Cobra Judy II Conversion

Abstract

The strategic community relies heavily on the Cobra Judy (CJ1) instrumentation to provide high-quality radar and telemetry data for ballistic missile system testing and development. The current CJ1 platform, USNS Observation Island (T-AGM 23), will be 50 years old in 2003, and the CJ1 system requires an upgrade in technology. This report investigates the feasibility of converting an existing ship to a Mobile Test Range Asset in order to field a platform carrying the Cobra Judy II (CJ2) system on a much newer ship. Based on a review of available hull forms and prior research, the Henry J. Kaiser class oiler (T-AO 187) was found to be the most suitable conversion candidate. All equipment pertaining to underway replenishment (UNREP) was removed and replaced with components of the CJ2 system. Additionally, systems to provide ballast and electrical power were evaluated and installed, as necessary. The Advanced Surface Ship Evaluation Tool (ASSET), Program of Ships Salvage and Engineering (POSSE), and Ship Wave Analysis (SWAN) software tools were used to evaluate the converted ship's general, structural/stability, and seakeeping characteristics, respectively. The MIT Cost Model was used to estimate conversion costs, excluding acquisition costs of CJ2 sensors. The following table summarizes the characteristics of the CJ2 ship conversion design.

CJ2 Conversion Design Summary

LBP 650 ft B 98 ft T 31 ft Full Load Displacement 35161 ltons KG 32.6 ft GMT/B 0.093 Max. Speed 20 knots Range 9300 nm (at 15 kts) Seakeeping Operable in Sea State 5 Conversion Cost 179 MDo