An Option for Short Range, Accurate Naval Fires

I have been thinking about this picture a lot. This is a slide found on page 13 of this Powerpoint, and in it the USS Tortuga (LSD 46) apparently loaded 16 CB-90s during an exercise back on February 27, 2002. I have a very high opinion of the CB-90, and note the US Navy is using the CB-90 on a limited basis with our Riverine Squadrons.

I've also been thinking about Libya. In a Congressional Research Report dated March 28, 2024 done by Jeremiah Gertler titled Operation Odyssey Dawn (Libya): Background and Issues for Congress (R41725), there are some interesting charts on costs. For example, the 3 B-2 bombers that flew from Missouri to Libya cost $2.3 million in flight hours, $800K in refueling costs, and if we assume each aircraft dropped 15 JDAMs (45 total), they delivered roughly $1.575 million in payload. That means those three B-2 strikes cost an estimated $4,675,000. If we assume the US Navy has fired 210 Tomahawk land attack cruise missiles to date, and each TLAM costs $1.4 million, that is roughly $294 million in war costs.

It was recently reported that one of the submarines moved away from Libya, scaling down US Navy presence. That news was received with a big yawn. I'm not really sure why, but I think it might in part be due to the reality the US Navy lacks capabilities for taking the fight to land below that of the $1.4 million Tomahawk. It seems to me the US Navy is missing a few critical pieces if seapower is to take a leading role in influencing the enemy from an offshore position in situations where military action on the land side of the littorals is required.

As I see it the US Navy is missing two important pieces. First, the US Navy needs an accurate weapon system for deploying fires up to a range of about 10km from a position offshore of about 2km. This needs to be a low tech, low cost rapid fires capability that can be supported and maintained from existing platforms at sea. Second, the US Navy needs an accurate weapon system for deploying fires up to a range of about 50km from a position offshore of around 25km. Again, this needs to be a low tech and low cost, selective fires capability that can be leveraged from existing platforms at sea.

It appears the Navy believes that long term, the Griffin missile will be capable of filling the role of the second weapon system. Obviously there will be a development process towards that conclusion to increase the capability of the Griffin, but since NLOS was going to be that short range offshore precision fires capability and the Griffin is intended to replace that weapon system long term, at minimum we can acknowledge the Navy is investing in a solution.

But that still leaves the gap at the very low tech, low cost, short range level... and when facing adversaries that are using low tech capabilities to drive our costs up, it is important that we too seek low tech solutions for those environments where we can keep our costs of conducting the business of war down. The cost difference between MRAP and IED demonstrates how long term, the US loses the cost equation in warfare if we too aren't looking for low cost solutions.

Again, that is why I have been thinking about the CB-90, and in particular the AMOS or Advanced Mortar System, a 120 mm automatic twin barreled, breech loaded mortar turret. If the USS Ponce (LPD 15) had 6 or so of these CB-90s with 120mm mortars, and was configured to fire the GPS Roll-Controlled Guided Mortar shell, your talking about a CB-90 being able to put up to 26 GPS guided 5 lb shells on top of several targets in a single minute out to 7-9 km and at a cost of $7,000 a shell. The nice thing about this capability is that it would fit in nice working with UAVs from LCS, and the low yield of the shell would make this capability useful in urban areas where civilian casualties are a critical concern.

High end missions like Ballistic Missile Defense are requiring resources to be concentrated towards capabilities that simply don't translate into the dirty work of littoral warfare. The LCS is coming, and with the LCS comes a significant number of ISR capabilities that will create opportunities for the US Navy to take the fight to the enemy. Part of that fight needs to be sustainable firepower capabilities that can move in and out of the littorals from 50 miles offshore, be moved forward quickly and maintained in the field. In times of tight budget resources, sometimes those capabilities will be poor man solutions.

The CB-90 with a 120mm mortar firing GPS rounds is an example of a poor mans solution to short ranged fire support, but I would point out that operating at night off the Libyan coast right now they would be a lethal, low cost uniquely naval capability that allows the US to use the sea as a maneuver space and sustain coverage over land areas with a much greater capacity for fires than UAVs will now, or in the future when LCS and other UAV platforms are fielded.