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A fishing vessel is powered with a 9 cylinder diesel engine. Power transfer from the engine to the gearbox is enabled through a flexible coupling arrangement. This coupling is made up of a rubber component attached to a finger coupling, shown in Figure 2 with an array of linkage arms. Failure of the linkage arms in this assembly occurred on repeated occasions. After the initial failure a 2mm vertical misalignment of the rubber component was found and fixed. The coupling and the new linkage arms failed after a further 400 hours.
Drill rods for geological operations consist of one end threaded internally to form a pin, and the other end threaded externally to form a box. The 3.1m long rods are fit together to provide the length needed for drilling. Originally, these AISI 4130 steel drill rods were imported. It was then decided to manufacture these locally by threading rods imported from India. These rods began seizing prematurely in the field.</p>
The fuel cam on an injector pump for a marine diesel engine failed after 1392 running hours. Failure occurred at the contact point between the roller and the load bearing surface.
The condenser tubes on a gas cooler used in a whisky distillation plant have shown extensive corrosion over a 5 year period resulting in failure of the condenser.
A derrick pole on board a boat hoists a lifeboat on and off the ship in open water. A winch attached to the rigid vertical member carries the cable allowing for hoisting of the lifeboat. The vertical member allows for rotation of the derrick pole i.e. to swivel between the deck and water (Figure 1). The derrick has a safe working load of 1 ton. During a hoisting operation, the derrick pole failed catastrophically, releasing its load.
The side members of an aluminium ladder, employed during salvage operations aboard a barge vessel failed catastrophically (Figures 1 and 2). The ladder consisted of two straight aluminium ladders fixed together by means of four pieces of duct tape and two polypropylene lashings; resulting in an extended ladder length.
A stainless steel expansion bellows was utilised in an air conditioning system at a shopping centre. It was used to compensate for linear movement of the pipes associated with inevitable thermal expansion. The bellows failed, allowing massive leakage from the system.
Two samples of an AISI 409 flange welded to an ASTM 240 material were provided for metallurgical investigation. The samples were welded with two different filler materials; Sample A with 308LSi filler and Sample X with 18CrCb filler.
Samples of High Impact Polystyrene (HIP) and Polypropylene (PP) were supplied by a pharmaceutical company. These polymers undergo an irradiation treatment that is required for sterilisation.
The hull of a vessel failed while at sea. The failure of the hull appears to have developed along a corner between the side and underneath of the hull.
