Safety must be sacrosanct

22 March, 2021

Among the panelists’ discussions on the topic, Eve Edwards, machinery safety specialist at Fortress Interlocks, spoke about safety in large systems, and how it is important to design any safety risk out of the systems from the start before they are put into use.

Edwards made the point that the additional level of risk associated with several large machines that are integrated means companies should consider things such as task zones. She said companies naturally do not want to have to shut down an entire production line in order for someone to put something in one end. So, explained Edwards, in order to maintain productivity while ensuring the workforce is safe, companies should consider which parts of the line could be shut down safely on their own, which parts could be turned off while the others keep running and how they interact with each other.

Whole-body access to potentially dangerous areas within or around machinery is another important aspect of machinery safety. With this in mind, Edwards said companies should, for example, check whether there is a risk of unexpected machine start-up when someone is in a vulnerable zone.

One question to ask yourself when re-setting machines is do you have a clear view of the whole zone? As Edwards explained, in a small area it can be easier to check whether there is anybody inside the perimeter before re-starting a machine. However, in larger areas with many different machines in play, checking whether someone is still in the perimeter can be more difficult. Edwards pointed out that one way of getting round this is issue is to install presence sensing technology to detect if someone is still inside the zone, but she added that this can sometimes prove not to be fully effective in large areas with lots of moving parts, shadows and places where people could be hidden from the range of the sensors. Edwards explained that this is where inhibit functions (a term particularly common in the US) are important – inhibiting the re-set function of a machine.

There are proactive and reactive inhibit functions. Proactive inhibit functions look at giving personal control to the personnel entering a large safe-guarded space. Proactive inhibit functions refer to the scenario whereby if personnel enter a large safe-guarded area to perform tasks, they know that while they are inside no one can reset and restart the machine due to the use of things such as safety keys, escape release technology or by being able to stop the machine if they are inside a perimeter and they realise that the machine is starting up and putting them in physical danger.

Edwards explained that there are also safeguarding supporting systems, which can add an extra layer of protection when connected to the control system. In this way, companies can more accurately determine who is trying to perform a task, whether they have the right credentials and whether they on the database as an authorised person for the tasks at hand.

The operational efficiency of machinery is, of course, critical for companies to continue to remain productive and to be able to deliver goods to customers within specified timelines. That said, the safety of your personnel can never be compromised and must remain a primary focus. Health and safety must remain sacrosanct.

Ed Holden, Editor