The Work At Height Regulations, introduced on 6th April
2005, have some major implications for users of Mobile Access Towers.
In particular, the assembly and dismantling of Towers now requires
a much higher level of safety than was previously the case.
At the AIF conference, held at the NEC in Birmingham in May 2005,
Peter Bennett stated on behalf of PASMA that there are:
"...two currently recommended and approved assembly,
dismantling and alteration methods in consultation with the HSE"
Peter stressed the word "currently", making it clear
that it was important to leave room for future innovations in this
area.
As the recommended and approved methods differ significantly from
those previously taught, we have issued this Technical Update to
allow our Customers to adopt them as soon as possible without the
need for further formal training. The Tower manufacturers will be
issuing revised assembly guides for their Towers taking these methods
into account, and we strongly advise all our Customers to contact
their Tower manufacturer for specific guidance as soon as possible.
Basic Requirements - Assembling & Dismantling Mobile Access
Towers:
Where assembly/dismantling of the Tower cannot be done from
the ground (i.e. above the base lift), all work should be carried
out from a deck surrounded on all four sides by a double handrail.
This has been the case for working decks for some time, but is a new requirement for temporary decks used for assembling/dismantling
Towers
These handrails MUST be in place before anyone stands on the
deck. This requires the handrails to be fitted/removed from
below the deck and it is this that has triggered the development
of Advance Guardrails (i.e. prefabricated units fitted or relocated
in advance), and the Through-The-Trap (3T) Method
Preferred Methods - Assembling & Dismantling Mobile Access
Towers:
Advance Guardrail - a specially manufactured component
allowing a full double handrail to be erected or relocated safely
and easily from the previous (fully protected) deck level. Most
(possibly all) PASMA Tower manufacturers already have prototype
AGs, and are due to launch their products shortly. Full instructions
will be provided, so we do not intend to comment any further on
this method for the time being
Through-The-Trap (3T) Method - the only method of assembly/dismantling
that uses standard Tower components (though often more of them)
considered to be sufficiently simple to learn, safe, and applicable
to all configurations of Span Towers, i.e. double width and single
width
Although the 3T Method appears to be straightforward, our experiments
have shown that in practice some initial planning is necessary before
a Tower can be built using this method:
Initial Planning - The 3T Method
Choice of Base Frames - the final deck height of the
Tower will dictate the size of frames that must be used as the
base frames - click here for details...
Positioning of Temporary Handrails - depending on the
type of frames used, this has an impact on where the handrails
are attached, and the number and type of decks required at each
level - click here for details...
Additional Components - you will frequently need to add
additional components to your tower to enable you to build it
in accordance with the 3T Method - we have produced a table, based
on extensive hands-on experimentation, of what we believe the
deck and handrail quantities should be (for the Boss 1450 Ladderspan
Tower). Click here for details...
Diagonal Bracing - the diagonal braces may have to pass
one or more full-width decks, careful positioning will ensure
ease and speed of assembly - click
here for details...
Fitting Toeboards To Intermediate Deck Levels - on the
Boss 1450 Ladderspan Tower this can be difficult unless you know
how - click here for details...
