19_0870_Sole_Source_Justification_Shaker_Redacted.pdf

SOLE SOURCE JUSTIFICATION

BACKGROUND:

The Naval Undersea Warfare Center (NUWC) has a pressure vessel called the Acoustic Pressure Test Facility (APTF) that is currently used to analyze acoustic data of structures at various pressure and temperature conditions. Typically, an acoustic projector is used to ensonify the structure and one or more hydrophones record reflected and/or transmitted acoustic energy.

Performance of the structure is then inferred from the acoustic data, usually by application of a structural acoustic model. This method has four shortcomings: the only wavenumbers that can be excited are in the acoustic regime, they can only be excited one wavenumber at a time, the structural acoustic radiation portion of the model is assumed to be accurate and complex structures made from composite materials are extremely difficult to quantify by single hydrophone measurements as the acoustic field tends to smear the effects of structural inhomogeneities. To develop an advanced capability, a high pressure resistant underwater shaker needs to be procured. Once this is done, a set of elastic models will be derived and corresponding tests will be developed. The testing and modeling will be coupled via inverse methods. When this is accomplished, NUWC will have the ability to test moderately sized underwater structures and analyze their performance in the 1 to 10 kHz frequency regime while they are subjected to high ambient pressure.

Failure to complete this effort would impact the Navy’s requirement to have accurate material measurement properties under significant pressure.

REQUIREMENT:

Request a sole source contract be awarded to Newton Labs, 441 SW 41st Street, Renton, Washington, 98057, for (1) mechanical shaker encapsulated in a pressure vessel that is rated to 600 feet of depth (260 psi), associated electrical amplifier to drive the shaker and fifty feet of depth rated cable. Estimated contract amount is

SOLE SOURCE JUSTIFICATION:

A search for mechanical shakers with pressure vessels and that could operate under high ambient pressure produced no results. Several vendors were contacted that sell these mechanical shakers, however, none of these vendors were able to meet the exact specifications that NUWC was looking for and were unable to provide a quote. One vendor that was contacted, Newton Laboratories, stated that they possess expertise in encapsulating lasers for deep water pipeline examination. Due to Newton Laboratories’ Low-Rate Initial Production (LRIP) manufacturing, this unique mechanical shaker is able to be manufactured with the exact specifications listed above. Newton Laboratories is the only developer and manufacturer of mechanical shakers that are able to be encapsulated in a pressure vessel that is rated to 600 feet of depth (260 psi) and possess an associated electrical amplifier to drive the shaker. Thus, I am requesting a sole source purchase of this item from Newton Laboratories.

RESELLERS:

N/A

Requiring Department:

Based on the above, I recommend this acquisition be conducted on a Sole Source/Brand Name Specification basis. I certify the technical data which form the basis of this justification are complete and accurate.