9
A mobile scaffold tower. Ladders must never
be leaned against tower since this might push the tower over. shock above the 50mA level there-
fore fatal unless the person quickly separated from the supply.
The level intensity the shock will depend upon many factors, such
as age, fitness and the circumstances which the shock received. Below
50mA only unpleasant tingling sensation may experienced you
may thrown across room shocked enough fall from roof lad-
der, but the resulting fall may lead serious injury.
. The
lethal level approximately 50mA, above which muscles contract, the
heart flutters and breathing stops. Outriggers can
be used increase stability effectively increasing the base width. The platform must not be
moved unless clear tools, equipment and workers and should be
pushed the base the tower and not the top. ratio base height 1:3 gives good stability.
The stability the tower depends upon the ratio the base width tower
height. out-
riggers are used then they must fitted diagonally across all four corners
of the tower and not one side only.
If the working platform above from the ground must closed
boarded and fitted with guardrails and toeboards. The tower must not built more
than 12m high unless has been specially designed for that purpose. Any
tower higher than should secured the structure the building to
increase stability. When the platform
is being used, all four wheels must locked.
Secure electrical isolation
Electric shock occurs when person becomes part the electrical circuit.Safe systems working
169
Guard rail
Close boarded
working platform
Toe board
Locking castors
Diagnal
bracing
FIGURE 8.
● isolate
● secure the isolation
● prove the supply‘dead’before
starting work.
Access the working platform scaffold tower should ladder
securely fastened vertically the inside the tower.
Safety First
Isolation
● never work‘live’
