Source : Photo from TWI-Global , Media and Event , Schenectady T2 tanker
The “ Liberty Ships ” that were built during World War II by the Western Allies via welding were built much faster than using the former riveting method . However , a handful of these ships suffered significant brittle fractures at the hull with the worst case being that the ship was broken in half . Since then , Scientists and Engineers have put major effort into studying the metal characteristics ( e . g ., fracture mechanics ) and improving the design , including weldment properties , to prevent future occurrences . The root cause was due to the Ductile-Brittle Transition Temperature of the specific metals , whereby the weldment becomes brittle in a relatively cold environment , meaning it lacks Charpy Toughness properties in resisting physical impact before fracture .
Note : In Malaysia , work on board a ship is governed by the Merchant Shipping Ordinance or the Arm Forces requirement , depending on the service .
Figure 5 : Example of the Ship Broken in Half
Test ( WQT ) is to ensure the personnel assigned to the job are competent and able to provide a good weldment . There are many International Welding Codes in our industry , such as AWS D1.1 ( Structural Welding Code - Steel ), ASME Section IX ( ASME Boiler & Pressure Vessel Code ), API 1104 ( Welding of Pipeline ), etc . Also , there may be additional Customer Specifications over and above these International Standards , based on Stakeholder requirements to further enhance the Quality Assurance of the final product .
Welding Procedure Safety Highlights ( Global Historical Flashback and Local Legislation )
Quality and Safety may sound different and vary in meaning . Nonetheless , these two subjects are highly associated with one another . A quality product will eventually lead to better product safety ; in other words , Quality improves Safety . Companies must perform the necessary analysis to balance Safety , Quality and Profit appropriately . Figure 5 is an example of a Safety-related incident due to poor quality weldment during fabrication , and most likely without a proper “ Welding Procedure Specification ” in hand .
With respect to the above Historical Flashback , one may inquire whether there is any existing local legislation to govern our engineering-associated industries and prevent related incidents from occurring in our place of work . Fortunately , the Malaysian Parliament had approved an Act in 1994 that ought to address this concern . Per OSHA 1994 Section 20 , any plant should be safe , without risk to health , when put to use , in terms of design and construction , including performing the necessary tests and providing adequate information to users . Moreover , the definition
OCCUPATIONAL SAFETY AND HEALTH ACT 1994 ( OSHA 1994 ) Section 20 . General duties of manufacturers , etc . as regards plant for use at work . ( 1 ) It shall be the duty of a person who designs , manufactures , imports or supplies any plant for use at work- ( a ) to ensure , so far as is practicable , that the plant is so designed and constructed as to be safe and without risks to health when properly used ; ( b ) to carry out or arrange for the carrying out of such testing and examination as may be necessary for the performance of the duty imposed on him by paragraph ( a ); and
( c ) to take such steps as are necessary to ensure that there will be available in connection with the use of the plant at work adequate information about the use for which it is designed and has been tested , and about any condition necessary to ensure that , when put to that use , it will be safe and without risks to health .
43