SPG-59 Installation on USS Norton Sound

The AN/SPG-59 was an electronically scanned radar like today's AN/SPY-1, but unlike using phased arrays (the technology of the 1960s, in particular, C band phase shifters were simply too large and inefficient in transmitting energy), it used a Luneberg Lens deep in the ship to act as a phase generator for radar signals. AN/SPG-59 was originally going to be produced in three versions, a 10,000 antenna element version for cruisers, a 7,000 element intermediate design, and a 3,400 element version for DLGs and DLGNs. Eventually, the 7,000 element system was dropped and the final two designs put forth were:

Both versions could track the same number of Typhon missiles inflight, but the Cruiser version had much more transmitted power, which meant more range, allowing it to support Typhon LR. The DLG/DLGN version only had the range to support Typhon MR. The difference in target track capability was due to the bigger and more powerful computer mainframes installed with the cruiser version.

A test version of the AN/SPG-59 was operational on the USS ''Norton Sound'' from June 1964 to July 1966. During this period, it was found that the AN/SPG-59 had reliability problems, and lost too much signal strength during processing, resulting in some tests of the system finding out that the maximum range of the AN/SPG-59 was less than the minimum range required to resolve targets (!!!). Reportedly these problems with the AN/SPG-59 were solved after it had been canceled officially in 1963 by McNamara, before the equipment was removed from ''Norton Sound'' in 1966.

This data seems to conform with the cruiser version, except for the number of tracks. The Navy probably didn't see the need to test the full size 400-track computer system until it was sure that the Luneberg Lens system worked. Since we know the specifications of both versions, it should be reasonable to assume that the production versions would have the following specifications:

The radar and missile elements together dictated the size of the ships which would carry the Typhon system, while the ship element was further complicated by the perceived need to get ship size and cost down to a level acceptable to then-Secretary of Defense Robert S. McNamara.

Typhon-equipped cruisers with a 10,000 element SPG-59 needed three dedicated 2,500 KW turbo generators to provide power for the AN/SPG-59 alone, which was a drain of 10,000 SHP from the main plant. This caused conventionally powered Typhon designs to be limited in endurance, and conventionally-powered designs usually carried a less powerful conventional air search radar (AN/SPS-43) which was operated all the time, and upon detecting targets, the AN/SPG-59 would be energized for a short time. Even with these economy measures, operating the SPG-59 just 10 percent of the time resulted in a significant decrease in the ship's endurance, usually on the order of a thousand nautical miles. This led to a predilection for nuclear-powered Typhon ships, increasing size and costs.

Many Typhon-equipped ships were proposed, ranging from the 1962 Scheme D-1 8,720 ton full load missile frigate (DLG), to the 1962 Scheme G 11,500 ton full load CONAG (Combined Nuclear And Gas Turbine) cruiser. For the purpose of this article, I shall be concentrating on the two schemes which I consider the most realistic, the 16,100 ton Typhon Cruiser and the evolution of the Typhon 10,000 ton DLGN. The DLGN went through many changes as the Navy tried to find a design that didn't cost significantly more than a 3T armed ship in an attempt to appease McNamara.

The Missiles

In order to rectify the shortcomings of the 3T (Terrier, Tartar, Talos) SARH system in which the missiles would home in on reflected radar energy from the target, limiting the number of targets capable of being engaged at any one time to the number of directors carried by the ship (usually only two), the Typhon system relied on a new technology called ''Track-Via-Missile'', in which the missile radioed what it's radar seeker saw back to the ship, where the data would be processed, and then course correction commands would be radioed back to the missile via a coded radio link. This system had the advantage of having all the really expensive parts in the weapons system be on the ship, dramatically lowering costs of the missile. The computing power required to do this would fit on a modern desktop computer, but back in the 1960s when Typhon was conceived, you needed several very large and heavy mainframes to do this, which also drove up tonnage, and most importantly, costs.

There were two missiles, a Long Range missile, and a Medium/Short Range missile, which would have replaced the Terrier, Tartar, and Talos completely. They would have been capable of intercepting Mach 3~ targets, and at very close ranges, Mach 4~ targets. A secondary anti-ship capability was also possible with them.

Bibliography/References

Norman Friedman 1981. ''Naval Radar''. Naval Institute Press. ISBN 0870219677.
Norman Friedman, 2003. ''US Destroyers: An Illustrated Design History; Revised Edition''. Naval Institute Press. ISBN 1557504423.
Norman Friedman, 1984. ''US Cruisers: An Illustrated Design History''. Naval Institute Press. ISBN 0870217186.
Typhon - A Summary by Tom Schoene