Background
MPR Associates provides hull, mechanical, electrical and propulsion engineering services for commercial and U.S. Navy ships, deep submergence vessels and offshore platforms. Our efforts include establishing entire programs for improving design or maintenance approaches, design review, problem solving, test and evaluation, computer software development and mathematical modeling of equipment and systems.

Independent Reviews
We have served as an independent source for design review, concept evaluations, feasibility studies and analysis of test data. Typical efforts include the application of submarine safety provisions to system design and maintenance, assessment of fire fighting system readiness on U.S. Navy ships and the establishment of a program to extend the operating period between shipyard overhauls of submarines. MPR has participated as technical consultant and a member of various Flag Level Steering Committees and Blue Ribbon Panels for the U.S. Navy.

Equipment Performance Monitoring
We have developed equipment monitoring programs for a full range of hull, mechanical and electrical equipments for the purposes of assessing thermal and mechanical performance, material condition and identifying degradation modes and degradation rates. Monitoring programs include gatherings and evaluating data during equipment overhauls, periodically during operation and on-line. Evaluation techniques used to monitor equipment/system performance vary from development of tables and flow charts for manual evaluations of symptoms and data to computerized expert diagnostic systems for automated evaluations.

Design and Analysis
MPR produces design and engineering solutions based on first-principles analyses and years of practical experience. Design projects are taken from the problem definition phase though concept formulations, feasibility, analyses and detailed design. Often, follow-up work includes installation, test programs and long-term monitoring and maintainability testing. For example, MPR analyses determined that poor performance of fire pumps in one class of U.S. Navy ships was due mainly to ineffective alignment techniques between the pump and motor. Early failure of pump bearings resulted from an inappropriate choice of bearings in the original pump design which were not tolerant of misalignment. MPR designed a retrofit kit that was installed and tracked for five years. That prototype achieved over 25,000 hours of documented monitored performance without overhaul.

Other MPR designs include prototype consoles for the boiler control station for one class of U.S. Navy ships including a complete analysis of the boiler and feed pump controls, simplification of alarms and human engineering of all operating stations), portable test devices to monitor voltage and frequency outputs of 60-to-400 Hz motor generator sets, and modifications to seawater valves to reduce reliability and maintainability problems.

Test and Evaluation
In test and evaluation projects, we study all aspects of the design and operation of the system, process, or component and develop mathematical equations to understand the physical and chemical principles the underlie the design. We have used this approach to define meaningful, practical tests and to quantify expected test results and minimum acceptable performance. For example, MPR developed a multi-branch hydraulic model of a shipboard firemain system which predicted that the system could not produce required flows at certain fireplugs; shipboard tests confirmed the predicted result. This work resulted in appropriate design changes, and in an engineered basis for decisions on when to clean the firemains. MPR has performed similar analyses on other multi-branch shipboard hydraulic systems.

Other test and evaluation projects have included shipboard distilling plants, air conditioning plants, bolted connections using specialized materials and lubricants, comparative testing of cleaning methods for heat exchanger tubes, and testing of safety features on shipboard elevators.

Mathematical Modeling
Fundamental to our problem-solving approach is our ability to model physical systems with mathematical models. For instance, we modeled a shipboard boiler along with its feed pumps, forced draft blowers, and pneumatic controls. Based on this model, we wrote alignment procedures and identified settings for adjusting the control system to provide the desired system responsiveness and controllability. The first boilers groomed with these alignment procedures and settings passed boiler flexibility tests on the first try.

Other equipments which we have mathematically modeled in detail include turbine generator governors, shipboard distilling plants, air conditioning units and diesel multi-engine propulsion systems.

Fire Protection
MPR has provided engineering support to the U.S. Navy in areas of shipboard fire protection, damage control and life safety, including assessments of hazards, specification of appropriate fire protection, design of fire fighting systems and development of standards. Typical tasks have included: development of entire programs such as foam system improvements for surface combatants; resolution of reliability problems in Halon 1301 total flooding systems; providing technical support as a member of shipboard fire investigation teams; development of design criteria and technical rationale for shipboard automatic sprinkling systems; and developing test and evaluation programs for various fire protection devices such as quick response automatic sprinklers, Halon system time delay devices, large flight deck water monitors, and solenoid operated pilot valves.

MPR has also taken an active role in the technical assessment of improved methods for recovering and recycling Halon 1301 in an effort to eliminate unnecessary discharge of the CFC to the atmosphere.

Computer Software Development
MPR Associates has developed a wide range of general and special purpose software as part of our problem-solving and engineering support and work. Typical general purpose software are a two-phase flow and pressure loss analysis for Halon 1301 piping distribution networks and a program for calculating torque, preload and stresses in threaded fasteners. Typical special purpose software include programs to calculate fouling of heat exchangers using measured data and a program to calculate the effects of bearing clearance on the maximum stress in submarine steering and diving journal bearings.

Contact
Contact MPR for further information on our marine engineering services, or other engineering services.