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Background
The practice of dowel pinning machinery was originally conceived within the U.S. Navy, well over a century ago.

This innovation was triggered by the need for a solution to the extreme conditions faced onboard naval surface vessels and submarines by directly-coupled rotating machinery with respect to hull and foundation deflection related to changing temperatures and storms at sea, as well as the forces generated by firing munitions (shells and depth charges.) The original concern that resulted in the use of dowel pins was positional security.

Given the fact that on Navy and commercial vessels excess mass is a major concern, the sound engineering practice of designing a base structure to weigh three to five times the mass of the machinery mounted upon it is impractical, resulting in flimsier, more flexible foundations. This is the principal justification for dowel pinning machines in the Navy, and this practice became almost universally adopted.

After World War II, the vast majority of the industrial maintenance workforce in the United States that dealt with rotating machinery was comprised of men who had served in the Navy, as this was the branch of the armed services with the bulk of such machinery and maintenance need. As a result of deeply ingrained Navy tradition and training, the practice of indiscriminately dowel-pinning all rotating machinery filtered out onto dry land installations, even though in most cases there was no longer any technical justification for this practice.

Download our article “Thoughts On Dowel Pins In Machine Feet” including Positional Security: Technical Considerations, Alternative Solutions, and Positional Repeatability.

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, by Alan Luedeking CRL CMRP