Lancet
Commissioned by Scottish and Southern Electricity Networks (SSEN) and UK Power Networks (UKPN), the 'Lancet' is a new tool developed by Steer Energy to allow oil samples to be taken from energised Pole Mounted Transformers safely, from the ground, without disruption to customers.
Distribution Network Operators use a statistical model to identify which Pole Mounted Transformers (PMTs) need to be tested for PCB contamination. If the oil is found to contain PCBs above the regulatory threshold, the transformer must be removed from service. Until now, the only way to obtain a sample has been to de-energise the asset, remove it from the pole, and send it to a laboratory for analysis. This process is disruptive to customers, incurs fines for the DNO, and requires a replacement transformer to be installed. Approximately 84% of transformers that go through this process are found to be below the contamination threshold — meaning the vast majority are removed unnecessarily, at a cost of between £3,000 and £6,000 per asset.
To develop a tool that would address this, we began by working closely with the live line teams at SSEN and UKPN. Through design reviews, workshop visits, and testing at both SSEN's Littleburn training centre and UKPN's Risby facility, we built a detailed understanding of how live line operatives work, the constraints they face, and the equipment already in their hands. That operational insight shaped every aspect of the Lancet's design.
The Solution
The Lancet is a remotely controlled sampling tool that attaches to the face of an energised PMT using permanent magnets, deployed from the ground using standard insulated rods. Once in position, the tool drills through the transformer wall, collects a minimum 7ml oil sample, and seals the entry point behind it — all while the operator remains safely at ground level, outside safe clearance distances. The tool is wirelessly controlled via a handheld pendant, and weighs under 5kg to remain within existing live line handling procedures.
Following Phase 1 concept development and Phase 2 engineering design and prototype build, four functional prototype tools have been delivered to SSEN and UKPN. Field trials are now under way, with Phase 3 covering certification, training, and transition to business as usual.
FAST FACTS – LANCET
- Enables oil sampling from energised PMTs without de-energising or removing the asset
- Operator remains at ground level throughout, outside safe clearance distances
- Wirelessly controlled; deployable using standard insulated live line rods
- Tool weight under 5kg — compatible with existing DNO live line handling procedures
- Collects a minimum 7ml sample — more than double the volume required for PCB analysis
- Jointly funded by SSEN, UKPN, and National Grid; delivered through the Energy Innovation Centre
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