Category Archives: AOPS

30mm “Swimmer” Round

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30x173mm ammunition for Mk44 Bushmaster II

30x173mm ammunition for Mk44 Bushmaster II

Ran across an interesting new type of ammunition, the 30 mm Mk 258 mod 1 APFSDS-T, which appears to be designed specifically to counter Fast Inshore Attack Craft (FIAC). It uses a unique configuration to allow it to maintain high velocity after entering the water. Being an armor-piercing, fin stabilized, discarding sabot, tracer round, I suspect it might help us attack the engine rooms of larger ships. if we upgrade our Mk38 gun mounts to use the 30mm. Might be able to disable propellers and rudders as well.

In a test “…it destroyed a representative FIAC target travelling at 30kts at a range of 4.8km with the first shot.”

It would probably be good against radio controlled boats like the one in the recent attack off Yemen. General Dynamics is advertising that this “swimmer version” is currently available. This might explain why the Navy replaced the 57mm on the DDG-1000 class will 30mm guns. 

There is a bit more in the 2014 NAMMO Bulletin, on page 8 (5/13 on the pdf), under the title “The Navy’s Best Ammunition”;

The nose-shaped configuration was originally patented by the U.S. Navy and NSWC Dahlgren, but was never turned into functional ammunition. Nammo, NSWC Dahlgren and FFI (Norwegian Defense Research Establishment) carried out a comprehensive study that resulted in the final design configuration of the penetrator nose. Today, Nammo’s Mk258 mod 1 ammunition is used on board the LPD-17 and LCS class of U.S. Navy ships. This has significantly increased the fleet’s capability to defeat aerial and surface threats, as well as submerged threats like torpedoes and mines.

At the very least the 110s in Bahrain (or their Webber class replacements–whenever?) probably should have these. I’d like to see them on all the Webber Class WPCs.

Towed Reelable Active Passive Sonar

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traps-janes-article1

NavyRecognition reports, “GeoSpectrum Technologies Inc. is pleased to announce that it has received a contract through the Build in Canada Innovation Program. Defence Research and Development Canada will test the TRAPS (Towed Reelable Active Passive Sonar) variable depth ASW sonar on Royal Canadian Navy ships.”

This system is seen as a possibility for both the twelve Kingston class “Coastal Defense Vessels” (970 tons, slightly smaller than the 210s) and the projected six icebreaking Arctic Offshore Patrol Ships. There is apparently no intention of using these on the more capable frigates.

TRAPS towing configuration, diagram from GeoSpectrum, Canada

TRAPS towing configuration

The system can be fitted in a standard sized 20 foot container.

TRAPS in 20 foot iso container.

TRAPS in 20 foot iso container.

GeoSpectrum claims :

“The modular design of TRAPS provides a variety of installation options, including containerization on multi-mission vessels and standard deck-mounting.

“The TRAPS system is ideal for small combatants such as OPVs, corvettes, ships of opportunity, and USVs. Applications include naval defence/surveillance, drug interdiction, homeland security, and other water-borne policing.”

In addition to detecting submarines and surface vessels, the system is claimed to be usable for:

  • Active torpedo detection
  • Torpedo decoy
  • Passive receiver
  • Black box pinger detection
  • Sonobuoy processor

A typical detection range of 50 nautical miles is claimed. If it works as advertised this might give most of our larger ships an ASW capability and perhaps help us detect semi-submersibles. Thales’ CAPTAS series is similar, with CAPTAS 2 and CAPTAS 1, designed for ships of over 1,500 and 300 tons respectively.

Russians Building Missile Armed Arctic Patrol Vessel

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Project23550IceClassPatrolVessel

Concept image issued by the Russian Ministry of Defence of the Project 23550 ice-class patrol ships for the Russian Navy. Source: Russian MoD

Janes360 is reporting that the Russian Ministry of Defense has awarded contracts for two new ice class patrol vessels that are reportedly capable of operating in ice up to 1.5 meters thick (approx. 5 feet).

The class is described (in Russian) by the MoD as being “without analogues in the world”, and combining “the qualities of tug, ice-breaker, and patrol boat”.

To me it looks an awful lot like the Norwegian Coast Guard vessel Svalbard or Canada’s Arctic Offshore Patrol Ship that is based on the Svalbard’s design.

Jane’s notes, “A concept image released by the MoD showed the vessel armed with a medium-calibre main gun on the foredeck (likely an A-190 100 mm naval gun), a helicopter deck and hangar, and two aft payload bays each fitted with a containerised missile launch system (akin to the Club-K system offered for export) armed with four erectable launch tubes – presumably for either Club anti-ship or Kalibr-NK land-attack missiles. Although billed as patrol boats, this level of armament makes them better armed than many corvettes.”

If these are in fact containerized missile systems, then they may simply be optional equipment, added to the conceptual image to give the ship a bit more swagger, and we may never actually see this. If you are breaking ice for a vessel following close behind, you may not want missiles with their warheads and high energy fuel located near the stern where a collision with a vessel following too close might rupture a missile and start a fire.

It does suggest that a few spaces for containers could turn almost any ship into a potential missile platform.