# Former

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> Source: https://en.wikipedia.org/wiki/Former
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{{Short description|Manufacturing tools used to give form to a malleable object}}

A '''former''' is an object, such as a template, [gauge](/source/Gauge_block), or [cutting](/source/cutting) [die](/source/Die_(manufacturing)), which is used to form something such as a [boat](/source/boat)'s [hull](/source/Hull_(watercraft)).  Typically, a former gives shape to a structure that may have complex [curvature](/source/curvature).

A former may become an integral part of the finished structure, as in an aircraft [fuselage](/source/fuselage), or it may be removable, being used in the construction process and then discarded or re-used.

==Aircraft formers==
thumb|Interior of an F-16B with the engine removed showing frames or formers
Formers are used in the construction of aircraft [fuselage](/source/fuselage), of which a typical fuselage has a series from the [nose cone](/source/nose_cone) to the [empennage](/source/empennage), typically perpendicular to the [longitudinal axis](/source/Flight_control_surfaces) of the aircraft.  The primary purpose of formers is to establish the shape of the fuselage and reduce the column length of stringers to prevent instability.<ref>Michael C. Y. Niu (1988). ''Airframe Structural Design''. Conmilit Press LTD. pp. 376.</ref>  Formers are typically attached to [longeron](/source/longeron)s, which support the skin of the aircraft.

The "former-and-longeron" technique (also called stations and stringers) was adopted from [boat construction](/source/boat_building)<ref>[https://timwestonboats.com Boat builder site]</ref> and was typical of [light aircraft](/source/light_aircraft) built until the advent of [structural skin](/source/structural_skin)s, such as [fiberglass](/source/fiberglass) and other [composite material](/source/composite_material)s. Many of today's light aircraft, and [homebuilt aircraft](/source/homebuilt_aircraft)<ref> ... such as the [ARV Super2](/source/ARV_Super2)</ref> in particular, are still designed in this way.

==Disposable formers==
thumb|Plywood formers await the application of strip planks on a strip-built catamaran.
A former may instead be a temporary shape over which a structure is built, the former subsequently being discarded in whole or part, as follows:
*[Strip-built](/source/Strip-built) boat construction uses formers over which thin plank strips are applied and glued.<ref>[https://www.glen-l.com/methods/methdstr.html Boat building with strip planking]</ref> In some cases, some of the formers may be incorporated as structural ribs.
* In [civil engineering](/source/civil_engineering), [bridge building](/source/Bridge), and [architecture](/source/architecture), arches may be built upon a wooden former, which is removed once the [keystone](/source/Keystone_(architecture)) is securely in place.

==References==
{{Reflist}}

Category:Boat building
Category:Aircraft components

{{Aviation-stub}}

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Adapted from the Wikipedia article [Former](https://en.wikipedia.org/wiki/Former) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Former?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.