Purpose. The purpose and extent of technical documentation required by
Navy Crane Center in its contracts is to ensure that the crane design is the
product of competent designers and that adequate drawings and calculations are
available for future needs to verify or re-evaluate design details, assess or
repair damage, and facilitate alterations or improvements. Custom designed
assemblies and components must be supported by detailed calculations and drawings;
serially produced items must be adequately described by published commercial
Design Responsibility. All portions of the crane design must be
performed by, or under direct supervision of, a registered professional engineer
(PE) competent in the particular engineering discipline. Alternatively, the
completed crane design may be reviewed and approved by a PE who is the
contractor's employee or a consultant retained by the crane contractor for that
purpose. In either case, the PE must be intimately familiar with the crane
contract specification and the details of the proposed crane design. Every
drawing and set of calculations must be stamped and signed by a PE. The stamp and
signature must be original, or otherwise comply with the rules or regulations
pertaining to their reproduction in the state of the PE's registration.
PE licensing must be by a board or agency authorized to license and
register professional engineers in any state of the U.S. or province of Canada.
Scope. The crane design calculations must, as a minimum, include
analyses for each identified load combination and operating condition or
configuration. The selection of standard, serially produced, components and
assemblies must be supported by their manufacturers' selection procedures. All
material must be fully identified including their condition, mechanical
properties, and allowable stress levels. Calculations must demonstrate that the
calculated stresses do not exceed the allowable values. Similarly, selection of
standard purchased assemblies and components, following the published methods of
selection or sizing, must demonstrate their adequacy for the imposed loadings.
The standard purchased items must be fully identified by manufacturer and part
number; and any additional information, such as material or test results, must
also be provided.
Additionally all alignment, torquing, and other assembly
procedures must be clearly specified on the drawings.
Drawings and calculations should be organized in a logical manner by
engineering discipline and level of detail. The technical documentation should
include drawings for assembly/disassembly of the crane or major components,
lubrication, and jacking arrangements.
Selection of critical items, such as rotate bearings, must include the
manufacturer's certification of proper selection for the intended service and the
identified load cases. Diesel engine-generator sets must be accompanied by a
torsional vibration analysis and certification that the set is free of critical
torsional frequencies in the normal operating speed range. Other items which are
required to comply with national, state, or local regulations (for example,
compressed air storage tanks) must be provided with appropriate certifications.