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Military Afloat Reach and Sustainability (MARS)

See also Fleet Tanker (FT)


The Rolls-Royce NVC replenishment ship concept is a just one of a number of proposals clearly developed with MARS in mind.  (Source: Rolls-Royce Marine)


The 175 metres long, 18,000 tonnes deadweight Aegir18 fleet replenishment ship is one of a family of designs being offered by BMT. (Source: BMT Defence Services Ltd & Skipskonsulent)


Graphic of an Aegir fleet replenishment ship conducting a RAS with a CVF carrier. (Source: BMT Defence Services Ltd)




Project designation:  ?
Status: Entered Assessment Phase in July 2005, Main Gate (fleet tankers only) expected March 2009.
In Service Date: 
2012 (first fleet tanker)


It's currently planned to procure about 11 replacement ships for the Royal Fleet Auxiliary under the "Military Afloat Reach and Sustainability "(MARS) program, at an estimated program cost of £2.5 billion.

The Royal Fleet Auxiliary urgently needs to replace most of its existing tankers in order to meet an amendment to MARPOL regulations (the International Convention for the Prevention of Pollution from Ships 1973 and the Protocol of 1978) that requires tankers to be double hulled.  With the exception of the new Wave-class tankers, the RFA has a single hulled tanker fleet which will be become non-compliant with MARPOL from 2010, although a waiver can be claimed for government owned ships

Six remaining Leaf and Rover class tankers provide logistic support to Royal Navy  vessels at sea, under current (early 2007) plans their decommissioning dates are as follows:  Gold Rover (2009),  Black Rover (2010), Brambleleaf (2009), Orangeleaf (2009), Oakleaf ( 2010) and Bayleaf (2010) - although these dates may be advanced. 

In November 2004, the First Sea Lord, Admiral West, confirmed that an important factor in the decision-making process for MARS was the International Maritime Organisation (IMO) pollution regulations issued in 2001, as well as the more stringent and subsequent European Commission regulations passed in 2003.  The IMO regulations imposed a timetable for phasing out single-hulled tankers by 2015, although the EC legislation advanced this to 2003 for vessels operating in European waters or under a European flag.  Vessels owned or operated by a state and used only on Government non-commercial service, such as Royal Fleet Auxiliary Oilers, are exempt from the regulations, although it continues to be MoD policy that, where practicable, it will comply with Shipping Acts and associated regulations.  It's hoped that the Military Tanker and MARS programmes will enable MoD to comply with these particular regulations.

It became clear in mid-2007 that an adaptation of a commercial off the shelf design built in EU shipyards (but almost certainly not UK yards) was likely to be adopted to meet a Military Tanker requirement spun off from a restructured MARS projects.

It is also necessary to eventually replace the now elderly Fort Series I class of stores and armament ships, Fort Rosalie (due to decommission in 2013) and Fort Austin (2014).

The two Fort Series II ships (Fort George  and Fort Victoria) are also single hull vessels, they are currently both due to leave service in 2019.  A rebuild of the Fort II’s was considered but apparently rejected - options for double-hulling or a cut-and-shut new midships tank section being considered. 

It is likely that two new fleet solid-support ships will replace all the Fort's.


Project History

A MARS Integrated Project Team (IPT) was established at the Ministry of Defence's (MOD) Defence Procurement Agency (DPA) in July 2002 to conduct studies into the required capability for MARS.  The initial focus was on the ability to Replenish At Sea (RAS) "Bulk Consumables" - that is the supply of petrol, oil and lubricants (POL), fresh water, food and ammunition.

Initial Gate approval to enter the Assessment Phase was originally expected in early 2004 (Feb to April), but was delayed to early 2005 due  to funding constraints.  During 2004 there was considerable pressure on the Royal Navy to accept cheaper but less capable alternatives to MARS, for example the use of commercially owned ships under PFI or PPP contracts.  The MOD is also believed to have investigated options to fill the gap between the withdrawal from service of existing RFA's and the entry in to service of their nominal MARS replacement up to 10 years later, however a shortage of suitable modern fast double-hulled tankers for lease and conversion presented serious problems.  In March 2005, the government stated that it was not planning to lease or purchase new tankers prior to the arrival of the MARS capability, but an extension of the service existing ships was under consideration.

In December 2004, there were reports that MARS had been delayed two years in the new Equipment Plan (EP05) and that Initial Gate was now likely in late 2005.  However the project team started to engage with Industry about possible contractual arrangements (normally an Assessment Phase activity) with an advertisement in the Contracts Bulletin in May 2004.  The DPA invited expressions of interest from candidate companies aspiring to take on the role of project integrator for the MARS programme.

In early April 2005 the MARS IPT issued a Pre-Qualification Questionnaire  to the potential integrators who replied to the advertisement in the Contracts Bulletin, responses to the questionnaire had to be submitted to the IPT by 14 June 2005.  Amec, BAE Systems, VT Group and KBR were among the nine companies which finally submitted proposals, and subsequently gave presentations to the MoD in August. 

In June 2005 there were reports that senior Royal Navy officers were pressing hard for progress on MARS, now ranking it only after CVF in importance.  On 20 July 2005, the Secretary of State for Defence (John Reid) announced that the project had finally passed Initial Gate:

"I am pleased to announce our decision that the military afloat reach and sustainability (MARS) programme should now enter its assessment phase.  This is excellent news for the Royal Fleet Auxiliary (RFA), which will operate the ships, the Royal Navy and the armed forces. MARS will be a cornerstone of our future worldwide operations, replacing many of the RFA's existing ships. It will support our new aircraft carriers and the rest of the fleet, as well as deployed amphibious, land and air forces close to the shore. The MARS programme is currently assuming three classes of ships, which will deliver fuel and other stores to the fleet, helicopter support and sea-based logistics for deployed forces. During the project's assessment phase, we will investigate a range of solutions to meet this capability."

The Project entered the Assessment Phase in July 2005, but the baseline user requirements and capabilities were cut back in January 2005 - presumably to conform with projected funding in the Equipment Plan, but details have not been revealed.  The project team is now focused on progressing the fleet tanker requirement.

In August 2005, the DPA issued an ITT for a MARS Alliance Project Friend, an involved but independent party who support the MARS IPT and the Potential Integrators in creating, maintaining and developing an effective MARS Alliance.  The choice appears to be between The Advance Consultancy Ltd and Soma Consulting Ltd.

On 14 February 2006 AMEC, KBR and Raytheon Systems Ltd were selected to work with the MoD's Military Afloat Reach and Sustainability project team to further develop the project.  At the time Lord Drayson said:

"The MARS vessels we intend to procure will provide fuel, food and stores to units afloat and a new seabasing facility to support forces ashore.

In due course we expect one of these companies will be selected as the Integrator for this project, and will work with the MOD to select the best delivery team to produce the ships. The key role of the Integrator will be to embed best project management and partnering practice throughout the MOD/industry delivery team.

The MARS vessels will have some military equipment and will be technically similar to specialist merchant ships. The priority for MARS is for the build of these ships to harness the efficiency of specialist commercial shipbuilding practice. UK yards and suppliers who can demonstrate these levels of efficiency will be given every opportunity to compete for shipbuilding work. With the high planned workload on CVF and Type 45, the complex ship design and integration capabilities that we intend to sustain in the UK will remain healthy for some years and we will consider what contribution the MARS programme will have to these capabilities. This approach follows the conclusions I have laid out in the MoD's Defence Industrial Strategy."

At the time a sole integrator was expected to be selected in by the end of 2006, and the main investment decision (Main Gate) and the entry in to the demonstration and manufacture phases be made about September 2008, with a  target date for the first ships to join the Royal Fleet Auxiliary service of 2012.  However doubts about the affordability of the £multi-billion programme surfaced in mid-2007, with suggestions that Main Gate would be deferred a year while this was reviewed. 

On 31March 2007 DE&S “Afloat Support” was formed through the merger of MARS IPT and the RFAS IPT, but the term "MARS IPT" is still in widespread use.

In late July or early August 2007 the MOD abandoned MARS as an integrated project with an estimated cost of £2.5 billion, and dropped plans to select a single integrator.  The MOD stated on 8 August 2007 that "The announcement of the CVF contract, combined with the changing industrial landscape ... led us to review our approach to MARS .. the decision not to proceed with the MARS integrator competition has been taken in this context".

The project will instead by restructured as separate, smaller, lower cost and faster moving projects.  The first of these will certainly be "Military Tanker", intended to provide the RFA's urgently needed new double hull tankers. 


Current Situation

On 10 December 2007 the MOD issued an "Invitation to Participate in Dialogue" to industry to for up to six fleet tankers at an expected cost of £800 million, more details are found on that page.

On 21 May 2008 the MOD announced the results of the invitation - four companies have been shortlisted:  Fincantieri (Italy); Hyundai (Republic of Korea); Navantia (Spain) and BAE Systems with BMT DSL and DSME (Republic of Korea).   Their proposals will now be tested for Value for Money and the MOD is expected to select one of the companies to design and build the new ships in early 2009.  None of the four bidders will build the Fleet Tankers in the UK.

It's presumed that the more complex fleet supply ships and possibly the joint sea-based logistics ships (which will need to be be relatively sophisticated if required to operate with little or no harbour facilities) will be allocated to the new BAE System / VT Group shipbuilding Joint Venture and the hulls built in the UK  - but the MOD refuses to confirm this and is keeping open the option to build them abroad.



The ‘force projection’ role of the Royal Navy requires three key tasks to be fulfilled by MARS:

  1. Fighting ships to be supplied with bulk consumables (BC) – fuel, food, ammunition, stores, water, and air stores to embarked forces.
  2. Joint sea-based logistics (JSBL) support and sustainment to be provided to land forces from the sea to locations potentially well inland from the beachhead and then sustain their operations. 
  3. Forward Aviation Support (FAS) – the provision of support to maritime rotary wing operations. The ships will be able to act as a forward maintenance facility for deployed helicopters. 

The forward aviation requirement was re-confirmed in late 2004 after the consideration of other options,

A CVF RAS'ing with a MARS unit

Other MARS roles include supporting:

  • A CVF centred carrier task group;
  • An amphibious task group;
  • Dispersed ships;
  • A medium sized brigade ashore;
  • Special forces; and
  • Joint forces aviation.

It's expected that the MARS ships will need to be able to operate in areas under threat, and some or all will be armed and therefore classed as ‘grey’ or ‘warlike’.  Individual MARS ships may operate alone in, for example they could be the assigned unit to Atlantic Patrol Task (North) in the Caribbean, undertaking drug interdiction roles and disaster relief. 

MARS will not consist of one uniform of class of ship, but a family of ships perhaps displacing as much as 40,000 tonnes deadweight. 

During 2004. the project seemed to be split in to two parts:

  1. A CVF and forward aviation support ship element (technically the Fort series I replacements); and
  2. A POL tanker element (the Rover and Leaf replacements).

The second part of the program was considered more urgent than the first. 

By mid-2005 it had become at least three classes would be needed to meet requirements described above, these being likely to be:

  1. POL Tankers - the provision of fuel, oils, lubricants, ammunition, food, water and air stores to embarked forces.
  2.  Fleet supply ships optimised to support CVF, with extensive aviation capabilities for FAS.
  3. Joint sea-based logistics ships.  Sufficient to support a full medium weight brigade ashore, but could also re-role when necessary to support ship operations.

The priority remained very much on the tankers, with the Rover's disappearing rapidly.  It was hoped that the first of about five will appear early next decade.  Design work on the supply ships wouldn't start until 2008-9 at the earliest, with an ISD of about 2017 for the first of up to four ships (depending whether any of the existing Forts are SLEP'ed).

In April 2006, reports indicated plans for a total of 11 new naval support ships under MARS, these comprising:.

  1. Five fleet tankers for delivery between 2011 and 2015.
  2. Three joint sea-based logistics (JSBL) vessels for delivery in 2016, 2017 and 2020.
  3. Two fleet solid-support (FSS) ships for delivery in 2017 and 2020.
  4. A single fleet tanker (CVF/carrier strike) for delivery in 2021.

The two solid-support ships and the final fleet tanker are primarily intended to support Future Carrier and carrier strike operations. In addition to providing fuel, food and stores to warships at sea, there will also be a new sea-basing facility to support forces ashore.

The above dates subsequently modified in early 2007 to:

  1. Five fleet tankers for delivery between 2011 and 2016.
  2. Three joint sea-based logistics vessels for delivery in 2018, 2020 and 2021.
  3. Two fleet solid-support ships for delivery in 2017 and 2019.
  4. A single fleet tanker (CVF/carrier strike) for delivery in 2016



Its expected that all MAR units will be designed to Lloyds Register Naval Ship Rules (NSR) with Naval Ship Auxiliary notation.

Until recently no official conceptual designs had been published in regards to MARS, although since at least 2005 a number of design concepts have appeared from industry that are clearly targeted at the MARS requirement - in particular Rolls-Royce’s NVC designed Modular Underway Replenishment Ship and British Maritime Technology Ltd’s Aegir family of fleet support ships.

By the most significant driver for the MAR programme at the moment is the need for early replacement of the remaining single hulled Rover and Leaf-class tankers - which bulk supply RN warships with fuel.  In November 2007 the MARS IPT published details of a project class of fleet tankers - for more information see here.

From presentation by MARS IPT, October 2007

The next phase of MARS will be to replace the four "Fort" RFA’s with a new class of two supply and replenishment ships, optimised to support the future aircraft carriers.  The requirements are still evolving, but good aviation and repair facilities are known to be included, and a capability to operate and support about 6 Merlin size helicopters and  possibly unmanned air vehicles is expected; also offering 'second line' aviation maintenance/repair services as well as providing for rapid vertical embarkation and transfer of people and stores.  Timescales are very uncertain, and will be affected by other factors such as funding availability and the viability of a service life extension for the existing Series II ships (Fort George  and Fort Victoria).  However, one schedule suggests an order for the lead ship being placed in 2012, with entry in to service in 2017.  It is considered almost certain that these ships will be built in UK shipyards - but the MOD is keeping its options open.


Commercial and Manufacture Aspects

According to the DPA website the preferred contractual route for meeting the MARS requirement is to create a form of alliance with a lead contractor (the Integrator).  The contract will be developed with Industry to include continuous communications & engagement, to identify and apportion appropriate ownership of risk, and allow visibility and access to the entire supply chain and shares in cost savings. 

It is expected that the new vessels will be built to largely commercial construction standards and design practices - albeit with some modifications to meet Naval Ship Rules and specific RN/RFA requirements. Using commercial standards is expected to help keep down the cost of procurement, and construction can take place at many shipyards around the Europe Union - unless the British government chooses (as the requirement can justify)  to classify some or all of them as military vessels under EU rules and restrict the tender for their construction to UK shipyards only on national security grounds.  Commercial practices, such as using a higher degree of automation in operations, will help keep the total operational cost down by keeping crew sizes small.

Affordability and construction times are major considerations, and several companies have pointed out the advantages in cost and time of building hulls abroad, at least for the first tanker phase - indeed the selected procurement path for the fleet tankers is via an OJEU Competition - so any EU company can bid.  The Defence Industrial Strategy announced in December 2005 specifically allows this approach. However BAE Systems for one is arguing that UK shipyards can and should be used for at least the more sophisticated ships. 

The procurement, ownership and operation strategy for the later MARS ships is still to be decided - although both the RFA and the RN are anxious that they be manned and operated by the former - and one MOD study in 2007 essentially backed continuing current arrangements and

However as well as traditional MOD funded operation of the MARS ships as part of the flotilla of the Royal Fleet Auxiliary (RFA) service, a number of alternative models now exist, including providing the tanker capability via a Private Finance Initiative (PFI) arrangement, with industry working in close partnership with the RN.   One relevant example is the MODs 25-year duration PFI contract with AWSR Shipping Ltd to provide a strategic sea transport capability using the six Point Class Ro-Ro’s.  AWSR is responsible for the provision of the crews, operation and maintenance of the ships throughout the life of the contract.  While the ships are in MOD use, AWSR must provide completely British officer and merchant seaman crews for the ships, these seafarers are eligible for call out as Sponsored Reserves for operational requirements. 



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 © 2004-13 Richard Beedall unless otherwise indicated.