This article is part 2 of the series “Confined Space Work: Missing a Hazard?”
A tripod. A couple of fall arrest harnesses. A retrievable inertia reel (fall arrest block). A gas monitor. A small opening in the ground above an underground cavity. A silo, vessel, valve chamber; any number of different confined spaces. This is a common scenario for many companies working in confined spaces.
Usually there’s a ladder or step irons to climb up and down on. Brilliant.
A worker climbs down fastened onto a retrievable inertia reel which will lock out if they slip or fall as they go. This means they have a fall arrest back up in place, most importantly keeping them safe, while also fulfilling some of the requirements of the Work at Heights Regulations 2005.
If they need to be rescued the handle on the retrievable inertia reel can be used to pull them back up. Great system; a worker protected in the case of a fall and able to be rescued relatively easily.
But what happens if there is no ladder?
What if the step irons are rusted or falling out?
What happens when someone doesn’t know the difference between 2 different types of kit?!
Accessing in suspension:
If there’s no primary means of access (no ladder or step irons), the most commonly used system of access is to use a man-riding winch, which looks like this:
The worker then hangs, suspended by the man-riding winch, and is lowered in. To exit, or in an emergency, they are simply winched up. The problem is that a man riding winch looks surprisingly similar to a retrievable inertia reel. They’ve both got a handle and have a wire coming out of them. A retrievable inertia reel usually looks something like this:
Retrievable Inertia Reel
Look similar don’t they?!
While people use the phrase “man-riding winch” for these 2 items interchangeably, they are not the same. People are just confused, although they may not know it. Let me be clear as this repeatedly comes up in discussion; a man riding winch and a retrievable inertia reel are 2 completely different pieces of kit. While a retrievable inertia reel is suitable for protecting someone climbing up or down a ladder (Fall Arrest), it is not designed to lower someone into a confined space (Work Positioning). What is designed for lowering someone into a confined space though is a man-riding winch.
Man riding winch for access in suspension
A man riding winch is operated by rotating a handle. Lift up or down. Simple. It is effectively a “work positioning system”, or sometimes a rescue system. The common mistake that people make though is in assuming that because they have a man-riding winch, they are ready to lower someone down. The issue is that if someone is only attached to one point (the man-riding winch), they are trusting only one system. If this wire was to fail it would be an extremely quick access followed by a thump, groans and perhaps worse. Because of this both the law (1) and most manufacturers’ instructions require that a fall arrest back up is used in addition to the man-riding winch.
They need to go in fastened on to 2 things. This is where the retrievable inertia reel comes in. So, if you’re accessing in suspension, hanging in your kit, you normally (2) need these 2 bits of kit:
That’s a standard access and rescue set up for vertical situations without a ladder or similar.
It’s also worth noting that a man-riding winch is not usually suitable for protecting someone climbing up or down a ladder (fall arrest) due to the difficulty of keeping the wire from becoming slack and lack of shock absorption in the event of a fall.
There’s a lot more to consider on this topic, but for now hopefully that might clear up any uncertainty and provoke discussion. Have you come across any aspects of work at height which are neglected or forgotten in confined space work? We’d love to hear you comments.
(1) Work at Height Regulations 2005, Schedule 5 Part 2
(2) While it is true that Regulation 5 Part 2 (c) does provide scope for a back up not being used in some work positioning systems, it would be difficult to claim that in most confined space work it was not “reasonably practicable” to do so. In addition, normal practice throughout the industry is to have a fall arrest back up.
This article is purely for reference and not a replacement for proper training. Please call us on +44 (0) 1253 767775 for details of courses.