Inspecting a storage tank has traditionally meant draining the tank, fitting scaffolding, sending engineers into a confined space, and losing the asset for days. ROV tank inspections do away with all of that. A remotely operated submersible camera surveys the interior while the tank remains in service, capturing high-resolution video of the shell, base, fittings, and anywhere corrosion or silt tends to gather. For sites running to compliance windows like TB203, the method has become the practical standard for storage tank inspection.
What Is an ROV Tank Inspection?
An ROV (remotely operated vehicle) is a submersible camera-equipped unit deployed inside the tank through an existing access point. The engineer pilots it from outside the tank while reviewing live high-definition footage. Our ROV internal tank survey covers the full interior:
- The shell and structural welds for unlined tanks & weld seams on lined tanks
- The tank base, where silt and sediment accumulate
- Fittings, pipework, suction connections, and anti-vortex plates
- Any visible corrosion, scale, or damage to liners, where fitted.
The whole survey is non-contact and non-invasive. No confined-space entry, no contamination of the stored water, and no interruption to service.
Why ROV Inspection Beats Draining the Tank
The commercial case sits on five points:
- Zero downtime: The tank stays in service throughout. No drained system, no temporary water cover required.
- No drain-and-refill cost: Refilling a large fire protection or drinking water tank is expensive in metered water alone, before accounting for the labour and time to recommission.
- No confined-space risk: Industry figures put UK confined space worker fatalities at around 15 per year; the majority involving asphyxiation or would-be rescuers entering unprepared. Under the Confined Spaces Regulations 1997 and HSE ACOP L101, the first principle of compliance is to avoid entry wherever the work can be done from the outside. ROV inspections do exactly that.
- Faster turnaround: A typical ROV tank survey is completed in hours rather than days.
- Better data: The engineer reviews high-resolution footage from a stable position outside the tank, not working in poor light and wet conditions inside it. Small defects that get missed by manual inspection are routinely picked up on ROV.
There are still situations where a drained-down inspection is the right call, typically for the deeper ten-year major review under TB203, or where the structure needs full physical access. Our Franklin Hodge tank surveys service handles both methods, so the inspection is matched to the compliance requirement rather than forced onto the job.
Which Storage Tanks Can ROV Inspections Cover?
The method works across the full storage tank range:
- Fire protection and sprinkler tanks: Firestore®, Liquistore®, Firetainer®, Liquitainer®, and equivalent legacy units from other manufacturers.
- Drinking water and potable storage: including WRAS-approved cylindrical drinking water tanks, where contamination risk rules out draining for inspection.
- Process water tanks: industrial cooling, manufacturing, and HVAC support systems.
Both sectional and cylindrical configurations are covered. Tank age is not a barrier. ROV works on legacy installations from other manufacturers as well as units we designed and built ourselves. The only practical requirement is a suitable existing access point.
Storage Tank Inspection Requirements: What Compliance Asks of You
Regulatory drivers vary by tank type, but the inspection cycle is rarely optional.
For fire protection tanks, the Fire Protection Association’s Technical Bulletin 203 (TB203), supported by BAFSA and the LPCB, sets the benchmark for the care and maintenance of automatic sprinkler systems. The 2022 update requires a full inspection or condition report every two years, with a major inspection at ten years. Sites certified to FM Global standards run on annual inspections with a deeper review every five years. Our Franklin Hodge tank surveys service runs to these cycles by default. For sites specifically focused on the TB203 sprinkler cycle, our ROV inspections for sprinkler tank compliance procedure walks through the TB203 process step by step.
Water hygiene regulations and the responsible person duty under the Regulatory Reform (Fire Safety) Order 2005 both require scheduled inspection of potable and cold-water storage tanks. ROV survey satisfies either requirement without disturbing the stored water.
Book Your ROV Tank Inspection with Franklin Hodge
Franklin Hodge tank surveys are carried out by the same engineers who design and manufacture the tanks themselves, working to ISO 9001:2015 procedures continually audited by the British Standards Institute. Every inspection produces a high-definition video record and a written report identifying issues, recommended actions, and a timeline for any follow-up work. Where the survey identifies silt build-up, our submersible vacuum system can remove it without draining the tank. Where structural or liner work is recommended, our tank refurbishment services team can act on the findings directly. One team, from inspection through to remedial work. Send us your tank details to scope a survey.
