We were asked to support the Silvertown Tunnel project by providing units that would measure oil run-off across both sides of the river. The OWI units installed across the Greenwich Peninsula and Silvertown Tunnel sites were supplied in two versions: a solar‑powered model housed in a green roadside cabinet with a 12 VDC, 30 W PV panel mounted on a three‑metre pole, and a mains‑powered 230 VAC model using the same cabinet design. The solar units include an internal pole connection to support the panel and battery system, giving them full autonomy in locations where mains power isn’t available.
Each OWI installation provides automated monitoring of the oil‑water interceptor, with the solar‑powered units operating on a controlled duty cycle to conserve battery life. Instead of running continuously, they activate every four hours for up to three minutes. During this window, the OSA control module checks both the hydrocarbon layer sensor and the silt/sludge sensor to confirm whether conditions are normal or in alarm. If GSM transmission is enabled, any alarm is sent out remotely. For the mains powered units, the outgoing signal was being sent via telemetry systems.
When an alarm is triggered, the OSA clearly identifies the issue, showing either Level Alarm Act (Hydrocarbon) or Sludge Alarm Act (Silt/Sludge), and it also reports if a sensor is in an error state. This gives operators reliable periodic checks and immediate visibility of any developing problems within the interceptor, whether the unit is solar‑powered or mains‑powered.
The completed installation provides a dependable, low‑power monitoring solution across two major London transport sites, combining solar efficiency, mains‑powered reliability and optional remote alarm capability in a simple roadside package. We’re proud to support a project that will form a key part of London’s future transport network.
