News

2015-04-01

new world of the torpedo

Technical innovations changes role of the projectiles

While the battleship evolved primarily around engagements between armoured ships with large-caliber guns, the torpedo allowed torpedo boats and other lighter surface ships, submersibles, and later, aircraft to destroy large armoured vessels without the use of large guns. However, this was sometimes at the risk of being hit by longer-range shellfire.

Human ingenuity and advancements in technology have taken underwater weapons from floating mines and spar torpedoes to the fast-moving, self-guided, homing torpedoes today. From submarine warfare to warship design and tactics development, the modern torpedo is one of the fundamental drivers of 20th century naval warfare. Its ability to sink ships and submarines with one shot is always in the mind of naval commanders. The modern torpedo enables submarines to defeat surface and undersea threats and gives surface ships and aircraft the means to reach beneath the surface and attack submarines.

But what does the future of the torpedo hold?

Torpedoes can be launched from a variety of platforms. Torpedo design must take into account several considerations: Speed (much faster than the target), Operating depth, endurance, quietness, reliability and cost (initial and through-life).

Torpedoes can be divided broadly into lightweight and heavyweight classes; and into straight-running, autonomous homers, and wire-guided. The heavyweight torpedoes are generally boarded on submarines, although a few navies deploy 533mm torpedoes from surface ships as anti-ship weapons. Lightweight torpedoes mostly arm helicopters, maritime patrol aircraft and surface ships.

BAE Spearfish (533mm torpedo)

The UK’s Ministry of Defence (MOD) awarded BAE Systems a £270 million contract in 2014 to upgrade the Spearfish Heavyweight Torpedo for the Royal Navy’s submarines. Following the completion of the design phase, existing torpedoes will be upgraded by BAE Systems at its Broad Oak facility in Portsmouth to the new design with initial deliveries in 2020 continuing until 2024.

The upgrade, known as Spearfish Mod 1 extends the life of the torpedo, improves safety through the introduction of an Insensitive Munitions warhead and by utilising a single fuel system and provides more capable data links between the weapon system and the launching vessel. This results in capability improvements for the Royal Navy as well as significant reduction in through-life operating costs.

The anti-submarine and anti-surface Spearfish torpedoes are currently deployed in the BAE Systems designed and built Trafalgar and Vanguard submarines, as well as the Astute Class submarines. Spearfish can be used in defensive and offensive situations and its advanced design delivers maximum warhead effectiveness at high speed with outstanding manoeuvrability, low radiated noise, advanced homing and sophisticated tactical intelligence.

The torpedo can operate autonomously from the time of launch and is capable of variable speeds across the entire performance envelope.

SAAB DEFENCE: New lightweight torpedo

Defence and security company Saab has received orders from the Swedish Defence Materiel Administration (FMV) for continued development of the New Lightweight Torpedo.

Based on the proven Torpedo 45 with its outstanding shallow-water anti-submarine warfare capability, the New Lightweight Torpedo will deliver significant performance improvements to deal with evolving threats in international scenarios. Torpedo 45 is a 400 mm torpedo intended for ASW and surface targets, providing multiple-target active/passive homing combined with wire guidance. Torpedo 45 can be launched from a variety of platforms including stationary, surface vessels, submarines and helicopters. It is operational with the Swedish Navy.

It is controlled using wire guidance and has a hydro-acoustic homing system for the final phase. The torpedo has features that are unique for lightweight torpedoes.

In exercise torpedo launches, the warhead is replaced by an exercise head carrying identical homing equipment. Instead of explosives, the exercise head has a tape recorder for logging a number of torpedo functions, communication with fire-control and hit indications. After each run, the recordings are analysed and torpedo and fire-control functions are checked.

VA-111 Shkval supercavitating torpedo

The Shkval (“squall”) is a high-speed supercavitating rocket-propelled torpedo designed to be a rapid-reaction defence against US submarines undetected by sonar. It can also be used as a countermeasure to an incoming torpedo, forcing the hostile projectile to abruptly change course and possibly break its guidance wires.

The torpedo has a nearly flat, conical disk at its nose that creates the gas cavity for supercavitation. The disc tilts to help guide the weapon and keep it stable. The cavity is supported by rockets venting just abaft the cavitator. Four popout cylinders toward the aft end of the nose section keep the body of the torpedo stable and out of contact with the walls of the bubble in which it rides. At the rear of the torpedo are deflected control surfaces. Eight small rockets surround the main sustainer rocket. The main engine cuts in when the weapon has achieved supercavitation speed.

The torpedo is guided by an autopilot rather than by a homing head as on most torpedoes. The initial version was unguided. However, the Russians have indicated there is a homing version that starts at the higher speed and then slows and enters a search mode.

Varunastra heavyweight torpedo

Varunastra is developed by the Defence Research and Development Organisation (DRDO) to counter threats from the sea. Varunastra is to defend Indian Navy from hostile submarines and ships. The DRDO’s Visakhapatnam-based Naval Science and Technology Laboratory (NSTL) developed the Varunastra. This torpedo targets ships and is the first heavyweight to be inducted into the Navy. The 7.6 m, 1,500 kg torpedo will be more lethal and has a range of up to 30 km.

This torpedo is wire-guided. In other words, the guidance wire acts as a medium for communication of data between the torpedo and the firing platform (ship or submarine). The wire is also a medium to communicate data to guide the torpedo towards the target during the underwater run.

DRDO has developed guidance wire spools for wire-guided torpedoes like Varunastra. DRDO has also developed an onboard instrumentation system for torpedoes. The instrumentation system performs pre-launch communication, monitors health of the torpedo and stores torpedo parameters online.

Mark 48

The MK 48 heavyweight torpedo is used by all classes of submarines as their anti-submarine warfare (ASW) and anti-surface warfare (ASuW) weapon.

The MK 48 ADCAP torpedo is a heavyweight acoustic-homing torpedo with sophisticated sonar, all-digital guidance-and-control systems, digital fusing systems, and propulsion improvements. Its digital guidance system allows for repeated upgrades to counter evolving threats through software upgrades. The last new ADCAP torpedo was delivered in 1996. Since then, the Navy has provided discrete improvements to the torpedo’s guidance and control and propulsion systems.

The MK 48 ADCAP Mod 6 torpedo combines two significant enhancements: one in guidance and control (G&C Mod), and the other in the torpedo propulsion unit (TPU Mod). The G&C Mod improves the acoustic receiver, replaces the guidance-and-control hardware with updated technology, increases memory, and improves processor throughput to handle the expanded software demands required to improve torpedo performance against evolving threats.

The latest version of the MK 48 ADCAP is Mod 7 Common Broadband Advanced Sonar System (CBASS) which is optimized for both the deep and littoral waters and has advanced counter-countermeasure capabilities.

MK 54 lightweight torpedo

In today’s changing high-tech world, new, more potent threats are emerging. Slow, quiet, diesel submarines, for example, are now operating in shallow-water, littoral areas. As a result, lightweight torpedoes designed to defeat high-speed, nuclear-powered submarines in open-ocean environments are ineffective. Navies now need a lightweight torpedo capable of delivering a devastating blow to submarine threats in both deep and shallow water — and in various acoustic environments.

The MK 54 can be deployed from a surface ship, helicopter or fixed wing aircraft to track, classify and attack underwater targets. It uses sophisticated processing algorithms to analyze the information, edit out false targets or countermeasures, and then pursue identified threats. The MK 54 program leverages the most modern torpedo technologies from the MK 50 and MK 48 ADCAP (advanced capability) programs. It also utilizes the proven MK 46 warhead and propulsion subsystems. The result is a low-cost weapon that meets all performance requirements for littoral warfare.

Featuring many improved capabilities, the MK 54 is the next-generation of the MK 46 torpedo.

Building a better torpedo

The MK48 Advanced Capability (ADCAP) Heavyweight Torpedo, along with the MK46 Mod 5 and the MK50 Lightweight Torpedoes, are currently the workhorses of the fleet. The heavyweight torpedo is the submarine’s key multi-mission underwater weapon, capable of performing both anti-submarine and anti-surface roles. The MK48 Mod 5, with its improved guidance system, and the MK48 Mod 6 with low-noise propulsion, provide the fleet with torpedoes whose performance is unmatched in deep-water scenarios. The lightweight torpedo gives surface ships, airplanes, and helicopters the means to destroy threat submarines.

The MK54 Lightweight Torpedo will bring considerably improved shallow water capabilities to the fleet. Building on the success of the ADCAP torpedo, new weapon technologies are being developed to tackle the challenging shallow-water littoral environment. These technologies will be common to both the heavyweight and lightweight torpedoes to keep costs down and maximize performance across the board.

Quiet as a mouse

Developing a truly stealthy torpedo will provide more approach-and-attack options for submarines. A stealth weapon that cannot be heard until very late in the encounter will delay the threat’s detection of the torpedo and impair its ability to respond effectively with either countermeasures or return fire. This will greatly increase the probability of killing the enemy and avoiding a potentially lethal counterattack.

Key to survival

Maximizing the survivability of the warfighter is crucial, and self-defense systems are necessary to ensure that all platforms have the capability to protect themselves from attack. Anti-torpedo torpedoes will provide our future platforms with an additional defence capability. Their primary mission is to destroy incoming torpedo threats that may have gotten through a countermeasure field. Based on technology under development at ONR, a 6.25 inch-diameter self-protection weapon is under study for the defense of surface ships and submarines using supercavitation technology.

Comments () Views (5773 ) Print

Send To Friend