TBN: Complex Towers
INTRODUCTION
BS EN 1004-1:2020 is the definitive general standard covering prefabricated mobile access towers. However, it applies only to wheeled towers up to 8 metres outdoors and 12 metres indoors. Towers outside of this description—constructed from mobile tower components but not standard straight-up towers—are regulated by BS 1139-6:2022.
Many applications require more complex towers, which place greater structural demands than standard towers. Alto HD towers are designed from the outset to safely execute these advanced structures without compromise.
TYPES OF COMPLEX TOWERS
Complex towers commonly fall into the following categories:
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Tall Towers – Exceeding 12 metres in height, requiring additional rigidity and stabilisation.
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Linked Towers – Towers joined “longways” or along building frontages for continuous access.
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Bridge Towers – Linking platforms at the top level only for targeted access.
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Large Deck Towers – Parallel bridge towers joined by lateral decks for uninterrupted work areas.
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Cantilever Towers – External platforms imposing significant tension and sway forces.
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Stepped Towers – Built on sloped or stepped surfaces using specialized components.
APPLICATION
These guidance notes provide an overview of each tower type and highlight best practices for safe and compliant construction. They are intended as general guidance and do not replace formal training, risk assessments, or method statements. Only competent and trained personnel should plan, erect, alter, or dismantle complex towers.
For further guidance, consult PASMA (www.pasma.co.uk | +44 (0)845 230 4041) or contact Alto Access Products.