The Project
Diverse Marine and Thames Rocket – IMO Tier II engine successfully upgraded to meet IMO Tier III emissions regulations
The Challenges
Diverse Marine Ltd were tasked with building a high speed craft compliant with the HSC Code & UK Flag to operate in the UK. The vessel was required to meet IMO Tier III emissions regulations.
During the specification process with the naval architects, it became apparent the preferred engines only reached IMO Tier II levels. This was not adequate for the River Thames emissions compliance which is within London’s ULEZ so requires IMO Tier III emission levels to be achieved.
This presented Diverse Marine with a challenge on how to utilise the chosen engines from the preferred OEM, meet the stringent ULEZ emissions standards and obtain class approval.
It was at this stage the preferred engine supplier recommended Eminox to Diverse Marine.
The Solution
There are several new engines which don’t currently reach IMO Tier III standards however, Eminox’s Selective Catalytic Reduction (SCR) technology means these engines can be upgraded to meet the demand for NOx reduction targets in ECAs and ultra low emission zones.
The Eminox worked with a team of naval architects Diverse Marine Design, to assist with the application of the Thames Rocket vessel. Using our exhaust aftertreatment, platform product to ensure IMO Tier III compliance meant the whole team could utilise our maritime technology and experience to best effect.
Most important to naval architects, boat builders and owners is DNV certification for the Eminox exhaust aftertreatment control system, which is tailored for the marine industry. By sharing the Type Approval number this eases the full vessel approval process.
The Results
Based on an engine out NOx limit of 6.0 g/kWh and a targeted tailpipe NOx mass of 1.96 g/kWh, the Eminox exhaust aftertreatment system was required to reduce NOx by a minimum of 67.5% to ensure tailpipe NOx emissions fell with the limits of the IMO Tier III NOx emissions guideline.
Under strict Portable Emissions Measurement System (PEMS) testing it was found that the system reduced NOx emissions by 87.1% at 25% load, 80.6% at 50% load and 90.6% at 75% load, far exceeding the IMO Tier III requirements.
This resulted in achieving full on-vessel approval, with the vessel often achieving lower than targeted emissions, and receiving single vessel emissions approval on the first occasion from Bureau Veritas.
The Outcome
The success of the project means that by implementing a Class B on-vessel approval, it is possible to use an IMO Tier II engine and achieve IMO Tier III compliance by specifying Selective Catalytic Reduction (SCR) technology, designed specifically to suit a range of engines, vessels and space envelopes.
What Diverse Marine Said
Barry White, Project Manager, Diverse Marine commented; “We’d become aware of Eminox and their maritime capabilities at Seawork but were also recommended by our engine provider when the preferred engines on this vessel didn’t meet IMO Tier III.
“We’ve had a good collaboration with the team, finding the required solution and achieving certification for the system making overall vessel certification much easier.
“We’ve already commenced our second project with Eminox for VARD Crew Transfer Vessels (CTVs) and together, we can continue to develop first of a kind solutions to meet necessary emission regulations in the maritime industry.”
