Introduction
Introduced in 1971, the Poseidon C3 was a significant advancement in the U.S. Navy’s strategic ballistic missile technology. Featuring Thiokol/Hercules solid-propellant motors, it offered twice the accuracy of the Polaris. Its MIT-developed guidance system used thrust-vector control for precision.
The Poseidon C3, the first missile with Multiple independently targeted Re-entry Vehicle (MIRV) warheads, could carry 8-14 50-kiloton warheads. Deployed on 31 SSBN submarines, it played a crucial role in the US Triad deterrent.
Development began in January 1965, with its first test launch in August 1968 at Cape Kennedy, Florida. The USS James Madison (SSBN-627), modified from a Polaris A3 submarine, first launched the Poseidon C3 from underwater in August 1970.
The missile’s Initial Operating Capability (IOC) was reached on 31 March 1971. By 1978, 30 more Polaris submarines were modified for Poseidon with Lockheed producing 619 Poseidon C3 missiles.
Contractors
The Poseidon C-3 was not the product of a single prime contractor. Instead, its development represented a collaborative effort among several specialized contractors, each responsible for distinct components of the missile system:
- Lockheed’s Missile and Space Division, serving as the primary contractor for the missile subsystem, also crafted the missile’s airframe.
- The reentry vehicle, or warhead, was contracted with the Atomic Energy Commission (AEC).
- Regarding propulsion, the main contractor was a joint venture between Thiokol Chemical Corp. and Hercules Inc. This was one of the two major new work areas for the Poseidon with the development and production contracts constituting approximately one-third of the missile’s projected costs
- The guidance system was designed by the Massachusetts Institute of Technology (MIT) and its procurement was competitively sourced including components from multiple contractors: the gimbal assembly by the Ordnance Division of GE and the electronic assembly by Raytheon
- The fire control system was developed by the Ordnance Division of General Electric, while Westinghouse’s Marine Division was responsible for the launcher.
- Navigation systems were provided by Sperry, a division of Sperry Rand, with the modification of the Ship’s Inertial Navigation System (SINS) undertaken by the Autonetics Division of Rockwell, specifically North American Rockwell.
The following table displays a list of main contractors of the Poseidon C3:
| Subcontractor | Work Contracted |
|---|---|
| Aerojet-General Corp. Sacramento, CA | Missile propulsion |
| Autonetics Div., Rockwell International Anaheim, CA | Navigation |
| Bell Telephone Labs Whippany, NJ | Communications |
| General Electric Co., Ordnance Systems Pittsfield, MA | Fire control/ missile guidance |
| General Electric Corp. Lynn, MA | Propulsion |
| Hercules, Inc. Wilmington, DE | Missile propulsion |
| Honeywell Minneapolis, MN | Missile guidance |
| Hughes Aircraft Co. Culver City, CA | fire control/ missile guidance |
| Interstate Electronics Corp. Anaheim, CA | Instrumentation |
| ITT Labs Nutley, NJ | Communications |
| MIT, Cambridge, MA | Missile guidance |
| Northrop Corp. Anaheim, CA | Missile checkout |
| Raytheon Co. Lexington, MA | Missile guidance |
| RCA, Princeton Labs Princeton, NJ | Communications |
| Sperry Systems Great Neck, NY | Navigation |
| Sylvania Electric Products Co. Buffalo, NY | Communications |
| Thiokol Chemical Brigham City, UT | 1st stage propulsion |
| Vitro Labs, Silver Spring, MD | Weapons system coordination |
| Western Electric Corp. Pittsburgh, PA | Propulsion |
| Westinghouse Electric Corp. Sunnyvale, CA | Missile launching |
Assembly
The assembly process for the Poseidon C-3 missile involved a distinct methodology, diverging from traditional practices where completed missiles are delivered directly from the manufacturer to the military.
Instead, the Poseidon C-3’s assembly was characterized by the distribution of its major components from various manufacturers to two key facilities: the POLARIS Missile Facility Atlantic (POMFLANT) and the Strategic Weapons Facility Pacific (SWFPAC).
At these facilities, the components were meticulously assembled into either tactical missiles or for use in flight demonstration tests. This approach mirrored the strategy implemented under the POLARIS Program, indicating a continuation of a proven system in missile assembly and logistics.
The responsibilities of POMFLANT and SWFPAC extended beyond mere assembly. These facilities were accountable for a comprehensive range of tasks encompassing the receipt and inspection of missile components. They also handled storage, disassembly, modification, maintenance, and repair of the missiles.
Additionally, these facilities were responsible for the meticulous checkout process, outloading and off-loading operations, and the meticulous surveillance of the missiles. They also managed the packaging and unpackaging of the Fleet Ballistic Missiles.
Production
In 1968 the U.S. Navy awarded Lockheed’s Missile and Space Division a 456.1 million-dollar contract for twenty-five development (C3X) flights and five production evaluation flight missiles.
The Poseidon C3 Production Program was initiated in early 1970 with Lockheed, the primary manufacturer, producing a total of 619 Poseidon C3 missiles. Each unit cost approximately $5.42 million through Fiscal Year 1979.
The following table shows an incomplete list of appropriations and missile production per year:
| Fiscal Year | Number produced | Total Appropiation ($ million) |
|---|---|---|
| 1971 | ?? | 530 |
| 1972 | ?? | 349 |
| 1974 & prior | 619 | 3421.6 |
| 1974 | 72 | 252.6 |
| 1975 | - | 48 |
| 1979 & prior | 619 | 3487.7 |
| 1980 | - | 23.8 |
| 1981 | - | 26.2 |
| 1982 | - | 18.7 |
| 1983 | - | 10.5 |
In Fiscal Year 1974, the U.S. Navy made the final planned acquisition of 72 Poseidon missiles. The decision to backfit Trident I missiles into Poseidon submarines set to commence in Fiscal Year 1979 led to notable changes in the production plan. This decision resulted in the cancellation of 61 missiles initially slated for procurement in Fiscal Year 1975, consequently reducing the Poseidon missile inventory objective.
The production line for the Poseidon C3 witnessed its closure in two phases. The production of the re-entry body concluded in October 1974, followed by the completion of the missile body in October 1975, marking the delivery of the last production units.
However, it’s important to note that the continuous production capability had ceased much earlier. For the reentry bodies, this cessation occurred in July 1973, and for the missile bodies, in July 1974. This was primarily due to the discontinuation of annual funding for additional Poseidon production, with the last procurement having been funded in the preceding year.
Further reading
Bibliography
- Cochran, T. B., Arkin, W. M., Hoenig, M. M. (1984). Nuclear Weapons Databook: U.S. nuclear forces and capabilities. United States: Ballinger Publishing Company.
- Francillon, R. J. (1987). Lockheed aircraft since 1913. United Kingdom: Naval Institute Press.
- McMurran, M. W. (2008). Achieving Accuracy: A Legacy of Computers and Missiles. United Kingdom: Xlibris US.
- Quarterly Review of Military Literature. (1968). United States: (n.p.).
- Military Construction Appropriations for 1977: Hearings Before a Subcommittee of the Committee on Appropriations, House of Representatives, Ninety-fourth Congress, Second Session. (1976). United States: U.S. Government Printing Office.
