Seen and unseen - Warning | Museum of Design in Plastics

As part of our series of blog posts relating to our Seen and unseen exhibition, I am taking a closer look at the Warning case particularly the Utility barrier.

The utility or manhole barrier acts as a warning sign and obstruction to prevent pedestrians from falling into a hole in the ground created during works on a road or pavement. This specific example was made in the UK by Melba Swintex and is red with red and white reflective tape.

Temporary road works of any kind are governed by the New Roads and Street Works Act, which was originally issued in 1991, and has subsequently been updated. The act is supported by relevant regulations and codes of practice to provide a legal framework for those undertaking maintenance work in our streets and roads. One such document is the Department for Transport’s Safety at Street Works and Road Works: A code of Practice of October 2013 which sets out the need for signage and barriers and how they should be used.

This document states that consideration should be given as to how pedestrians can be protected from risks inside the area of work and that it is important that they are set up properly to ensure they do not fall over. Our barrier has a unique D-hinge™ and D-clip™ system, which has been designed to connect to existing metal gates and other plastic barriers on the market making it extremely stable when set up. The clips and hinges are made of polypropylene, which is a tough and semi-rigid material with good heat, fatigue, and chemical resistance. These clips ensure that the barrier meets standards that require that barriers should be joined in a way that resists tampering. The barrier itself is made of red coloured high-density polyethylene (HDPE) and has deep channels to prevent the collection of rainwater. It is lightweight and compact meaning it can be easily carried by a single person, deployed quickly, and takes up minimal space in vehicles whilst in transit. The colour red has connotations of danger and warning, so people instinctively know they need to be aware of potential risk.

A close view of the polypropylene hinge clips on a warning barrier.

A close view of the deep ridges on the inner surface of a warning barrier.

As a pedestrian barrier, design standards require it to have a handrail fixed at between 1 metre and 1.2 metres above ground level, which should be reasonably smooth. It should have a visibility panel at least 150 mm deep, which may be integral with the handrail or, if separate, must be fixed so that its upper edge is a minimum of 0.9 metres above ground level and should have the red and white panel ensuring it is highly visible. It should also have a tapping rail of at least 150mm depth either at ground level or with a lower edge set at up to 200mm from the ground. Tapping rails are used to ensure the barrier will be detected by visually impaired people who use long-canes to help them perceive obstacles.

In all, the Melba Swintex utility barrier meets the following Standards:

Reflectivity requirements of BSEN12899-1
Chapter 8 - The Traffic Signs Manual
Traffic Signs Regulations & General Directions

One morning on my way to work I encountered a similar barrier in the wild. It was being used to protect pedestrians from an open hole in the ground. It is always great to spot objects that are similar to those in our collection being used in the way they were designed as it helps to put them into context.