Page 49: of Maritime Reporter Magazine (January 2021)

WATER TREATMENT SYSTEMS

Focus on the Aftpeak Tank

This rendering shows oneTank as it will be installed for

OSG. This uses a oneTank supplied circulation pump. The bulk chemical drum is shown to the right on the oneTank unit, which costs $200 and can treat the aftpeak tank twice. The chemical is bleach. The small neutralizing tote (sodium thiosulfate costing about $25) is shown to the left of the unit. It can neutralize the aftpeak tank twice.

Image courtesy oneTank oneTank. “These are all large and complex systems that when tank, circulates that ballast water through the oneTank unit properly ? tted and commissioned do a great job of processing where bleach is added and circulated back into the ballast many tens of thousands of cubic meters of ballast water.” water tank. This approach can be performed at any time in-

The aftpeak tank is a different story. Typically, the aftpeak tank, meaning that it doesn’t have to be performed during port tank is just 5% of the total ballast water volume on the vessel, and cargo periods. It also means that there are no ? lters to the aftpeak is separated from the cargo body tanks on tank- clog. Because aftpeak tank volumes are relatively small and ers by gas-hazardous regulations and on bulkers by practical infrequently ? lled, oneTank is a bulk chemical solution, or considerations. The ballast water ? ow rate to the aftpeak tanks as Reynolds explained in a recent interview with Maritime are typically 200 cubic meters per hour, and the aftpeak tank is Reporter TV, “about $80 worth of bleach.” used for many practical purposes such as cooling the stern tube bearing, dampening propeller vibration and more recently as salty feedwater for electrolytic based ballast water treatment systems. Despite its size, it can be just as time consuming as the cargo body re? t. oneTank seeks to simplify the process in terms of design, install and maintenance of this system. “We worked closely with OSG on ballast water management since 2008,” said Reynolds. “Much of this work has been focused on the cargo body ballast water tanks which in this case are

FRAMO style tankers. This means that the vessel does not have a cargo pump room, but rather specialty cargo and bal- last water pumps similar to deepwell style pumps. There are several innovative solutions for this style tanker. However, all of them require an independent ballast water treatment system for the aftpeak ballast water tank.” oneTank is an in-tank ballast water treatment solution. It takes a small amount of ballast water from the ballast water

SOCP: BWMS User Guide

The Ship Operations Cooperative Program (SOCP) released the Ballast Water Management Systems (BWMS) User

Guide. Developed by Glosten in cooperation with the SOCP

Members and support from the United States Maritime

Administration (MARAD), the Guide simpli? es the complex regulatory framework around ballast water management and provides step-by-step methods for integrating and oper- ating a compliant BWMS. Register to download the BWMS

User Guide here: https://www.socp.us/bwms www.marinelink.com 49

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