Mobile Access Towers: The UK Safety Rules (PASMA Tower Guide)

What a Mobile Access Tower Is — and the Standard

A mobile access tower is a free-standing, prefabricated working platform built from lightweight aluminium frames, braces, platforms and guardrails, mounted on lockable castors so it can be moved. It gives you a stable, guarded platform to work from at height without erecting fixed scaffolding.

The relevant product standard is BS EN 1004-1, which covers prefabricated mobile access and working towers made from prefabricated elements. A compliant tower is supplied with an instruction manual that specifies the configuration, the components, the stabiliser requirements and the maximum platform heights. That manual is not optional reading — it is the document that tells you how to build the tower safely for the height you need.

The Legal Framework

Three pieces of UK legislation sit behind tower use, and you need to know how they fit together:

• Work at Height Regulations 2005: The core law. It requires that work at height is properly planned, supervised and carried out by competent people, that equipment is suitable, and that the risk of a fall is prevented so far as is reasonably practicable.
• PUWER (Provision and Use of Work Equipment Regulations 1998): A tower is work equipment. It must be suitable for the task, maintained in good order, and only used by people who have received adequate information, instruction and training.
• Competence requirement: Towers must be assembled, altered and dismantled by people who are trained and competent to do so. An untrained operative throwing a tower together is a breach of both the Work at Height Regulations and PUWER.

The practical message is simple: planning, the right equipment and trained people are not nice-to-haves. They are the legal baseline, and the HSE treats tower falls as serious, often prosecutable, events.

PASMA Training — the Recognised Card

PASMA (the Prefabricated Access Suppliers' and Manufacturers' Association) runs the recognised industry training scheme for mobile access towers. A PASMA card demonstrates that the holder has been trained to assemble, alter, use, inspect and dismantle towers safely and in line with the manufacturer's instructions.

For most trades, the standard course is "Towers for Users", which covers building, inspecting, moving and dismantling a standard tower. Cards are typically valid for five years, after which you refresh. If you build towers on site — or you send staff up them — being able to show valid PASMA training is the cleanest way to evidence competence under PUWER and the Work at Height Regulations. It also matters commercially: principal contractors increasingly ask for the card before anyone touches a tower.

Safe Build Methods: 3T and AGR

The most dangerous moment in tower work is building or dismantling the upper levels, because that's when an operative could be standing on a platform that doesn't yet have its guardrails fitted. Two recognised methods exist specifically so you are never exposed on an unguarded platform.

3T — Through The Trapdoor

With the 3T method, the operative positions themselves in the trapdoor of the platform and fits the guardrails for the next level from that protected position before moving up onto it. You only step up onto a platform once its guardrails are already in place. It requires no additional components beyond the standard tower.

AGR — Advance Guard Rail

The AGR method uses temporary guardrail units that are fitted from the level below and locked into place in advance. The operative then climbs onto a platform that is already fully guarded, because the guardrail was advanced ahead of them. AGR requires the specific advance guardrail components designed for your tower system.

Both methods achieve the same goal: nobody is ever on an unguarded platform. Use the method your tower system and training support — but never improvise a build that leaves an operative standing at height without guardrails.

Key Safety Points

The following points come up again and again in HSE guidance and incident reports. Treat them as the non-negotiables of tower use.

• Stabilisers and outriggers: Fit them exactly as the manufacturer's instruction manual specifies for the height you are building. They are what stop the tower tipping — they are not optional ballast.
• Maximum height: Never exceed the manufacturer's maximum platform height. As a typical rule of thumb this is around 8m outdoors and 12m indoors for the working platform unless the tower is tied to a structure — but always follow the figure in your specific manual.
• Climb inside, not outside: Always climb the tower using the internal ladder built into the frames. Never climb up the outside — it pulls the tower over and there is nothing to fall back into.
• Lock the castors: Lock all castors before anyone climbs the tower, and check they are locked. A tower that rolls under load is a fall waiting to happen.
• Full guardrails and toe boards: The working platform must have a complete set of guardrails and toe boards fitted before it is used, to prevent both people and materials falling.
• Firm, level ground: Check the ground is firm and level before building. Soft, sloping or made-up ground can let a leg sink and the tower lean.
• Safe working load: Do not exceed the maximum safe working load for the platform — count people, tools and materials together.
• Never move with people or materials on board: Always clear people and loose materials off the tower before moving it. Move it by pushing or pulling at the base, never the top.
• Mind the wind: Stop work and do not move or use a tall tower in strong or gusting wind. A common guide is to stop at around 17mph (Beaufort force 4 and above) — and reduce the tower or tie it for exposed sites.
• Avoid overhead hazards: Check for overhead power lines and obstructions before building and before moving.

Inspection and Tagging

A tower must be inspected at the right points, and the inspection must be done by a competent person:

• Before first use after assembly, to confirm it has been built correctly to the manual.
• After any event that could affect its stability or safety — being struck, moved a significant distance, exposed to high winds or left unattended.
• At regular intervals in line with your risk assessment for towers in continued use.

Where a person could fall 2m or more from the platform, the inspection should be recorded. A tag or scaffold-tag system is the simplest way to show a tower's status at a glance: a clearly tagged tower tells everyone on site that it has been inspected and is safe to use.

Just as important — never use an incomplete tower. If a tower is mid-build, missing guardrails or has been part-dismantled, it should be physically marked as out of use (remove the access or apply a "do not use" tag) so nobody climbs it by mistake. Most tower falls involving missing components happen because someone used a tower that was never finished.

Quick Reference: UK Mobile Access Tower Checks

The Bottom Line

A mobile access tower is one of the safest ways to work at height — provided it's a BS EN 1004-1 tower, built to its manual by PASMA-trained people, fitted with stabilisers and full guardrails, kept within its height and load limits, climbed from the inside, moved empty and inspected and tagged at the right points. Get those basics right on every job and you stay compliant with the Work at Height Regulations 2005 and PUWER — and, far more importantly, your team comes home in one piece.