NSWC Adds to its Arsenal of 32-channel OROS Analyzers

Over the past few years, the Naval Sea Systems Command, Naval Surface Warfare Center has procured a large fleet of OR38 analyzers for machinery vibration monitoring.

OROS is the original developer and sole manufacturer of the Machinery Vibration Monitoring System (MVMS) previously used on the DD(X) Engineering Development Test Site and to be installed on the Littoral Combat Ship (LCS) class surface combatant for ship trials.

The design of the MVMS is based on requirements originally set forth by DD(X) test engineers to acquire order-normalized vibration data on propulsion machinery at multiple speeds.  The data needed to be in a format that could be transferred and stored to an on-site Data Acquisition System (DAS).  The LCS class trials’ DAS is based on the same requirements.  The article provided was sophisticated and needed to have met several unique interface formats to be considered acceptable.
Littoral Combat Ships (LCS) are the first of a new family of surface combatant ships for the US Navy.  The trials DAS and MVMS that were specified had to have the ability to provide reliable, high data throughput with many unique capabilities and at low risk.
The LCS is a novel hull design for a ship of this size that includes propulsion components that have not previously been used by the US Navy.  Due to the propulsion configuration and the unique, high speed hull form, there is a great need to characterize the ship through large amounts of trials data at a high rate of speed.  The OROS MVMS is a tried and true system that had the capability to acquire the necessary vibration data in a reliable fashion and meet the requirements of the test team.
Machinery on high speed ships such as the LCS are likely be subjected to vibration in excess of MIL-STD-167-1 Type 1 levels from the following excitation sources:

• Propulsion system
• Slamming
• Wave slap
• Turbulent boundary layer

The Navy sought to increase its body of knowledge on high speed ships, acquire baseline vibration data for LCS-installed machinery and assess machinery reliability.
The original purchase of the MVMS for the DD(X) test site was intended to be a commercial off-the-shelf purchase.  OROS was selected on the basis of meeting all the major specifications with the ability to meet the remaining items with minimal effort.  Additionally, many macros were developed in-house to work with this state-of-the-art OROS system.