Raytheon: Raytheon’s combat-proven Excalibur moves closer to sea-based application – Sep 30, 2015

Raytheon Company (NYSE: RTN) successfully fired its new Excalibur N5 projectile during a recent live guided flight test at Yuma Proving Ground, Ariz.A company-funded initiative, Excalibur N5 is a 5-inch/127 mm naval variant of the combat-proven Excalibur precision projectile used by the U.S. Army, the U.S. Marine Corps and several international armies. It is expected to more than triple the maximum effective range of conventional naval gun munitions and deliver the same pinpoint accuracy of the Excalibur Ib, which is in production today. “Excalibur N5’s range, precision and lethality will revolutionize naval gunfire and increase the offensive firepower of our Navy’s destroyers and cruisers,” said Duane Gooden, vice president of Raytheon’s Land Warfare Systems product line. “This demonstration showcases the N5’s maturity as a proven low-risk solution, and is ready for the Navy now.”Excalibur N5 can be used to support several critical mission areas including Naval Surface Fire Support, Anti-Surface Warfare (ASuW) and countering Fast Attack Craft (FAC).”With the significant amount of re-use from the Army’s Excalibur program, the N5 provides the Navy with an affordable, direct path to employ a critical capability,” said Gooden. “We continue to build on Excalibur’s unmatched reliability and performance by investing in a fire-and-forget, dual-mode seeker that will vastly improve the 5-inch gun’s current ASuW and counter-FAC capability.”

Source: Raytheon: Raytheon’s combat-proven Excalibur moves closer to sea-based application – Sep 30, 2015

Emphasis mine. Adding an Excalibur guided round capability to the existing 5″/62 Mk54Mod4 mount is important for providing fire support ashore, but I hope URR will forgive me for thinking a rapid response, mid range anti-ship capability is even more important in the long term. While the N5 round tested doesn’t have that capability yet, some of the architecture, and the techniques used to embed sophisticated electronics in a gun projectile, will prove very useful in adapting a terminal seeker.

Currently, the M54Mod4 can only fire conventional “dumb” rounds at surface ship targets. And while the Mk92 or SPQ-9 Gun Fire Control System is quite accurate, the time of flight out to the maximum effective range of about 13 miles is long enough that a ship can fairly easily dodge shells a while.

But consider a round that triples the range to around 40 miles, and with an terminal seeker (either infrared or millimeter wavelength radar, or both). First or second round hit probability goes up tremendously.

Currently, the a DDG-51 Flight IIA can only engage such a target beyond gun range with either its embarked helicopter (which puts it at risk of air defenses) or with a very expensive SM-2 missile out to the radar horizon.

Instead, with a guided round, the ship’s embarked helicopter can be used to generate situational awareness while the destroyer remains radar silent. But because the helicopter doesn’t have to close within attack range, the risk to it is greatly reduced.

Will a 5″ round sink a destroyer? Not hardly. But consider that the Chinese PLAN operates oodles of small fast missile armed corvettes.  The ability to engage them quickly in sequence will be quite valuable. And while one or two 5″ rounds won’t destroy them, it will likely cause enough damage to prevent them from accomplishing their mission.