Hybrid Scrubber (EGCS)
Scrubber that can switch between open- and closed-loop modes depending on local discharge regulations.
In practice
Run in open mode at sea, closed mode in port. Operating-mode switch is logged; the duty engineer ensures the correct mode is selected before crossing a regulatory boundary. Misconfiguration is a documented PSC finding under ECA inspections.
Regulatory detail & full definition
A hybrid scrubber is an exhaust-gas-cleaning system that can switch between open-loop and closed-loop operation according to local discharge rules, and it is the most common scrubber type on newbuildings because of that flexibility. It runs in open-loop mode in the deep ocean, using seawater alkalinity, and switches to closed-loop mode when transiting waters that restrict open-loop discharge, such as US territorial waters, China and Singapore. It costs roughly 30% more than an open-loop-only system, and the payback depends on the price spread between compliant VLSFO and cheaper high-sulphur fuel oil.
Authoritative source: IMO Resolutions Index ↗
Related
Source: MEPC.259(68); CIMAC Position Paper on Scrubbers
High confidence
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