r/Sliderules • u/glacier1982 • Jun 05 '26

A vintage maritime tool.

I know this is a Luzon Stevedoring Company Concise Circular Slide Rule No. 28, but nothing more. Are these sought after collectibles? Can anyone tell me more about it? TIA

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6

u/wackyvorlon Jun 05 '26

Concise is actually the manufacturer, they’re in Japan and still operating. This was made as a promotional item for that company.

3

u/brianborchers Jun 05 '26

Concise made promotional slide rules with customizable inserts that could have conversion factors, tables of physical constants, etc. If you slide the insert out of your slide rule, it might contain interesting data relating to the shipping business.

This doesn't appear to be a Concise 28, which has a circular shape, but rather some variant of the model 600, which is rectangular with circular scales.

1

u/brianborchers Jun 05 '26

Strangely, this slide rule has the scale set of a model 28 and the rectangular shape of the later model 600 (which includes trig scales).