Early in my career, inert entry was standard practice for tanks and vessels that had held pyrophoric material. Our team would deliberately purge the atmosphere with nitrogen to remove any risk of ignition, which also meant the atmosphere couldn’t sustain human life without breathing apparatus. Every entry depended on the procedure and the equipment being followed exactly, because there was no margin for getting it wrong. It was, and still is, the only way to get eyes and hands on some of these assets. That’s about as extreme as confined space risk gets.
Why Confined Space Risk Varies So Much
But most confined space work doesn’t sit at that end of the scale, and that’s where real change has happened. Confined spaces vary enormously — in atmosphere, in geometry, and in the task at hand — and it’s that variation, not a single risk category, that determines the right approach.
The Confined Spaces Regulations 1997 and HSE guidance define a confined space by two things together: it’s substantially enclosed, and there’s a reasonably foreseeable risk of serious injury from something in or near it, such as a lack of oxygen, dangerous fumes, or engulfment.
How UAV Inspection and Robotic Crawlers Are Changing Confined Space Access
Across the wider confined space workload — tanks, vessels, ductwork, and structures where the atmosphere isn’t the primary hazard but access still carries real risk — UAV inspection now removes the need to send someone in at all. The Elios 3, for example, can map a tank or vessel interior in detail without a person needing to enter, using LiDAR to build a 3D model as it flies.
For geometries a drone can’t reach — long pipe runs, tight ducting — robotic crawler systems do the same job, travelling the space itself rather than flying through it. Either way, that’s a genuine reduction in how many people we put into these environments overall.
The Current Limits of Confined Space Technology
There are limits to that, and it’s worth being precise about them. Atmospheric testing still has to happen before any access equipment or personnel work near the entry point, and physical intervention — for example, carrying out a repair — currently still needs a person and the full confined space procedure, although robotics are now being developed to eliminate these scenarios too.
Information or Intervention? The Question That Shapes the Job
The question worth asking early on any job is simple: is this about gathering information, or about doing something physical?
If it’s the former, a drone or crawler, whichever suits the geometry, can often remove entry from the equation entirely. If it’s the latter, either can still do a useful first-pass survey to scope the work, but the confined space team and rescue plan remain part of the picture.
One Team, One Honest Assessment
At Sutro Group, we run UAV, robotics and confined space rescue capability under one team, so that assessment happens honestly at the planning stage, and clients get whichever method is safest and most efficient for the job in front of them.
Seeing how far the technology has come is one of the more satisfying parts of this job — we’re sending far fewer people into high-risk confined spaces than we used to. That reduction is real progress, and it’s worth being proud of.
Contact Sutro Group
To find out how Sutro Group’s specialist inspection services can support your maintenance programme, contact our team:
0800 069 9395
info@sutrogroup.co.uk