Interest in non-hull penetrating optronics periscopes began in the 1980s. They were envisaged to improve submarine design flexibility and safety. The operational advantages conferred by these systems included the sharing of the periscope's imagery on several crew screens, rather than just for the crewmember using the periscope, simplified operation and improved capabilities including a Quick LookRound (QLR) function which exposed the periscope to the surface for the shortest possible time to subsequently reduce the platforms exposure and hence the possibility of detection by anti-submarine warfare platforms. This QLR function has become increasingly important given the growing use of submarines for the collection of intelligence.
In addition to improving submarine design flexibility by decoupling the control room's location from the optronics masts, the latter enhances control room ergonomics by freeing up space which would usually be occupied by the periscopes. Non-hull penetrating masts also can be reconfigured with relative ease with new systems and capabilities, and have fewer moving parts, thus reducing overall periscope life cycle costs and correspondingly the maintenance, repair and overhaul burden. Ongoing technological advancements are helping to reduce periscope detection with further improvements heralded via the push towards low-profile optronics masts.
Earlier this year the US Navy installed a new stealthy periscope onboard one of its 'Virginia' class nuclear-powered attack submarines (SSNs) based on L-3 Communications' Block 4 Low-Profile Photonics Mast (LPPM). The company is working to provide a slimmer version of the current Kollmorgen (now L-3 Kollmorgen Electro-Optical/KEO) AN/ BVS-1 photonics mast installed on the same class of SSNs to help reduce the possibility of radar detection.
L-3 Communications announced on 26 May that its optronics business L-3 KEO (in February 2012, L-3 Communications absorbed KEO resulting in the formation of L-3 KEO) had been awarded a $48.7 million, competitively bid contract from the US Navy's Naval Sea Systems Command (NAVSEA) to perform engineering and design work for the lower-profile mast, with options to produce up to 29 photonics masts over a four-year period, as well as to provide engineering services. The LPPM initiative is realising the capabilities of the vessel's current periscope, but is reduced in size to resemble a more traditional periscope, like the Kollmorgen Type-18 periscope which began to be rolled out on the US Navy's 'Los Angeles' class SSNs as they entered service from 1976.
Although offering unique capabilities, the AN/BVS-1 is large and its shape is unique to the US Navy, allowing the immediate identification of the submarine's nationality if the periscope is detected. According to publicly available information, the LPPM has the same diameter as the Type-18 periscope, with an external look resembling the basic shape of the same periscope. The LPPM is a modular non hull-penetrating design in a telescopic universal modular mast bay that provides submarines with improvements in stealth and survivability. Design features include short wave infrared and high definition visual imaging, laser range finding and an antenna suite providing broad electro-magnetic spectral coverage. The L-3 KEO LPPM prototype is, to date, only operational on board the USS Texas 'Virginia' class SSN, providing an initial operational capability with the new system. The first production mast will be completed in 2017 and the first installation will commence in 2018. According to L-3 KEO, the company plans to develop its LPPM so that NAVSEA can use the same mast onboard new submarines, as well as retrofits to existing vessels, as part of a continuous modernisation programme that addresses reliability, performance and affordability. The export version of the AN/BVS-1, known as the Model 86, was first sold internationally to the Egyptian Navy as part of a larger retrofit of four 'Romeo' class conventional hunterkiller submarines (SSKs) under a contract announced in 2000. Other users include an unidentified European customer which uses the Model 86 onboard its SSKs.
Together with the LPPM, L-3 KEO provides the US Navy with the Universal Modular Mast (UMM). This is a nonhull penetrating mast that is installed on Virginia class submarines. The UMM serves as a lifting mechanism for five different sensors which includes the AN/BVS-1, the OE-538 radio mast, a high data rate antenna, a special missions mast, plus the US Navy's Submarine Integrated Antenna System and integrated Electronic Support Measure (ESM) mast. KEO received the contract from the US Department of Defence for the development of the UMM in 1995. In April 2014, L-3 KEO was awarded a contract worth $15 million to provide 16 UMMs to furnish several 'Virginia' class SSNs.
Other customers for the UMM include the Marina Militaire (Italian Navy) which has so equipped the first and second batch of its 'Todaro' class SSKs; the latter two boats to be delivered respectively in 2015 and 2016. L-3 KEO also owns the Italian periscope specialists Calzoni which has developed an Electronic UMM (E-UMM), which eliminates external hydraulics to raise and lower the periscope via the introduction of electronic actuation.
L-3 KEO's latest offering is the nonpenetrating Attack Optronic System (AOS). This is a low-profile mast combining the features of the company's conventional Model 76IR search periscope and its Model 86 optronic mast (see above). Offering reduced visual and radar signatures, the new mast has a head diameter of only 190mm (7.4 inches) and a 453 kilogram (996.61b) weight penalty. In addition to a laser rangefinder, thermal imager and a High-Definition Colour Television (HDTV) camera the AOS includes a low-light TV camera.
In the first half of the 1990s, Germany's Carl Zeiss (now Airbus Defence and Space) began the preliminary development of its Optronic Mast System (OMS). The first customer for the production version of the OMS, known as the OMS-110, was the South African Navy which selected the system for its three 'Heroine' class SSKs delivered between 2005 and 2008. The Hellenic Navy also chose the OMS-110 for its 'Papanikolis' class SSKs, followed by the Republic of Korea Navy (RoKN) for its 'Chang Bogo' class SSKs. The OMS-110 was also installed on the Indian Navy's 'Shishumar' class SSKs and the 'Tridente' class conventional hunter-killer boats for the Marinha Portuguesa (Portuguese Navy). One of the latest procurements of the OMS-110 has been to outfit the UMM (see above) of the Italian Navy's 'Todaro' class SSKs, and the Deutsche Marine (German Navy) 'Type 212' class conventional hunter-killer boats. These boats will combine the OMS-110 with the Airbus Defence and Space non-penetrating SERO 400 attack periscope. The OMS-110, meanwhile, features two-axis line-of-sight stabilisation, a third-generation mid-wave thermal camera, HDTV and an optional eye-safe laser rangefinder. The periscope's QLR mode allows a fast, programmable 360 degree panoramic view. Reportedly, this can be accomplished by the OMS110 in less than three seconds.
Airbus Defence and Security has developed, either as a complement to the OMS-110 or as a standalone solution, the OMS-200 low-profile optronics mast. Unveiled at the 2013 Defence Security and Equipment International exhibition in London, this mast sets itself apart through enhanced stealth technology as well as its compact design, according to the manufacturer. The OMS-200 is a compact, modular, low-profile, non-hull penetrating, search/attack optronics mast integrating multiple mission sensors in a single radar absorbent housing. In its role of being a 'replacement' for the traditional direct view periscope, the OMS-200 was specifically designed to retain stealth characteristics in the visual, infrared and radar domains. The OMS-200 combines three sensors including HDTV, a shortwave thermal imager and an eyesafe laser rangefinder. The high image quality and resolution of the shortwave infrared camera can be complemented with a mid-wave thermal imager to enhance surveillance, particularly in poor visibility when there is mist, fog or haze. The OMS-200 can merge its imagery to deliver a single picture while benefitting from high-performance line-of-sight stabilisation, the company told Armada.
During the 2014 Euronaval 2014 exhibition held in Paris, Sagem announced that it had been selected by Daewoo Shipbuilding and Marine Engineering (DSME) to supply non-hull penetrating optronic masts to equip the RoKN's new 'Son-WonII' class SSKs, for which DSME is the prime contractor. This contract award marked a key export success for Sagem's latest Series 30 Search Optronic Mast (SOM) family. This is a non-hull penetrating optronics search mast which can simultaneously accommodate more than four advanced optronics channels and a full range of electronic warfare and Global Positioning System (GPS) antennae; all housed in a lightweight sensor pod. Optronics sensors on the Series 30 SOM include a high-definition thermal imager, HDTV, lowlight TV and an eye-safe laser range finder. Supported antennae include GPS, an early warning Electronic Support Measure (ESM), a direction-finding ESM and communications. Among the operational modes, the system offers fast QLR (see above) while all its optronics channels are available simultaneously. The full digital dual screen displays have an intuitive graphical interface.
Sagem is already supplying a variant of the Series 30 SOM for the Marine Nationale (French Navy) new 'Barracuda' class SSNs, while another variant is understood to have been sold to a further, as yet unidentified, export customer. According to Sagem, the Series 30 SOM being supplied to the RoKN will include an ESM, as well as discreet infrared communications. An attack version of the Series 30 SOM, known as the Series 30 AOM, featuring a low-profile mast is also available and is fully compatible with the Series 30 SOM version in terms of mechanical, electronic and software interfaces. The same cabinet and cables can be used with both sensor pods, enabling navies to select the optimal configuration for a specific mission. Baseline sensors include a high-definition thermal imager and HDTV, while optional systems include an eye-safe range finder, short-wave thermal imager and a day/night backup camera.
With a pedigree dating back to 1917 when its predecessor became sole supplier to the Royal Navy, Pilkington Optronics (now Thales) initiated the development of its private-venture CM010 family of optronics masts, installing a demonstrator onboard the Senior Service's 'Trafalgar' class SSN in 1996 prior to the company's selection by BAE Systems in 2000 to equip the Royal Navy's new 'Astute' class SSNs with a dual CM010 optronics mast for the first three boats (out of a total class size of seven vessels). Thales was subsequently awarded contracts to equip the balance of the class with the dual CM010 configuration.
The adoption of the CM010 design onboard the 'Astute' class makes the Royal Navy second only to the US Navy's 'Virginia' class in operating an entirely non-penetrating visual system onboard its submarines. The CM010 includes HDTV and a thermal imager while Thales' CM011 combines the HDTV with a high-performance image intensification camera to provide an underwater viewing capability that a conventional thermal imager cannot offer. In May 2007 Thales started delivery of CM010 masts to Japans Mitsubishi Electric Corporation for installation aboard the Japanese Maritime Self-Defence Forces new 'Soryu' class SSK, under a contract received in November 2004. Thales is currently developing a low-profile variant of the CM010 with the same functionality and a sensor suite comprising HDTV, a thermal imager and low-light TV or a laser range finder, intended for specific missions or for smaller SSKs. Conceived to support special operations on highend platforms, the ULPV (Ultra-Low Profile Variant) will offer a pod option combining dual sensors (HDTV, an image intensifier or a thermal imager) in a ultralow profile sensor head with a visual signature similar to an attack periscope of under 90mm (3.5 inches), but with stabilisation and ESM support.
THE PANORAMIC MAST
The largest operator of advanced submarines, the US Navy is moving periscope technology forward via the Affordable Modular Panoramic Photonics Mast (AMPPM) programme. Launched in 2009, the AMPPM initiative aims "to develop a new submarine sensor mast designed to provide the highest quality sensors for a panoramic search capability in the visible and infrared ranges, as well as long range detection and identification capabilities with short-wave infrared and hyper-spectral sensors," according to the US Navy's Office of Naval Research (ONR) which is overseeing the programme. The AMPPM is designed to drastically reduce fabrication and maintenance costs by its modular design and non-rotational structure. In addition, it is expected to significantly increase operational availability compared with current photonics masts, says the ONR. According to the latest programme developments, the prototype mast developed by Panavision, which was selected by the ONR in June 2011 to develop the AMPPM, will undergo at least two years of tests on land. This will be followed by sea trials expected to commence by the start of 2018. The AMPPM is earmarked for the eventual installation onboard the 'Virginia' class SSNs. These will provide the boats with a 360 degree field-of-view using a nonrotational mast.
Caption: L-3 KEO provides the US Navy with the Universal Modular Mast (UMM), which serves as a lifting mechanism for five different sensors including the AN/BVS1 photonics mast, a high data rate mast, multi-functional masts and an integrated I electronics support measure [C] US Navy
The 'Virginia' class nuclear-powered attack submarine USS Missouri seen here with her two L-3 KEO AN/ BVS-1 photonics masts. This class of SSN has been the first to carry only non-hull penetrating photonics masts for surveillance and attack [C] US Navy
Caption: A German Navy 'Type 212A' class conventional hunter-killer submarine showing its masts. The second batch of 'Type 2I2A'and 'Todaro'class SSKs to be delivered to the German and Italian navies has a combination of SERO-400 and OMS-110 penetrating and nonpenetrating masts [C] Luca Peruzzi
Caption: Imagery from an L-3 KEO AN/BVS-1 photonics mast is seen here on an operator console. Non-hull penetrating masts bring benefits regarding control room ergonomics and also improve submarine safety by improving the structural integrity of the hull [C] US Nav
Caption: Sagem has developed and put into production the family of Series 30 surveillance (SOM) and attack (AOM) masts, which have customers worldwide including the French Navy. The AOM mast has been designed to present a very low-profile visual signature [C] Luca Peruzzi
Caption: The latest customers of DONS' 'Scorpene' class SSKs are equipped with a mix of Sagem penetrating and non-penetrating masts, including the Series 30 mast which includes four optronics sensors, notably HDTV, thermal imager, low-light TV and an eye-safe laser rangefinder [C] DCNS
Caption: Thales has equipped all the Royal Navy's 'Astute' class submarines with an Optronics mast suite which includes CMOW and CM011 sensor head units. These products are providing the baseline for a new series of submarine periscopes [C] UK MoD
Caption: The JMSDF's JNS Hakuryu SSK belongs to the 'Soryu' class and is equipped with Thales' CM010 mast. These are supplied to Mitsubishi, the prime contractor for the 'Soryu' class, for installation onboard the submarines [C] US Navy
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