Crémaillère

A Crémaillère is a French, mechanical term for the rack, or a straight bar with teeth on one edge designed to work into the teeth of a wheel or a pinion (French pignon) that predates the Renaissance. The term was generally applied in English to engineering applications which had notched, toothed or drilled surface, even when only visually so, such as the edge of the staircase. The term is also applied to the rack railway.

During the 17th to 19th centuries the term was widely applied to lines of entrenchment that are usually formed in a saw-tooth pattern, known as indented lines, particularly during sieges. These lines are usually employed on banks of rivers, or on ground which is more elevated than, or which commands, that of the enemy. The defence of these lines is sometimes strengthened by double redans, and flat bastions constructed at intervals, along their front. Just such a constructed defence was used at Centreville in 1862 during the American Civil War.

The term is also applied in Artillery to refer to an indented battery, or à Crémaillère constructed with salient and re-entering angles for obtaining an oblique, as well as a direct fire, and to afford shelter form an enfilade fire of the enemy.

References

• Glossary of Automotive Terminology: French-English English-French, Engineering Standards and Data Dept, Society of Automotive Engineers, Chrysler Corporation, 1977
• Mahan, Dennis Hart, Prud'homme, John Francis Eugene, A Treatise on Field Fortification: Containing Instructions on the Methods of laying out, constructing, defending and attacking entrenchments with the general outlines also of the arrangement, the attack and defence of permanent fortifications, (3rd ed.) Confederate States of America Collection (Library of Congress), Joseph Meredith Toner Collection (Library of Congress), John Wiley, New York, 1862
• Henry Lee, (Colonel ), Military dictionary: comprising technical definitions: information on raising and keeping troops; actual service, including makeshifts and improved materiel; and law, government, regulation, and administration relating to land forces, D. Van Nostrand, Trubner and co, New York, 1861
• Spearman J. Morton, (Captain), The British gunner, (3rd Ed.)Military Library Whitehall, 1844
• Moore, Frank (ed.), Everett, Edward, The Rebellion Record: A Diary of American Events, with Documents, Narratives, Illustrative incidents, Poetry, etc., G.B. Putnam & Henry Holt, New York, 1864fr:Crémaillère