QM-13b Quartermaster Engines Elective Instructors: George Crowl

Course Outline  b. Engines:  i) Explain the principal features of steam turbine, turboelectric, direct reversing diesel, diesel-electric, gas turbine, nuclear, gasoline, and diesel engines and the relative advantages of each type.  ii) Explain the operation of spark ignition and compression ignition for internal combustion engines used aboard small vessels.  iii) Demonstrate your familiarity with the engine aboard the vessel used by your ship, including its principles of operation, fuel, lubrication, cooling and electrical systems, and their component parts.  iv) Demonstrate your ability to locate and correct minor engine troubles according to the engine manufacturer's troubleshooting guide.

QM-13b i) Explain the principal features of steam turbine, turboelectric, direct reversing diesel, diesel-electric, gas turbine, nuclear, gasoline, and diesel engines and the relative advantages of each type.

Let's Organize  Several different basic types of engines  Reciprocating – gasoline, diesel, like car  Turbine – spins in one direction all the time, like a jet engine  Electric motors – driven by something else, like a train engine  Nuclear – heat drives a turbine

Reciprocating  Gasoline  4-stroke (old inboards, newer outboards)  2-stroke (old outboards)  Diesel 4-stroke  Direct reversing Diesel  Diesel-electric

Gasoline 4-stroke  Like the engine in your car  Intake Compression Power Exhaust  Spark plug

Gasoline 4-stroke (2)  Animated version

Gasoline 2-stroke  Compression and power stroke are similar  Intake and exhaust are done simultaneously at the bottom of the stroke, less efficient  Requires oil / gas mixture, engine no longer made

Diesel 4-stroke  Main differences – higher compression, squirt fuel into cylinder (injector), no spark plug  Better fuel economy, less fire danger

Direct Reversing Diesel  The engine is stopped  Various adjustments (such as moving the cam shaft) are made so the engine will run properly in the other direction  The engine is started in the other direction, often by a compressed air charge  Advantage – no need for a transmission  Major disadvantage – it might not start in the other direction

Reciprocating Steam  Very first steam engines, first ship engines  No longer in use  Steam released into the pistons, drove the wheel, which drove either the paddle wheel or the propeller

Turbines  Several kinds – steam, gas,  Several uses – generate electricity, geared down direct drive

Steam Turbine - Oldest  Have to have a boiler producing high pressure steam (was coal-fired)  Release steam into front of turbine  Steam expansion drives turbine very fast  Gear down the speed to turn the propeller  Requires gear box for forward and reverse  “Turbina” was first turbine ship, and fastest of its day

Electric Drives  Electric motors are very useful and flexible  They draw current only when they are working  They can actually generate current when they are braking  They are almost instantly reversible  They are mechanically linked to the propeller, but nothing else  They have to have a source of power, but many are available – diesel, steam, turbines, nuclear

Electric Drive (2)  On board ship, power plant drives alternator or generator  Electricity then drives the propulsion motors

Diesel-Electric  Diesel engine turns shaft  Shaft turns generator to produce electricity  Electricity powers motor to turn propeller

Turboelectric  The power plant is a steam or gas turbine  Linked to the high RPM output of the turbine is an electric generator  The generator provides electrical power for ship's motors and for other ship electrical needs

Gas Turbine  Uses air instead of steam  Fueled by petroleum product or hot gasses from an exhaust  Similar to a jet engine  Can run using low grade bunker fuel

Nuclear  Nuclear fuel heats high pressure water, which creates steam  Steam turns turbines to generate electricity  Electricity runs propulsion motor

Advantages / Disavantages  Gasoline – OK for small boats, especially outboards, most dangerous fuel, requires transmission for fwd/rev  Diesel – safe, fuel efficient, less dangerous fuel, requires transmission  Direct reversing diesel – requires no transmission, engine more complex, engine may not restart

Advantages / Disadvantages (2)  Diesel-electric – high efficiency, no transmission, better propeller efficiency, high reliability, more payload (smaller equipment)  Gas turbine – highly reliable, light weight, responsive, significantly more expensive to run  Nuclear – great for submarines and aircraft carriers, no emissions, very expensive, not suitable for commercial ships  Steam turbine – no longer in use

QM-13b ii) Explain the operation of spark ignition and compression ignition for internal combustion engines used aboard small vessels.

Comparison  “Apples-to-apples” – 4-stroke marine engines  Both have 4-stroke reciprocating engines  Gasoline are usually lighter, can turn faster  Fuel is less expensive, burn more of it  Engine maintenance is usually less expensive  Diesels are usually heavier, have better torque  Fuel cost per mile is usually less  Engines can handle continuous use, but more expensive to repair

Spark Ignition  Gasoline & other fuels  Moderate compression (5:1 > 8:1)  Spark sets off explosion in cylinder  Spark plug is key  Needs electricity, right spark gap

Compression Ignition  Diesel fuel  High compression (16:1 > 24:1)  Fuel is injected into very hot mixture, explodes  No spark plug  Very reliable  Injectors do need occassional maintenance

QM-13b iii) Demonstrate your familiarity with the engine aboard the vessel used by your ship, including its principles of operation, fuel, lubrication, cooling and electrical systems, and their component parts.

Your Engine, Your Boat  The requirement is to discuss your engine, and your boat  Someone in your ship may change the following presentation to reflect what is in your ship  The following is build around a nominal 30-foot diesel-powered sloop  Principles should apply to many vessels  Details will be different for nearly every vessel

Principles of Operation  4-cycle Diesel engine, as described above  Fuel is Diesel, a heavy, less volatile fuel  A transmission is behind the engine, with forward and reverse gears, gear shift in cockpit  Engine is connected to the prop shaft through the transmission  Propeller has fixed pitch blades

Engine Lubrication  Requires oil compatible with Diesel engines  Depending on the age of the engine, the code will begin with a C (such as CC) and may be CJ  The thickness of the oil will usually be SAE 30, but may vary by engine and climate or season  Check oil dipstick, should be between two marks  Add oil if needed at oil cap on top of engine  Change at manufacturer's specified interval

Lubricating Diagram

Cooling System  Engines need to be cooled  Car engines are closed cycle, cooled by radiator  Boat engines are different  Two major kinds, open and closed cycle  Open cycle uses raw water, closed uses raw water to cool ethylene glycol

Cooling System (2)  Both require a water pump  Requires occassional change because it wears out easily  Both systems usually mix exhaust with raw water to cool exhaust  Important to check water coming out exhaust, proves water pump is working

Electrical System  TWO electrical systems  AC electric (110V) – from dock box  DC electric (12V) – from motor generator  On most pleasure boats, completely separate systems

AC Electrical System  110V, on the dock, circuit breaker protected  30 amp or 50 amp circuits, different connectors  Heavy duty cables run to boat receptacle  May have additional boat circuit breakers / panel  AC appliances – lights, microwave, toaster, TV, air conditioner, etc., used in port  Often cannot run all AC appliances at once, too much load for the circuit

DC Electrical System  12V power from 2-4 batteries in parallel  12V power from engine driven generator to provide power and recharge batteries  Controlled by main power switch - OFF – 1 – BOTH – 2  Circuit breakers protect each sub-system

DC Electrical System (2)  Power provided to –  Nav lights, cabin lights,  Engine starter motor, ignition system (if required), fuel pump,  Bilge pump(s),  Instruments, radio, depth sounder, GPS, chartplotter,  Inverter, etc., etc.

N  Would be nice to have very simple electrical diagram here, but I did not find one I liked

QM-13b iv) Demonstrate your ability to locate and correct minor engine troubles according to the engine manufacturer's troubleshooting guide.

Engine Guide  Get one! Almost all guides are available on the Internet. Google your engine make and model.  Download it to a computer  Print a hard copy, put it on the boat so it is available for consultation

Troubleshooting  Some engine guides are more tear-down and assembly manuals, rather than troubleshooting guides  Diesel engines need air and fuel to run, usually electricity to start  The Notes pages following trace common problems and solutions

Troubleshooting (2)  Failure to start – Check battery sw / breaker  Check battery charge / jump start  Check electrical / battery connections  Check starter motor  Turns over, won't start – fuel level OK?  Fuel / water separators, fuel valves  Fuel dirty? - need clear red or amber  Injectors OK?  Check air supply – clean filter, no blocks

Troubleshooting (3)  Overheating – check exhaust water & color  No water – clogged strainer / water pump bad  Enough coolant? - takes time to cool to check safely  Overloading – crab traps, etc., on prop  Make your own checklist from your ship's experiences and / or readings

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Questions? 