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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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