# Calculation of Displacement, LWT and DWT

July 16, 2017 | Author: Miftahuddin Nur | Category: Tonnage, Fuel Oil, Ships, Ton, Oil

#### Short Description

estimasi tentang perhitungan dispasmen...

#### Description

Document no : 01 - 42 08 071 -ES

Displacement, LWT and DWT

Attachment Number of pages

Miftahuddin nur rev.

date

Document Title

Prepared by

Ir. Dwi Priyanta Ir. Hari ,MSE Prastowo, Msc. Reviwed by Approved by

Electrical Systems and Engine Room

Project Doc. No Displacement, LWT and DWT Rev. No page. No

: DESIGN IV : 01 - 42 08 071 - ES : : II

Table of contents 1. Introduction…...………………………………………………………………………………………………….. 1 2. Objective……………...……………………………………………………………………………………………. 1 3. Reference………...………………………………………………………………………………………………… 1 4. Abbreviation……………...………………………………………………………………………………………. 1 5. Description of calculation…………….....……………………………………………………………….. 2 6. Summary ............................…………………………………………………………………………….. 7 List of attachments attachments 1 Detail Equipment list code…………………………………………………………..

4

Project Doc. No Displasement, LWT dan DWT Rev. No page. No

: DESIGN IV : 01 - 42 08 071 - ES : : 01

1. Introduction 1.1. Displasement Displasemen volume is the total volume of water displaced by the weight of an object. There are two factors that affect the displacement of the ship, the weight of the ship components that can be transformed (DWT) and the weight of the ship components that can not be changed (LWT). 1.2. Light Weight Tonnage Based on the book "Practical ship design chapter 4" LWT ship explained that consists of several components: 1.Weight of ship's structural 2.Weight of outfitting 3.Weight of Machinery 4.Recidual Weight

1.3. Dead Weight Tonnage Is the weight that come from the value of weight displacement minus the light weight tonnages. That consist of cargo's weight, fuel oil, fresh water, ballast water, provision and ship's crew weight 2. Objective The objective of this document is to determine the estimation of displacement, light weight tonnage, and dead weight tonnage in order to find the relation between 3. Reference Practical Ship Design, Chapter 4 Weight-Based Designs, D.G.M. Watson

4. Abbreviation Lpp = Length of between perpendicular Lwl = Length of waterline B = Breadth of ship H = Height of ship T = Draught of ship Vs = Ships velocity Cb = Block coefficient ρsea water = Sea water density K = Wet steel weight's constant SFOC = Specific Fuel Oil Consumption

Project Doc. No Displasement, LWT dan DWT Rev. No page. No W res ▼ ∆ Wst E l1 l2 h1 h2 Woa Wm Wd MCR RPM Wr Wres

= = = = = = = = = = = = = = = =

: DESIGN IV : 01 - 42 08 071 - ES : : 02

Reserve weight Displacement volume Ships displacement Wet steel weight Steel weights parameter Length of forecastle deck Length of poop deck Height of forecastle deck Height of poop deck Weight of outfit and accomdation Machineriy weight Main engines weight Maximum continous rating (kW) Engine RPM Auxiliary engines weight Reserve weight

5. Description of calculation 5.1 Displacement Calculation a. Displacement Volume ▼= Lwl x B x T x Cb where : ▼ = Displacement volume Lwl = Ships length on the water line B = Ship width in the middle of ship T = Draft on fully cargo Cb = Block coefficients b. Weight Displacement ∆ = ▼x ρ sea water where : = ships displacement ∆ = ships displacement volume ▼ ρ sea water = the density of sea water 5.2 Light Weight Tonnage a. Weight of ship's structural According to the book "Practical Ship Design chapter 4/4.2.4"by DGM Watson, to calculate the weight of the structure of the ship can use the formula :

Project Doc. No Displasement, LWT dan DWT Rev. No page. No

: DESIGN IV : 01 - 42 08 071 - ES : : 03

Wst = K x E1,36 where : K = Coefisien, depend on ship type E = Equipment Numerical

According the value of the number of equipment (E) Lyold appropriate as written in the book "Practical Ship Design"by DGM Watson, referring to the 1877 RINA (Lecure Ship Design and Ship Theory, Poels Herald p. 69A) with the following formula: E = L ( B +T ) + 0.85 L ( D -T ) + 0.85 ( l1 h1 ) + 0.75 ( l2 h2 ) Where : L = legth between perpendicular B = breadth T = draft D = depth l1 = length of full width erection h1 = height of full width erection l2 = length of houses h2 = height of houses Calculation above,is for ship having Cb = 0.70 to 0.8 H. But, this ship have a Cb = 0,615, so that needed to do a correction .

b. Weight Outfit and accommodation (Woa) For heavy outfit and accommodation according to Practical Ship Design, page 99 chapter 4.4, it can be seen the value of Wo/L xB.For container ships withLpp 112 m = 0,3

c.

Weight of Machinery Divided into two components: propulsion machinery and remainder.

c.1. Based on the book "Principal Ship Design"by DGM Watson page 108 Chapter 4.5.4, Main Engine weight can be estimated with the following formula : Wd = 12 (MCR/RPM)

0,84

c.2 Based on the book "Principal Ship Design"by DGM Watson page 110 Chapter 4.5.5, weight of remainder can be estimated with the following formula : Wr = K x (MCR)^0.70

Project Doc. No Displasement, LWT dan DWT Rev. No page. No

: DESIGN IV : 01 - 42 08 071 - ES : : 04

So the result of Machinery Weight is Wd+Wr, Wm = Wd+Wr

d. Recidual Weight According to Practical Ship Design on page 114, for the calculation of reserves it is necessary to add weight. Weight by 2-3% due to avoid mistakes in planning and things that might not been included in previous calculations. So the formula of recidual weight is : Wres = 2% (Wst + Woa + Wd + Wr + Wmt)

Now we know the value - the value of weight above in accordance with the previous explanation, then we can calculate the value of LWT by summing the weight calculation remains the ship: LWT = Wst + Woa + Wd + Wr + Wmt + Wres

5.3 Dead Weight Tonnage According to the book "Ship Knowledge A Modern Encyclopedia" page 28, Deadweight is the weight of that load cargo ship laden water up to a maximum allowable. This can be formulated with the formula: DWT = ∆ - LWT 5.4 Payload Payload is the total weight of cargo that can be transported by ship to the income (profit) of a ship. Here are steps in determining the payload. Payload = DWT - Wtotal where, DWT = Dead Weight Tonnage Wtotal =Weight of fuel oil, diesel oil, lubricating oil, crews and provision, fresh water i. HFO (Heavy Fuel Oil) a. HFO's weight The formula, as follows : WHFO = SFOC x BHP x time to voyage x constants addition of fuel Where, WHFO

= weight of heavy fuel oil SFOC = specific fuel oil consumption (project guide) BHP = break horse power of main engine (project guide) constants addition of fuel = 1.3 - 1.5

Project Doc. No Displasement, LWT dan DWT Rev. No page. No

: DESIGN IV : 01 - 42 08 071 - ES : : 05

b. HFO's tank volume We should consider about the increasing temperature inside the tanks of HFO, so we add some alocation of expansion margins approximately 2% - 3%. The formula, as follows : VHFO = ((100%+3%)*WHFO)/ ρHFO Where, VHFO = HFO's tanks volume WHFO

= weight of heavy fuel oil Alocation of expansion = 3% 3 ρHFO = 0.991ton/m ii. DO (Diesel Oil) a. DO's weight estimation of diesel oil's weight is 10%-20% of hfo weight for the result : WDO = 20% x WHFO b. DO's tanks volume We should consider about the increasing temperature inside the tanks of DO, so we add some alocation of expansion margins approximately 2% - 3%. The formula, as follows : VDO = ((100%+3%)*WDO)/ ρDO Where, VDO

= DO's tanks volume

WDO

= weight of heavy fuel oil Alocation of expansion = 3% 3 ρDO = 0.85 ton/m iii. LO (Lubricating Oil) a. LO's weight The formula, as follows : WLO = SLOC x BHP x time to voyage x constant addition of fuel where, SLOC = Specific Lubricating Oil Consumption = 0.95 g/BHPh Constants of fuel = 1.3 - 1.5, take 1.4

Project Doc. No Displasement, LWT dan DWT Rev. No page. No

: DESIGN IV : 01 - 42 08 071 - ES : : 06

b. LO's tanks volume We should consider the increasing temperature inside the tanks of LO,so we add some alocation of expansion margins approximately 2% 3%. The formula, as follows : VLO = WLO / ρLO where, 3 ρLO = 0.9 ton/m iv. Fresh Water a. Consumption for crew fresh water needs estimation = 20 kg/persons/day b. Bath and laundry needs fresh water needs estimation = 200 kg/persons/day c. Cooking needs fresh water needs estimation = 4 kg/persons/day d. Machinery needs 1. main engine fresh water needs estimation = 7 gr/kWh 2. auxiliary engine fresh water estimation = 0.2 from main engine's fresh water Total fresh water machinery = fw ME + fw AE Total Weight of Fresh Water = consumption for crew + bath and laundy + cooking + machinery Total Volume of Fresh Water = divide the total weight of fresh water by its density. v. Crew and Provision a. crew's weight total crews = 20 persons average weight of crews = 70 kg b. provision's weight average provisions needs =

5 kg/person/day

Weight Total of Ship Supplies W total = WHFO+WDO+WLO+Wfreshwater+Wcrews+Wprov PAYLOAD

=

DWT - W supplies total

Project Doc. No Displasement, LWT dan DWT Rev. No page. No

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6. Summary NO

CALCULATION

1 2 3 4 5

Displacement Volume

9402,12

m3

Weight Displacement

9637,17

ton

Light Weight Tonnage

LWT

3953,68

ton

DWT

5683,49

ton

5538,85

ton

SYMBOL

RESULT

Attachment 1 Detail Calculation of Displasement, LWT dan DWT

Project

Estimation of Displasement, Doc. No Rev. No LWT dan DWT page. No

: DESIGN IV : 01 - 42 08 071 - ES : : 08

1. Calculation Details Principal Dimension Container Ship Lpp = 112,00 meter

h deck =

2,50

meter

Lwl = 117,60 meter

Power Engine =

3900

kW

B = 20,00 meter

5230

HP

1487

n mile

120

Hours

H=

8,30

meter

= Sailing distance =

T=

6,50

meter

Sailing time =

Cb =

0,62

Vs = 16,50 knots =

>

8,49

m/s

Calculation of Ship's Displacement Volume Displacement ▼ = Lwl x B x T x Cb =

9402

Weight Displacement

Because the ships operating at sea, then the value of rho(density) was used sea water rho(density) : ρ = 1,025 ton/m³ ∆=∇xρ = 9637,2 ton Determination of the number of crew

In determining the number of the crew should be as efficient as possible, as this affects the size of the room and the limited amount of supplies of food and fresh water. Factors that influence the type of ship, large ship, the number of jobs served by the crew, sailing routes, sisitem existing automation on ships, and regulations of the country concerned.In determining the number of crew that is used is 20 people. Payload

The payload is the cargo on board and pay (making money). The formula can be used to determine the payload is : Payload = DWT - WProvision

So to be able to know the payload on the vessel which is designed we must calculate the first (LWT), which brought supplies and Weight Lightweight

Project

Estimation of Displasement, Doc. No Rev. No LWT dan DWT page. No >

: DESIGN IV : 01 - 42 08 071 - ES : : 09

Light weight (LWT) ~ Weight of ship's structural According to the book "Practical Ship Design chapter 4/4.2.4"by DGM Watson, to calculate the weight of the structure of the ship can use the formula perndekatan as follows:

Wst = K x E

1,36

where : K = Coefisien, depend on ship type E = Equipment Numerical According the value of the number of equipment (E) Lyold appropriate as written in the book "Practical Ship Design"by DGM Watson, referring to the 1877 RINA (Lecure Ship Design and Ship Theory, Poels Herald p. 69A) with the following formula:

E = L x (B + T) + 0,85L x (H - T) + 0,85 (l1 x h1) + 0,75 (l2 x h2) L = Lpp = 112

m

H=

8,3

m

Lfore =

7,85

m

(the length of forecastle)

Hfore =

2,5

m

(the height forecastle)

=

29,5

m

(the length of MAIN DECK )

H MAIN DECK =

3,0

m

(the height of MAIN DECK)

LDECK A =

8,0

m

(the length of DECK A )

H DECK A =

2,5

m

(the height of DECK A)

LDECK B =

8,0

m

(the length of DECK B)

H DECK B=

2,5

m

(the height of DECK B)

L DECK C =

8,0

m

(the length of DECK C)

H DECK C=

2,5

m

(the height of DECK C)

L

=

8,0

m

(the length of DECK D)

H DECK D=

2,5

m

(the height of DECK D)

Lnav =

7,0

m

Hnav =

2,5

m

L

MAIN DECK

DECK D

l1 x h1 = the length and height of full width erections l2 x h2 = the length and height of houses l1 x h1 = Lfore x Hfore = 20 m2

Project

Estimation of Displasement, Doc. No Rev. No LWT dan DWT page. No

: DESIGN IV : 01 - 42 08 071 - ES : : 10

l2 x h2 = (LDECK A x HDECK A)+(LDECK B x HDECK B)+(LDECK C x HDECK C)+ (LDECK D x HDECK D)+ (Lnav x hnav)+(L MAIN DECK x H MAIN DECK) =

186

m2

E = L x (B + T) + 0,85L x (H - T) + 0,85 (l1 x h1) + 0,75 (l2 x h2) = 3295,5

K = 0,036 (for container ship) Wst = k x E1.36 = 2191 Ton Calculation above,is for ship having Cb = 0.70 to 0.8 H. But, this ship have a Cb = 0,615, so that needed to do a correction : correction of Cb = Cb + ( 1 - Cb x (0,8H - T) / 3T = 6,662 Thus obtained the weight of steel : Wst = Wst x [1 + 0,05 (Cb0,8H – 0,7)] = 2844,4 Ton ~

Weight Outfit and accommodation (Woa) For heavy outfit and accommodation according to Practical Ship Design, page 99 chapter 4.4, it can be seen the value of Wo/L xB. For container ships with Lpp 112 m= 0,3 Woa = the value of(Wo / L xB) x Lpp x B = 672,00 Ton

~

Propulsion machinery weight Based on the book "Principal Ship Design"by DGM Watson page 108 Chapter 4.5.4, Main Engine weight can be estimated with the following formula :

Project Estimation of Displasement, Doc. No LWT dan DWT Rev. No page. No 0,84 Wd = 12 (MCR/RPM) = 139,6 ton

: DESIGN IV : 01 - 42 08 071 - ES : : 11

BHPMCR = 3900 kW rpm= 210

~

Calculation weight of remainder (Wr) Based on the book "Principal Ship Design"by DGM Watson page 110 Chapter 4.5.5 , weight of remainder can be estimated with the following formula : Wr = K x (MCR)^0.70 = 225,2 ton K = 0,69 (for bulk carriers and general cargo ship)

~

Weight of generator set (Wmt)

Based on the book "Principal Ship Design"by DGM Watson page 111 Chapter 4.5.6 Generator weight can be estimated with the following formula : Wmt = 0.72(MCR)^0.78

where is : MCR

=

Maximum

Continous Rating genset However, because of the power generator to be installed is not known, it is assumed that the generator will be installed is with the power of 120 kW of 3 sets. So the value can be calculated as follows wmt : Wmt = 0.72(MCR) 0.78 = 71,00 ton

~

Calculation of Recidual weight According to Practical Ship Design on page 114, for the calculation of reserves it is necessary to add weight. Weight by 2-3% due to avoid mistakes in planning and things that might not been included in previous calculations. Wres = 2% (Wst + Woa + Wd + Wr + Wmt) =

~

1,42

ton

Calculation of LWT Now we know the value - the value of weight above in accordance with the previous explanation, then we can calculate the value of LWT by summing the weight calculation remains the ship: LWT = Wst + Woa + Wd + Wr + Wmt + Wres = 3953,7 ton

Project

Estimation of Displasement, Doc. No Rev. No LWT dan DWT page. No >

Dead weight (DWT) According to the book "Ship Knowledge A Modern Encyclopedia" page 28, Deadweight is the weight of that load cargo ship laden water up to a maximum allowable. This can be formulated with the formula: DWT = ∆ - LWT =

>

: DESIGN IV : 01 - 42 08 071 - ES : : 12

5683,5

ton

Payload Calculation Payload is the total weight of cargo that can be transported by ship to the income (profit) of a ship.Here are the steps in determining the payload weight. Payload = DWT - Wconsumable Where : Wconsumable = WHFO + WMDO + WLO + WFW + WP + WCP

~

Calculation of Heavy Fuel Oil (HFO) Unknown: SFOC =

177

g/kWh

P=

3900

kW

Constanta addition of fuel oil = 1,3-1,5 taken = 1,3 -6 WHFO = SFOC x P x (S/Vs) x constanta addition of fuel oil x 10 =

107,7 ton

Calculation of Volume HFO Tank VHFO = WHFO/ ρ HFO ρHFO = 1 Ton/m3 3 = 108,66 m

According to the book "Ship Design and Construction section 5" page 65, in the calculation of the volume of the fuel tank (HFO) will need to add a margin of 2% ~ 4% to anticipate expansion of fuel because of increases in temperature in the tank, so that the volume of HFO tanks required: VHFO = (1+4%) x WHFO) 3 = 111,99 m

~

Calculation of Marine Diesel Oil (DO) Diesel oil is usually used as fuel for generators and motor process of flushing the mains when not operated in the long term. Heavy Diesel Oil which is carried in shipping approximately 0.1 ~ 0.2 of weight carried HFO, in this case tken 0,2 Weight of Marine Diesel Oil (WMDO) WMDO = 0.2 x WHFO = 21,54 ton

Project

Estimation of Displasement, Doc. No Rev. No LWT dan DWT page. No

: DESIGN IV : 01 - 42 08 071 - ES : : 13

Calculation of tank volume MDO Selected : type of DO = DM-A ρ DO (at 15° C) = 1 ton/m3 VMDO = WMDO/ ρ MDO 3 = 24,20 m According to the book "Ship Design and Construction section 5" page 65, in

the calculation of the volume of the fuel tank (DO) should be added margin of 2% ~ 4% to anticipate if fuel (DO) terekspansi because of increases in temperature in the tank, so that the volume of tank DO required: V MDO = (1+4%)x VMDO ~

3 = 25,17 m Calculation Lubricating Oil (LO) Based on data from "Project Guide Engine (MAN B & W L35MC) " on the condition of maximum obtained the following data: unknown : Lubricating Oil Consumption System Oil Approximate kg/cyl.24hours Cylinder Oil 2 0,8-1,2 g/kWh taken = 0,8 g/kWh -6 WLO = P x SLOC x (S/Vs) x 10 = 0,5 ton Calculation of Volume LO Tank Selected : 3 ρ LO = 0,9 ton/m VLO = WLO / ρLO 3 = 0,52 m need increase 4% for construction and expansion, so loss volume = 1,04 x Vlo

= 0,541 m ~

3

Weight of Crew and Provision Weight provision = Total crew x provision needed per day x Longest trip

Total crew = Weight per crew =

20 70

man kg

Project

Estimation of Displasement, Doc. No Rev. No LWT dan DWT page. No

: DESIGN IV : 01 - 42 08 071 - ES : : 14

Wcrew = 1,4 ton weight of total crew = total crew x the average weight of crew where : porvision need = 3.5 kg ~ 5 kg /man/day porvision need = 5 kg/man/ day Sea time = 5,00 day Wprov= 0,50 ton ~

Project

Estimation of Displasement, Doc. No Rev. No LWT dan DWT page. No

: DESIGN IV : 01 - 42 08 071 - ES : : 15

= 7,0 day ∑ Water Needs = 0,6 ton d. Cooling engine - Cooling main engine (Wfwj) Taken (c) = 5 kg/kWh (cooling requirement estimated between 5 - 7 kg/kWh) -6

Wfwj = P x c x (S/Vs) x 10 = 2,34 ton - Cooling auxiliary engine (Wfwae) Taken (c) = 0,15 kg/kWh (cooling fresh water requirement estimated between 0,1 - 0,2 Wfwj) Wfwae = Wfwj x c = 0,35 ton After knowing the weight of fresh water for each - each needs it, can know the total requirement of fresh water during travel and handling that is equal to: Wfw = Wfwd + Wfws + Wfwc + Wfwj + Wfae = 13,05 ton From the calculations above requirement can be further calculated the total weight by using the following calculation: W total provision = WHFO + WMDO + WLO + Wcrew + Wprov + Wfw = 144,64 ton Calculation of Payload After knowing the total weight of supplies and deadweight ship, the vessel can be calculated the amount of payload: Payload = DWT - W total provision = 5538,8 ton Type of container carried = @18 ton (20') Jumlah kontainer = Payload /container = 308 Container So,total 20' container which can be carried is 308 TEUS