Wikisea - User contributions [en]

MediaWiki:Sitenotice

2017-11-02T16:32:24Z

DavidShaw:

== Share your knowledge & experience! Help fill out the pages. [mailto:info@wikisea.net Email] your content and we'll help. ==



==== New: [https://s3.amazonaws.com/CHINFO/USS+Fitzgerald+and+USS+John+S+McCain+Collision+Reports.pdf Report on the Collision between USS FITZGERALD (DDG62) and Motor Vessel ACX CRYSTAL] ====

MediaWiki:Sitenotice

2017-11-02T16:30:28Z

DavidShaw:

== Share your knowledge & experience! Help fill out the pages. [mailto:info@wikisea.net Email] your content and we'll help. ==



==== New: [Official Report on the Collision between USS FITZGERALD (DDG62) and Motor Vessel ACX CRYSTAL https://s3.amazonaws.com/CHINFO/USS+Fitzgerald+and+USS+John+S+McCain+Collision+Reports.pdf] ====

ElectricalCapacityAC

2016-05-16T14:11:34Z

DavidShaw: /* Peak Load */

{{#TwitterFBLike:right|small|like}}

= Calculating AC Electrical Capacity =
== Summary ==
Calculating AC (alternating current) load is an activity in determining the capacity of the boat's house bank of DC (direct current) batteries. Peak load is also necessary in sizing the inverter to convert DC to AC. Over estimating the numbers to provide comfort in the individual calculations is not recommended. It is better to add spare capacity calculations directly to the [[:Category:InverterSystems|inverter]] and [[:Category:ElectricalPrimarySupply|house bank]] specifications.

Do the AC load calculation first because it will provide data for the peak load. However, peak load is shown first because it is shorter, and so it won't get lost at the bottom of the page.

A link to a [[#spreadsheet]] is provided.

See also [[ElectricalCapacityDC]].

== Peak Load ==

To determine the peak-load requirement divide the day into [[https://en.wikipedia.org/wiki/Watch_system watches]] that conform to the ebb and flow of your day. Here we are using the merchant-marine watch system. You can use a finer grained system if you know that your lifestyle uses a lot of electricity at a specific time.

The peak load period might be a good time to run the generator to recharge the [[:Category:ElectricalPrimarySupply|house bank]].

List the appliances and enter their power consumption in watts (W) in the period when they are used. Add up each column to determine what the peak load is and when it occurs, then divide by the number of hours in the watch (4 h in the example) for the average — or, you might want to analyze AC usage per hour for that period to get a better assessment of the actual peak consumption.

<table border="1" style="width:80%">
<tr><th align="right">Watch Period:</th><th>0000 - 0004 (w)</th><th>0004 - 0008 (w)</th><th>0008 - 1200 (w)</th><th>1200 - 1600 (w)</th><th>1600 - 2000 (w)</th><th>2000 - 0000 (w)</th></tr>
<tr><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td></tr>
<tr><td>e.g., Toaster</td><td> </td><td>1500</td><td> </td><td> </td><td>1500</td><td> </td></tr>
<tr><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td></tr>
<tr><td>Total:</td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td></tr>
</table>

==AC Load ==

<div id="spreadsheet">Download spreadsheet: [[Media:CalculatedLoadAC.xlsx|Microsoft Office xlsx]] | [[Media:CalculatedLoadAC.ods|Libre/Open Office ods]]</div>

The AC load is based on the duty cycle of an appliance. The duty cycle is the hours it is used in a day (24 hours).

AC load is calculated thusly:
* <number of this appliance type> * <watts rated> = <watts total>
* <hours used per day> / 24 = <duty cycle>
* <watts total> * <duty cycle> = <watts/hour>

The below table identifies many common appliances and suggests some default values. [http://www.oksolar.com/technical/consumption.html OK Solar] also has some typical energy consumption for different devices. Always confirm your actuals.

<table border="1" style="width:90%">
<tr><th>ITEM</th> <th>NUMBER</th> <th>WATTS</th> <th>WATTS TOTAL</th> <th>HOURS PER DAY</th> <th>DUTY CYCLE</th> <th>WATTS PER HOUR</th></tr>

<tr><td colspan="7">LIGHTING & SMALL APPLIANCES</td> </tr>

<tr> <td>Blender</td> <td>1</td> <td>300</td> <td>300</td> <td>2.0</td> <td>0.08</td> <td>25</td></tr>

<tr><td>Breadmaker</td> <td>1</td> <td>600</td> <td>600</td> <td>6.0</td> <td>0.25</td> <td>150</td></tr>

<tr><td>Coffepot</td> <td>0</td> <td>200</td> <td>0</td> <td>3.0</td> <td>0.13</td> <td>0</td></tr>

<tr><td>CoffeeMaker</td> <td>1</td> <td>800</td> <td>800</td> <td>3.0</td> <td>0.13</td> <td>100</td></tr>

<tr><td colspan="7"> Computer </td></tr>
<tr><td style="text-align:right">Laptop computer </td><td> 0 </td><td> 50 </td><td> 0 </td><td> 6.0 </td><td> 0.25 </td><td> 0 </td></tr>
<tr><td style="text-align:right">Desktop computer </td><td> 0 </td><td> 250 </td><td> 0 </td><td> 6.0 </td><td> 0.25 </td><td> 0 </td></tr>
<tr><td style="text-align:right">Printer </td><td> 0 </td><td> 100 </td><td> 0 </td><td> 0.5 </td><td> 0.02 </td><td> 0 </td></tr>
<tr><td bgcolor="#FF0000" colspan="7"> </td></tr>
<tr><td> Electric frying pan </td><td> 0 </td><td> 1200 </td><td> 0 </td><td> 1.0 </td><td> 0.04 </td><td> 0 </td></tr>
<tr><td> Waffle Iron </td><td> 0 </td><td> 1200 </td><td> 0 </td><td> 0.4 </td><td> 0.02 </td><td> 0 </td></tr>
<tr><td bgcolor="#FF0000" colspan="7"> </td></tr>
<tr><td> Drill 1/2" </td><td> 0 </td><td> 750 </td><td> 0 </td><td> </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td> Drill 1" </td><td> 0 </td><td> 1000 </td><td> 0 </td><td> </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td> Circular saw 8-1/4" </td><td> 0 </td><td> 1400 </td><td> 0 </td><td> </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td> CD Player </td><td> 0 </td><td> 35 </td><td> 0 </td><td> </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td bgcolor="#FF0000" colspan="7"> </td></tr>
<tr><td> Hot plate </td><td> 0 </td><td> 1200 </td><td> 0 </td><td> </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td> Deep fryer </td><td> 0 </td><td> 1500 </td><td> 0 </td><td> </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td> Pressure cooker </td><td> 0 </td><td> 1000 </td><td> 0 </td><td> </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td> Curling Iron </td><td> 1 </td><td> 50 </td><td> 50 </td><td> 1.0 </td><td> 0.04 </td><td> 2 </td></tr>
<tr><td> Hair Dryer </td><td> 1 </td><td> 1250 </td><td> 1250 </td><td> 1.0 </td><td> 0.04 </td><td> 52 </td></tr>
<tr><td> Shaver </td><td> 0 </td><td> 15 </td><td> 0 </td><td> 0.3 </td><td> 0.01 </td><td> 0 </td></tr>
<tr><td> Kettle </td><td> 1 </td><td> 1500 </td><td> 1500 </td><td> 3.0 </td><td> 0.13 </td><td> 188 </td></tr>
<tr><td> Microwave </td><td> 1 </td><td> 1500 </td><td> 1500 </td><td> 5.0 </td><td> 0.21 </td><td> 313 </td></tr>
<tr><td> Toaster </td><td> 1 </td><td> 1200 </td><td> 1200 </td><td> 3.0 </td><td> 0.13 </td><td> 150 </td></tr>
<tr><td colspan="7"> Outlets </td></tr>
<tr><td style="text-align:right">Engine Room </td><td> 1 </td><td> 1500 </td><td> 1500 </td><td> 1.0 </td><td> 0.04 </td><td> 63 </td></tr>
<tr><td style="text-align:right"> Pilot House </td><td> 1 </td><td> 1500 </td><td> 1500 </td><td> 1.0 </td><td> 0.04 </td><td> 63 </td></tr>
<tr><td style="text-align:right"> Heads - GFC </td><td> 2 </td><td> 1500 </td><td> 3000 </td><td> 2.0 </td><td> 0.08 </td><td> 250 </td></tr>
<tr><td style="text-align:right"> Port Berth </td><td> 1 </td><td> 1500 </td><td> 1500 </td><td> 1.0 </td><td> 0.04 </td><td> 63 </td></tr>
<tr><td style="text-align:right"> Starboard Berth </td><td> 1 </td><td> 1500 </td><td> 1500 </td><td> 1.0 </td><td> 0.04 </td><td> 63 </td></tr>
<tr><td style="text-align:right"> Galley </td><td> 4 </td><td> 1500 </td><td> 6000 </td><td> 1.0 </td><td> 0.04 </td><td> 250 </td></tr>
<tr><td style="text-align:right">Dinette </td><td> 1 </td><td> 1500 </td><td> 1500 </td><td> 1.0 </td><td> 0.04 </td><td> 63 </td></tr>
<tr><td style="text-align:right">Salon </td><td> 4 </td><td> 1500 </td><td> 6000 </td><td> 1.0 </td><td> 0.04 </td><td> 250 </td></tr>
<tr><td style="text-align:right">Aft Cabin </td><td> 3 </td><td> 1500 </td><td> 4500 </td><td> 1.0 </td><td> 0.04 </td><td> 188 </td></tr>
<tr><td style="text-align:right">SubTotal </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> 1954 </td></tr>
<tr><td bgcolor="#FF0000" colspan="7"> </td></tr>
<tr><td colspan="7"> MOTORS & HEATERS </td></tr>
<tr><td> Air Compressor </td><td> 0 </td><td> 0 </td><td> 0 </td><td> 0.0 </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td> Battery Charger </td><td> 0 </td><td> 0 </td><td> 0 </td><td> 0.0 </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td> Exhaust & Supply Fans </td><td> 0 </td><td> 0 </td><td> 0 </td><td> 0.0 </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td> Air Conditioners </td><td> 0 </td><td> 0 </td><td> 0 </td><td> 0.0 </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td> Water Heater </td><td> 1 </td><td> 4000 </td><td> 4000 </td><td> 4.0 </td><td> 0.17 </td><td> 667 </td></tr>
<tr><td> Electric, gas or oil Heaters </td><td> 0 </td><td> 0 </td><td> 0 </td><td> 0.0 </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td> 25% of Largest Motor </td><td> 1 </td><td> 0 </td><td> 0 </td><td> 0.0 </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td style="text-align:right">SubTotal </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> 667 </td></tr>
<tr><td bgcolor="#FF0000" colspan="7"> </td></tr>
<tr><td colspan='7"> BUILT-IN APPLIANCES </td></tr>
<tr><td> Clothes </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td></tr>
<tr><td> Clothes Dryer </td><td> 0 </td><td> 1300 </td><td> 0 </td><td> 3.0 </td><td> 0.13 </td><td> 0 </td></tr>
<tr><td> Clothes Washer </td><td> 0 </td><td> 500 </td><td> 0 </td><td> 3.0 </td><td> 0.13 </td><td> 0 </td></tr>
<tr><td> Clothes Dryer/Washer Combo </td><td> 1 </td><td> 1300 </td><td> 1300 </td><td> 3.0 </td><td> 0.13 </td><td> 163 </td></tr>
<tr><td> Dishwasher </td><td> 1 </td><td> 1500 </td><td> 1500 </td><td> 3.0 </td><td> 0.13 </td><td> 188 </td></tr>
<tr><td> Disposal </td><td> 0 </td><td> 450 </td><td> 0 </td><td> </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td> Freezer </td><td> 0 </td><td> 0 </td><td> 0 </td><td> </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td> Vacuum cleaner </td><td> 0 </td><td> 700 </td><td> 0 </td><td> </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td> Ice Maker </td><td> 0 </td><td> 200 </td><td> 0 </td><td> </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td> Oven </td><td> 0 </td><td> 0 </td><td> 0 </td><td> </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td> Refrigerator </td><td> 0 </td><td> 750 </td><td> 0 </td><td> 8.0 </td><td> 0.33 </td><td> 0 </td></tr>
<tr><td colspan="7"> Stove Top </td></tr>
<tr><td style="text-align:right"> Induction </td><td> 1 </td><td> 2600 </td><td> 2600 </td><td> 4.0 </td><td> 0.17 </td><td> 433 </td></tr>
<tr><td style="text-align:right"> Halogen </td><td> 0 </td><td> </td><td> 0 </td><td> </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td style="text-align:right"> Coils </td><td> 0 </td><td> </td><td> 0 </td><td> </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td style="text-align:right"> Solid Disc </td><td> 0 </td><td> </td><td> 0 </td><td> </td><td> 0.00 </td><td> 0 </td></tr>

<tr><td> Towel Rail </td><td> 5 </td><td> 100 </td><td> 500 </td><td> </td><td> 0.50 </td><td> 250 </td></tr>
<tr><td> Trash Compactor </td><td> 0 </td><td> 0 </td><td> 0 </td><td> </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td> TV </td><td> 1 </td><td> 1500 </td><td> 1500 </td><td> </td><td> 0.25 </td><td> 375 </td></tr>
<tr><td> Vacuum System </td><td> 0 </td><td> 0 </td><td> 0 </td><td> </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td> Other </td><td> 0 </td><td> 0 </td><td> 0 </td><td> </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td style="text-align:right">SubTotal </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> 875 </td></tr>
<tr><td bgcolor="#FF0000" colspan="7"> </td></tr>
<tr><td colspan="7"> FREESTANDING RANGE </td></tr>
<tr><td> Load Watts </td><td> 0 </td><td> 0 </td><td> 0 </td><td> </td><td> 0.00 </td><td> 0 </td></tr>
<tr><td style="text-align:right"> SubTotal </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> 0 </td></tr>
<tr><td bgcolor="#FF0000" colspan="7"> </td></tr>
<tr><td style="text-align:right">TOTAL </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> 3496 </td></tr>

</table>

[[Category:ElectricalCapacity]]

[[Category:Appliances]]

User:DavidShaw

2016-05-03T00:45:47Z

DavidShaw: /* David Shaw */

= David Shaw =

David Shaw is a Project Management Professional [http://www.pmi.org (PMP)]; Professional in Critical Infrastructure Protection [http://www.ci-institute.com/overview.html (PCIP)]; and the founder of [http://wikisea.net/Wikisea:About WikiSea].

David is a senior management consultant and information architect. He has managed more than 100 projects, using waterfall, spiral, incremental development and Agile methodologies — in systems for knowledge-management, eLearning and XML/SGML component content-management — in the USA, Canada, UK, Switzerland, Denmark, Greenland, Alaska, and Trinidad & Tobago.

[[File:Iqaluit_skyline.jpg|thumb|right|250px|Iqaluit in winter -- WikiPedia]]

David's experience with online information systems began with [https://www.ieee.ca/millennium/telidon/telidon_about.html videotex systems] based on [https://en.wikipedia.org/wiki/Telidon Telidon]. He co-managed the [https://en.wikipedia.org/wiki/Telidon#Commercial_efforts international Telidon project for the Third General Assembly of the Inuit Circumpolar Council] in Frobisher Bay (now Iqaluit) on [https://en.wikipedia.org/wiki/Baffin_Island Baffin Island].

[[File:Hmcs-onondaga.gif|thumb|left|250px|HMCS Onondaga, Oberon-class diesel-electric submarine]]

David once spent a week on [https://en.wikipedia.org/wiki/HMCS_Onondaga_%28S73%29 HMCS Onondaga] writing Life on a Canadian Submarine for [https://en.wikipedia.org/wiki/Weekend_%28magazine%29 Weekend Magazine]. For the [https://en.wikipedia.org/wiki/Montreal_Star Montreal Star] he was on board [http://www.navy-marine.forces.gc.ca/en/fleet-units/huron-history.page HMCS Huron] for her Maker's Trials and experienced a December blizzard off [https://en.wikipedia.org/wiki/Anticosti_Island Anticosti Island]. He also flew ice patrol from [https://en.wikipedia.org/wiki/Summerside,_Prince_Edward_Island Summerside] in [https://en.wikipedia.org/wiki/Prince_Edward_Island Prince Edward Island] to [https://en.wikipedia.org/wiki/Iqaluit Iqaluit] in [https://en.wikipedia.org/wiki/Baffin_Island Baffin Island] in an [http://www.airliners.net/photo/Nordair-%28Environment-Canada/Lockheed-L-188C%28IR%29-Electra/0070408/M/ Electra L-188] used for ice reconnaissance. During the same period he was a columnist for Driving Magazine, and volunteered as chief pit marshal at [https://www.lecircuit.com/ Le Circuit Mt Tremblant] during the heyday of [https://en.wikipedia.org/wiki/Can-Am Can-Am racing].

In another life David raised [https://en.wikipedia.org/wiki/Hereford_%28cattle%29 Hereford cows] and [https://en.wikipedia.org/wiki/Arabian_horse Arabian horses].

David writes four very occasional blogs (infrequently!) and has published two technical books. He also makes an amazing [https://en.wikipedia.org/wiki/Trinidad Trinidad] hot sauce that has been called a gateway drug for [https://en.wikipedia.org/wiki/Capsaicin capsaicin] addiction;)

In his current life he lives downtown without cats, dogs, horses, cows or other creatures.

Download: [[Media:3-PointEstimate.xlsx|Free 3-point estimating tool (xlsx)]]

[mailto:davidshaw@wikisea.org Email David]

[[Category:People]]

2016-04-02T21:17:41Z

DavidShaw: /* Diesel Engines */

= Diesel Engines =

The engine of choice for a boat is a marine diesel from a manufacturer such as: [http://www.caterpillar.com/ Caterpillar], [http://www.cummins.com/ Cummins], [http://www.detroitdiesel.com/ Detroit Diesel], [cwww.deutz.de/ Deutz], [http://www.northern-lights.com/ Lugger], [http://www.MAN-MEC.com Man], [http://www.Perkins-Sabre.com Perkins], [http://www.Vetus.nl Vetus], [http://www.volvo.com/volvopenta/se/sv-se/ Volvo Penta], [http://www.westerbeke.com/ Westerbeke], [http://www.yanmar.com/ Yanmar], [http://www.ZF-Marine.com ZF-Marine]. Diesels are more efficient per gallon of fuel than a gasoline engine and much much safer. The only significant alternatives on the horizon are fuel cells. [http://boatdiesel.com/ BoatDiesel.Com] has a wealth of information on diesel engines, transmissions and propellers.

Invented by Rudolf Diesel circa 1898, diesel engines are pressure ignited. They use the familiar four-stroke Otto Cycle of intake-compression-combustion-exhaust.<ref>How Engines Work, http://www.keveney.com/Engines.html</ref> Unlike a gasoline engine, which uses spark plugs to ignite a compressed mixture of air and fuel, diesel engines use the heat of compression to ignite the fuel-air mixture. Diesels use very high compression to do this. Like all modern engines, diesels use fuel injectors to spray fuel into the combustion chamber at the precise best moment.

A good diesel engine will produce about 20 hp per gallon/hour compared to 12 hp per gallon/hour for a gasoline engine.<ref>Fuel Horsepower, Tony Athens, http://boatdiesel.com/Articles/</ref> Put another way, a 300-hp diesel will consume about 15 gallons an hour while a similar gasoline engine will consume about 25 gallons.

Diesels are very reliable and robust, but they are only as good as the fuel system. Most troubles with diesel engines stem from the fuel system, and can be prevented through maintenance and a high-quality filtering system. The engine should also be fitted with a starter button, bypassing the one on the bridge; and a dry sump and drip pan.

== Fuel System ==

Diesel fuel deteriorates when stored. (So does gasoline, for that matter.) Diesel fuel has a shelf life of approximately 100 days. The chief causes of deterioration are oxidation, condensation, micro organisms, corrosion and sedimentation.

Oxygen combines with the hydrocarbon molecules, forming particulates, water and gum. Condensation inside the tank deposits more water. Bacteria and fungi collect and grow at this water-fuel interface in the fuel tank. They eat diesel fuel and give off more water and acids. Corrosion in the fuel tank releases metal into the fuel, accelerating the oxidizing process.

Water, microbial growth, and stray voltages can cause corrosion in steel tanks. In addition, fuel can be contaminated with water and sediments on delivery; and air can be drawn into fuel lines where fuel is leaking.

Sediments, moisture, and air can block fuel filters or disrupt an injector. Sediments such as clay and sand originate in the crude oil; others from the sludge that precipitates as the fuel deteriorates.

Good practice is to keep tanks full to avoid condensation, and minimize mixing fuel from different sources, as this can reduce the stability of the fuel. Condensation on the outside of a tank is a good sign! It means the dew point inside the tank will not be low enough for condensation inside.

Religiously maintain filters, injectors and fuel pumps, and inspect fuel lines for leaks. It also helps to use a petroleum solvent such as Pri-D or Run-Right<ref>Power Research Inc., http://www.priproducts.com/</ref> <ref>. C.A.T. Products, Inc., http://www.run-rite.com/</ref>, but avoid the regular use of [https://en.wikipedia.org/wiki/Biocide biocides], as they are corrosive. Note also that diesel substitutes like bio-diesel, made from vegetable oils, animal fats, and recycled cooking oils, introduce new sets of problems.

A high-quality filtering system consists of at least three micron filters, water separator and a circulating fuel system to polish fuel. The term polishing means cleaning the fuel. A polishing system should have a high flow rate to turn over a tank quickly and also because most filters are designed internally to work better with a higher flow. Depth-type filters are better than edge-type filters.

Avoid using a day tank. It is better to constantly polish the fuel in the main tanks. A day tank holds enough fuel for a day’s run, but if you don’t use all of the fuel, the day tank becomes just another fuel tank with the attendant problems. Fuel should be polished at least three times a week; and always returned to the tank of origin. A top-outlet fuel tank eliminates the risk of dumping fuel if a line breaks.

Tanks should not have open cross-connections as this will reduce stability. As the boat heels, fluid will run to the lower side, adding weight. Consider a fuel-shut-off valve outside the engine room in case of fire.

[[File:FuelPolishingSystem.jpg|thumb|left|250px|Fuel polishing system for one or two engines with ganged valves. Booster pump flushes air from the system or transfers fuel from tank to tank. Oberdorfer or Walbro pump circulates fuel constantly to polish it. A day tank is not used. Filter details for second engine not shown. Detail of ganged filters not shown.
– Adapted from Gulf Coast Filters (http://www.gulfcoastfilters.com/) & SeaSkills (http://www.seaskills.com/)]]

A polishing system for two tanks and one engine is shown. It is designed to polish fuel with or without the engine running. When running, the filters can be bypassed if they clog and you need to hot-swop them. If the engine fuel pump fails, the polishing pump serves as a backup to keep the engine going. The vacuum gauge after the filters monitors their condition. A new set of filters will show about 3-inches of mercury. An engine will begin to starve around 10 inches as the filters become restricted.<ref>Fuel Filters, Tony Athens, http://boatdiesel.com/Articles/</ref>

== Lubrication ==

Finally, to protect the engine from lack of lubrication during heeling, the engine should have a dry sump. Wet sumps are the most common. In a wet-sump engine, the lubricating oil, usually several quarts, is contained in a sump (oil) pan bolted underneath the engine block. During heeling, the oil runs to the side and, in the worst case, can starve the engine of oil, causing damage to the bearings. Oil can also slosh onto the lower cylinder walls, reducing power.

In a dry-sump engine, the oil is kept in an external tank. The tank can be as large as you want. Typically, there are two oil pumps, one for pressurising the oil galleries, another for scavenging the oil from the sump.

While this provides protection during stormy weather, when the boat is being tossed around, it doesn’t provide full engine protection in a knockdown. The engine won’t suffer oil starvation in a knockdown, but it can still be flooded by oil if the scavenging pickup sucks air.

An ignition shut-down switch activated by oil pressure is also advisable. Such a switch (e.g., a universal voltage switch) should also be fitted with an alarm.

== Cold Weather Starting ==

Consider adding a block heater to the engine, controlled by a thermostat, for starting in cold weather.

== References ==

[[Category:PowerpackDiesel]]

AcousticalIsolation

2016-03-25T12:57:25Z

DavidShaw: /* Eliminate Source */

{{#TwitterFBLike:right|small|like}}
= Acoustical Isolation =

== Isolation and Well Being ==

Noise reduction through acoustical isolation is necessary for well being at all times. It is extremely important in a live-aboard boat to keep noise within a comfortable range. We experience sound in terms of a frequency range measured in Hertz (Hz) and air pressure measured in decibels (dB). The ear has a very wide non-linear response to the intensity of sound, so each 10 dB increase is ten times louder. Thus a 20 dB increase is 100 times more intense. Duration is also important. Constant noise over 85 dB will damage hearing.

For reference, the ambient noise level in most homes is 30-35 dB. Car interiors are around 40 dB. A normal conversation is around 60 dB. A diesel engine room is around 125 dB (wear ear protectors!}. A jet plane taking off is around 140 dB. For bedrooms, to get a good restful sleep, the [http://www.who.int/ World Health Organization] recommends 30 dB with no single noise event exceeding 45 dB.

== Eliminate Source ==

A good strategy is to eliminate sound at its source, especially in the engine room. This reduces the cost of acoustical insulation elsewhere. Noise attenuation of 100 dB is feasible. Some areas for consideration are:

* Engine and exhaust-system mounts to decouple engine noise from structural members
* Engine enclosures for generators with heat-resistant sound-dampening materials
* Exhaust mufflers
* Air intake baffles
* Flanking noise via holes in bulkheads and water, plumbing and [[HVACIntegration|HVAC distribution systems]]
* Floor, ceiling and walls of the engine room
* Bulkheads and doors in living spaces
* [[HullInterior#Interior Fittings|Isolating all wall panels]] from structural boat walls

In addition to the noise of combustion, there are several considerations in designing acoustical-isolation systems for an engine room. These are drive-train vibration, especially from the propeller, the peak frequencies generated by large noise generators such as the engine, and the range of noise to which the ear is most sensitive.

Complicating matters a bit, every engine and engine room is a unique case. However, noise radiation from the crank case and oil sump is typically 500 to 1,000 Hz. Engine block vibrations run below 1,250 Hz while gear noises run above 2,000 Hz.

The human ear responds to sounds in the range of 20 Hz to 20 kHz but is most sensitive in the 1,000-5,000 Hz band with a peak around 4,000 Hz. The auditory canal alone has a closed-tube resonance of 2,000-5,000 Hz.

For a production boat it’s feasible to do a spectrum analysis and design suitable sound attenuation and test it. For a bespoke boat this is unlikely to be feasible. Thus a good cost-effective approach is to focus on reducing sound transmission, in a target range for engine noise such as 1,000-2,500 Hz (wavelengths of 13.5 to 5.4 in or 34.3 to 13.72 cm).

== Methods of Isolation ==

Acoustical isolation works by converting sound waves into heat that is then dissipated. Some methods of isolation are:

* Reflecting sound waves
* Dampening sound waves
* Converting sound waves to heat energy
* Decoupling surfaces

Reflecting sound within a room causes sound to lose energy, reducing the amount of sound radiation outside the room. A common method of achieving this is to have reflective material on the outside surface of insulation. However the room shape and size can also have a major impact. The best shape for noise cancellation is a cube. The next best is a room where all dimensions are a multiple of the height, e.g., a room that is 7 x 14 x 14 ft.

Dampening sound is achieved by absorbing it in insulation. The depth of insulation should be calculated to absorb the desired wavelengths (see above, 6-14 in for engine noise). Cabins can be quietened with hollow walls and doors filled with acoustic dense fibre matting (DFM) mineral wool or an aerogel sheet<ref>Aspen Aerogel Inc., http://www.aerogel.com/</ref> or use [[HullInteriors#Structural Insulated Panels|structural insulated panels]] (SIP). Aerogel is also an excellent thermal insulator, with a value of around R22 per inch.

DFM mineral wool is non-flammable and chemically inert. A random arrangement of fibres ensures no water penetration in any direction. It is rot proof, non-[https://en.wikipedia.org/wiki/Hygroscopy hygroscopic] and will not encourage the growth of fungi, moulds or bacteria.

Sound waves can be converted to heat energy by adding mass to surfaces. Vibrating a mass absorbs more of the sound energy. Mass can be added by marine-grade plywood panels or lead surfaces on insulation. Medium-density fiberboard (MDF) is not as hard as plywood and can sag under heavy weight. MDF doesn't handle moisture very well, either.

Decoupling is achieved by using [https://en.wikipedia.org/wiki/Viscoelasticity viscoelastic] dampers between surfaces, and air gaps to prevent direct conduction. Air gaps need especial attention because they can resonate, especially at the lower frequency (1000-400 Hz) wavelengths of 13.50 to 33.76 in (34.3-85.75 cm). [http://www.physicsclassroom.com/class/sound/Lesson-5/Resonance Resonance] will transfer acoustical energy across the gap. An ideal space of 100-200 mm (3.9-7.9 in) is recommended in building construction.<ref>http://www.build.com.au/window-acoustics-and-noise-control</ref>

=== Isolating the Engine Room ===

Design an engine room entrance that has a double door. The inside door should be watertight (with a view port) and the outside one should be air tight. The space in-between would make a good place to hang ear protectors and other safety equipment. Both doors should have significant solid mass to absorb sound.

With a saloon above the engine room, sound can be attenuated in the design of the sole and the engine-room ceiling below that.

For acoustic isolation in the sole build up a layered floor consisting of (starting at the bottom) a sub-sole, viscoelastic glue as a damper, an underlayment of acoustic mat made of dense rubber (similar to the mat used in horse stalls), then cement board and flooring.

In the engine room an ideal ceiling would provide attachment points for a drop ceiling. This would require spring hangers (or even rubber engine mounts) capable of withstanding high accelerations of mass to avoid detaching the ceiling in a capsize. The attachment points should be 100-200mm long. Attach two layers of non-combustible panels bound with viscoelastic glue. Several marine-approved panel materials are available.

[[File:DropCeiling.png|thumb|left|280px|Schema for a robust drop ceiling]]

Where the composite panel meets the walls, prevent flanking noise leaking through using a flexible acoustic strip such as neoprene.

On the room side, apply to the composite panel composite insulation such as lead-fibreglass with the fibreglass rated at, say, R13. Since we are dealing with wavelengths of, say, 5 to 14 in, the thickness of the insulation should be in the same range.

An alternate arrangement is shown in the image.

A ceiling of this type, combining mass, decoupling, resilient mounts and insulation is capable of attenuating noise 60-75 dB over 1000-5000 Hz.<ref>The Green Glue Company, http://www.greengluecompany.com</ref>

If there is ductwork originating in the engine room, use round lined ductwork (insulated on the inside). Round ducts transfer less sound than square ones. In the engine room coat the exterior of the duct with a viscoelastic material, and cover it with a soffit to prevent exposure to direct sound. Consider a 90 or 180 degree bend to force sound to interact with the duct liner. Where possible, use serpentine lengths of lined flex duct to create a more complex path for sound.

Similar techniques could be used on the bulkheads. For example, in the engine room use a viscoelastic glue to stick a non-combustible panel on the bulkhead, then attach the composite insulation. In the living space on the other side attach furring strips using neoprene rubber. If more isolation is needed incorporate rubber mat or more insulation. Always leave an air gap to prevent conduction.

== Some Cautions ==

Finally, some cautions. Some complex isolation schemes were described above for the purpose of illustration, but you should keep the design as simple and robust as possible. For example:

* The performance of two mass panels isolated by a viscoelastic glue can exceed that of a limp mass, such as lead-loaded composite insulation. It may be feasible to use just ~R13 fibreglass with the mass panels.
* A triple mass-panel sandwich alone that consists of a mass panel glued (viscoelastic) to either side of a bulkhead can achieve attenuations of 60 dB.<ref>ibid</ref>
* Test. Sound meters with a range of 35-130 dB can be rented (or use an iPhone app):
** Start with a basic installation of isolation in the engine room. Run the engine and use a sound meter to measure the noise in adjacent cabin areas. Upgrade the isolation to reach your sound goal.
** Or, build a small test box with a logging sound meter inside. Add test isolation externally. Evaluate the performance of your choices by suspending the test box in the engine room and running the engine.

== Links ==

http://www.audioholics.com/room-acoustics/a-guide-to-sound-isolation-and-noise-control

http://www.audiology.org/sites/default/files/journal/JAAA_09_06_02.pdf

== References ==

[[Category:HullGeneral]]