Working At Height Regulations/HSE & PASMA recommendations for safe assembly and dismantling of Mobile Access Towers
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...
The 3T Method
Having dealt with the necessary planning, it's time to look at the 3T Method itself - click here to view our photo-walkthrough