The Future of Industrial Inspection

As energy from waste plants, refineries, chemical facilities, and utilities prioritise cost efficiency and safety culture, confined space drone inspection is becoming the baseline expectation—not the innovation.

At DJM Aerial Solutions, we’ve now conducted over 100+ industrial inspections across confined spaces, culverts, pipe networks, and elevated structures across the UK. Spring hanger assessment is a routine application, but each site teaches us something new about adapting drone methodology to real-world constraints.

The message to facility managers is simple:

Drone Inspection of Spring Hangers in Energy from Waste Plants: Why Confined Space UAVs Beat Scaffold Access

Introduction

Thermal expansion in industrial pipework is a fact of life. Every facility manager knows it: when hot fluid flows through steel pipes—whether in energy recovery, process heating, or waste heat systems—those pipes expand. Controlling that expansion safely requires precision-engineered spring hangers. But inspecting them? That’s where traditional methods break down.

Last week, DJM Aerial Solutions deployed a Flyability Elios 3 confined space drone to inspect spring hanger systems at a major energy from waste facility in North Wales. What we discovered challenges a common assumption: you don’t need scaffolding to verify whether a spring hanger is actually working.

This post explains why drone-based confined space inspection is transforming how industrial plants approach spring hanger maintenance—and why it’s becoming the default choice for facilities serious about cost, safety, and uptime.

What Are Spring Hangers and Why Do They Matter?

Spring hangers are engineered support systems that allow pipework to move vertically (and sometimes horizontally) while remaining anchored. They work by:

• Accepting thermal movement as fluid temperature changes
• Storing and releasing elastic energy through compression or extension
• Maintaining pipe alignment without binding or excessive stress
• Protecting downstream equipment from thermal shock and vibration

In energy from waste plants, where process temperatures swing from ambient (during startup/shutdown) to operating temperatures well above 100°C, spring hangers perform critical work. If they fail to move through their designed range—if they “freeze” or become stuck—the consequences include:

• Pipe stress, cracking, and rupture
• Thermal shock to heat exchangers and downstream equipment
• Unplanned downtime and safety incidents
• Regulatory non-compliance

The challenge: Most spring hangers are installed in confined spaces, at height, or in locations where close visual inspection requires either:

1. Expensive, time-consuming scaffold erection (days of planning, weeks of lead time, high cost)
2. Risky manual climbing with harness systems
3. Invasive shutdown periods to lower equipment for inspection
4. Guesswork about actual spring condition

The Problem With Traditional Spring Hanger Inspection

Scaffold Access: The Old Default

Traditional thinking says: If you can’t reach it safely, build scaffolding. But at an EfW facility with sporadic spring hanger locations scattered across multiple levels and restricted-access zones, this approach becomes impractical:

• Cost: Temporary scaffold hire and erection can exceed £5,000–£15,000+ per location, plus engineering surveys
• Lead time: 2–4 weeks to plan, permit, and erect
• Disruption: Scaffolding competes for space with operating equipment, utility runs, and personnel access
• Shutdown requirements: Some locations demand production halts during scaffold work
• Safety exposure: Increased foot traffic, working at height, coordination complexity

For a facility with 20–30 spring hanger locations, scaffold-based inspection becomes a multi-month, multi-hundred-thousand-pound exercise.

Why Cold Setting Matters

Here’s where the technical detail becomes important: spring hangers are rated for both hot setting (at operating temperature) and cold setting (at ambient temperature). Many facilities inspect the hot setting during operation—you can sometimes visually assess position under normal running conditions. But the cold setting is equally critical, and far harder to verify:

• It occurs during startup, shutdown, and seasonal ambient swings
• Visual inspection alone can’t confirm a spring is moving through its full designed range
• A “frozen” spring hanger may pass visual inspection but fail functionally
• Without close physical access, you’re relying on history and assumption

At the North Wales EfW plant, cold setting verification was the explicit goal. Previous hot setting inspections had been completed; this visit was to confirm that—after the spring cooled and pipework returned to ambient geometry—the hanger was still within operating range.

The Drone Solution: Flyability Elios 3 for Confined Space Inspection

What Makes the Elios 3 Different

The Flyability Elios 3 is purpose-built for exactly this scenario:

• Mechanically robust: Carbon fibre collision-tolerant cage. Unlike standard UAVs that rely on avoiding obstacles, the Elios 3 can withstand light contact with pipes, walls, and structure—though deliberate contact should still be avoided where possible.
• High-resolution optics: Dual 4K fixed focal cameras with stabilised imaging allow detailed visual assessment of spring hanger components from centimetres away. Close-focus capability enables examination of indicator positions, thread condition, corrosion products, and lock nuts.
• Battery-powered autonomy: Up to 12 minutes flight time per battery. Multiple batteries enable extended inspection campaigns without tether constraints, providing flexibility in confined, cluttered environments where tether routing would be problematic.
• LiDAR localisation: Integrated LiDAR sensor provides real-time positioning within GNSS-denied confined spaces. Generates point cloud data for digital asset records and future baseline comparison.
• Thermal capability: Optional radiometric thermal imaging for temperature assessment of pipework and spring hanger components—useful for correlating component state with operating vs. cold conditions.
• Constrained space flight: Precise hovering and control in tight, complex environments (pipe bridges, equipment clusters, steelwork) where standard commercial drones would be unstable or impossible to operate safely.

Why This Changes Spring Hanger Inspection

For spring hanger assessment, the Elios 3 delivers:

1. Close-range visual assessment of spring position, indicator status, and mechanical condition from centimetres away
2. High-resolution photographic documentation—suitable for engineering baseline records and future comparison
3. Rapid deployment: Flight can begin within hours of site arrival, no lead-time requirements
4. Cost-effective: A single drone survey typically costs 70–90% less than equivalent scaffold work
5. Operational flexibility: Inspection during operation (hot setting) or during shutdown windows (cold-state checks) without production impact
6. Repeatability: Easy to return and inspect the same components on regular schedules—building a condition trend database
7. Safety: Eliminates working-at-height exposure for inspection personnel

Our North Wales EfW Inspection: Real-World Application

The Scenario

The facility operates a waste-heat recovery system with multiple spring-supported pipework networks. The spring hangers in focus were located:

• Embedded within a confined, cluttered equipment zone (ruled out ladder and harness access)
• At heights of 4–8 metres above accessible floor level
• Inaccessible during normal operation due to thermal radiation and congested pipe runs
• Sporadic locations across the plant, making a single scaffold erection uneconomical

The Method

1. Pre-flight planning: Identified all target spring hanger locations, assessed accessibility windows, planned battery staging for extended coverage
2. Flight path optimisation: Planned routes to avoid snagging on pipework and allow safe battery transitions between multiple survey areas
3. Close-range inspection: Deployed the Elios 3 to hover adjacent to each spring hanger, capturing high-resolution imagery at multiple angles
4. Thermal assessment: Used optional thermal imaging to correlate spring position with ambient vs. elevated states (supporting cold-setting confirmation)
5. Documentation: Timestamped photos with location reference, hanger identification, and observable condition notes

Key Findings

• All target spring hangers were confirmed within acceptable range for cold setting
• No visible corrosion, cracking, or mechanical damage
• Spring pre-load and compression geometry matched design specification
• Baseline imagery captured for future trend analysis and condition monitoring
• Inspection completed in one site visit, under half a day, at a fraction of scaffold cost

Business Impact

• Avoided £12,000+ in scaffold hire and erection costs
• Eliminated 3–4 week planning and permitting delay
• Zero production downtime
• Established repeatable baseline for seasonal monitoring
• Reduced safety exposure for inspection personnel

Why Drone Inspection Is Now the Industry Standard

Regulatory and Safety Drivers

UK health and safety guidance increasingly favours elimination of hazards over PPE and administrative controls. The hierarchy of controls places:

1. Elimination (don’t work at height) ✓ Drone inspection achieves this
2. Engineering substitution (provide safer equipment) ✓ Confined space drone inspection replaces harness work
3. Administrative controls (procedures, training)
4. PPE (harnesses, lanyards) Traditional fallback

Drone-based inspection climbs the hierarchy, reducing overall risk and liability.

Operational Advantages

Beyond cost and safety, drone inspection enables:

• Condition-based maintenance: Objective, dated evidence of component state supports data-driven maintenance scheduling
• Predictive analytics: Trend analysis from repeated inspections helps forecast failure risk
• Insurance and compliance: Documented inspection history demonstrates due diligence to regulators and underwriters
• Contractor accountability: Timestamped, georeferenced imagery proves what was inspected and when

When to Call in Drone Inspection: Decision Criteria

Drone inspection of spring hangers (and similar confined, elevated components) makes sense when:

✓ Spring hangers are located in confined spaces, at height, or in thermally challenging zones
✓ Scaffold erection cost exceeds £10,000
✓ Lead time for scaffold is unacceptable
✓ Production downtime must be minimised
✓ Baseline documentation or trend monitoring is required
✓ Multiple sporadic locations make single-access methods uneconomical

Scaffold inspection may still be justified if:

• Hands-on repair or replacement is required (drones inspect but don’t service)
• Thermal conditions prevent drone operation safely
• Confined space is too restricted even for a collision-tolerant drone

What Makes a Professional Drone Inspection Service?

Not all drone operators are equipped for industrial confined space work. A credible partner should provide:

• Specialist equipment: Purpose-built confined space drones (Elios 3, not consumer-grade alternatives)
• Engineering expertise: Inspectors who understand structural integrity, thermal mechanics, and asset condition grading
• Professional reporting: Timestamped imagery, condition assessment tables, and actionable findings—not just a USB stick of photos
• Regulatory compliance: CAA operational authorisation, insurance, and compliance with site safety protocols
• Repeatability: Documented methods enable consistent baseline comparisons on future visits

Get in Touch

If your facility operates spring hangers, pipeline networks, or other elevated, confined equipment that demands close visual inspection, we’d like to help.

DJM Aerial Solutions offers:

• Confined space inspection using the Flyability Elios 3
• Engineering-grade reporting with condition grading and recommendations
• CAA-authorised operations across the UK
• Rapid deployment with minimal site disruption

📧 Contact us to discuss your inspection requirements—whether it’s spring hangers, culverts, ductwork, or other confined assets.

Inspection Versus Functional Assessment

It’s important to recognise that drone inspection has defined boundaries. A confined space UAV inspection can determine whether a spring hanger appears to be positioned within its expected range and identify obvious defects such as corrosion, mechanical binding, or damaged indicators.

However, drone inspection cannot confirm:

• Actual support load being applied
• Spring stiffness or remaining spring constant
• Remaining fatigue life
• Calibration accuracy of indicator systems
• Whether travel indicators precisely match original design calculations

For facilities where these factors are critical to asset integrity decisions, drone-based remote visual inspection should be considered complementary to specialist pipe stress engineering assessments rather than a complete replacement. The drone provides visual evidence and baseline documentation; pipe stress analysis provides the mechanical confirmation.