J & A Enterprises, Inc.
Noise and Vibration Control Engineers

16 Broadway
Salem, MA 01970
01 + 978-741-1551
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Technical Specifications Definition and Review
A proper set of technical specifications is the primary means by which a client's expectations are communicated to designers and builders.  Information contained in a technical specification is the measure by which success or failure is assessed.  In the absence of quantitative guidelines for allowable noise and vibration levels, there is little recourse in the event of an unsatisfactory outcome.  For this reason (among others) we strongly advocate the use of comprehensive technical specifications to define allowable noise and vibration levels.

A comprehensive technical specification, including limits on noise and vibration, provides an owner, architect or builder with the following benefits.

  • The owner's expectations with respect to noise and vibration are unambiguous.
  • Defined levels help determine the scope of appropriate engineering solutions.
  • Defined levels provide a means for estimating the cost of treatment options early in a project.
  • Defined levels provide the measure against which the finished project is judged.
  • Levels contained in a technical specification can be enforced under the terms of a contract. 


J&A Enterprises has long been involved in the development and review of technical specifications for noise and vibration in a wide variety of vessels.

Specification Development
J&A Enterprises has been involved in projects ranging from the world's finest super-yachts to high performance patrol craft.  We routinely provide engineering services to the world's most prestigious shipyards, and those desiring a level of comfort comparable with the world's premier luxury vessels.  We are therefore uniquely qualified to translate an owner's desires into quantitative, realistic and achievable noise and vibration level specifications prior to soliciting bids for construction.
Specification Review
J&A Enterprises can evaluate an existing document on behalf of an owner, marine architect or builder.  A specification should always be reviewed to ensure that the noise and vibration limits are realistic and within cost and weight budgets.  It is obviously better to discuss the prospect of relaxing noise limits in contract negotiations than upon discovering a noise problem during an acceptance sea trial.  We understand the engineering, material and construction techniques required to achieve a quiet vessel.   Given a specification, we can provide critical information on the difficulty and expense of meeting the targets.
Compliance Assessment
In the closing phase of a project, J&A Enterprises provides measurement services to determine compliance with a technical specification.  We use precision instruments with calibration traceable to the National Institute of Standards and Technology (NIST) and highly qualified engineers to ensure a valid result.  A formal sea trial report documenting the measured noise and vibration levels is submitted for use by interested parties.