Ballast Water Management Retrofit Installations – Where, When and How?

One of the most important aspects of planning a retrofit installation is the installation methodology – where, when and how? Owners and operators have to juggle the importance of completing the retrofit installation efficiently and, most importantly, correctly, with the commercial pressures of minimising vessel downtime. The suitability of different installation approaches are entirely vessel, owner and operator specific.

BWMS retrofit installations typically follow one, or a combination, of the following processes:

  • During scheduled drydocking of vessel
  • Whilst vessel is trading – using riding squads onboard
  • Alongside with vessel out of service


Installation During Scheduled Drydocking

Instinctively, carrying out the retrofit installation of the BWMS during a scheduled drydocking is an efficient approach. With the vessel out of service anyway, installing during this period results in minimised additional vessel down-time. The drydock is likely to also have the required resources, trades and materials on-site to carry out the installation effectively.

However, there are some important considerations when carrying out the retrofit installation during a scheduled drydocking, some of which are outlined in more detail below:

Cleanship Solutions - Turnkey Ballast Water Treatment System Retrofit

Cleanship Solutions – Turnkey Ballast Water Treatment System Retrofit



Firstly, scheduled drydockings generally have very busy programmes of refit works, upgrades and maintenance of the vessel, hence adding the retrofit installation of a BWMS may be a significant challenge for both the drydock itself, as well as the onsite superintendent . Beyond the simple resourcing issue, there may also be safety challenges, particularly where the BWMS components are being installed nearby items of machinery likely to be undergoing major overhauls during the drydocking.

Secondly, many drydockings are carried out in yards that are either convenient to the vessel’s current trading patterns, or at yards that offer significantly more competitive pricing. Crucially, this selection process may not be congruent with the skills and experience necessary to undertake the retrofit installation of a BWMS – especially across a limited timeframe. Whilst contracting an experience BWMS retrofit project manager, from a retrofit partner such as Cleanship Solutions, will help ensure the retrofit installation is as efficient  as possible, the final quality of the installation works at remote yards can be difficult to control.

In summary, the main benefits and key considerations of carrying out a BWMS retrofit during a scheduled drydocking can be summarised as follows:


  • Vessel already out of service for drydocking – so minimised additional downtime of vessel
  • Drydock will likely have required trades and materials on-site
  • Vessel superintendents will already be on-site for drydock works
  • Scheduled drydocking is highly likely to coincide with vessel’s compliance dates – maximise time available prior to retrofitting

Key Considerations:

  • Drydock programme likely to already be very busy – hence drydock may struggle to resource additional scope of BWMS retrofit installation
  • The drydock duration may not be sufficient to complete the BWMS retrofit installation
  • Vessel superintendent unlikely to be able to oversee BWMS retrofit installation without assistance
  • Selected drydock may not offer sufficient experience or quality required
  • Selection of drydock may be made, or altered, at short notice due to vessel trading patterns, hence logistics & delivery of key equipment to vessel may challenging
  • Commissioning shall still have to be carried out once the vessel leaves drydock – as the commissioning engineer shall require full ballast flow rates during commissioning – this may impact cabin availability onboard
  • Minimal opportunity to address installation issues / defects – and construing contractual obligations of drydock to address


Installation During Service using Riding Squads

Carrying out the retrofit installation of a BWMS during normal vessel operation can also be an attractive option for vessel owners and operators. Sending riding squads onboard to carry out the installation during service has the significant benefit of minimising, or eliminating completely, any downtime of the vessel. However, as with the drydock installation option, carrying out the retrofit installation during service has its own challenges too:

Firstly, the impact of the works onboard to the ongoing operation of the vessel is a critical point, and one that drives the suitability of this option. Inherently, retrofitting a BWMS to an existing vessel does require removal of existing ballast system pipe spools, installation of new spools, and subsequent connection to the new BWMS equipment. Because of this, the existing ballast system could be out of commission for several days – which may not be an option on ballast dependent vessels with short voyages.

Secondly, safety concerns also play a significant role in the suitability of this option. Setting aside the risks associated with draining and disconnecting an existing ballast system at sea, the necessity to undertake other intrusive works at sea also present risks – such as hot works, new bulkhead / deck penetrations etc.

Cleanship Solutions - Turnkey Ballast Water Treatment System Retrofit

Cleanship Solutions – Turnkey Ballast Water Treatment System Retrofit


Again, to summarise, the main benefits and key considerations of installing a BWMS whilst the vessel is trading:


  • Minimised, or eradicated, downtime of vessel
  • Controllable installation process due to small team onboard
  • Time is unlikely to be a factor – so installation can be carried out in a methodical fashion

Key Considerations:

  • Can present operational challenges to the vessel
  • Loss of ballast system / blackout for connection to switchboard etc)
  • Team size limited by cabin and/or lifeboat availability onboard
  • Safety concerns of intrusive hot works onboard
  • Inability to source additional or replacement materials or parts if required – requires careful consideration during planning stage
  • For vessels requiring significant alterations for installation (such as deckhouses or similar), this is unlikely to be a suitable approach


Installation Alongside

The third retrofit installation approach is to take the vessel out of service, alongside a commercial quay or shipyard, and carry out the works in situ. Most obviously, this approach has the added benefit of ensuring adequate resources, trades and materials are on site, and the entire project can be pre-planned and executed in an effective, and dedicated manner.

Conversely to the scheduled drydock option, bringing the vessel alongside has the attractive advantage of ensuring water is available to conduct the commissioning – hence the entirety of the retrofit project could be carried out without requiring a commissioning engineer sailing with the vessel.

There are some drawbacks to this approach, however, which can also be summarised as follows:

Firstly, the vessel will be required to come out of service, and remain out of service for potentially an extended period of time (up to two weeks for complex retrofit projects). For vessels that awaiting a charter this is obviously less of an issue, however, for vessels that have long term charters or busy trading patterns, this approach may be too commercially impactful.

Secondly, bringing the vessel alongside a commercial quay or shipyard will again be dependent on the quality and workmanship of the local shipyard or subcontractors. For vessels trading in particular areas of the world, the ability to source adequate quality for critical and highly technical trades, such as instrumentation, pipe fitting and electrical works, may be challenging.

Finally the main benefits and key considerations of the alongside installation approach can be summarised as follows:


  • Availability of trades and materials can be controlled
  • Vessel shall be afloat hence commissioning can be carried   out   alongside – no   requirement   for commissioning engineer to sail with vessel
  • Ability to be highly planned and installation
  • Immediate access to additional materials or spare parts where required

Key Considerations:

  • Vessel will be out of service for potentially extended period of time
  • Local quality of workmanship may be difficult to control



Whilst the three installation approaches listed in this chapter are fairly typical across the industry, many owners and operators utilise hybrid installation models, or combinations of each of the three. Such strategic planning serves to minimise the risks associated with each approach, whilst simultaneously maximising the benefits of each.

Ultimately, owners and operators will have to work closely with their retrofit partner to identify the most suitable installation opportunities, and plan ahead sufficiently to cover all eventualities.