Quantity Schedule - 850 3T Method
6
Number of working platforms allowed
The MAXIMUM SAFE WORKING LOAD (the combined weight of the users, tools
and materials) that may be placed on the tower is the total weight less the self
weight of the tower. The total weight for the towers shown in the schedule is 950kg
.
Example 1:
An 850 tower built using the 3T method with a 4.2m platform height and a
platform length of 1.8m has a self weight of 151kg.
950kg — 151kg =
799kg maximum safe working load
total weight
self weight
(users, tools and materials)
Example 2:
An 850 tower built using the 3T method with a 11.7m platform height and a
platform length of 2.5m has a self weight of 410kg.
950kg — 410kg =
540kg maximum safe working load
total weight
self weight
(users, tools and materials)
For greater heights and loads, consult Youngman for guidance.
Platform Loading
On an 850 tower a platform comprises a single deck. The maximimum safe
working load (the combined weight of the users, tools and materials) that may be
placed on a platform is 275kg, evenly distributed over the deck.
The quantities on page 5 will enable BOSS towers to be built safely and therefore
comply with the requirements of the Work at Height Regulations 2005. They include
double guardrails to all platforms, and toeboards will need to be added if any levels
are used as working platforms and for storage of materials. BS1139 requires
platforms at least every 4m, and these measures will exceed that requirement.
Ballast: Internal/External use
Stabiliser requirements are based on calculations from BS1139:
1.
Up to 8.2m (platform height) the stabilisers and ballast are shown for
external use.
2.
Above 8.2m the shedule is for internal use only.
For internal use only towers may be erected up to 12.2m without ballast.
SP10 stabilisers may be fitted up to 9.7m platform height. For greater
rigidity, fit SP15 stabilisers at lower height.
Mobile Outriggers
MP7 and MP16 mobile outriggers can be used instead of SP10 and SP15 telescopic
stabilisers respectively, as detailed below. MP7 mobile outrigger kits comprise:
MP7 MOBILE OUTRIGGER
4
125/150/200mm CASTOR
4
(Use same diameter castors as on tower)
250mm ADJUSTABLE LEG
4
PLAN BRACES
4
The above components replace:
SP10/SP15 STABILISER
4
