FIGURE 8.
.7
Correct procedure for erecting long extension ladder. least one-third the trestle must
be above the working platform. The tower built slotting the sections
together until the required height reached.5m for boards 50mm thick. The boards which form the working platform should
be equal length and not overhang the trestles more than four times
their own thickness.
TRESTLE SCAFFOLD
Figure 8. The maximum span boards between trestles is:
● 1. The platform must be
at least two boards 450mm wide.5m from the working
platform, trestles may not used.
Trestles which are higher than 3.6m must tied the building give
them stability. the platform more than above the
ground, toeboards and guardrails must fitted, and separate ladder
provided for access. scaffold tower shown in
Fig.9.8
A trestle scaffold.Basic Electrical Installation Work
168
Safety First
Scaffold
● scaffold mobile towers are
always safer than ladders for
working above ground. Where anyone can fall more than 4. Two pairs trestles spanned scaf-
folding boards provide simple working platform.
MOBILE SCAFFOLD TOWERS
Mobile scaffold towers may constructed basic scaffold components
or made from light alloy tube.8 shows trestle scaffold. 8.3m for boards 40mm thick
● 2.
Start position
Footing
base of
ladder
Lift and walk
towards wall
Continue until
upright
FIGURE 8
