SPM-34 Hose Failure Investigation Report2

Terminal Operation Department Investigation Report

TERMINAL OPERATION DEPARTMENT Terminal Engineering Division Juaymah Terminal Engineering Unit

Investigation Report of SPM-34 Hose Failure

August 23, 2011

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EXECUTIVE SUMMARY th

On Tuesday August 9 , 2011 at approximately 21:00 hours, informed by port control center senior pilot reported the SPM 34 hoses observed bending and need to be check. At 2130 hours BERRI # 5 with RIMTHAN II coordinator inspected SPM 34 and observed two of the port surface hoses P-28 and P-27 before breakaway coupling squeezed and bending. The hose P-28 was observed squeezed about more than one meter and the hose P-27 was observed bending more than 45degrees. Two surface full float hoses at SPM-34 were observed collapsed completely while in service. Next day, third hose was discovered suffering from the same collapse effect. An investigation committee was formed to determine the root cause of such premature failure and to prevent reoccurrence in future. The failed hoses are located near the breakaway coupling in a sequence ( #26, 27 and #28).The failed hoses are manufactured by Parker ITR (formerly known as Treg Pirelli) and had failed while in service for only 383 days. This type of hose is supposed to stay in service for around 2190 days (i.e. 17% only of the required service life). It is worth mentioning that this type of failure has happened before two times already in May 2010 and April 2011. An on-going investigation and analysis is being conducted right now by the vendor and a third party office to determine the cause of this type of failure. Several tests have been conducted on the failed hoses and other analysis and recommendation will be issued in this investigation report. Fortunately, there was no product leak or spill associated with this failure.

Moreover, this report represents the analysis leading to the hose failure, defines the causes and suggests recommendations to prevent similar failures. In addition, the report addresses the following important points:  

The root causes of the failure and the action plan to avoid reoccurrence of such incident. The adequacy and quality of the hose manufacturer providing this type of hoses.

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TABLE OF CONTENTS

1.

INTRODUCTION

2.

DESCRIPTION OF THE FAILURE

3.

FINDINGS & ANALYSIS

4.

DETAILED DISCUSSION

5.

RECOMMENDATIONS

6.

ATTACHMENTS

7.

INVESTIGATION TEAM MEMBERS

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1.0 INTRODUCTION: This report presents the analysis leading to the hose failure, identifies root causes and suggests recommendations to prevent reoccurrences. The investigation was based on the following standards, manuals and publications: o

o

o o o

o

o

Saudi Aramco Material Specifications; 22-SAMSS-004 Oil Hose for Offshore Tanker Loading General Instruction manual; GI 86.001 Handling, Storage, Inspection and Testing of SPM Hoses Terminal Instruction Manual; TIM 934601 Hose Evacuation and Backfill System Terminal Instruction Manual; TIM 934201 Loading Hoses Inspection and Testing Oil Companies International Marine Forum OCIMF; Single Point Mooring Maintenance and nd Operations Guide, 2 Edition 1995 OCIMF; Guidelines for the Handling, Storage, Inspection and Testing of Hoses in the Field, nd 2 Edition 1995 OCIMF; Guide to Manufacturing and Purchasing Hoses for Offshore Moorings (GMPHOM th 2009), 5 Edition 2009

2.0 DESCRIPTION OF THE FAILURE: th

On Tuesday August 9 , 2011 at approximately 21:00 hours, informed by port control center senior pilot reported the SPM 34 hoses observed bending and need to be check. At 2130 hours BERRI # 5 with RIMTHAN II coordinator inspected SPM 34 and observed two of the port surface hoses P-28 and P-27 (before breakaway coupling) squeezed about more than one meter and the other hose was observed bending more than 45 degrees. Third hose P-26 was discovered one day later suffering from the same problem. Fortunately, there was no product leak or spill associated with this failure. ̊

2.1Sequence of Events: Following is the timed events, which indicate the actions that were taken before and after the failure of the hoses as logged by operations. DATE August 7th August 8

August 9

th

th

August 10

th

TIME 19:31

EVENTS Started Loading operation via SPM-34

18:30

Completed Loading operation via SPM-34

19:00

Started Evacuation Operation down to -18.50 inch of Hg

21:00

Full Float Port Surface Hoses#27 and 28 were reported with severe squashing and bending. rd Another (3 ) full float hose#26 was reported suffering the same

18:00

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August 11

th

12:00

collapse effect. Crew replaced defective hoses and SPM-34 back in service.

August 12

th

06:30

Started new loading operation via SPM-34

2.2Effect on Operations: There was no effect on Crude Offshore operations as a result of this Failure: 1. Hoses were replaced directly during the free window of SPM-34 as can be seen from the above sequence of events. 2. There was no leak associated with the failure of these hoses.

3.0 FINDINGS & ANALYSIS: 3.1 Single Point Mooring (SPM) Normal Operation During the normal operation of the SPMs, the offshore platform operator, in preparation for the coming tanker, gradually evacuate the intended SPM Hose to reduce the weight of the hose for tanker handling and to prevent product spillage. Once vacuum pressure of between 10” Hg – 20” Hg (inch of Mercury) is maintained in the hose, hose connection is made to the tanker and loading commence. Upon completion of the loading, once again, hose is subjected to vacuum pressure to disconnect the hoses from ship’s manifold. After that and according to TIM#934601, Hose must be backfilled with product to protect floating hoses from collapsing when not in use. The required pressure inside the hoses shall be 35 psig.

3.2 What Happened? After Ship completed loading at SPM-34, Evacuation process was started on SPM-34 hoses down to -18 inch/Hg.

3.3 Why it Happened (Immediate Causes)? The investigation that was carried out by the team members revealed that the immediate cause of the incident was the poor design of Parker ITR Full Floating Hoses to sustain vacuum pressure above the designed setting of -25inch\Hg. These hoses are designed to withstand vacuum down to -25inch/Hg yet failed at values within the design tolerances. Associated with the vacuum deficiency, vacuum pressure of -18inch/Hg was maintained in the SPM-34 Hose for excessive duration of time violating the requirement to backfill the hose after each evacuation process.

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3.4 Causal Factors: The below chart indicates several ‘causal factors’ associated with two immediate causes related to the incident events.

START

Pre-arrival Preparation and Evacuation /Backfilling Operation

END

IMMEDIATE CAUSES

Poor Internal Design of Parker ITR Full Floating Hoses

Excessive Vacuum Duration imposed on Hoses

Failure of the Full Floating Hoses

Causal Factors

So far, Seven (7) Parker ITR hoses reported with failure against vacuum.

1. All failed hoses manufactured between March-May 2009 2. Inadequate adhesion between the Liner and main body components of the hose. 3. Not withstand vacuum under design tolerances.

1. No inspection. 2. No PM on joints. 3. Seizing of swivel screwed pin and bushings. 4. No clearance between pins and bushings.

5. No greasing nipples installed by FMC. 6. Not included in the pre-arrival check list.

Causal Factor Chart

Consequently, the contributed immediate causes of this failure are attributed to the followings: 3.4.1

The bolts that secure the outboard cylinder maneuvering axis to the sheave sleeve bearing flange were loosen and not well tighten in place as a result of frequent use of the loading arm. Consequently, these bolts could not carry the load of the 8 tons counterweight causing them to shear off during the movement of the outboard arm.

3.4.2

As a result of lack of lubricant, some of the sheared bolts were found corroded and eroded which did not help in carrying the shearing force on the axis.

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3.5 Root Causes: The root causes of this incident were attributed to the followings: 3.5.1. Hose Design was less than adequate o

o

Parker ITR Full Floating Hoses shows clear indication of design deficiency when subjected to vacuum pressure even within the design tolerances included in the hose certificate. Parker ITR Hoses tends to fail under vacuum especially if they were installed in critical areas in the SPM string. This includes first-off buoy and hoses near the breakaway coupling for CALM SPMs and the subsea/surface transition area in the SALM SPMs.

3.5.2. SPM Hose Backfilling and Evacuation Operation is not Clear o

Not including the FMC manufacturer’s maintenance instructions in neither the annual external Inspection Work (IW) for the loading arm components nor the PM program tasks. The greasing application task is not part of the PM procedure as it is not indicated in the attached PM sheet for the loading arm.

o

3.5.3. Equipment design was less than adequate o

o

o

The use of normal washers by the FMC loading arm manufacturer. Instead, spring type of washers should be installed with the bolts to keep them well secured in place and accordingly avoid looseness. Missing of greasing nipples on the screwed swivel pins. Grease should be periodically injected between the cylinder securing bracket bushings and the pins to allow free 90 degrees movement of the cylinder during the outboard arm extension. There was no clearance between the moving swivel screwed pins and the outboard cylinder securing bracket bushings which resulted from frequent use of the loading arm and could be FMC fault during the installation of the arm. This clearance is required for free movement of the cylinder and to avoid seizing mechanism.

3.5.4. Problem detection was less than adequate o

Other cause of the failure was aging of the securing bolts for the outboard cylinder ‘maneuvering assembly’ where two bolts were found broken before the incident occurred as it is clear from their corroded surfaces compared to the shiny surfaces of the newly sheared bolts. Page 9 of 25


o

Abnormal noise from the adjacent loading arm (L/A-5C) outboard cylinder securing bracket during simulation was an indication of possible mechanical failure that might occurred to loading arm (L/A-4C) before the incident occurred.

4.0 DETAILED DISCUSSION: An investigation team was formed by Juaymah Terminal Operations Superintendent to investigate SPM-34 Full Float Hoses Failure on August 10, 2011. The kick-off meeting was held on Saturday August 13. The team has subsequently collected the related data and documentations to investigate this failure and has conducted a vacuum test on the failed hoses and also on a new hose as well. The followings are the aspects of the discussion.

4.1 SPM Evacuation and Backfill Operation The team has reviewed the operation procedure of the evacuation and backfilling following each ship loading. It is noted that disconnection of SPM hoses to ship manifold takes usually from 2 to 3 hours. So, it is normal to have vacuum for this duration on SPM hoses without affecting the integrity of the hoses. Sometimes, this duration increases when changing hoses for planned or emergency situations by Rimthan Vessel crew. The team observed a real operation at SPM-33 where pressure inside the hoses was reduced from 28 psig to -18 inch/Hg in about 10 minutes. The visual alarm of the hose pressure reduction was started when pressure in the hoses dropped to 10 psig. In the nearest SPM-34 Hose Failure, the vacuum remained in the hose for almost 23 hours until discovered. It remains for an additional 40 Hours until replacing the defective hoses. Similar hose failures had happened in the past as follows: o Two Full Floating Hoses in SPM-34 (March 2011), the team found for this case that vacuum was kept inside the hoses for more than 23 hours. Two Full Float Hoses in SPM-35 (April 2010), the vacuum was kept inside the o hoses for more than 26 hours. In addition, the investigation team found that in a random selection of SPM-31, 32, 33, 34 and 35 during the last year, long duration of vacuum has been maintained in the hoses for more than one day as can be seen from the Historical Trend Data in Attachment# X.

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4.2 Parker ITR Marine Hoses Performance The investigation team found from the documents that there is no dedicated task as a Preventive Maintenance measure for the securing parts of the moving components including the ‘maneuvering assembly’ of the outboard cylinder neither in the PM program nor the FMC manufacturer maintenance manual. However, FMC is insisting in his maintenance manual on the application of periodic lubrication merely for the swivel joints such as outboard cylinder joint at a frequency of 500 hours of operation or obligatory every six months. It was found by the team that FMC did not provide greasing nipples on the swivel joint screwed pins of the outboard cylinder securing bracket to comply with his PM recommendation.

Hose Brand

Total In Service

Total in Warehouse

Total

BS- Bridgestone

33

6.4%

39

7.6%

72

7%

DU- Dunlop

76

14.8%

343

67%

419

41%

KL- Kleber (Trelleborg)

32

6.3%

30

5.9%

62

6%

TP- Parker ITR (Treg Pirelli)

260

51%

77

15%

337

33%

YK- Yokohama

112

21.8%

22

4.3%

134

13%

Total Table 1:

513

Hose Brand Distribution for Juaymah SPMs

SPM# SPM#31

Total In Service 14

SPM#32

73

SPM#33

60

SPM#34

67

SPM#35

47

Total Table 2:

260

In‐Service TP Hoses Distributions among five SPMs

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511

1024


The CSD Structural Engineer evaluated the incident and indicated that there could be three reasons for the failure. The friction between the cylinder (where the bolts are fastened to) and the housing is very high – notice the grease nipples and grease lines may not be doing their job in getting enough grease to lubricate the cylinder. If the cylinder is frozen (or nearly frozen), then the torque exerted will be resisted by the frozen cylinder and bolts will shear off. The loading arm is forced to turn while it is in the locked position (with a locking mechanism). The bolts will resist the arm movement and the applied torque eventually overcame the strength of the bolts and sheared them off. Some bolts are shown in the pictures are loose. If this was the case, then the load sharing between bolts would have been different, putting more load on some bolts that are tight, shearing them off, transferring the load to the remaining bolts that could not handle it and also sheared off. Loose bolts also weakens the connection making the cross-sectional area of the bolts as the only resisting mechanism, while if they are torqued correctly, additional contact area (metal on metal) will be resisting the applied forces. Furthermore, FMC highlighted by e-mail that the screwed bolts for the ‘manoeuvring assembly’ should be periodically checked for tightness, as they can become loose due to vibrations after some time of frequent loading arm operations. Also when one or two screws got loose, the probability of all screws getting loose and shearing is very high. On the other hand, Ras Tannura Terminal reviewed Berth 64 L/A-4C incident and they suspected possible multiple problems if the following assumptions derived from the pictures of the incident are correct. First, the bolts in the outboard drive assembly broke due to them being loose. Judging from the pictures of the bolts being bent and broken at different lengths and the smearing of the bolt-hole metal, other arms bolts should be checked for looseness at the bracket in question. Second, if the other outboard cylinder brackets are being deformed/bent as it appears to be in the pictures, something else much more serious could be happening and the arm where hydraulic systems and operating envelopes should be checked very closely. This could be an indicator of very excessive overloading or misalignments. In addition, Ras Tanura Terminal indicated that they have typical type of FMC loading arms at their loading jetties but fortunately they did not encounter similar incident since they increased the PM program on the securing parts by modifying the outboard cylinder ‘manoeuvring axis assembly’ and installing grease nipples on the screwed pins. The investigation team members discussed the requirements of conducting PM on the critical moving components and the securing parts of the loading arm such as the ‘maneuvering axis assembly’, hydraulic cylinders and counterweights securing mechanisms. The PM should consist of cleaning, greasing, and checking the looseness of the securing parts.

Sent: Sunday, March 13, 2011 10:55 AM Thank you for your follow up and please be noted that the ITR-Parker proposal is not

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acceptable as submitted due to the following reasons: Based on the information we have, the failure mode of ITR-Parker hoses cannot be associated with positions or operational conditions as failures had occurred in different location of the same string. Additionally, failure type has been only occurring on ITR-Parker hoses and not to any of the other marine hose brands which are installed in the same string and position and have been exposed to similar condition. The root cause of the collapsed hose failure has not been identified yet. Saudi Aramco still have large number from the marine hoses Inferior Roma Design which are either installed or in the warehouse. Until a genuine evaluation of the actual cause of failure is concluded, it would be risky to use these hose design without close monitoring and evaluation as a mass failure may occur in the future similar to what had happened to those two hoses. It should also be highlighted that Saudi Aramco still have an outstanding failure issue with ITR-Parker hoses that have failed in Jazan in 1994 and so far had not been resolved as ITR-Parker were reluctant to pursue this issue or even admit it. For this reason, we would like to ensure that this will not happen again and therefore this failure issue will be tackled at the beginning rather than waiting until it gets bigger to a point that ITR-Parker unable to resolve. To avoid any unexpected mass failure of the remaining hoses and to ensure full responsibility of ITR-Parker to the performances of their marine hoses at Saudi Aramco facilities, the hose strings with suspected inferior design will all be removed from service next year and then subjected to rigorous testing and inspection. Based on the result, a decision can then be made and ITR-Parker will be notified accordingly.

4.3 Marine Hose Management Moreover, FMC emphasized on the periodic inspection for the loading arms components. The team found that there was no inspection performed on the securing mechanism parts for all critical moving components since the commissioning of BI-8339 ‘YCOT Expansion Project’ in 1993. In spite of, the FMC maintenance manual indicates that there should be a periodic inspection on monthly basis on the moving components of the loading arms for their general operating condition and security, for example all swivel joints lubrication and leakage, an untightening of screws on the flanges, foundation anchor bolts and nuts and counterweights and security rods. In addition, the loading arms inspection should be performed every six months for damages, cracks, bent parts and looseness of securing nuts and bolts.

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5.0 RECOMMENDATIONS: The investigation team derived the following recommendations for immediate action plan and avoidance of future reoccurrence of such incident. Item #

Description

Recommended By

Action by

1

Determine the maximum duration of vacuum that the hoses should be applied to without subjected to failure

Team Members

JTEU

2

Ensure that

Team Members

RU

3

Perform immediate Inspection for all TP Full Floating Hoses to ensure their integrity and to establish the baseline for future inspection.

Team Members

COS Maint.

4

The berth operator who usually operates the loading arms should be more attention for any abnormal noise that Team Members indicates possible failure of the moving component and he should report it for immediate action for maintenance.

5

Include the PM requirements for the loading arm critical components in the Instruction Manual (including the rules and responsibilities of all parties).

6

Test the pressure relieve valve in the hydraulic circuit to check if excessive force was exerted on the cylinder bracket and caused the bolts to shear off.

7

Check other arms bolts for looseness at the bracket.

8

Hydraulic systems and operating envelopes should be checked very closely. This could be an indicator of very excessive overloading or misalignments.

9

Provide greasing nipples on the swivel joint screwed pins for the outboard cylinder securing bracket.

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Team Members RT Terminal (e-mail) RT Terminal (e-mail) RT Terminal (e-mail)

COS Maint. (Innovation Idea)

COS Operatio n COS OME COS OME COS OME COS OME COS OME


10

12

13

The set of screws for the ‘manoeuvring assembly axis’ should FMC be periodically checked for tightness, as they can become (e-mail) loose due to vibrations after some time of loading arms operation. And when one or two screws loose, the probability of all screws getting loose and shearing is very high. On monthly basis, inspect the condition of all moving FMC components for general operating condition and security. (maintenance manual) Area OME will provide scaffoldings for inaccessible locations. Replace or repair parts that indicate possible malfunction. FMC On six months basis, inspect all components for damage or (maintenance safety, fix all loose nuts and bolts, cracks, bent parts, etc. manual)

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COS OME

COS OME

RU


6.0 ATTACHMENTS 1.

Investigation Team Members Sign Sheet

2.

SPM-34 Loading Historical Trend

3.

Other SPMs Loading Trends

4.

SPM Hose Change Out Schedule

5.

Failed Hoses Data Sheet

5.

Inspection Failure Hose Report 2010

6.

Inspection Failure Hose Report 2011

7.

Manufacturer Hose Inspection and Test Certificate of the Failed Hoses

9.

Parker ITR e-mail response

10.

FMC Maintenance Manual and Loading Arm Drawing

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7.0 INVESTIGATION TEAM MEMBERS

___________________________ Abdullah S. Al-Zahrani Mech. Engineer & Chairman

____________________________ _______________________ Ali H. Al-Noor Abdulrehman I. Ansari Foreman, Juaymah Pier Maint. Unit Foreman, Juaymah Offshore Unit

________________________ _____________________ Amin A. Bushnag Noori M. Hashim Mechanical Engineer, Juaymah Pier Maint. Unit Inspector, Terminal Inspection Unit

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ATTACHMENT#1

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ATTACHMENT#2

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ATTACHMENT#3

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ATTACHMENT#4

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ATTACHMENT#5

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ATTACHMENT#6

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ATTACHMENT#7

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ATTACHMENT#8

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SPM-34 Hose Failure Investigation Report2

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