problem with cutting fibrous root systems that hamper excavation
was identified by studying the data in the Database of Demining
Accidents, where several excavation incidents appear
to have been caused by the deminer pulling roots. The deminers
did not have a tool to cut roots and so inadvertently pulled
the root while trying to sever it with an inappropriate tool.
The root then put pressure on a nearby mine.
root-cutter design is based on an existing effective cutting
tool a pair of anvil secateurs. Anvil secateurs do not
have cross-over blades and so do not pull fibrous
material. This tool is seen as an improvement on existing gardening
tools but not a final design solution for the task.
tool is designed for one handed use. This limits the length
of handles that can be used. The entire tool is 25cm long but
the hand may start only 15cm from any blast. The number of separate
parts has been reduced and the spring pivots moved well away
from a blast.
root-cutter has a securely welded all metal construction with
the exception of the anvil itself which is made from polycarbonate
(the same material as demining visors). Polycarbonate burns
or distorts rather than shatters in blast situations. The cutting
blade is made from hard steel, the springs from spring-steel
and the rest of the tool from mild steel. The handles and springs
are galvanised after manufacture. It can cut roots up to 2cm
tool is released by gentle pressure on the handles and is naturally
in an open position, so making one-handed use easy.
tests, the metal parts of the tool stayed in one piece when
placed on top of a mine. The polycarbonate anvil
for the blade was blown off and was not found. Its mild steel
rivet stayed in place.