Water, gas and sewage pipes are hard to inspect because they are buried and often too narrow to enter. Small robots that crawl or swim through them carry cameras and sensors to find cracks, blockages and corrosion, mapping the condition of a network from the inside.
Finding problems precisely means utilities can dig only where needed, saving disruption and cost, and can fix faults before they cause leaks or failures. The robots must handle debris, bends and flowing contents, and sending data out of a buried pipe is tricky, so many are tethered, but they reach places that would otherwise stay hidden until something broke.