Undersea Technology: Improved outlook for Collins periscopes? | ADM August 2012

In what appears to be something of a ‘first article’ trial, the two periscopes for one Collins submarine are being updated from analogue to digital systems.

BAE Systems announced last month that it had been awarded a $15 million contract to update the analogue periscope subsystems for one of the six Collins class submarines, replacing them with digital systems. Should the upgrade prove successful at trial, it is hoped that the periscope systems in the rest of the fleet would be similarly upgraded.

It is not clear whether this is part of Sea 1439 phase 5B.2 which is aimed at improvingthe electronic warfare and external communications systems fitted to the Collins submarines and which, according to the DCP, will also include enhancements to the fitted electronic warfare (EW) capability and to the thermal imaging (TI) capability of the search periscopes, or a contract awarded by ASC Pty Ltd under its original through life support (TLS) contract, replaced from 1 July by a new In- Service Support Contract (ISSC).

Designed in the 1980s and housed in 12.5 metre-long tubes that are raised and lowered about six metres, the CKO43 Search and CH093 Attack periscope systems are the primary above water sensors for the Collins combat system, embodying what was regarded at the time as state-of-the-art electro-optics. These include still camera, low light TV, passive range-finder, image intensification and a thermal capability which interface with and update the submarine's combat system during surveillance and strike missions. They are thus critical to the Collins stealth characteristics and its mission effectiveness.

The periscopes originally had two problems, the first of which was shared with the other masts in that they were not streamlined and raising a periscope while moving created enough drag and turbulence to shake the entire submarine. As with many elements of the submarine, there were disagreements as to who was responsible for the problem. It was solved with the help of the DSTO by modifying the masts to redirect the water flow around them (for example, a spiral wrap was fixed around the head of each periscope).

The periscopes also had problems with their optics: periscope users reported difficulty in refocusing after changing magnification, duplication of images, and bands across the field of vision. These problems were attributed to RAN demands that the optical view be the first exposed when a periscope was raised above the water, instead of placing the infrared sensor and single-pulse radar at the head as on other submarines, requiring the optical path to be routed around these components. The periscopes were gradually improved, and were no longer a problem by the time the fast track submarines entered service.

Local work

At a dedicated facility in Adelaide, BAE Systems has been responsible for the licensed manufacture, assembly, system testing, onboard installation and setting to work of the Thales Optronic (formerly Barr & Stroud) periscope systems for the submarines. The company also undertook the design and manufacture of the LLTV sensor, supplied also to the Royal Navy for service with the UK Vanguard class submarine periscope systems.

It was evident that these very complex systems required a multi-level support structure to ensure the effectiveness of the sensors over time and that the crews gained the maximum performance capabilities from the advance systems. The periscopes form part of the hull integrity of the Collins submarine and, other than some controls and power Line Replaceable Units (LRUs) at the bridge end of the periscopes, must be removed from the boat for servicing. Over the years BAE Systems Australia has received a series of support contracts to maintain the periscope systems, initially at its Adelaide facility but later supplemented by a purpose built facility at HMAS Stirling, WA, to provide depot level support for the Attack and Search Periscopes together with a periscope installation and removal team.

Now off boat servicing is handled in the clean room environment at Stirling, without the specialist packaging and transport back to Adelaide that was previously necessary. The facility has provision for storage of complete spare systems with a periscope test tower for system test and verification.

The Adelaide periscope facility and its associated engineering skills and experience, continues to be used for periscope test and evaluation trials and new developments, as well as revalidation of the hull integrity certification, as part of the submarine full cycle docking period. It also continues as a depot level repair facility for the periscope LRUs.

Digitising the ‘scopes

BAE Systems is working with Thales Optronics in Glasgow over a 26-month period on what the company describes as the design, development and manufacture of the digital electronics on the two periscope systems provided for fitting out with upgraded electronics, prior to their installation in Adelaide.

It is assumed that the design broadly follows Thales Optronics digital life extension solution for legacy periscopes, which is seen as suitable for retrofit to all submarine periscopes and all submarines. Known as TADPOLE (Thales All Digital Periscope for Operational Life Extension) this digital upgrade is said to minimise platform modifications through use of existing tube structure while interchangeable (mission-specific) sensor packages improve supportability.

According to Thales Optronics the TADPOLE digital periscope represents an innovative submarine visual system solution that based on the latest proven optronic mast technology to provide an operational life extension to any submarine periscope.

The system makes use of the existing hull-penetrating periscope or mast tube to mount a mission-configurable optronic payload incorporating a broad range of multi-spectrum sensors. The system can be controlled from a dedicated or multi-function console equipped with high resolution displays and can be operated with partial or complete integration with the submarine’s existing combat and data systems.

Key features of the updated system includes high performance digital sensors to provide enhanced situational awareness and range advantage, while real time processing provides rapid and precise threat analysis on live and recorded images.

The included stealth features minimise risk of counter detection while ease of integration reduces platform modifications and maintenance activity with no major hull overhaul. Sensor packages are interchangeable thus enhancing the sustainment of capabilities.

It is anticipated that both Search and Attack periscopes will have four fields of view and will be equipped with optical filters, heated windows and eyepieces.

Both masts will also be equipped with high definition low light TV, stabilisation, still camera, azimuth torque drive, and remote control. However only the Search periscope has thermal imaging and a sextant, while only the Attack periscope has an image intensifier.

Other improvements

Over the years the Collins internal and external communications systems have been upgraded intermittently, but a major boost has been the class fit of multi-functional antennas, under Phase 5B.1 to be followed by a high data rate EHF antenna and mast under this phase, which have prepared the ground for the upgrade/replacement of the external communications system including the communications centre (CommCen).

With these improvements the Collins submarines will have access to fast developing satcom capabilities with bandwidth and data rates unimagined when they were first designed. One driver for higher data rates and more comprehensive communications capabilities has surely been the new AN/BYG-1 replacement combat system (RCS) with its own demand for higher tactical throughput and assured interoperability as well as the demands of a less benign strategic outlook.

It may be safely assumed that the fitment of the new combat systems, now completed on HMA Ships Waller, Farncomb, Dechaineux and Sheean, with the final two systems to be installed on HMA Ships Collins and Rankin during their respective dockings in 2011 and 2012 has also driven the need to upgrade the periscope systems beyond improving their thermal imaging capability.

This phase will also include enhancements to the fitted electronic warfare (EW) capability which has its own mast as distinct from ESM, and ESM-DF being incorporated into some Thomson Optronic Search periscopes. In this regard, the Collins fleet is equipped with the ITT (EDO) ES-5600 electronic support system sensor. It provides automatic detection, direction finding and identification of radar signals. An EDO Argo Systems AR-740 radar warner is also fitted. The upgrade sought for the ESM under Phase 5B2 is likely concerned with extending the submarines’ ELINT capabilities.

If the periscope upgrade was funded under Phase 5B.2 there should be plenty of funds left over from the $350-450 million project estimate.