Electrically & Hydraulically Operated Large Grab Dredger
The feature & dredging capacity of “GOSHO” and “661 RYOSEIMARU”
andTheir performance in Singapore Tuas Terminal Phase 1 Project

GOSHO The world’s Largest grab dredger

Hydraulic system
for grab bucket up/down

Hydraulic system
for grab bucket open/close

136m3 grab bucket
for hard material

200m3 grab bucket
for normal material

Height 6m Draft 3.6m
Length 100m

Width 36m

Electric & Hydraulic Grab Dredger “GOSHO”

Conventional grab dredger (Winch style)2661 RYOSEIMARU

Electrically & hydraulically operated large grab dredger

Hydraulic system
for grab bucket up/down

56m3 grab bucket for normal material

Hydraulic system
for grab bucket open/close

Height 5m
Lengths 70m

Draft 2.75m

38m3 grab bucket for hard material

Width 26m
3

The feature of electric & hydraulic grab dredger

Frame

Power supply cableHydraulic unit for bucket open/close

Energy savingwith counterweight system
Tooth

Grab bucket up

Grab bucket down

ShellWidth
幅 5.2mWhen the bucket
長さ15.2m(バケット全開時)
LengthA frameCounterweight frame

Hydraulic cylinder forgrab bucket up/down

open completelyWeight
重量: 370t

200m3 Grab bucket for normal material

Large volume & hard material dredging
with power of hydraulic cylinders
Hydraulic units
16 main pumps/
8 main motors
In the equipment

Counterweight 1380t

The feature of electric & hydraulic grab dredger

Frame

Power supply cableHydraulic unit for bucket open/close

Energy savingwith counterweight system
Grab bucket up

ToothGrab bucket down

Shell
A frameWidth
幅 5.2mCounterweight frame

Hydraulic cylinder for
grab bucket up/down

When the bucket
長さ15.2m(バケット全開時)
Lengthopen completely
Weight
重量: 370t

200m3 Grab bucket for normal material

Large volume & hard material dredging
with power of hydraulic cylinders
Hydraulic units
16 main pumps/
8 main motors
In the equipment

Counterweight 1380t

The feature of electric & hydraulic grab dredger
200m3 grab bucket
for normal material①Large Volumedredging

136m3 grab bucket
for hard material②Hard material
dredging

Large volume dredging

GOSHO
200m3 grab bucket for normal material

Conventional grab dredger(Winch style)Grab bucket capacity

200m3

23m3

Approx. 8.7 times of capacity

Dredging ability*

2,315m3/h

610m3/hApprox. 3.8 times of ability*Data of dredging ability per hour for cohesive soil (SPT<10) at -10m below the sea level

Large volume dredging

661 RYOSEIMARU
56m3 grab bucket for normal material

Conventional grab dredger(Winch style)Grab bucket capacity

56m3

23m3

Approx. 2.4 times of capacity

Dredging ability*

818m3/h

610m3/hApprox. 1.3 times of ability*Data of dredging ability per hour for cohesive soil (SPT<10) at -10m below the sea level

Large volume dredging
GOSHO

Hourly dredging capacity comparison
GOSHO 200m3 grab bucket for normal material calculated capacity

Target depth -10ｍ

Target depth -15ｍ

Target depth -20ｍ

Dredging capacity (m3/h)

Material condition

Dredging capacity (m3/h)

Material condition

Dredging capacity (m3/h)

Material condition

2315（Cohesive soil N<10)2186（Cohesive soilN<10)2071（Cohesive soilN<10)1930（Cohesive soil10<N<30)

1823（Cohesive soil10<N<30)1727（Cohesive soil10<N<30)962（Cohesive soil30<N<50)917（Cohesive soil30<N<50)876（Cohesive soil30<N<50)2105（Sandy soilN<10)1988（Sandy soilN<10)1884（Sandy soilN<10)1574（Sandy soil10<N<30)1487（Sandy soil10<N<30)1408（Sandy soil10<N<30)23m3 class grab dredger calculated capacity

905（Sandy soil30<N<50)863（Sandy soil30<N<50)825（Sandy soil30<N<50)

Target depth less than -15

848（Graveled soil30<N<50)809（Graveled soil30<N<50)773（Graveled soil30<N<50)788（Soft rock50<N<100)752（Soft rock50<N<100)718（Soft rock50<N<100)

525（Medium rock100<N<300)

501（Medium rock100<N<300)

479（Medium rock100<N<300)* Regarding the shaded area, the theoretical capacity can be calculated even for material with SPT of 30 or more, but since the 200m3
grab bucket was developed for normal material with SPT of less than 30, soil with SPT 30 or more NOT recommended.
GOSHO 136m3 grab bucket for hard material calculated capacity
Target depth -10ｍ

Target depth -15ｍ

Target depth -20ｍ

Dredging capacity (m3/h)

Material condition

Dredging capacity (m3/h)

Material condition

Dredging capacity (m3/h)

Material condition

1582（Cohesive soilN<10)1494（Cohesive soilN<10)1415（Cohesive soilN<10)1319（Cohesive soil10<N<30)1246（Cohesive soil10<N<30)1180（Cohesive soil10<N<30)657（Cohesive soil30<N<50)627（Cohesive soil30<N<50)599（Cohesive soil30<N<50)

1438（Sandy soilN<10)1359（Sandy soilN<10)1287（Sandy soilN<10)1076（Sandy soil10<N<30)1016（Sandy soil10<N<30)963（Sandy soil10<N<30)

618（Sandy soil30<N<50)590（Sandy soil30<N<50)564（Sandy soil30<N<50)580（Graveled soil30<N<50)553（Graveled soil30<N<50)529（Graveled soil30<N<50)539（Soft rock50<N<100)513（Soft rock50<N<100)491（Soft rock50<N<100)359（Medium rock100<N<300)

342（Medium rock100<N<300)

327（Medium rock100<N<300)

Dredging capacity (m3/h)

Material condition

610（Cohesive soilN<10)481（Cohesive soil10<N<30)

530（Sandy soilN<10)409（Sandy soil10<N<30)296（Graveled soil30>N)9

Large volume dredging
661 RYOSEIMARU

Hourly dredging capacity comparison
23m3 class grab dredger calculated capacity

RM661 56m3 grab bucket for normal material calculated capacity
Target depth-8m

Target depth-10m

Target depth

-12m

843

（Cohesive soilＮ<10)818（Cohesive soilＮ<10)795（Cohesive soilＮ<10)703（Cohesive soil10<Ｎ<30)682（Cohesive soil10<Ｎ<30)663（Cohesive soil10<Ｎ<30)

333（Cohesive soil30<Ｎ<50)

325（Cohesive soil30<Ｎ<50)318（Cohesive soil30<Ｎ<50)

767（Sandy soilＮ<10)745（Sandy soilＮ<10)723（Sandy soilＮ<10)573（Sandy soil10<Ｎ<30)556（Sandy soil10<Ｎ<30)

540（Sandy soil10<Ｎ<30)314（Sandy soil30<Ｎ<50)

307（Sandy soil30<Ｎ<50)300（Sandy soil30<Ｎ<50)

294（Graveled soil30<Ｎ<50)

287（Graveled soil30<Ｎ<50)281（Graveled soil30<Ｎ<50)273（Soft rock50<Ｎ<100)266（Soft rock50<Ｎ<100)261（Soft rock50<Ｎ<100)

182（Medium rock100<Ｎ<300)

178（Medium rock100<Ｎ<300)

174（Medium rock100<Ｎ<300)

Target depth less than -15
Dredging capacity (m3/h)

Material condition

610（Cohesive soilN<10)481（Cohesivesoil10<N<30)

530（Sandy soilN<10)409（Sandy soil10<N<30)296（Graveled soil30>N)* Regarding the shaded area, the theoretical capacity can be calculated even for material with SPT of 30 or more, but since the 56m3
grab bucket was developed for normal material with SPT of less than 30, soil with SPT 30 or more NOT recommended.

RM661 38m3 grab bucket for hard material calculated capacity
Target depth-8m

Target depth-10m

Target depth

-12m

580

（Cohesive soilＮ<10)563（Cohesive soilＮ<10)547（Cohesive soilＮ<10)484（Cohesive soil10<Ｎ<30)469（Cohesive soil10<Ｎ<30)455（Cohesive soil10<Ｎ<30)

229（Cohesive soil30<Ｎ<50)

224（Cohesive soil30<Ｎ<50)

219（Cohesive soil30<Ｎ<50)527（Sandy soilＮ<10)512（Sandy soilＮ<10)497（Sandy soilＮ<10)394（Sandy soil10<Ｎ<30)383（Sandy soil10<Ｎ<30)371（Sandy soil10<Ｎ<30)

216（Sandy soil30<Ｎ<50)

211（Sandy soil30<Ｎ<50)

206（Sandy soil30<Ｎ<50)

203（Graveled soil30<Ｎ<50)

198（Graveled soil30<Ｎ<50)

193（Graveled soil30<Ｎ<50)

188（Soft rock50<Ｎ<100)183（Soft rock50<Ｎ<100)179（Soft rock50<Ｎ<100)125（Medium rock100<Ｎ<300)

122（Medium rock100<Ｎ<300)

120（Medium rock100<Ｎ<300)

10

Hard material dredging

It is a heavy and rigid grab bucket
opening and closing by the power of hydraulic cylinders

High dredging ability for materials with more than SPT30
Also high dredging ability for materials with around SP300 by
136m3 grab bucket

Contributing to shortening project period without chiselingwork.
Cohesive material that Cutter Suction Dredger, Trailer Hopper
Suction Dredger can not dredge, is also applicable by ourgrab dredgers

Performance in Singapore Tuas Terminal Phase 1 project
Project Name:

Tuas Terminal Phase 1

Client: MPA
Contractor: DDJV(Dredging International Asia Pacififc Pte.
and Daelim Co.,Ltd）

Location: Tuas Finger2, fairway, berth
Period:2015/3/1~2018/7 (planned)

TUAS

Target depth: Original -15m, dredge to -23.5m(Partially -40 dredging at the caisson installation area)
Volume: 67Mm3 (41Mm3 for grab dredging）
Dredgers:
Large size CSD, THSD from the European nation
18~23m3 class grab dredgers from Singapore
Our grab dredger “GOSHO” “661 Ryoseimaru” “381 Ryoseimaru”

Dredging performance【GOSHO】15,544,300m3【RM661】 13,330,097m3【RM381】 5,195,574m3
Total: 34,069,971m3

83% of grab dredging volume
50% of total dredging volume

Blue Line：Fairway & berth dredging area
Green Line：Caisson installed area

1km

are implemented by our grab dredgers
12Performance in Singapore Tuas Terminal Phase 1 projectIn this project,GOSHO operated from Apr 2016 to April 2019,
then dredged 15,544,300m3 totally

Actual dredging time is 18,083 hours.
Thus the dredging ability in this project is;
Avg. 515,765m3 per month
Avg. 20,630m3 per day

13Performance in Singapore Tuas Terminal Phase 1 projectIn this project,661RYOSEIMARU operated fromApr 2016 to May 2020, then dredged
13,330,097m3 totally
Actual dredging time is 26,855 hours.
Thus the dredging ability in thisproject is;
Avg. 297,824m3 per month
Avg. 11,913m3 per day

14

Dredging ability by each SPT value of dredged material in TTP project③Record④Calculate①Pick up a sample material②SPT value examination⑤Analyze15

Dredging capacity by each SPT value of dredged material in TTP projectCalculated capacity: The figure of -22mGOSHO
200ｍ3 grab bucket for normal material

136ｍ3 grab bucket for hard material

2,500

2,500

2,028
2,000

2,000
1,691

1,840
1,500

1,500

1,386
1,155

1,368
1,202
1,000

1,000

1,091

925

902

588

775

482
500

500
519

0445

0
N<10

10<N<30

浚渫実績
Dredging
performance

30<N<50

能力算定値(粘土)Calcuated
Capacity(Cohesive soil)

50以上

N<10

10<N<30

浚渫実績

能力算定値(粘土)Dredging
performance

Calcuated
Capacity(Cohesive soil)

30<N<5050以上

能力算定値(レキ混じり~岩盤)
Calcuated
Capacity(Graveled soil ~ Rock)16

Dredging capacity by each SPT value of dredged material in TTP projectCalculated capacity: The figure of -22m

RM661 RYOSEIMARU
56m3 grab bucket for normal material

38m3 grab bucket for hard material

1,000

1,000

826
800

800

653
695

602

600

600
579
441
390

400

378

400

478

360
398
279
196

200

161

200
173

00
N<10

10<N<30
浚渫実績
Dredging
performance

30<N<50
能力算定値(粘土)Calcuated
Capacity(Cohesive soil)

50以上

N<10
浚渫実績
Dredging
performance10<N<30

30<N<5050以上

能力算定値(粘土)能力算定値(レキ混じり~岩盤)

Calcuated
Capacity(Cohesive soil)

Calcuated
Capacity(Graveled soil ~ Rock)

17Dredging capacity by each SPT value of dredged material in TTP project
200m3 grab bucket for normal material
Regression analysis value (Least-squares
method/logarithmic approximation) *Same hereafter

The depth average of material sample: -23.1m
Calculated capacity: The figure of -22m

2,400

2,200
2,000
1,800

Hourly dredging volume(m3/h)

1,600
1,400
Sample(Cohesive soil)
サンプル(粘土)1,200

Sample(Consolidated silt)
サンプル(固結シルト)1,000

サンプル(岩)Sample(Rock)800

能力算定値(粘土)(Cohesive soil)

Calculated capacity

対数(全体) (All data)
Logarithm

600
400
200

001020304050100

150200250300Measured SPT of sample material
18Dredging capacity by each SPT value of dredged material in TTP project
136m3 grab bucket for hard material

The depth average of material sumple: -23.1m
Calculated capacity: The figure of -22m

2,400
2,200
2,000
1,800

Hourly dredging volume(m3/h)

1,600
Sample(Cohesive soil)
サンプル(粘土)1,400

サンプル(固結シルト)
Sample(Consolidated silt)
1,200サンプル(岩)Sample(Rock)

1,000
Calculated capacity
能力算定値(粘土)(Cohesive soil)

Calculated capacity
能力算定値(レキ混じり~岩盤)

800(Graveled soil ~ Rock)

対数(全体)(All data)
Logarithm
600
400
200001020304050100150200250300

Measured SPT of sample material
19

Dredging capacity by each SPT value of dredged material in TTP project
136m3 grab bucket for hard material Rock dredging of SPT More than 300●Rock800

700

600

Hourly dredging volume(m3/h)

500

400300200100001020304050

Measured MPa of sample material

150250350

45055020Dredging capacity by each SPT value of dredged material in TTP project56m3m3 grab bucket for normal material

The depth average of material sumple: -23.1m
Calculated capacity: The figure of -22m

1000

900

800

700
Soft cohesive soil
軟性粘土

硬性粘土
Hard cohesive soil

600

固結シルト
Consolidated silt
軟岩
Soft rock500

中硬岩
Medium~Hard rock全体

400

Calculated capacity

算定値(粘土)(Cohesive soil)

対数(全体)
Logarithm (All data)

300

200

100005101520253035404550100

Measured SPT of sample material

150200250300

21Dredging capacity by each SPT value of dredged material in TTP project38m3 grab bucket for hard material

The depth average of material sumple: -23.1m
Calculated capacity: The figure of -22m

1000
900
800
Soft cohesive soil
軟性粘土

700

硬性粘土
Hard cohesive soil
固結シルト
Consolidated silt

600

軟岩Soft rock500

中硬岩
Medium~Hard rock全体

400

Calculated capacity
算定値(レキ混じり)(Cohesive soil)

300

Calculated capacity
算定値(粘土)(Graveled soil ~ Rock)対数(全体)(All data)
Logarithm

200
100005101520253035404550100

150200250300

Measured SPT of sample material

22

Fuel consumption in Singapore TTP1 projectMonthly engine operating hours and fuel consumption are recorded, and fuel consumption per hour is calculated.
GOSHO
年

2016

月

運転時間(hr)

使用燃料(ℓ)

1－

－

2

－

－

3－

4
5

2018

2020

使用燃料(ℓ)

－

－

－

－

－

－

－

－

－

－

－

－

－

－

－

－

395

59,800

151

－

－

－

418

67,100161

658

243,000

369

651

117,300

180

7

521

182,000

349

694

124,100

179

8

565

193,000

342

625

118,100

189

9

683

238,000

348

634

110,400

174

10

417

168,000

403

719

125,700

175

11

690

283,000

410

301

51,200

170

12

719

238,000

331

716

122,300

171

1

663

291,000

439

670

122,100

182

2

559

234,000

419

611

107,500

176

3

629

210,000

334

626

105,600

169

697

120,000

172

－－－

5

472

178,000

377

698

124,300

178

6

531

211,000

397

626

112,800

180

7

632

257,000

407

496

83,600

169

8

524

241,000

460

699

123,400

177

9

479

194,000

405

701

91,900

131

10

660

276,000

418

609

105,600

173

11

404

177,000

438

542

84,500

156

12

613

276,000450

716

122,300

171

1

711

275,000

387

711

116,800

164

2

586

226,000

386

626

109,200

174

3583

235,000

403

638

107,300

168

4

663

232,000

350

574

97,300

170

5

680

283,000

416

683

115,800

170

6

682

267,000

391

648

112,300

173

7

616

255,000

414

591

98,600

167

8

488

237,000

486

729

106,700

146

9

710

235,000

331

670

101,350

151

10

643

276,000

429

695

105,400

152

11

545

221,000

406

709

106,200

150

12

604

249,000

412

701

105,900

151

1

699

242,000

346

697

102,500

147

2

605

252,000

417

628

93,400

149

3

647

253,000

391

731

110,300

151

346

165,000

477

4

2019

時間当たり使用燃料 日平均運転時(ℓ/hr)
間(hr)

運転時間(hr)

642017RM661

時間当たり使用燃料 日平均運転時(ℓ/hr)間(hr)719

115,600

161

5－

－

－

728

117,700

162

6－

－

－

703

112,100

159

7－

－

－

721

115,100

160

8－

－

－

698

105,100

151

9－

－

－

662

104,600

158

10－

－

－

633

98,200

155

11－

－

－

701

106,750

152

12－

－

－

735

108,800

148

1－

－

－

723

103,200

143

2－

－

－

669

95,600

143

3－

－

－

710

103,300

145

4－

－

－

673

101,800

151

5－

－

－

213

38,700182

32,1635,215,200

162

20,227

7,993,000

395

19.6

Average hourly fuel consumption
GOSHO
Total fuel consumption: 7,993,000L ÷ Total operating hours: 20,227 hours

395L/h661 RYOSEIMARU
Total fuel consumption: 5,215,200L ÷ Total operating hours: 32,163 hours

162L/h2421.1

Minimum staffing for 24-hour operation
GOSHO

661 RYOSEIMARU

Area of Responsibility

Day shiftNight shift

Area of Responsibility

Day shiftNight shift

Supervision

Superintendent

Superintendent

Supervision

Superintendent

Superintendent

Crane/spud operation

Barge Master

Operator

Crane/spud operation

Barge Master

Operator

Crane/spud operation

Operator

Operator

Crane/spud operation

Operator

Operator

Crane/spud operation

Operator

Operator

Crane/spud operation

Operator

Operator

Deck

Bosun

BosunDeckBosun

Bosun

Deck

Deckhand

Deckhand

DeckDeckhand

Deckhand

DeckDeckhand

DeckhandEngine room

Chief Engineer

1st Engineer

Engine room

Chief Engineer

1st Engineer

Engine room

1st Engineer

Engine room

1st Engineer

2nd Engineer

Engine room

2nd Engineer

Engine room

2nd Engineer

All equipment

Electrician

All equipment

Electrician

All equipment

WelderAll equipment

WelderGalleyCookGalley

Cook

Total

12Total13

WelderWelder810■ is dispatched from our group company Pacific Marine Japan Co., Ltd. Other than that, local crew worked on board.

25

GOSHO spec.
Dredger name：GOSHO

Dredging Equipment

PowerDredger type： Grab Dredger

Manufacturer：

Grab Sumitomo Heavy Industry

Main engine： 2,795KW 3pcs

Int’l tonnage： 7,052T

S.W.L.：

690t

Aux. engine： 160KW

Class：

BV

Max. dredging depth：-48m

Register：Japan (Nagoya)Working radius：

31m

Built year：

2000

max. swinging angle：

150°

Hull size：

L100m W36m H6m

Grab bucket：

200m3 grab bucket for normal material (370t)

Draft：

3.6m

136m3 grab bucket for hard material（400t）

661 RYOSEIMARU spec.
Dredger name：RM661 RYOSEIMARU

Dredging Equipment

PowerDredger type： Grab Dredger

Manufacturer：

SKK

Main engine： 2,059KW 2pcs

Int’l tonnage： 2,928T

S.W.L.：

240t

Aux. engine：

95KW

Class：

Foresight (Singapore)

Max. dredging depth：-30m

Register：

MongolWorking radius：

18.1m~24.2m

Built year：

1989

Grab bucket：

56m3 grab bucket for normal material (130t)

Hull size：

L70m W26m H5m

Draft：

2.75m

38m3 grab bucket for hard material（130t）

28

29