Friday, June 03, 2005

The Migraine Program: A Name That Says It All

Towards the end of the Second World War, the Navy started kicking around the idea of using submarines as early warning radar platforms, which would extend the much needed radar coverage for surface formations. In addition to the early warning, it was thought that the boats would help to direct friendly aircraft towards enemy contacts.

Early on, it was thought that these radar pickets would operate in pairs or at least close enough so that their radar coverage would overlap each other. This redundancy would come into play if one of the boats had to dive in order to evade enemy aircraft, the other boat would take over until the other boat could surface again and resume coverage of the threat axis.

The first boats to undergo the conversion to a radar picket were REQUIN (SS-481) and SPINAX (SS-489), the latter of which was still on the building ways in Portsmouth. Both boats were mounted with high-powered SR-2 search radars, located on its own mast abaft the conning tower and SV-2 height finders were then installed on the deck further aft. Homing beacons, acting as reference points for combat air patrols, were also installed on deck.

The radar equipment and the associated electronics for the newly developed CIC were then located in the after torpedo room. Because the four torpedo tubes had not been removed it resulted in a seriously crammed compartment and required the after tubes to be reloaded externally. Additional air conditioning and an extra motor-generator were also part of the conversion. If routine maintenance in the compartment had been difficult before, it was now a serious pain in the ass.

Although both the REQUIN and SPINAX were relatively successful in their new rolls, from the very start the conversion showed flaws that were hard to ignore or overlook. Because of the submarines’ low silhouettes, the effective range of the radars was seriously handicapped and breaking seas over the deck aft caused nightmares with the SV-2 height finders.

But in spite of these flaws, the Navy’s need for radar picket vessels forced them to continue the development of the program and BuShips tagged the follow-on program as Project MIGRAINE. You got to love it.

MIGRAINE I conversions of TIGRONE (SS-419) and BURRFISH (SS-312) saw the crew’s mess and galley modified into the CIC, with the tubes being removed in the ATR so that it could be used for berthing. Two tubes were removed in the FTR to make room for more equipment and storage. The AN/BPS-2 search radar was moved to a mast on the after part of the conning tower, with the height finder just abaft that on its own mast.

The MIGRAINE II modifications of the REQUIN and SPINAX included moving the surface search radar and the removal of the stern torpedo tubes, but the height finder stayed put on the deck aft. Both the MIGRAINE I and II boats were fitted with AN/BPQ-2 guidance equipment for the Regulus cruise missiles.

1951 to 1953 saw the conversion of six more subs (all Manitowoc built boats) to MIGRAINE III. More “drastic” than the previous modifications, the MIGRAINE III boats had an additional 24-foot section added just forward of the control room for an expanded CIC and the removal of the stern tubes. The BPS-2 search radar was mounted aft of the periscopes and the entire sail was enlarged and streamlined to enclose the masts. The AN/BPS-3 height finder was located just aft of the sail and an AN/URN-3 TACAN beacon was installed on the afterdeck.

The Navy now had ten radar pickets in its arsenal but the threat of the Red Menace was still too great and two more new construction boats were tapped for the role as radar pickets. By 1956, both SAILFISH (SSR-572) and SALMON (SSR-573) were in commission and were essentially MIGRAINE III submarines but built for prolonged surface operations and a modified BPS-2 air search radar that was able to retract into the sail fairwater.

The culmination of the MIGRAINE program was the nuclear-powered TRITON (SSRN-586), which was commissioned in 1959 and could boast that it was the longest US submarine ever built until the OHIO (SSBN-726). Although the TRITON was a nuke, many of its features were based on the idea that it would operate on the surface more than submerged and had a knife shaped bow and substantial reserve buoyancy. She was also the last to have stern torpedo tubes, twin screws and a conning tower in the sail.

But just as the most advanced radar picket joined the fleet, the introduction of carrier-based early warning aircraft, the E-1B Tracer and then the E-2 Hawkeye, put it out of a job. Before the 1960’s drew to a close, all the MIGRAINE submarines were either reclassified as SS or AGSS or placed out of service.

The MIGRAINE program sheds light on the flexibility of the submarine service and how it’s able to adapt again and again to an ever-changing threat and fulfill the role it’s given in spite of serious flaws or shortcomings.


At 10:40 PM, Blogger Vigilis said...

Impressive detail and background. Enjoyed! I had been wondering about the older nukes (before the Skipjack). Do you know which was the last one to have teakwood decks, or where I could find out?

At 7:52 PM, Blogger bothenook said...

i don't know if it was the last, but seawolf had them. i swiped a piece after we decommed her, prior to sending her to bremerton to be cut up.


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