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Marine Auxiliary
MachineryChapter 9 Lesson 1
Deck MachineryGeneral
By Professor Zhao Zai Li
05.2006
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Deck machinery (1)
The range of eck machinery is extensi!e an!arie" it can #e i!ie #roaly into$
Anchor hanling (%inlasses an capstans)& Mooring (%inches an capstans)& Cargo hanling (%inches an cranes)&
The #asic re'uirement of all the a#o!e is to control
loas associate %ith chain ca#le or %ire rope an%hilst each type of e'uipment has its o%noperational re'uirements" certain aspects of esignan operation are common&
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Deck machinery ()
Most eck machinery is ile uring much of its life an ue to
this intermittent uty re'uirement" gears an ri!es are
normally esigne to a limite rating of one half to one hour& Despite long perios of ileness" often in se!ere %eather
conitions" the machinery must operate immeiately" %hen
re'uire&
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Deck machinery ()
*t is essential that eck machinery shoul re'uire minimummaintenance&
Totally enclose e'uipment %ith oil #ath lu#rication for gearsan #earings is no% stanar #ut maintenance cannot #ecompletely eliminate an routine checking an greasingshoul #e carrie out on a planne #asis&
+rime mo!ers may #e use to perform more than one #asic
uty&
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Deck machinery (,)
-or example" mooring %inches are often com#ine %ith
%inlass units so that one prime mo!er ri!es #oth&
The port mooring %inch motor can thus #e use to ri!e thestar#oar %inlass an !ice !ersa&
This applies also to the po%er supply %here generators or
hyraulic pumps are also cross.connecte&
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Deck machinery (/)
There are many instances %here remote or centralise
control is of great a!antage" for example" the facility for
letting go anchor from the #rige uner emergencyconitions" the use of shipsie controllers %ith mooring
%inches or the central control position re'uire for the
multi%inch sle%ing errick system&
The three most common forms of main ri!e use on eckauxiliaries are steam" electric an hyraulic&
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Deck machinery(0)
hen fitte" steam auxiliaries are fre'uently of the totally
enclose type using force or splash lu#rication or a
com#ination of #oth& A typical arrangement has an oil pump ri!en from the
crankshaft supplying pressure oil to the crankshaft an
connecting ro #earings %hilst crossheas" eccentrics an
gearing are splash lu#ricate from the sump or rip trays&
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Deck machinery (2)
The steam cyliners an !al!es are not normally lu#ricate as"
ue to the lo% %orking pressure an conensation" steam
temperatures encountere on eck rarely excee 1345 C& A superheate steam supply creates pro#lems %ith cyliner
lu#rication an in any e!ent has little effect on non.expansi!e
%orking&
*nlet steam temperatures are limite for use %ith cast ironcyliners #y Classification 6ociety rules&
-ull loa crankshaft spees are normally #et%een 94.104
re!7min increasing to t%ice this figure for light line uties
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Deck machinery (3)
An alternati!e form of steam ri!e is the re!ersing steam tur#ine
%hich is illustrate in -igure 1&1&
This machine re'uires less maintenance an it is a#le to accepthigher steam pressures an temperatures" (up to , #ar"945 C)
irectly through a reucing !al!e from the main #oilers" thus
increasing tur#ine efficiency an minimising its si8e an %eight&
n large e'uipment" e!en though the tur#ine has to #e geare
o%n from a normal full loa spee of 444./44 re!7min there
is a sa!ing in total %eight %hen compare %ith engine ri!en
e'uipment
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Deck machinery (9)
As illustrate in -igure 1&1" the tur#ine shaft an rotor are
supporte in anti.friction #earings: the coupling en #earing
is grease lu#ricate an the go!ernor mechanism anlocation #earing are splash oil lu#ricate&
Although the #earings %arm up rapily ue to conuction of
heat along the shaft from the exhaust casing" normal
lu#ricating oils an greases ha!e pro!e satisfactory
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Deck machinery(14)
;oth reciprocators an tur#ines" as use on supertankers
ri!e the 1argest eck machinery in ser!ice&
This e'uipment is normally locally controlle at themachinery position" ho%e!er" it is of great a!antage to
ha!e shipsie control for #oth %inlass an mooring %inch
operation an this can #e simply achie!e #y the use of push
pull hyraulic mechanisms %hich are effecti!e up toapproximately ,/m
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-igure 9&1
6ectionalarrangementof re!ersingsteam tur#ine
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The ma?ority of &c& %inch motors e!elop full output at
spees of the orer of /44 re!7min an %here!er necessary
are arrange to run up to t%o to four times this spee forlight line uties&
inlass motors on the other han o not normally operate
%ith a run up in excess of $1 an usually ha!e a full loa
%orking spee of the orer of 1444 re!7min
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thyristor=
con!erters %hich con!ert a&c& supply into a !aria#le & c&
!oltage of the re'uire magnitue an polarity for any
re'uire armature spee&
These con!erters must #e of a type capa#le of controlle
rectification an in!ersion %ith #i.irectional current flo% if
full control is to #e o#taine (-igure9&) &
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-igure 9&
Loa7spee characteristicof ar Leaoar thyristorcontrolle %inch&
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hoist=
control #ut" as %ith the resistance controlle &c& motor"
ifficulty is experience in pro!iing effecti!e control of an
o!erhauling loa e&g lo%ering a suspene loa&
These isa!antages are often out%eighe #y lo%er cost"
particularly of the cage inuction motor& in comparison %ith
the more flexi#le &c&
Typical performance cur!es are sho%n in -igure 9&&
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-igure 9&
+erformancecur!es of a tonne %inch&
A C+ole.changingcage motor&
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