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Performance analysis of cargo-handling equipment from a green container terminal perspective
Transportation Research Part D 23 (2013) 9–11
Contents lists available at SciVerse ScienceDirect
Transportation Research Part D journal homepage: www.elsevier.com/locate/trd
Performance analysis of cargo-handling equipment from a green container terminal perspective Yi-Chih Yang a,⇑, Chao-Liang Lin b a Department of Shipping and Transportation Management, National Kaohsiung Marine University, No. 142, Haijhuan Road, Nanzih District, Kaohsiung City, Taiwan, R.O.C b Evergreen Marine Corporation, Kaohsiung City, Taiwan, R.O.C
a r t i c l e
i n f o
Keywords: Seaports Container terminal Cargo handling equipment Green terminal perspective
a b s t r a c t This study employs a green container terminal perspective to compare the performance of four types of cargo handling equipment used in container yards – automatic rail, rail, electric tire, and tire transtainers – based on working efficiency, energy saving performance, and carbon reductions. It is found that automatic rail and electric tire transtainers are the optimal types of green cargo handling equipment. Ó 2013 Elsevier Ltd. All rights reserved.
1. Introduction This paper adopts a green container terminal perspective to compare four types of cargo handling equipment used in container yards (automatic rail, rail, electric tire, and tire transtainers1). The comparison is based on three performance dimensions of working efficiency, energy saving, and carbon reduction performances.
2. Methodology Container terminals consist of three subsystems: the gate, container yard, and berths, and employ container handling equipment such as transfer cranes, gantry cranes, yard tractors, and trailers to perform tasks including ship to shore movements, transfers, storage, and deliveries/receipts. The choice of terminal operating system influences the performance of a container terminal (Yang and Sam, 2009); and terminals can improve productivity by increasing the efficiency of cargo handling and storage equipment, including such yard cranes as rail transtainers (RTs), tire transtainers (TTs), straddle carriers, reach stackers, and tractors. There are 26 container terminals at the Port of Kaohsiung are managed by Evergreen, Yang Ming, Wan Hai, OOCL, APL, NYK, Han Jin, Hyun Dai, Kao Ming and Lien Hai and they use a variety of handling technologies. This study make use of information on performance gathered from the internal materials of ABC company which rents six wharfs at the port, and uses 6 ARTs, 24 RTs, 16 E-TTs and 5 TTs for cargo handling, this information allows efficiency comparisons to be made. Comparisons are based on working efficiency (e.g. time per movement), energy used (e.g. the average energy consumption for each type of equipment) and CO2 emissions (e.g. emission volume per equipment type). The Characteristics of the equipment are summarized in Table 1. ⇑ Corresponding author. Tel.: +886 7235407. E-mail address: [email protected] (Y.-C. Yang). Transtainers are used for transferring containers from seagoing vessels onto either trucks or rail wagons. A transtainer is mounted on rails with a large boom spanning the distance between the ship’s cargo hold and the quay, and moving in a direction parallel to the side of the ship. 1
1361-9209/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.trd.2013.03.009
10
Y.-C. Yang, C.-L. Lin / Transportation Research Part D 23 (2013) 9–11
3. Performance of cargo handling equipment The time needed by each type of equipment to move containers consists primarily of the time needed by their hoist system, which accounts for approximately 53–67% of overall moving time; the trolley system accounts for 26–28% of the movement time and the pick/stack system for 6–9%. As shown in Tables 2 the four types of equipment at the ABC company are ranked in the order of TT, RT, ETT, and ART based on time consumption using
CM ¼ HS þ TS þ PS
ð1Þ
WE ¼ ð60 60Þ=CM
ð2Þ
where CM is time per movement (seconds/move), WE is working efficiency (moves per hour), HS is time per movement by the Hoist system (seconds per move), TS is time per movement by the Trolley system (seconds per move), and PS is time consumption per movement need by the Pick/Stack system (seconds per move). As it can also be seen that the ranking order changes to ART, ETT, RT, and TT if one considers operating efficiency in terms of move per hour. The differences can partly be explained by the fact that an RT’s working span is about 22 m that results in more time consumption compared with the ART, a difference reinforced by a RT trolley’s lower movement frequency. We focus on carbon dioxide emissions to gauge differences between the types of equipment in terms of environmental benefits. Working capacity and energy consumption are determined using data collected from ABC in 2010. Because electric equipment on standby does not waste energy, hence we assume that equipment is in an operational mode, and working time is calculated from equipment’s annual operating time divided by its average operating efficiency. Energy consumption is calculated as the working time of the equipment multiplied by its hourly energy consumption. Each type of equipment’s average energy consumption is found by dividing its energy consumption by the units of equipment.
CE ¼ ðWT=WEÞ ðWE ECÞ
ð3Þ
AE ¼ CE=EQ
ð4Þ
TE ¼ AE AC
ð5Þ
where CE is the energy consumption cost per KWH/L, WT is the number of movements, WE is moves by per hour, EC is energy cost by per move, AE is the average energy consumption cost for one unit of equipment, EQ is quantity of equipment (units), TE is the total energy cost in Taiwan dollar, and AC is the average energy consumption cost by Taiwan dollars. For instance, in the case of the automatic rail transtainer, a report issued by the ABC company in 2010 indicates that its working capacity is 257,990 moves and its operating efficiency is 29 moves/per hour. The relevant data for 2010 is seen in Table 3. Assuming that the average cost of electricity is TWD2.38/KWH, the table also shows the financial costs of the various types of equipment. CO2 emission for each unit of equipment is obtained from the average energy consumption for one unit of equipment multiplied by an emission coefficient;
CO2 ¼ AE CC
ð6Þ
where CO2 is emission volume for one unit of equipment, AE is the average energy cost per unit of equipment (KWH/L), and CC is the emission coefficient.
Table 1 Characteristics of cargo handling equipment used by ABC at the Port of Kaohsiung. Action
ART (m)
RT (m)
ETT (m)
TT (m)
Maximum length Maximum width Maximum height Working area Lifting height Wheel Span
54 23 27.2 47 33 17.9
54 22 25.2 47 33 16
23.47 11.9 26.7 17.7 17.75 6.9
23.47 11.6 26.7 18.8 18 6.4
Table 2 Working time (seconds) and operating efficiency of the equipment used by the ABC company. Category
Hoist system
Trolley system
Pick/stack system
Total time
Efficiency (moves/ph)
Equipment volume (units)
ART RT ETT TT
67.2 101.27 115.44 115.44
47.52 60.22 45.18 46.1
11 11 11 11
125.72 172.49 171.62 172.54
29 21 21 21
6 24 16 5
11
Y.-C. Yang, C.-L. Lin / Transportation Research Part D 23 (2013) 9–11 Table 3 Energy consumption of different types of handling equipment in 2010. Equipment type
ART
RT
ETT
TT
Working capacity (moves) Operating efficiency (moves/per hour) Working time (hours) Energy consumption per move (KWH/L) Energy consumption per hour (KWH/L) Energy consumption (KWH/L) Quantity of equipment (units) Average energy consumption per unit of equipment (KWH/L) Average cost per KWH (TWD) Total costs (TWD) CO2 emission coefficients (kg) CO2 emission volume for one unit of equipment (kg)
257,990 29 8,896 4.2 121.8 1,083,558 6 180,593 2.38 429,811 0.637 115,037
1,460,555 21 69,550 3.34 70.14 4,878,253 24 203,260 2.38 483,760 0.637 129,476
918,920 21 43,758 3.02 63.42 2,775,138 16 173,446 2.38 412,801 0.637 110,485
280,929 21 13,377 2.41 50.61 677,038 5 135,407 26.36 3,569,349 2.7 365,601
Table 4 Carbon emission performance of each type of handling equipment. Category of equipment
Average energy consumption for one unit of equipment (KWH/L)
CO2 emission coefficient (kg)
CO2 emission for one unit of equipment (kg)
ART RT ETT TT
180,593 203,260 173,446 135,407
0.637 0.637 0.637 2.7
115,037 129,476 110,485 365,601
The inputs are seen in the last rows of Table 3, and the emissions level in Table 4. Use is made of data from the Chinese Petroleum Corporation and Taiwan Power Company to assess the CO2 emissions associated with production of electricity (0.637 kg CO2/KW) and diesel use (2.7 kg CO2/L). 4. Conclusions In terms of ‘‘greening’’ container terminals, automatic rail, rail and electric tire transtainers offer lower greenhouse emissions and less energy consumption. Acknowledgements The authors greatly appreciate Editor-in-Chief of Transportation Research Part D, Prof. Kenneth Button and two anonymous reviewers for their valuable comments and exerted efforts. This research was partially sponsored by the National Science Council in Taiwan (R.O.C.) under Grant No. NSC 100-2410-H-022-005. Reference Yang, Y.C., Sam, K.Y., 2009. To evaluate operating efficiency of cargo handling facilities in the Container Yard. Maritime Quarterly 18, 37–54 (in Chinese).
Contents lists available at SciVerse ScienceDirect
Transportation Research Part D journal homepage: www.elsevier.com/locate/trd
Performance analysis of cargo-handling equipment from a green container terminal perspective Yi-Chih Yang a,⇑, Chao-Liang Lin b a Department of Shipping and Transportation Management, National Kaohsiung Marine University, No. 142, Haijhuan Road, Nanzih District, Kaohsiung City, Taiwan, R.O.C b Evergreen Marine Corporation, Kaohsiung City, Taiwan, R.O.C
a r t i c l e
i n f o
Keywords: Seaports Container terminal Cargo handling equipment Green terminal perspective
a b s t r a c t This study employs a green container terminal perspective to compare the performance of four types of cargo handling equipment used in container yards – automatic rail, rail, electric tire, and tire transtainers – based on working efficiency, energy saving performance, and carbon reductions. It is found that automatic rail and electric tire transtainers are the optimal types of green cargo handling equipment. Ó 2013 Elsevier Ltd. All rights reserved.
1. Introduction This paper adopts a green container terminal perspective to compare four types of cargo handling equipment used in container yards (automatic rail, rail, electric tire, and tire transtainers1). The comparison is based on three performance dimensions of working efficiency, energy saving, and carbon reduction performances.
2. Methodology Container terminals consist of three subsystems: the gate, container yard, and berths, and employ container handling equipment such as transfer cranes, gantry cranes, yard tractors, and trailers to perform tasks including ship to shore movements, transfers, storage, and deliveries/receipts. The choice of terminal operating system influences the performance of a container terminal (Yang and Sam, 2009); and terminals can improve productivity by increasing the efficiency of cargo handling and storage equipment, including such yard cranes as rail transtainers (RTs), tire transtainers (TTs), straddle carriers, reach stackers, and tractors. There are 26 container terminals at the Port of Kaohsiung are managed by Evergreen, Yang Ming, Wan Hai, OOCL, APL, NYK, Han Jin, Hyun Dai, Kao Ming and Lien Hai and they use a variety of handling technologies. This study make use of information on performance gathered from the internal materials of ABC company which rents six wharfs at the port, and uses 6 ARTs, 24 RTs, 16 E-TTs and 5 TTs for cargo handling, this information allows efficiency comparisons to be made. Comparisons are based on working efficiency (e.g. time per movement), energy used (e.g. the average energy consumption for each type of equipment) and CO2 emissions (e.g. emission volume per equipment type). The Characteristics of the equipment are summarized in Table 1. ⇑ Corresponding author. Tel.: +886 7235407. E-mail address: [email protected] (Y.-C. Yang). Transtainers are used for transferring containers from seagoing vessels onto either trucks or rail wagons. A transtainer is mounted on rails with a large boom spanning the distance between the ship’s cargo hold and the quay, and moving in a direction parallel to the side of the ship. 1
1361-9209/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.trd.2013.03.009
10
Y.-C. Yang, C.-L. Lin / Transportation Research Part D 23 (2013) 9–11
3. Performance of cargo handling equipment The time needed by each type of equipment to move containers consists primarily of the time needed by their hoist system, which accounts for approximately 53–67% of overall moving time; the trolley system accounts for 26–28% of the movement time and the pick/stack system for 6–9%. As shown in Tables 2 the four types of equipment at the ABC company are ranked in the order of TT, RT, ETT, and ART based on time consumption using
CM ¼ HS þ TS þ PS
ð1Þ
WE ¼ ð60 60Þ=CM
ð2Þ
where CM is time per movement (seconds/move), WE is working efficiency (moves per hour), HS is time per movement by the Hoist system (seconds per move), TS is time per movement by the Trolley system (seconds per move), and PS is time consumption per movement need by the Pick/Stack system (seconds per move). As it can also be seen that the ranking order changes to ART, ETT, RT, and TT if one considers operating efficiency in terms of move per hour. The differences can partly be explained by the fact that an RT’s working span is about 22 m that results in more time consumption compared with the ART, a difference reinforced by a RT trolley’s lower movement frequency. We focus on carbon dioxide emissions to gauge differences between the types of equipment in terms of environmental benefits. Working capacity and energy consumption are determined using data collected from ABC in 2010. Because electric equipment on standby does not waste energy, hence we assume that equipment is in an operational mode, and working time is calculated from equipment’s annual operating time divided by its average operating efficiency. Energy consumption is calculated as the working time of the equipment multiplied by its hourly energy consumption. Each type of equipment’s average energy consumption is found by dividing its energy consumption by the units of equipment.
CE ¼ ðWT=WEÞ ðWE ECÞ
ð3Þ
AE ¼ CE=EQ
ð4Þ
TE ¼ AE AC
ð5Þ
where CE is the energy consumption cost per KWH/L, WT is the number of movements, WE is moves by per hour, EC is energy cost by per move, AE is the average energy consumption cost for one unit of equipment, EQ is quantity of equipment (units), TE is the total energy cost in Taiwan dollar, and AC is the average energy consumption cost by Taiwan dollars. For instance, in the case of the automatic rail transtainer, a report issued by the ABC company in 2010 indicates that its working capacity is 257,990 moves and its operating efficiency is 29 moves/per hour. The relevant data for 2010 is seen in Table 3. Assuming that the average cost of electricity is TWD2.38/KWH, the table also shows the financial costs of the various types of equipment. CO2 emission for each unit of equipment is obtained from the average energy consumption for one unit of equipment multiplied by an emission coefficient;
CO2 ¼ AE CC
ð6Þ
where CO2 is emission volume for one unit of equipment, AE is the average energy cost per unit of equipment (KWH/L), and CC is the emission coefficient.
Table 1 Characteristics of cargo handling equipment used by ABC at the Port of Kaohsiung. Action
ART (m)
RT (m)
ETT (m)
TT (m)
Maximum length Maximum width Maximum height Working area Lifting height Wheel Span
54 23 27.2 47 33 17.9
54 22 25.2 47 33 16
23.47 11.9 26.7 17.7 17.75 6.9
23.47 11.6 26.7 18.8 18 6.4
Table 2 Working time (seconds) and operating efficiency of the equipment used by the ABC company. Category
Hoist system
Trolley system
Pick/stack system
Total time
Efficiency (moves/ph)
Equipment volume (units)
ART RT ETT TT
67.2 101.27 115.44 115.44
47.52 60.22 45.18 46.1
11 11 11 11
125.72 172.49 171.62 172.54
29 21 21 21
6 24 16 5
11
Y.-C. Yang, C.-L. Lin / Transportation Research Part D 23 (2013) 9–11 Table 3 Energy consumption of different types of handling equipment in 2010. Equipment type
ART
RT
ETT
TT
Working capacity (moves) Operating efficiency (moves/per hour) Working time (hours) Energy consumption per move (KWH/L) Energy consumption per hour (KWH/L) Energy consumption (KWH/L) Quantity of equipment (units) Average energy consumption per unit of equipment (KWH/L) Average cost per KWH (TWD) Total costs (TWD) CO2 emission coefficients (kg) CO2 emission volume for one unit of equipment (kg)
257,990 29 8,896 4.2 121.8 1,083,558 6 180,593 2.38 429,811 0.637 115,037
1,460,555 21 69,550 3.34 70.14 4,878,253 24 203,260 2.38 483,760 0.637 129,476
918,920 21 43,758 3.02 63.42 2,775,138 16 173,446 2.38 412,801 0.637 110,485
280,929 21 13,377 2.41 50.61 677,038 5 135,407 26.36 3,569,349 2.7 365,601
Table 4 Carbon emission performance of each type of handling equipment. Category of equipment
Average energy consumption for one unit of equipment (KWH/L)
CO2 emission coefficient (kg)
CO2 emission for one unit of equipment (kg)
ART RT ETT TT
180,593 203,260 173,446 135,407
0.637 0.637 0.637 2.7
115,037 129,476 110,485 365,601
The inputs are seen in the last rows of Table 3, and the emissions level in Table 4. Use is made of data from the Chinese Petroleum Corporation and Taiwan Power Company to assess the CO2 emissions associated with production of electricity (0.637 kg CO2/KW) and diesel use (2.7 kg CO2/L). 4. Conclusions In terms of ‘‘greening’’ container terminals, automatic rail, rail and electric tire transtainers offer lower greenhouse emissions and less energy consumption. Acknowledgements The authors greatly appreciate Editor-in-Chief of Transportation Research Part D, Prof. Kenneth Button and two anonymous reviewers for their valuable comments and exerted efforts. This research was partially sponsored by the National Science Council in Taiwan (R.O.C.) under Grant No. NSC 100-2410-H-022-005. Reference Yang, Y.C., Sam, K.Y., 2009. To evaluate operating efficiency of cargo handling facilities in the Container Yard. Maritime Quarterly 18, 37–54 (in Chinese).