Hi - assistance required please I seem to remember from my Construction Cert a couple of years ago that the max height of a tower must not exceed 3 times the narrowest base measurement but was informed this morning that it is not the case now for some reason and it has recently changed. Has anything changed and where do I look for the info please? Thanks / Regards SW

SW who told you this morning? Could it have been an operator trying a fast one?

Having recently completed the PASMA course, their operators code of practice (see section 9.11 stability) states "It is no longer appropriate to apply simple rules of the thumb (eg measure 3x minimum base dimension for external use) but instead the manual the supplier provides will show the safe height to which various configurations can be erected and will give information on the use of stabilisers and outriggers to increase the stability of high towers. If these instructions are observed, aluminium alloy towers provide a stable and firm work platform for a wide variety of applications. PASMA recommends that stabilisers or outriggers are added at the first available opportunity, usually after the first module is complete" PASMA Manufacturers towers all comply to European and British standards. This is your guarantee that amongst other things, your tower meets very strict requirements for stability and meets stringent quality control criteria. Both Youngmans and Turner Access manuals do not specify the base dimensions, but simply a table of quantities of particular components required to achieve a specified tower height! Hope this clarifies your query. Alex

To Firesafety101, Your version of cis10 (2002) is well out of date. Download the 2005 version from HSE. JohnW

Hi frankc - thanks for your reply The tower in question is what you picked up on I think - light alloy type, castors, internal ladder, each length of "pipe" has clip each end to go over a cross member. (If I am honest I didn't know there were other aluminium types - except the very old type made with steel) JohnW - thanks for the heads-up about the revised edition. It is double the pages of the previous and now does not use the X3 shortest dimension - just go by manufacturers guidance. Thanks again to all who replied