Manitowoc, Wisconsin, December 10, 2008 -- Manitowoc Cranes has learned that the chord mounting pads on the head section of the #79A tops on the above-referenced Model 18000 cranes and luffing jibs may delaminate. Manitowoc has also determined that the #79A tops may be missing internal welds in the plate work of the head section which may cause cracks to develop in the welds between the chord mounting pads and plate work. Units with delaminated boom chord pads and/or cracked welds at these locations may be structurally compromised and must be immediately taken out of operation.
Figure 1: Location of chord mounting pads and welds which must be M.T. inspected.
Continued use of affected #79A tops without performance of the inspection, repairs, and modification required under this product improvement program could result in boom and/or luffing jib failure. Boom and/or luffing jib failure could result in death, serious bodily injury as well as damage to the crane and other property.
Manitowoc requires your immediate assistance in shutting down all affected #79A tops until the head section on those tops have been inspected by means of Magnetic Particle Test (“M.T.”) performed on all locations specified in this Product Improvement Program (Click here for a pdf of the detailed Manitowoc memorandum).