Propulsion of 46,-, dwt Handymax Tanker
Content Introduction... EEDI and Major Ship and Main Engine Parameters...6 Energy Efficiency Design Index (EEDI)...6 Major propeller and engine parameters...7 46,-, dwt Handymax tanker...9 Main Engine Operating Costs 1.1 knots...1 Fuel consumption and EEDI...1 Operating costs...13 Main Engine Operating Costs 14. knots...14 Fuel consumption and EEDI...14 Operating costs...17 Summary...18
Propulsion of 46,-, dwt Handymax Tanker Introduction The main ship particulars of 46,-, dwt Handymax tankers are normally as follows: the overall ship length is 183 m, breadth 32.2 m and design/ scantling draught 11. m/12.2 m, see Fig. 1. Recent development steps have made it possible to offer solutions which will enable significantly lower transportation costs for Handymax tankers (and bulk carriers) as outlined in the following. One of the goals in the marine industry today is to reduce the impact of CO 2 emissions from ships and, therefore, to reduce the fuel consumption for the propulsion of ships to the widest possible extent at any load. This also means that the inherent design CO 2 index of a new ship, the socalled Energy Efficiency Design Index (EEDI), will be reduced. Based on an average reference CO 2 emission from existing tankers, the CO 2 emission from new tankers in gram per dwt per nautical mile must be equal to or lower than the reference emission figures valid for the specific tanker. This drive may often result in operation at lower than normal service ship speeds compared to earlier, resulting in reduced propulsion power utilisation. The design ship speed at Normal Continuous Rating (NCR), including 1% sea margin, used to be as high as 1.-1. knots. Today, the ship speed may be expected to be lower, possibly 14. knots, or even lower. A more technically advanced development drive is to optimise the aftbody and hull lines of the ship including bulbous bow, also considering operation in ballast condition making it possible to install propellers with a larger propeller diameter and, thereby, obtaining higher propeller efficiency, but at a reduced optimum propeller speed. As the two-stroke main engine is directly coupled with the propeller, the intro- Fig. 1: Handymax tanker Propulsion of 46,-, dwt Handymax Tanker
duction of the Green ultra long stroke GME-B9.3 engine with even lower than usual shaft speed will meet this drive and target goal. The main dimensions for this engine type, and for other existing Handymax tanker (and bulk carrier) engines, are shown in Fig. 2. On the basis of a case study of a 47, dwt Handymax tanker in compliance with IMO Tier II emission rules, this paper shows the influence on fuel consumption when choosing the new GME-B engine compared with existing Handymax tanker engines. The layout ranges of 6 and 7GME-B9.3 engines compared with 6 and 7SME- B9.3 and existing 6 and 7SME-C8.2 engines are shown in Fig. 4. EEDI and Major Ship and Main Engine Parameters Energy Efficiency Design Index (EEDI) The Energy Efficiency Design Index (EEDI) is a mandatory instrument to be calculated and made as available information for new ships contracted after 1 January 212. EEDI represents the amount of CO 2 in gram emitted when transporting one deadweight tonnage of cargo one nautical mile. For tankers, the EEDI value is essentially calculated on the basis of maximum cargo capacity, propulsion power, ship speed, SFOC (Specific Fuel Oil Consumption) and fuel type. However, certain correction factors are applicable, e.g. for installed Waste Heat Recov- ery systems. To evaluate the achieved EEDI, a reference value for the specific ship type and the specified cargo capacity is used for comparison. The main engine s 7% SMCR (Specified Maximum Continuous Rating) figure is as standard applied in the calculation of the EEDI figure, in which also the CO 2 emission from the auxiliary engines of the ship is included. According to the rules finally decided on 1 July 211, the EEDI of a new ship is reduced to a certain factor compared to a reference value. Thus, a ship built after 22 is required to have a 3% lower EEDI than the present reference figure (212). 1,86 1,2 1,76 1,19 1,673 1,98 9,91 9,32 8,86 3,896 GME-B9 3,3 SME-B9 3,1 SME-C8 Fig. 2: Main dimensions for a GME-B9 engine and for other existing Handymax tanker engines 6 Propulsion of 46,-, dwt Handymax Tanker
Major propeller and engine parameters In general, the highest possible propulsive efficiency required to provide a given ship speed is obtained with the largest possible propeller diameter d, in combination with the corresponding, optimum pitch/diameter ratio p/d. As an example, this is illustrated for a 46,-, dwt Handymax tanker with a service ship speed of 1 knots, see the black curve on Fig. 3. The needed propulsion SMCR (Specified Maximum Continuous Rating) power and speed is shown for a given optimum propeller diameter d and p/d ratio. According to the black curve, the existing propeller diameter of.8 m may have the optimum pitch/diameter ratio of.72, and the lowest possible SMCR shaft power of about 9,9 kw at about 131 r/min. The black curve shows that if a bigger propeller diameter of 6.8 m is possible, the necessary SMCR shaft power will be reduced to about 9, kw at about 9 r/min, i.e. the bigger the propeller, the lower the optimum propeller speed. If the pitch for this diameter is changed, the propulsive efficiency will be reduced, i.e. the necessary SMCR shaft power will increase, see the red curve. The red curve also shows that propulsion-wise it will always be an advantage to choose the largest possible propeller diameter, even though the optimum pitch/diameter ratio would involve a too low propeller speed (in relation to the required main engine speed). Thus, when using a somewhat lower pitch/ diameter ratio, compared with the optimum ratio, the propeller/engine speed may be increased and will only cause a minor extra power increase. Propulsion SMCR power kw 1, 4-bladed FP-propellers d = Propeller diameter p/d = Pitch/diameter ratio Design Ship Speed = 1. kn Design Draught = 11. m SME-B9.3 SME-C8.2 SME-C8.2.8 m.72 d p/d 9, 9, 8, 1..9 GME-B9.3 7.3 m GME-B9.3.78.8 6.8 m.76 SME-B9.3 6.3 m.74.6.6 6 7 8 9 1 11 12 13 14 1 16 r/min Engine/propeller speed at SMCR p/d. Power and speed curve for various propeller diameters (d) with optimum p/d ratio Power and speed curve for the given propeller diameter d = 6.8 m with different p/d ratios SMCR power and speed are inclusive of: 1% sea margin 1% engine margin % propeller light running Fig. 3: Influence of propeller diameter and pitch on SMCR for a 46,-, dwt Handymax tanker operating at 1. knots Propulsion of 46,-, dwt Handymax Tanker 7
Propulsion SMCR power kw 4-bladed FP-propellers 14, constant ship speed coefficient =.28 12, 1, 8, 6, SMCR power and speed are inclusive of: 1% sea margin 1% engine margin % light running T des = 11. m 7GME-B9.3 6GME-B9.3 Increased propeller diameter GME-B9.3 M3 M3 Possible Dprop=6.8 m (= 61.8% of T des ) 7SME-B9.3 Possible Dprop=6.3 m (= 7.3% of T des ) 6SME-B9.3 7SME-C8.2 M2 M2 6SME-C8.2 M1 M1 13. kn 14. kn 14. kn Existing Dprop=.8 m (= 2.7% of T des ) 1.1 kn 1. kn 1. kn 16. kn 4, 2, GME-B9.3 Bore = mm Stroke = 2, mm V pist = 8.33 m/s (9. m/s) S/B =. MEP = 21 bar L 1 = 1,72 kw/cyl. at 1 r/min (L 1 = 1,86 kw/cyl. at 18 r/min) 1 r/min 18 r/min 117 r/min 127 r/min M = SMCR (14. kn) M1 = 8, kw x 119 r/min, 6SME-C8.2 M2 = 8,31 kw x 11 r/min, 6SME-B9.3 M3 = 7,9 kw x 94 r/min, 6GME-B9.3 M = SMCR (1.1 kn) M1 = 9,96 kw x 127 r/min, 6SME-C8.2 (L 1 ) M2 = 9,73 kw x 117 r/min, 6SME-B9.3 M3 = 9,31 kw x 1 r/min, 6GME-B9.3 6 7 8 9 1 11 12 13 14 1 r/min Engine/propeller speed at SMCR Fig. 4: Different main engine and propeller layouts and SMCR possibilities (M1, M2, M3 for 1.1 knots and M1, M2, M3 for 14. knots) for a 46,-, dwt Handymax tanker operating at 1.1 knots and 14. knots, respectively The efficiency of a two-stroke main engine particularly depends on the ratio of the maximum (firing) pressure and the mean effective pressure. The higher the ratio, the higher the engine efficiency, i.e. the lower the Specific Fuel Oil Consumption (SFOC). Furthermore, the higher the stroke/bore ratio of a two-stroke engine, the higher the engine efficiency. This means, for example, that an ultra long stroke engine type, as the GME-B9.3, may have a higher efficiency compared with a shorter stroke engine type, like an SME-C8.2. The application of new propeller design technologies may also motivate use of main engines with lower rpm. Thus, for the same propeller diameter, these propeller types can demonstrate an up to 6% improved overall efficiency gain at about 1% lower propeller speed. This is valid for propellers with Kappel technology available at MAN Diesel & Turbo, Frederikshavn, Denmark. Hence, with such a propeller type, the advantage of the new low speed GME-B9.3 engine can be utilised also in case a correspondingly larger propeller cannot be accommodated. 8 Propulsion of 46,-, dwt Handymax Tanker
46,-, dwt Handymax tanker For a 47, dwt Handymax tanker, the following case study illustrates the potential for reducing fuel consumption by increasing the propeller diameter and introducing the GME-B9.3 as main engine. The ship particulars assumed are as follows: Scantling draught m 12.2 Design draught m 11. Length overall m 183. Length between pp m 174. Breadth m 32.2 Sea margin % 1 Engine margin % 1 Design ship speed kn 1.1 and 14. Type of propeller FPP No. of propeller blades 4 Propeller diameter m target Based on the above-stated average ship particulars assumed, we have made a power prediction calculation (Holtrop & Mennen s Method) for different design ship speeds and propeller diameters, and the corresponding SMCR power and speed, point M, for propulsion of the Handymax tanker is found, see Fig. 4. The propeller diameter change corresponds approximately to the constant ship speed factor α =.28 [ref. P M2 = P M1 x (n2/n1) α. Referring to the two ship speeds of 1.1 knots and 14. knots, respectively, three potential main engine types, 6SMC-C8.2, 6SME-B9.3 and 6GME-B9.3 and pertaining layout diagrams and SMCR points have been drawn-in in Fig. 4, and the main engine operating costs have been calculated and described below individually for each ship speed case. The layout diagram of the GME-B9.3 below or equal to 1 r/min is especially suitable for Handymax tankers (and bulk carriers) whereas the speed range from 1 to 18 r/min is particularly suitable for tankers with limited room for installation of a large propeller. The SMC-C and SME-C engines (127 r/min) have often been used in the past as prime movers for Handymax tankers, and the relatively new SME- B9 (117 r/min) has already been installed in some ships. Therefore, a comparison between the new 6GME-B9.3 and the existing 6SME-C8.2 is of major interest in this paper. It should be noted that the ship speed stated refers to NCR = 9% SMCR including 1% sea margin. If based on calm weather, i.e. without sea margin, the obtainable ship speed at NCR = 9% SMCR will be about. knots higher. If based on 7% SMCR, as applied for calculation of the EEDI, the ship speed will be about.2 knot lower, still based on calm weather conditions, i.e. without any sea margin. Propulsion of 46,-, dwt Handymax Tanker 9
Main Engine Operating Costs 1.1 knots The calculated main engine examples are as follows: 1.1 knots 1. 6SME-C8.2 (D prop =.9 m) M1 = 9,96 kw x 127. r/min 2. 6SME-B9.3 (D prop = 6.2 m) M2 = 9,73 kw x 117. r/min. 3. 6GME-B9.3 (D prop = 6.7 m) M3 = 9,31 kw x 1. r/min. The main engine fuel consumption and operating costs at N = NCR = 9% SMCR have been calculated for the above three main engine/propeller cases operating on the relatively high ship speed of 1.1 knots, as often used earlier. Furthermore, the corresponding EEDI has been calculated on the basis of the 7% SMCR-related figures (without sea margin). Propulsion of 47, dwt Handymax Tanker 1.1 knots Expected propulsion power demand at N = NCR = 9% SMCR Propulsion power demand at N = NCR kw 1, 8, 6, 4, 2, Dprop: 8,964 kw % 6SME-C8.2 N1.9 m 4 Inclusive of sea margin = 1% 8,77 kw 2.3% 6SME-B9.3 N2 6.2 m 4 8,379 kw 6.% 6GME-B9.3 N3 6.7 m 4 Fig. : Expected propulsion power demand at NCR = 9% SMCR for 1.1 knots Relative power reduction % 1 9 8 7 6 4 3 2 1 Fuel consumption and EEDI Fig. shows the influence of the propeller diameter with four propeller blades when going from about.9 m to 6.7 m. Thus, N3 for the 6GME-B9.3 with a 6.7 m propeller diameter has a propulsion power demand that is about 6.% lower compared with N1 valid for the 6SME-C8.2 with a propeller diameter of about.9 m. 1 Propulsion of 46,-, dwt Handymax Tanker
Fig. 6 shows the influence on the main engine efficiency, indicated by the Specific Fuel Oil Consumption, SFOC, for the three cases. N3 = 9% M3 for the 6GME-B9.3 has an SFOC of 164.1 g/kwh and almost the same 164.3 g/ kwh for N2 = 9% M2 with 6SME- B9.3 where in both cases for the ME-B engine is included +1 g/kwh needed for the Hydraulic Power Supply (HPS) system. The 164.1 g/kwh SFOC of the N3 for the 6GME-B9.3 is 2.2% lower compared with N1 for the nominally rated 6SME-C8.2 with an SFOC of 167.8 g/kwh. This is because of the greater derating potential and the higher stroke/bore ratio of this G-engine type. Propulsion of 47, dwt Handymax Tanker 1.1 knots Expected SFOC SFOC g/kwh 18 179 178 177 176 17 174 173 172 171 17 169 168 167 166 16 164 163 ME-B9.2 (without VET) Standard ME-B9.3 (with VET) IMO Tier ll ISO ambient conditions LCV = 42,7 kj/kg Standard high-load optimised engines (VET = Variable Exhaust valve Timing) N2 N1 N3 M1 6SME-C8.2 Savings in SFOC % M2 6SME-B9.3 M3 6GME-B9.3 2.1% 2.2% Dprop.9 m 4 6.2 m 4 6.7 m 4 162 2 3 3 4 4 6 6 7 7 8 8 9 9 1 % SMCR Engine shaft power N = NCR M = SMCR For ME-B9.3 engines the fuel consumption (+1g/kWh) for HPS is included. Fig. 6: Expected SFOC for 1.1 knots Propulsion of 46,-, dwt Handymax Tanker 11
When multiplying the propulsion power demand at N (Fig. ) with the SFOC (Fig. 6), the daily fuel consumption is found and is shown in Fig. 7. Compared with N1 for the existing 6SME-C8.2, the total reduction of fuel consumption of the new 6GME-B9.3 at N3 is about 8.6% (see also the above-mentioned savings of 6.% and 2.2%). The reference and the actual EEDI figures have been calculated and are shown in Fig. 8 (EEDI ref =1,218.8 x dwt -.488, 1 July 211). As can be seen for all three cases, the actual EEDI figures are equal to or lower than the reference figure. Particularly, case 3 with 6GME-B9.3 has a low EEDI about 92% of the reference figure. Propulsion of 47, dwt Handymax Tanker 1.1 knots Expected fuel consumption at N = NCR = 9% SMCR Fuel consumption of main engine t/24h 4 3 3 2 8.6% 9 2 8 7 1 6 4.3% 1 4 3 2 1 % Dprop: IMO Tier ll ISO ambient conditions LCV = 42,7 kj/kg 36.1 t/24h 34.4 t/24h 33. t/24h 6SME-C8.2 N1.9 m 4 6SME-B9.3 N2 6.2 m 4 For ME-B9.3 engines the fuel consumption for HPS is included. 6GME-B9.3 N3 6.7 m 4 Relative saving of fuel consumption % 16 1 14 13 12 11 1 Fig. 7: Expected fuel consumption at NCR = 9% SMCR for 1.1 knots Propulsion of 47, dwt Handymax Tanker 1.1 knots Energy Efficiency Design Index (EEDI) 7% SMCR: 14.9 kn without sea margin Reference and actual EEDI CO 2 emissions gram per dwt/n mile Actual/Reference EEDI % 8 12 EEDI reference 212 EEDI actual 7 11 6.4 6.42 6.4 6.4 6.18 1 1% 6 97%.91 92% 9 4 3 2 1 Dprop: 6SME-C8.2 N1.9 m 4 6SME-B9.3 N2 6.2 m 4 6GME-B9.3 N3 6.7 m 4 8 7 6 4 3 2 1 Fig. 8: Reference and actual Energy Efficiency Design Index (EEDI) for 1.1 knots 12 Propulsion of 46,-, dwt Handymax Tanker
Operating costs The total main engine operating costs per year, 2 days/year, and fuel price of 7 USD/t, are shown in Fig. 9. The lube oil and maintenance costs are shown too. As can be seen, the major operating costs originate from the fuel costs about 96%. After some years in service, the relative savings in operating costs in Net Present Value (NPV), see Fig. 1, with the existing 6SME-C8.2 used as basis with the propeller diameter of about.9 m, indicates an NPV saving for the new 6GME-B9.3 engine with the propeller diameter of about 6.7 m. After 2 years in operation, the saving is about 9.6 million USD for N3 with 6GME-B9.3 with the SMCR speed of 1. r/min and propeller diameter of about 6.7 m. Propulsion of 47, DWT Tanker 1.1 knots Total annual main engine operating costs IMO Tier ll ISO ambient conditions Dprop: 6SME-C8.2 N1.9 m 4 6SME-B9.3 N2 6.2 m 4 Fig. 9: Total annual main engine operating costs for 1.1 knots 6GME-B9.3 N3 6.7 m 4 Relative saving in operating costs 2 days/year Annual operating costs NCR = 9% SMCR Million USD/Year Fuel price: 7 USD/t % 7 14 13 6 Maintenance 12 Lub. oil 11 Fuel oil 1 8.3% 9 4 8 7 3 6 4.2% 2 4 3 1 2 1 % Propulsion of 47, dwt Handymax Tanker 1.1 knots Relative saving in main engine operating costs (NPV) Saving in operating costs (Net Present Value) Million USD 12 1 8 6 4 IMO Tier ll ISO ambient conditions N = NCR = 9% SMCR 2 days/year Fuel price: 7 USD/t Rate of interest and discount: 6% p.a. Rate of inflation: 3% p.a. N3 6.7 m 4 6GME-B9.3 N2 6.2 m 4 6SME-B9.3 2 N1.9 m 4 6SME-C8.2 2 Lifetime 1 1 2 2 3 Years Fig. 1: Relative saving in main engine operating costs (NPV) for 1.1 knots Propulsion of 46,-, dwt Handymax Tanker 13
Main Engine Operating Costs 14. knots The calculated main engine examples are as follows: Propulsion of 47, dwt Handymax Tanker 14. knots Expected propulsion power demand at N = NCR = 9% SMCR Propulsion power demand at N = NCR kw 1, Inclusive of sea margin = 1% Relative power reduction % 1 14. knots 9 1. 6SME-C8.2 (D prop =.9 m) M1 = 8, kw x 119. r/min 2. 6SME-B9.3 (D prop = 6.2 m) M2 = 8,31 kw x 11. r/min. 8, 6, 7,6 kw 7,479 kw 7,1 kw 6.% 8 7 6 3. 6GME-B9.3 (D prop = 6.7 m) M3 = 7,9 kw x 94. r/min. 4, 4 The main engine fuel consumption and operating costs at N = NCR = 9% SMCR have been calculated for the above three main engine/propeller cases operating on the relatively lower ship speed of 14. knots, which is probably going to be a more normal choice in the future. Furthermore, the EEDI has been calculated on the basis of the 7% SMCR-related figures (without sea margin). 2, % 6SME-C8.2 N1 Dprop:.9 m 4 2.2% 6SME-B9.3 N2 6.2 m 4 6GME-B9.3 N3 6.7 m 4 Fig. 11: Expected propulsion power demand at NCR = 9% SMCR for 14. knots 3 2 1 Fuel consumption and EEDI Fig. 11 shows the influence of the propeller diameter with four propeller blades when going from about.9 m to 6.7 m. Thus, N3 for the 6GME-B9.3 with an about 6.7 m propeller diameter has a propulsion power demand that is about 6.% lower compared with the N1 for the 6SME-C8.2 with an about.9 m propeller diameter. For the two ME-B engine cases, an extra SFOC of +1 g/kwh has been added corresponding to the power demand needed for the Hydraulic Power Supply (HPS) system. 14 Propulsion of 46,-, dwt Handymax Tanker
Fig. 12 shows the influence on the main engine efficiency, indicated by the Specific Fuel Oil Consumption, SFOC, for the three cases. N3 = 9% M3 with the 6GME-B9.3 has a relatively low SFOC of 161.6 g/kwh compared with the 16.1 g/kwh for N1 = 9% M1 for the 6SME-C8.2, i.e. an SFOC reduction of about 2.1%, mainly caused by the greater derating potential and higher stroke/bore ratio of the G-engine type. Propulsion of 47, dwt Handymax Tanker 14. knots Expected SFOC SFOC g/kwh 179 178 177 176 17 174 173 172 171 17 169 168 167 166 16 164 163 162 161 Standard ME-B9.3 (with VET) ME-B9.2 (without VET) IMO Tier ll ISO ambient conditions LCV = 42,7 kj/kg Standard high-load optimised engines (VET = Variable Exhaust valve Timing) 16 2 3 3 4 4 6 6 7 7 8 8 9 9 1 % SMCR Engine shaft power N2 N1 N3 M1 6SME-C8.2 Savings in SFOC % M2 6SME-B9.3 M3 6GME-B9.3 2.% 2.1% Dprop.9 m 4 6.2 m 4 6.7 m 4 N = NCR M = SMCR For ME-B9.3 engines the fuel consumption (+1g/kWh) for HPS is included. Fig. 12: Expected SFOC for 14. knots Propulsion of 46,-, dwt Handymax Tanker 1
The daily fuel consumption is found by multiplying the propulsion power demand at N (Fig. 11) with the SFOC (Fig. 12), see Fig. 13. The total reduction of fuel consumption of the new 6GME- B9.3 is about 8.% compared with the existing 6SME-C8.2 (see also the above-mentioned savings of 6.% and 2.1%). The reference and the actual EEDI figures have been calculated and are shown in Fig. 14 (EEDI ref = 1,218.8 x dwt -.488, 1 July 211). As can be seen for all three cases, the actual EEDI figures are now somewhat lower than the reference figure because of the relatively low ship speed of 14. knots. Particularly, case 3 with 6GME-B9.3 has a low EEDI about 82% of the reference figure. Propulsion of 47, dwt Handymax Tanker 14. knots Expected fuel consumption at N = NCR = 9% SMCR Fuel consumption of main engine t/24h 3 3.32 13 t/24h 29. 3 t/24h 27.7 12 t/24h 11 2 1 8.% 9 2 8 7 1 6 4.2% 1 4 3 2 1 % 6SME-C8.2 Dprop: N1.9 m 4 IMO Tier ll ISO ambient conditions LCV = 42,7 kj/kg 6SME-B9.3 N2 6.2 m 4 For ME-B9.3 engines the fuel consumption for HPS is included. Fig. 13: Expected fuel consumption at NCR = 9 SMCR for 14. knots 6GME-B9.3 N3 6.7 m 4 Relative saving of fuel consumption % 14 Propulsion of 47, dwt Handymax Tanker 14. knots Energy Efficiency Design Index (EEDI) 7% SMCR: 14.9 kn without sea margin Reference and actual EEDI CO 2 emissions gram per dwt/n mile Actual/Reference EEDI % 8 12 EEDI reference 212 EEDI actual 7 11 6.4 6.4 6.4 1 6.71. 9 89% 86%.26 82% 8 4 3 2 1 Dprop: 6SME-C8.2 N1.9 m 4 6SME-B9.3 N2 6.2 m 4 6GME-B9.3 N3 6.7 m 4 7 6 4 3 2 1 Fig. 14: Reference and actual Energy Efficiency Design Index (EEDI) for 14. knots 16 Propulsion of 46,-, dwt Handymax Tanker
Propulsion of 47, DWT Tanker 14. knots Total annual main engine operating costs Annual operating costs Million USD/Year 6 4 3 2 1 Dprop: % 6SME-C8.2 N1.9 m 4 IMO Tier ll ISO ambient conditions 2 days/year NCR = 9% SMCR Fuel price: 7 USD/t 4.% 6SME-B9.3 N2 6.2 m 4 Fig. 1: Total annual main engine operating costs for 14. knots Propulsion of 47, dwt Handymax Tanker 14. knots Relative saving in main engine operating costs (NPV) Saving in operating costs (Net Present Value) Million USD 1 8 6 IMO Tier ll ISO ambient conditions N = NCR = 9% SMCR 2 days/year Fuel price: 7 USD/t Rate of interest and discount: 6% p.a. Rate of inflation: 3% p.a. Maintenance Lub. oil 8.2% Fuel oil 6GME-B9.3 N3 6.7 m 4 Relative saving in operating costs % 12 11 1 9 8 7 6 4 3 2 1 N3 6.7 m 4 6GME-B9.3 Operating costs The total main engine operating costs per year, 2 days/year, and fuel price of 7 USD/t, are shown in Fig. 1. Lube oil and maintenance costs are also shown at the top of each column. As can be seen, the major operating costs originate from the fuel costs about 96%. After some years in service, the relative savings in operating costs in Net Present Value, NPV, see Fig. 16, with the existing 6SME-C8.2 with the propeller diameter of about.9 m used as basis, indicates an NPV saving after some years in service for the new 6GME-B9.3 engine with the propeller diameter of about 6.7 m. After 2 years in operation, the saving is about 7.9 million USD for N3 with the 6GME-B9.3 with the SMCR speed of 94. r/min and propeller diameter of about 6.7 m. 4 N2 6.2 m 4 6SME-B9.3 2 N1.9 m 4 6SME-C8.2 2 Lifetime 1 1 2 2 3 Years Fig. 16: Relative saving in main engine operating costs (NPV) for 14. knots Propulsion of 46,-, dwt Handymax Tanker 17
Summary Traditionally, super long stroke S-type engines, with relatively low engine speeds, have been applied as prime movers in tankers. Following the efficiency optimisation trends in the market, the possibility of using even larger propellers has been thoroughly evaluated with a view to using engines with even lower speeds for propulsion of particularly tankers (but also bulk carriers). Handymax tankers (and bulk carriers) may be compatible with propellers with larger propeller diameters than the current designs, and thus high efficiencies following an adaptation of the aft hull design to accommodate the larger propeller, together with optimised hull lines and bulbous bow, considering operation in ballast conditions. The new ultra long stroke GME- B9.3 engine type meets this trend in the Handymax tanker (and bulk carrier) market. This paper indicates, depending on the propeller diameter used, an overall efficiency increase of 8-9% when using GME-B9.3, compared with existing main engine type SME- C8.2 applied so far. Compared with existing SMC-C8 or even SME-C7/MC-C7 often used in the past, the overall efficiency increase will be even higher when using GME- B9.3. The Energy Efficiency Design Index (EEDI) will also be reduced when using GME-B9.3. In order to meet the stricter given reference figure in the future, the design of the ship itself and the design ship speed applied (reduced speed) has to be further evaluated by the shipyards to further reduce the EEDI. 18 Propulsion of 46,-, dwt Handymax Tanker
All data provided in this document is non-binding. This data serves informational purposes only and is especially not guaranteed in any way. Depending on the subsequent specific individual projects, the relevant data may be subject to changes and will be assessed and determined individually for each project. This will depend on the particular characteristics of each individual project, especially specific site and operational conditions. Copyright MAN Diesel & Turbo. 1-11-2ppr Dec 212 Printed in Denmark MAN Diesel & Turbo Teglholmsgade 41 24 Copenhagen SV, Denmark Phone +4 33 8 11 Fax +4 33 8 1 3 info-cph@mandieselturbo.com www.mandieselturbo.com MAN Diesel & Turbo a member of the MAN Group