DPA Projects

General Characteristics
Commercial Aspects
International Collaboration

Sonar 2087

Service - Navy


The need for a more capable Anti Submarine Warfare (ASW) sensor for the Type 23 Frigate to replace the Sonar 2031 passive towed array is driven by the noise quietening advances in the construction both of SSNs (Nuclear Propelled Attack Submarines) and SSKs (Conventionally Propelled Attack Submarines). Separate programmes to develop Sonar 2080, a towed low frequency active only system, and Sonar 2057, a very long passive towed array system for surface ships and submarines, were begun as long ago as 1988 but were combined into Sonar 2087 in 1993 as part of a sonar rationalisation process. A combined Staff Target was approved in April 1994 for a fully integrated, variable depth, towed active and passive sonar system, designated S2087, to counter current and future SSN and SSK threats. The sonar will significantly improve the Type 23 Frigate's ability to detect, classify and localise submarines at a range beyond the threat of attack.

The sonar suite will be fully integrated into the Type 23 Combat System whilst requiring minimum change to the T23 Command System (DNA(1)).

Sonar 2087 will be fitted to T23 Frigates during refit and integrated with the existing bow-mounted active sonar. The system is also a candidate for the ASW sensor for the Future Surface Combatant.

General characteristics / technical performance

Sonar 2087 will transmit at frequencies lower than those used currently in RN Surface Ship active sonars. These lower frequencies take advantage of better propagation of sound, giving greater detection ranges. In order to exploit advantageous environmental conditions, the towed body, which contains the transmit array, can be deployed to the optimum depth for detection and tracking of the target. The transmit array is physically large and heavy, in order to put the desired amount of power in the water at these low frequencies, and requires a sophisticated handling system safely to deploy and recover the towed body in a wide range of sea states; the whole handling system is to be designed to fit within the constraints of the current T23 Frigate quarter-deck dimensions.

Sonar 2087 also incorporates a passive array, as passive sonar detection of submarines remains an important ASW tenet. This array must be stored and handled using the space currently occupied by the Sonar 2031 winch and will feature digital telemetry rather than the current analogue system.

The active and passive modes are capable of independent streaming, recovery and operation and will facilitate easy transition between the two, such that uninterrupted operations can be achieved with the chosen mode while the other is streamed or recovered. Both the receive and transmit arrays are independently deployable to their optimum operating depths in order to provide the best possible sonar performance commensurate with the prevailing oceanographic conditions.

Sonar 2087 will be able to operate in a wide range of environments from the deep blue ocean to littoral waters and from tropical through temperate to arctic waters.It is possible to deploy and recover the active and passive outboard systems in sea conditions up to sea state 6. Both systems are also capable of operation up to the maximum operating sea state of the Type 23 Frigate. Also, Sonar 2087 should not be affected by electrical storms or lightening strike. In addition, the operation of the active towed body and the passive array should be unimpaired up to a speed of 15kts. All arrays are designed to survive up to the maximum designed speed of the towing unit/vessel.

The Sonar 2087 suite will be designed to integrate with the existing T23 Sonar 2050 bow mounted sonar, the future Surface Ship Torpedo Defence system and the T23 Command System (DNA(1)) via a Combat System Highway. It should require no increase in manning over that currently required for Sonar 2031 and the extensive use of Commercial Of The Shelf (COTS) hardware, re-use of software and the imposition of ILS disciplines should ensure reduced Life Cycle Costs.

Costs / In-Service Date (ISD) / Major Milestones / Quantities

Project Costs Summary at out-turn prices to the nearest 10M: 360M VAT Inc estimated acquisition cost.

A total of 21 sets are to be produced, 16 of which are full sea-based sets. The remaining 4/5 are shore based part sets for: a Shore Integration Facility; a contractor reference set; and appropriate cost effective facilities for the training of both operators and maintainers.

In-Service Date (ISD) is the date at which the equipment contributes to force effectiveness in its main role, and when the first Type 23 system has been cleared for operational use. Subject to negotiations with the successful contractor (see below), the ISD will be at the end of 2005. Another major milestone in the future is the Fleet Weapon Acceptance which is planned for June 2009.

Commercial Aspects

The assessment phase is now complete. The two competing contractors, Babcock Defence Systems Ltd and Thomson Marconi Sonar Ltd, submitted 'Revise or Confirm' bids for the Demonstration, Manufacture and Support phases in Sept 1999. A one-year project delay then provided the opportunity for further risk reduction activity. Following the successful conclusion of the work, a re-baselined ITT, inviting tenders against Key Performance Characteristics, was issued on 1 August 2000. Tenders were received on 11 Oct 2000; contract award is planned for spring 2001.

International Collaboration

International collaboration has been considered, but because of the unique UK requirements and the constraints of the Type 23 Frigates it was decided that a national programme was more appropriate.

Both contractors have international representation as part their teams bidding for the next phase.

Point of Contact - S2087_TL@dpa.mod.uk

Last Updated - May 2001

  Sonar 2087 and the Environment

Crown Copyright 2001