1.0 PURPOSE
2.0 SCOPE
3.0 APPLICABLE DOCUMENTS
4.0 RESPONSIBILITY
5.0 MANPOWER
6.0 TOOLS & EQUIPMENT
7.0 METHODS/PROCEDURES
8.0 QUALITY CONTROL
9.0 SAFETY PRECAUTION
10.0 ATTACHMENTS
1.0 PURPOSE
1.1 This method statement shall provide minimum guidelines to carry out the overhead crane load testing procedure for Commercial buildings, plants and refineries to ensure that the work is carried out in accordance with Project Drawings and Project Specifications.
2.0 SCOPE
2.1 This method statement will cover the overhead crane load testing procedure at Commercial buildings, plants and refineries.
2.2 Overhead Cranes
Single Girder Crane for NHT recycle gas compressor
Manufacturer name: Eastern Morris Cranes Co. Ltd.
Equipment model: EL-B 100.0-12.000 Eexn
Equipment serial no.: 10628-CR1
Rated capacity (SWL): 10 tons
3.0 APPLICABLE DOCUMENTS
3.1 ARAMCO Project Specification and Standards
3.1.1 Saudi ARAMCO Construction Safety Manual
3.2 Industry Codes and Standards
3.2.1 ASME B30.2 Overhead and Gantry Cranes (Top running bridge, single or multiple girder, top running trolley hoist).
3.2.2 ASME B30.9 Slings
3.2.3 ASME B30.17 Overhead and Gantry Cranes (Top running bridge, single girder, underhung hoist)
3.2.4 GI 7.028 Crane Lifts: Types and Procedures
3.2.5 GI 7.029 Rigging Hardware Requirements
3.2.6 GI 7.030 Inspection and Testing Requirements for Elevating/ Lifting Equipment
3.2.7 FEM 9.811 & BS 466
3.3 Inspection and Test Plan
3.3.1 JRTP-ITP-MECH-005 Overhead Crane Field Installation.
3.3.2 SATIP-P-113-04 Typical Inspection Plan for Crane, Hoist and Elevators.
3.3.3 SATR-P-3414 Test Report for Crane Insulation Resistance and Functional Testing.
3.3.4 SATR-P-3415 Test Report for Hoist Insulation Resistance and Functional Testing.
3.4 Vendor Document
SAT Procedure wit SAT Record Form
4.0 RESPONSIBILITY
4.1 Construction Manager is responsible for implementing HSE and shall study, analyze and schedule all activities for load testing of overhead crane with third party and his department to include manpower and equipment assist as well as other possible resources required for the successful implementation of load testing activities.
4.2 Mechanical Supervisor shall study and review all necessary documents for overhead crane load testing procedure. He shall be directly reporting to the Construction Manager. He shall coordinate with other discipline to visualize possible conflicts of activities to provide other options
in preventing unnecessary delays.
4.3 QC Inspector shall be responsible in monitoring of load testing activities to ensure that the work is performed in accordance with the procedure and Technical Scope of Work and Standards.
4.4 Safety Officer/Supervisor shall be responsible in monitoring safety aspects and ensuring that the work is done in accordance with Safety Standard Procedure. He shall discuss to the third party/field supervisor’s the status of work area giving reminders as an additional point to work safely.
5.0 MANPOWER
5.1 Manpower will consist of the following, but not limited to as listed to as below:
• Third Party Inspector
• Overhead Crane Operator
• Rigger
• Mechanical Supervisor
• E & I Supervisor
• Safety Officer
• QC Inspector
6.0 TOOLS AND EQUIPMENT
6.1 Tools and equipment needed should be in good condition and must be checked by Rigging Supervisor / Safety Officer prior to use in the good condition area. These includes but not limited as below:
• Certified test loads OR Test Load Cell
• Suitable slings & shackles
• Measuring device to check girder deflection
• Stop watch for speed check
• Megger
• Ammeter & Multi meter (to be used just in case of electrical trouble)
7.0 METHODS/ PROCEDURES
7.1 Pretest Inspection
7.1.1 For overhead crane it is necessary to ensure that the runway and supporting structure are thoroughly examined. A visual inspection of the runway within the test area should be made prior to commencing the test to ensure their suitability to withstand the test loads.
7.1.2 Review the crane runway dimensions survey report and building clearances.
7.1.3 Insulation test. After completion of erection and before connection of the power supply, the insulation of the electrical system shall be tested. The voltage used shall be a D.C. voltage of not less than twice the rated voltage of the system concerned and all phases shall be checked for each crane motion or system.
7.1.4 Earth Continuity. Earth continuity of the equipment shall be checked to ensure that at no point the reading is greater than 0.50.
7.1.5 The orientation of the crane, location of the Power line/Main switch and the height of control pendent for convenience of operation shall be checked with reference to GA drawing.
7.2 No load test Procedure
7.2.1 Before the application of any load, a thorough examination of the crane by a functional test with no load to be carried out to ensure the correct operations of controls, switches, contactors, relays and other devices. The operation and correct adjustments of the brakes and limit switches should be checked and tests carried out to ensure the primary safety and emergency systems are operating correctly.
7.3 Load Test Procedure at 100% Safe Working Load
7.3.1 Deflection Test:
7.3.1.1 At the start of the test the crane should be positioned over a supporting stanchion or column of the runway beam in order to minimize the influence of runway beam deflection in the girder deflection readings. The hoist to be positioned at center of the crane span.
7.3.1.2 Using a suitable measuring device (Scale) note down the Girder level (Reading-1)
7.3.1.3 The safe working load should now be raised ~0.3m height.
Measure and note down the Girder level (Reading-2).
7.3.1.4 The difference between the Reading-1 & 2 is the deflection of the girder.
7.3.1.5 The maximum deflection of the main bridge with the hoist and safe working load at the center of span should not exceed 1/900 of the span.
7.5.1.1.1 Eg. For a crane with a span of 24 meters the following calculation would apply. Maximum deflection = 24,000/900 =26.6mm
Note: If the allowable deflection is different for a specific project, the same has to be calculated based on the project specification.
7.3.2 The safe working load should now be raised~1.5 to 2m height to ensure that each tooth of the hoist train of gears is subjected to the load. The load should be held in this position for 10 minutes check the brake.
7.3.3 The load should then be raised by a further~200mm and then lowered to check the ability of the hoist to lift the suspended load.
7.3.4 The load should then be transverse towards one side for 2M both right and left so that each tooth of the cross travel train gears is subjected to the load. Move the load towards either side of the runway to the hook approach position and then crane should be returned to its original lift position.
7.3.5 Brake Test. Check whether the Hoist brakes arrest the motion & hold the load when the power is cut off. (i.e Push button is released). Check whether the travel/traverse brakes arrest the respective motion & bring the fully loaded trolley/Crane to rest without shock at high speed.
7.3.6 Speed check: Hoisting, Traversing & travelling speeds to be measured using stop watch.
Travel distance = d(m) => 0.5m for hoist & 2 to 4m for Trolley & Crane
Time taken = t(sec)
=> Speed
= d*60/t => The speed should be ±10% of the Rated Speed
Do this procedure for hoist/trolley/crane for both slow & fast speeds. Allow acceleration to reach full speed before taking initial reading.
7.3.7 Overload Device check: The working load to be increase by 25% & hoisting to be performed. Due to the overload, the overload device should trip.
7.4 Overload Test Procedure at 125% Safe Working Load
7.4.1 Bypass the overload device as stipulated in the O&M instructions. The working load should be increased by 25% to form a test load.
e.g. Over load for 10T crane – 10T + 25% of 10T = 12.5T
The load shall be moved in all the directions so that each train of gears is subjected to the load as elaborated in above section. This test is only to check the stability of the crane and hence no measurement is required to be taken.
7.4.2 During the overload test the crane should only be operated at speeds appropriate to the safe control of the load.
7.4.3 On completion of the tests, a further thorough examination of the crane should be carried out and overload protection devices should be reset and their correct operation verified.
Note: This may include inspection for cracks, permanent deformation, and gear teeth damage.
7.5 Test Report
7.5.1 Typical test report is attached which may be used to record the results of the testing. When the procedure had been satisfactorily completed, the testing engineer should issue a test certificate as required.
7.6 List of safety devices to be checked:
7.6.1 Hoist overload device
7.6.2 Hoist/ Trolley/ Bridge breaks
7.6.3 Hoist up/down limit switch
7.6.4 Trolley Limit Switch
7.6.5 Bridge Limit Switch
Note: If it is necessary to make mechanical alterations to the equipment to meet the specified operating criteria, the test shall be repeated after the correction has been made.
8.0 QUALITY CONTROL
8.1 QC Inspector will be present at site during the activity to ensure that the activity will be done in accordance to Saudi Aramco load testing procedure.
8.2 QC Inspector will produce all the documents attesting to the acceptability of the works and submits to DEC/JGC.
9.0 SAFETY PRECAUTION
9.1 Approved work permit should be obtained to concerned personnel prior to the start any activities.
9.2 Work execution shall be carried out in accordance with this method of statement.
9.3 Ensure all construction personnel use correct PPE.
9.4 Lifting operation shall not be performed in wind speeds exceeding 32km/h (9m/s), electrical storms or other severe weather.
9.5 Ensure that all rigging tackles are inspected with color codes and in good condition.
9.6 Use softener to avoid cutting wire rope or web sling during lifting operation.
9.7 A designated signalman shall be used at all times during the load test of overhead crane. Only one designated signal man shall give signals to the crane operator.
9.8 To operate following the instructions from signalman. The emergency stop signal shall be implemented immediately whoever instruct.
9.9 Only authorized personnel shall be allowed within the barricade area.
9.10 Safety devices shall be sensitive and reliable.
10.0 ATTACHMENTS
10.1 Job Hazard and Risk Assessment (JHRA)
10.2 SAT Procedure with SAT Record Form