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Discussions of naval high-tech usually involve weapon systems. But the transition from steam to gas-turbine propulsion in surface combatants has precipitated a technological revolution below the main deck, as evidenced by the more than 1,200 standard electronic modules (inset) used in the Arleigh Burke (DDG-51) machinery control system.
Everyone in the ship is talking in terms of hits, bytes, and multiplexing systems. Digital logic, with its “and/or” gates, is discussed over chow. This is the engineering department of a naval warship, but it sounds like we have slipped on board the Starship Enterprise. Computers have arrived full force in the engineering departments of today’s surface navy.
U. S. Navy gas-turbine combatants already have microprocessors that automatically execute the start/stop sequence for the main engines and help monitor the health of the engineering plant. The new diesel-powered minesweeper has a high-speed, 16-bit microprocessor that serves as the brain of its engineering plant, and the Arleigh Burke (DDG-5 l)-class destroyer design has six standalone microcomputers in a control system that monitors and controls the status, health, and commands to just about everything below the main deck. Each console talks tors and displays its own health and the health of its ass0 ciated electronics.
The engineer with an oily rag hanging out of his pocf is gone forever. In his place is an enlisted specialist trains to discuss digital electronics as well as mechanical pr0 lems with the oil distribution box for the controllable re versible-pitch propeller. He probably has a computet his home and two to four years of technical college train ing. But can we recruit enough of these people for : future? And can we retain enough of them to man t high-tech ships of our 600-ship Navy?
Technology’s Toehold _____ ^
The introduction of gas-turbine propulsion to naV^j combatants in the early 1970s marked the beginning widespread use of electronics in the engineering sPaC
DDG-51 Machinery Control System i
NOT PART OF MCS
ENGINE ROOM NO. 1
DATA MULTIPLEX SYSTEM AN/USQ 82 (V)
ENGINE ROOM NO. 2
Centralized machinery control and a high degree o- mation (compared to steam or diesel) was possible ^
to every other console at least twice each second, discussing everything from the weather (ambient conditions) to the status of the intrusion alarms in the ship’s armory. No single piece of wire connects these consoles; instead, a sophisticated multiplexing system allows the passage of several million bits of information each second. If one path of this communication system is disabled, the system chooses another path automatically. Each computer moni-
cause of the gas turbine’s simpler engine-control face.1 The engineering control and surveillance sysfg, (ECSS) in the Spruance (DD-963)-class destroyd'^- motely controls and monitors the propulsion plant. elee plant, and major support auxiliaries. The aero-deriv ^ gas-turbine engines are controlled by electronic
Proceedings / Oct°ker
, ands from any of the three levels of control—from the ri(*ge, in a central control station, and locally in the engi- Cer'ng spaces—and are repeatedly checked for safety of •Nation by means of a small microprocessor.2 Other eil§ineering plant parameters, including the electrical gen- atl°n and distribution systems, damage-control sensors, a selected auxiliaries, are monitored by an executive *ltr°l unit, which receives input from a redundant datamation bus.
^ similar hierarchical system-control architecture is in the Oliver Hazard Perry (FFG-7)-class frigates.
| Coprocessors are used to automatically start and stop e §as-turbine engines and diesel generators, and to keep cerT1 operating within safe parameters. The maneuvers °a>manded by the officer of the deck are converted into Tronic commands, which a designer has numerically ulated in an effort to optimize ship response, engine r °rtnance and safety, and overall economy. This profu- |.°n of electronics and early computers required new ena ratings, with specific skills and training to operate Maintain this equipment.
tro ■ Navy’s newest ship designs rely heavily on elec- u n'Cs in general, and computers in particular (see Figure d' ^ach of the control consoles in the DDG-51 (except the dI11age-control console) has the Navy’s latest microcom
could exceed the limits of the propulsion train. In addition, the numerous interlocks and safe operating permis- sives are easily checked by a high-speed computer for a simple on/off condition. Although backed up by complete manual operation, the computer provides an added measure of safety and protection for the machinery.
Technology’s Effect on People
the AN/UYK-44. This standard microcomputer, uses a standard high-order programming language,
vces numerous assembly-coded processors. Coupled I, the plasma display on the console front, the computer allowed the designer to reduce the dedicated panel
e required for meters, alarms, and indicators. Only
highest level alarms and indicators have a spot re
for them on the front panel; all others appear on the
todSnia display. The computer also helps the watchstander theS°rt through a large number of alarms, or to determine Sll °verall status of the plant, by displaying a series of t),rmarY groups. The summary groups logically sort n'^gh data and present related information in an easily ^stood format. Communication among the consoles Pli ,rri0n‘toring of thousands of sensory signals is accom- f0rS e<f by a data multiplexing system, which is designed re*iable operation and graceful degradation under dam-
of, ,e need for electronics can be traced directly to the use 9(j highly responsive gas turbines. Computers take full ^untage of the gas turbines’ features. Orders to the en- ProT 3re combined with the required propeller pitch to the desired ship response. The naval architect the£*S hydrodynamic characteristics of the ship and p Performance of the propulsion plant. The goal is to Sitf£Uce a repeatable, highly responsive, and inherently de$' ,°r^er to the propulsion system. The latest gas-turbine thg'®11. recognizes the fuel savings that can be obtained in enra'l-shaft mode—one shaft windmilling and only one pr0'ne °n the other shaft. This operational mode has been inJjrarnmed for high response and fuel economy. The c0mniZed gas turbine has a very low moment of inertia If. Pared to other components in the transmission system. e*Pe Carefully monitored and controlled, the high torques er'enced in transients, especially high-speed turns,
Perhaps the most challenging aspect of high-technology application is how it affects the operators. If technology can reduce the number of people required to run a ship (and that is debatable), then one must recruit, train, and retain the best technical talent. The designer can develop a system that helps an operator or maintainer to diagnose problems, but the required skill level of that person will continue to rise as the sophistication of the engineering plant increases. No matter what the design, the petty officer technician in the spaces will have to fix the anticipated problems and be prepared to fix other problems not anticipated by the designer. Perhaps the biggest challenge will be repairing an electronic component or computer that has been damaged in battle. Specialized schooling must follow at least a high school education to develop the technician’s diagnostic skills. Thus, we are competing with other highly technical fields, inside and outside the Navy. After we have recruited and trained these technicians, we must retain them and develop their leadership skills.
Recently the Navy took action to ensure that its best sailors will be assigned to key engineering billets afloat.1 The detailing process for E-6 through E-9 engineering ratings will be handled in a manner similar to that for officers. Senior enlisted engineers will be assigned to key engineering billets on board ships based on experience and performance. More than 1,400 engineering billets will be filled by top performers. Among the ratings selected for this special screening are the gas-turbine specialist, machinist’s mate, boiler technician, interior communications electrician, hull technician, and machinery repairman.
Maintenance and Repair
A key feature of technology application is our ability to maintain and repair systems. The challenge for a warship designer is to anticipate the failure mode under battle conditions, and probable battle damage. The effect of the damage on the ship’s overall war-fighting capability must be calculated as well. The shipboard petty officer must be properly trained, and given the proper documentation and spare parts to repair the damage or at least reestablish some minimum capability.
One part of the maintenance and repair solution is the use of standard electronic modules (SEMs)—electronic cards designed and manufactured by industry and tested by the Navy. Discrete building blocks of electronics are packaged in limited sizes, called formats. They are described in terms of their overall function to allow for updating the specific components on the cards. An inventory of these cards can be kept on board for troubleshooting and repair. The DDG-51 machinery control system uses
">Rs / October 1988
areas to show damaged or inoperative areas. It should ?e possible to present the damage-control officer with a list
High tech does exist below the main deck. A very
more than 1,200 SEM cards in the system’s seven consoles. However, there are only about three dozen different types of SEMs used. This helps to minimize the number and types of spares required on board.
Electronic components can be designed to check on themselves and report any problems to the operator; this is called the built-in test. Personal computers often do this during start-up. Shipboard computers are designed to conduct built-in tests on their associated electronics, such as peripherals and other electronic assemblies. The Navy’s latest computer uses the built-in test to guide the technician to three or four SEMs, which can be changed in an effort to correct the problem. While computers are communicating at the rate of several million bits of data per second, they also can monitor the quality of that communication by checking particular bits (“parity”) or the sum of bits (“checksum”).
One of the most exciting aspects of future maintenance is the concept of on-line health monitoring of equipment. With the advent of electronics in the machinery spaces, the designer has access to a large body of data. We have logged numerous plant parameters for years on the gas- turbine combatants. The job of reviewing this unprocessed data is how left to the shipboard engineers. In the future, this data could be processed by an on-board computer that could be programmed to look for trends. Have oil temperatures or measured vibrations been increasing? Has the output of a pump been decreasing compared to its designed head/flow curve? What is an acceptable degradation before repairs are required? The capability to gather and process this data is now available. Processing this data should be left to a computer, and interpretation of the information that results should be left to the engineer.
The Designer’s Challenge
The challenge to today’s ship designer is how to cull from a much larger field those technical advances that are suitable for shipboard use. Several concepts must be kept in mind:
► Does this technological advance help the ship perform better as a warship?
► Does this advance help put more ordnance on target?
► Can this advance survive on a ship after battle damage?
► Does this advance enhance any existing capability?
► Can this advance be supported by petty officers afloat and the maintenance organization ashore?
This list is by no means inclusive. It is meant to show that a relatively small number of technical advances will be suitable for incorporation into naval warships, especially their machinery, electrical, and auxiliary systems. More and more, we will be pushing the limits of what a technician can maintain and operate in the harsh marine environment. In a laboratory environment, systems are groomed to perform at their best by engineers with advanced degrees and senior technicians. This is not the way we man ships.
The ship designers must be thoroughly familiar with the environment that their designs will operate in. What may work in commercial practice may fail at sea, owing to the
harsh environment, lack of logistic support, or the effects of battle damage.
The Future ^
More high technology is coming to ships’ engineering spaces. Already dominant in the machinery control syS' terns and communications highways of today’s ships, m1 croprocessors eventually will grace equipment control^5 and other auxiliary equipment. In the future, digital com munication will probably unite all shipboard informati°n transfer, both for the weapon systems and the machine1? systems. The top watchstanders will have access to >n creasing amounts of data. The designer must process this data and present it so it provides usable and easily undet standable information to the operator. Graphics will used to a greater degree. System diagrams will be played in color on computer monitors, with highlig*1
options that could be used to reconfigure a system afte battle damage or a major accident at sea. (As our syste^ become more complex, something of this nature will required. On a destroyer-sized ship, electrical isolat)0^ and the effects on the combat system of reduced electric power are already complex problems.) The compute would not make any decisions, but would gather data 0 the situation from system sensors, examine its memory' similar situations, and present various options to the ope^ ator. This could save valuable time in the first momel1 after a casualty, and could slow the spread of damage Today’s machinery design buzzwords include fiber °P tics, electric drive, and superconductivity. Our future Pr^ pulsion and electrical systems will probably be linked the same prime mover and share the electrical power Pr°j duced from large generators. Electronics in general, a computers in particular, will be an integral part of me^ designs. The challenge to operator and engineer alike i* make the best use of this technology and recognize changes the new technology will cause.
damental revolution has taken place as surface combatu11- have made the transition from steam to gas turbines. El tronics and computers in the engineering spaces fl18* these ships more powerful weapon systems.
‘J. Dor, “The Design of Gas Turbine Propulsion Control Systems for Ne^ batant Ships,” Selected Major Issues, Third Ship Control Symposium- .$j' 2“Propulsion Plant System for CG 47 Class Ship, Engineering Plant Contf° S9234-D8-GTP-040/CG 47 PPM, 1 October 1984. tf ^
3John Burlage, “Navy Starts New Process to Fill Key Enlisted Billets,
Times, 7 December 1987, p. 1.
Commander Preisel is the program manager for the DDG-51 land'h" ^ engineering site in Philadelphia, and recently completed a tour ®s Naval Sea Systems Command representative at the simulation anC*,C,nly trol systems department at General Electric. A 1972 Naval graduate, he served in various destroyer billets and studied naval e -.p neering at the Naval Postgraduate School. He has worked in surface • design, maintenance, and repair, serving at Charleston Naval Shtp^jp at NavSea in the DD-963 engineering office, and as Director of the Systems Engineering Division.
Proceedings / October