Breakdown of changes to EN 1004

This is a comprehensive list of all differences between EN 1004:2004 and EN 1004-1:2020. You will find it useful to read this alongside our general guidance for the public, which does not go into as much detail.

Introduction

The standard has a new introduction, which confirms 3 important points:

• The wind load requirement for mobile towers is 0.1kN/m2 (low compared to scaffolding). What this means is that mobile towers are “generally intended for shorter duration tasks” and “may be relocated or quickly dismantled”. This is to give a steer as to the kind of work mobile towers can be used for.
• The existence of the European Temporary Work at Height Directive enacted in the UK by the Work at Height Regulations.
• “Mobile access and working towers are not anchor points for personal fall arrest equipment unless they are specifically designed in accordance with relevant European standards” At this moment in time, there are no relevant European standards of this nature, so there’s nothing that would guide someone to design a mobile tower with fall arrest. Mobile towers are not currently intended to be used with fall arrest.

National Foreword

In this part of the standard, each state can mention anything they feel is necessary because of their local situation and how towers are used.

There was some concern within UK temporary works groups and the Health and Safety Executive (HSE) about changes in the standard that refer to the use of ballas (weight placed on a tower to stabilise it). Previously only solid materials could be used, like concrete or steel. However, this has now changed to allow liquid or granular. This change was required in some parts of Europe but caused concern in the UK because of past issues. As such, the new National Foreword in BS EN 1004 confirms the UK position regarding the changes in the standard to the use of liquid and granular ballast:

• “The UK committee recommends that the use of liquid or granular materials used as ballast in accordance with Subclause 7.7.2 should be considered carefully, risk assessed and managed by a competent person”.

PASMA guidance will continue to recommend the use of solid materials e.g. steel or concrete.

Scope

This section sets out what the standards covers. Here’s what you need to know:

• EN 1004 has been changed to cover towers heights from ground level up to 8m outdoors and 12m indoors. You’ll recognise that the maximum heights haven’t changed but the minimum working platform height has changed from 2.5m to ground level. This was one of the key objectives of the revision.
• The revised text confirms that mobile towers have dimensions” which are fixed by the design” (i.e. the dimensions of frames, braces and platforms cannot be changed). This is to highlight the differences between mobile towers and scaffolding.
• It confirms that EN 1004 does not apply to scaffolding such as those covered in EN 12810 and EN12811- the standards for other types of scaffolding.

Normative references

This is a list of other standards where some of their requirements are applicable to mobile towers. Changes made here were:

• It now includes EN 131 Ladders. There’s lots of info in this standard that could be applied when considering the means of access to a tower.
• EN 74, the standard for base plates, has been removed. The revision of EN 1004 confirms that mobile towers must be mobile i.e. on wheels, so all references to the use of base plates have been deleted. Sometimes little changes actually mean big things – for the first time, we can say that a mobile tower is mobile. Towers on base plates now fall under the UK national standard BS 1139 Part 6.

 Terms and definitions

Special terms are defined in this section, i.e. anything not defined in the dictionary or used in common parlance. The definition of a mobile access tower has changed slightly to read:

Mobile access and working towers

• Temporary free-standing structures consisting of prefabricated elements, having dimensions fixed by the design and four legs with castors, providing one or more platforms (anything bigger = BS1139-6)
• Note 1 : Mobile access and working towers can have outriggers or stabilizers. They can be stabilized by supports on the ground or wall struts against a stable structures or ballast.
• Note 2 : Mobile access and working towers have castor wheels. Mobile access and working towers can be removed immediately, in case of arising wind greater than equivalent dynamic pressure 0.1 kN/m2 or at the end of the work shift

Classification

The classes of mobile tower in EN 1004 remain unchanged, but the minimum clear height classes have been explained better.

Materials

Changes have been made to this section to allow use of alternative materials to steel and aluminium, for example GRP fibreglass. This section now reads:

“Materials shall fulfil the requirements given in European Standards, where design data are provided. If European Standards do not exist, ISO Standards can be applied. Materials shall be sufficiently robust and durable to withstand normal working conditions. Additional requirements for some materials are given in EN 12811-2 [for scaffolding]. When materials are used, whose properties in relation to the intended application (e.g. temperature, ageing, UV-degradation) are not given in any available standard an adequate assessment is required. Steel shall be protected by one of the methods given in EN 12811-2, or zinc plated to the level required for the design service environment stated in EN ISO 2081.”

General requirements

This is where the majority of requirements are kept. The changes and clarifications made here are:

• EN 1004 mobile towers can only be single bay structures. Linked towers, towers with bridges, cantilever towers and large deck structures are all covered in BS 1139-6.
• EN 1004 towers must be designed so they do not require the use personal fall protection.
• EN 1004 towers have only one working platform at a time; they are not designed for multiple people to work on multiple platforms. Intermediate platforms can be converted to working platforms if they have 3-part side protection (i.e. guardrails and toe boards).
• EN 1004 towers have a maximum 2.25m vertical distance between platforms (previously it was 4.2m), which reduces the height a person could fall. This is the smallest number that was practical to achieve while maintaining the height classes.
• EN 1004 towers have a maximum 3.4m vertical distance from ground to first platform (previously it was 4.6m).
• New geometry for side protection is confirmed. This allows for new developments in AGR systems, which are becoming more prevalent. It was clear that current requirements were limiting innovation.
• The minimum clear width between toe boards is 0.5m.
• There are new requirements to prevent castors falling out.
• Strength test procedures for castors have been clarified.
• Quite demanding new requirements for ballast which is not made from solid materials, e.g. must be puncture proof and used in container provided by manufacturer. PASMA will continue to recommend solid material – see National Foreword section above.
• Platforms must be secured at both ends to prevent uplift. This is a new requirement. It’s referred to as ‘wind locks’ – it stops the platform uplifting in wind.
• For towers with a working platform below 2m, it’s now possible for manufacturers to develop products that allow access from outside the tower. There are also new requirements for stability on such towers.

 Other

• The requirements for the Annex A Test for Stiffness have been clarified, which is an area that has always raised questions for designers.
• Annex B contains a list of any national laws that contract the standard. In these cases, law takes precedent. This list has been updated to include a new Swedish law.
• There’s now an Annex C, which gives information about wind factors used in design calculations.