MUH. HIDAYAT ARIF D311 12 003
113
3 EnvironmentCondition :
a The depth of water under the keel in testing area should be at least twice the vessel’s draft amidship.
b The distance from the stern of the towing vessel to the bollard fixed point should be at least two ship length LOA
c Wind speed should be 10 mph 1 knot = 1,150 mph or less, or such, that it does not
measurably affect the bollard pull result.
d If current exceeds 1 knot, its effect is to be substacted from the bollard pull by
either : Direct measurement of drag effect pulling direction downstream and reduction
of bollard pull accordingly; or Conducting pull test both upstream and downstream and averaging the result
e The dynamometer load cell is : Calibrated and suitable for use in horizontal position. It should be fitted with
swivels or should be torque insensitive, such as a hydraulic dynamometer. It should be easily read from a safe location or a remote readout should be
provided. The dynamometer should be located at the ashore end of the tow hawser.
f The towing vessel should be on an even keel or trimmed to the intended operating
condition in tow.
g The draft of the towing vessel should be equal to or deeper than ballast condition, but need not be down to the summer load line mark.
4 Duration of Bollard Pull : The static Bollard Pull should be computed as the average of evenly spaced load
cell recordings taken over a sustained pull interval of three to five minutes.
5 Miscellaneous Item :
During the test, one surveyor is located in the vessels engine room and one surveyor
is located at the shore station.
b. Tets Preparation
MUH. HIDAYAT ARIF D311 12 003
114
1 Re-check all load cell unit ; telemetry indicator and load cell. Ensure all equipments in proper connection, sufficient power and function able. Beside that, Surveyor must be
review calibration certificate of the load cell in use.
Figure 101 : Load Cell Unit System Configuration
MUH. HIDAYAT ARIF D311 12 003
115
Figure 102 : Load Cell Certificate
2 Load cell installation, fitted load cell in suitable horizontal position with 2 bolt nut shackles, in 2 ways: to the bollard fixed point and to towing vessel wire rope tow
hawser, by secure connections.
Figure 103 : Installed Bollard Pull Equipment
3 Observe the load cell position in suitable condition in way vessel movement during testing, not in twisting position, free from other objects what obstruct load cell
capabilities. 4 Check and record the towing vessel draft condition: fore, amidship and after.
MUH. HIDAYAT ARIF D311 12 003
116
Figure 104 : Vessel Draft
5 Recording of vessel data including Draft Forward
Draft Aft Ballast Tank Capacity
Balast Tank Onboard Fuel Oil Capacity
Fuel Oil Onboard
Figure 105 : Tank Capacity During Test 3.21.5 Bollard Pull Procedure
1. Move the towing vessel to the required position that describe in Fig. 104
MUH. HIDAYAT ARIF D311 12 003
117
Figure 106 : Recommended Minimum Towline Length and Water Depth Under Keel
Figure 107 : Wire Connect To Towing Left and Wire Connect To Towing Right
2. Smoothly extend wire rope to avoid instantaneous spike tension load reading and maintain towing vessel in steady condition.
3. Gradually increased main engine load to maximum continuous rpm MCR 100
Figure 108 : RPM Reading Process in Engine Room
4. Continuous load cell reading from ashore should be informed to the onboard bollard pull test officer for reference to determining vessel steady condition with continuous steady
tension load reading indication. 5. Confirmation is required from onboard bollard pull test officer to the ashore officer to
start measurement recording the tension load reading. 6. Duration of bollard pull test measurement is 3~5 minutes
7. Load tension reading displayed informed continuously to the onboard by ashore officer.
MUH. HIDAYAT ARIF D311 12 003
118
8. When measurement completed, the ashore officer should be informed to onboard officer.. 9. Testing condition when tension load recording should be recorded by onboard officer and
informed to ashore officer for documentation, i.e.: Wind speed
Current speed Towline length
Water depth under keel
3.21.6 Result and Conclusion of Survey
The result of bollard pull as the following: Vessel Name : Perdana Marathon
Draft Fwd : 5,5 m
Draft Aft : 6,4 m
Length of Tow Wire : 390 m Water Depth : 17 meter
Target Bollard Pull : 150 ton Maximum Bollard Pull : 151,04 ton
Conclusion : Acceptable
Figure 109 : The Final Result of Bollard Pull Test
MUH. HIDAYAT ARIF D311 12 003
119
3.22 SPECIAL SURVEY FOR BARGE 3.22.1 Reference Document
