop was still used by
many countries at this time e.g. Austria,
Czechoslovakia, Poland & Russia.
The long drop method was designed to break the prisoners neck by allowing them
to fall a pre-determined distance and then be brought up with a sharp jerk by
the rope. At the end of the drop, the body is still accelerating under the
force of gravity but the head is constrained by the noose.If the eyelet is positioned under the left
angle of the jaw it rotates the head backwards, which combined with the
downward momentum of the body, breaks the neck and ruptures the spinal cord
causing instant deep unconsciousness and rapid death. The later use of the
brass eyelet in the noose tended to break the neck with more certainty.It is only in the last six inches or so of
the drop that the physical damage to the neck and vertebrae occur as the rope
constricts the neck and the force is applied to the vertebrae.The duration of this part of the process is
between 0.02 and 0.03 of a second depending upon the length of drop given.Generally the diameter of the noose is found
to have reduced some five to seven inches after the drop.
The accurately measured and worked out drop removed most of the prisoner's
physical suffering and made the whole process far less traumatic for the
officials who now had to witness it in the confines of the execution shed
instead of in the open air.
The drop given in the later part of the 19th century was usually between 4 and
10 feet depending on the weight and strength of the prisoner. The weight used
to calculate the correct drop is that of the prisoner's clothed body. In
accordance with the recommendations of the Aberdare Committee, from 1886 to 1892,
the length of drop was calculated to provide a final "striking" force
of approximately 1,260 ft. lbs. force which combined with the positioning of
the eyelet caused fracture / dislocation of the neck, usually at the 2nd and
3rd or 3rd and 4th cervical vertebrae. This is the classic "hangman's
fracture". The length of the drop was worked out by the formula 1,260 foot
pounds divided by the body weight of the prisoner in pounds = drop in feet.
Between 1892 and 1913, a shorter length of drop was used, presumably to avoid
the decapitation and near decapitations that had occurred with old table. The
1892 table produced a force of 840 ft. lbs.However there are a number of properly documented instances of
substantially longer drops being given during this period and it seems that
this table was seldom adhered to.After
1913, other factors were also taken into account and the drop was calculated to
give a final "striking" force of around 1,000 ft. lbs. The Home
Office issued a rule restricting all drops to between 5 feet and 8 feet 6
inches as this had been found to be an adequate range. In Britain, the
drop was worked out and set to the nearest half of an inch to ensure the
desired outcome.From around 1939 it
became customary to add a further nine inches to the drop calculated from the
1913 table, to give a force of around 1100 ft. lbs..
The 1913 table is still used in Singapore and probably Malaysia
and may have been adopted by other countries which use the British method, e.g.
Australia, Canada, the Caribbean nations and Egypt.Pakistan,
India and Bangladesh use
the measured long drop but it is not known whether they use the British drop
tables.Trace the evolution of
the long drop in the 19th century here and in the
20th century here.
British
drop tables.
The
weight of the prisoner is the weight recorded when they were weighed, clothed,
the day before execution.
1892 table
1913 table
Weight of prisoner
Drop in feet & inches
Ft. lbs. energy developed
Weight of prisoner
Drop in feet & inches
Ft. lbs. energy developed
|
