openarch presentation by the iberian citadel of calafell, burgos may 2014 and kierikki june 2014

From evidences to facts. The Iberian siderurgy chain under an experimental perspective in the Iberian Citadel of Calafell.

WP5 The dialogue with Science

J. M. Gallego*, M. Gómez**, J. Pou***

*ARTIFEX, conservación y recreación del patrimonio arqueológico** OAM Fundació Castell de Calafell*** Ajuntament de Calafell

7th OpenArch Conference, Kierikkikeskus, Finland

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Location/ Localización

Source: Google Maps

El Vendrell (Tarragona, Catalonia, Spain)

3Photos: Aucat; Draw: J. Morer, A. Rigo

Site digging/ Excavación del yacimiento

- Arch. digging 1996- 1997.- Construction of A-16/ Pau Casals highway.- Directors: J. Morer and A. Rigo- 5000 m2 extension- Iber- Cossetans ethnic group.- Evidences of the integral iron chain from 4th to 2nd cent. BCE (Full Iberian period)- Iron intensive production: main economical activity.

4Photos: Aucat; Draw: J. Morer, A. Rigo

Experience location/ Localización de la experiencia

Iberian Citadel of CalafellCiudadela Ibérica de Calafell

- Arch. digging since 1980 under the Universitat de Barcelona supervision and advice.- Reconstructed from 1992 to 1994 according to J. Santacana’s and J. Sanmartí’s project.- EXARC member since 2007.- Experimental Archaeology research center. - 2800 m2 extension- Iber- Cossetanian ethnic group.- Aristocratic settlement.- Inhabited from 5th cent. to 2nd cent. BCE.

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Direct archaeological evidences/ Evidencias arqueológicas

directas

Ore extraction zonesZonas de extracción de mineral

Opencast mines (4th to 3rd cent. BCE)/ Minas a cielo abierto (ss. IV al III a. C.)

Photos: J. Morer, A. Rigo

UE7072

UE7083

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Bloomery furnacesHornos de reducción directa

Drawing and photo.: J. Morer, A. Rigo

UE- 7438 (4th cent. BCE)

UE- 7235 (2nd cent. BCE)


directas

UE- 7438

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Ore enrichment/ charcoal making trenches and forgesRasas de enriquecimiento de mineral/ carboneras y fraguas

Enrichment ore structure (roasting) and possible charcoal kiln (3rd cent. BCE)/Estructura de enriquecimiento del mineral (tostado) y posible carbonera (s. III a. C.)

Bifid tuyere ubication/ Ubicación de la pieza de insuflación bífida.

Forge (3rd cent. BCE)/ Fragua(s. III a. C.)

Ashes and charcoal / Cenizas y carbón

Draw.: J. Morer, A. Rigo


directas

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Ore, metal, iron slags and furnace wall.Mineral, metal, escorias de hierro y pared fornaria.

Lemonite (FeO(OH)·nH2O) /Limonita (FeO(OH)·nH2O)

Iron slag/Escoria de hierro

Metallic piece/Fragmento metálico

Furnace wall piece/Fragmento pared fornaria

Photos: J. M. Gallego


directas

9Photos: E. Allart, AFAN/ J. Morer y A. Rigo

Mound- kilnsCarboneras

Mound- kiln evidences from Sarthe (Mans, Fr.) (4th cent. BCE)/ Evidencias de una carbonera en Sarthe (Mans, Fr.) (s. IV a. C.)

Indirect archaeological evidences/ Evidencias arqueológicas indirectas

SU- 7443, possible polyvalent combustion structure from Les Guàrdies (4th cent. BCE)/ UE-7443, posible estructura de combustion polivalente de Les Guàrdies, (s. IV a. C.)

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Evidencias arqueológicas indirectas/ Indirect archaeological evidences

ToberasTuyeres

Section D tuyeres (Guardamar de Segura, Alicante) (7th cent. BCE)/ Toberas de seciión en D, La Fonteta (Alicante) (s. VII a. C.)

Photos and drawings.: M. Renzi/ X. L. Armada

Tuyere from El Calvari (El Molar, Tarragona) (7th cent. BCE)/ Tobera del Calvari (El Molar, Tarragona) (s. VII a. C.)

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Indirect archaeological evidences/ Evidencias arqueológicas indirectas

Bifid tuyeresPiezas de insuflación bífidas

Bifid tuyere from Mas d’en Gual (El Vendrell, Tarragona), (3rd cent. BCE)/. Pieza de insuflación bífida de Mas d’en Gual (s. III a. C.)

Bifid tuyere from Olèrdola (S. Martí d’Olèrdola, Barcelona), 3rd cent. BCE/ Pieza de insuflación bífida de Olerdola (s. III a. C.)

Draw.: R. Jornet; Photo: N. Molist

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Interpretation and reconstruction/ Interpretación y reconstrucción

Identification, extraction and washing of the ore: L’Argilera (Calafell, Tarragona)Identificación, extracción y lavado del mineral: L’Argilera (Calafell, Tarragona)

Photo

s: J.

More

r/ J.

M.

Galle

go

13


Identification, extraction and washing of the ore: Rocabruna (Gavà, Barcelona)Identificación, extracción y lavado del mineral (Rocabruna (Gavà, Barcelona)

Photo

s: J.

M.

Galle

go

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Mound- kilns/ Charcoal- kilnsCarboneras

Photo

s: E

. A

llart

, A

FA

N/

J. M

. G

alle

go

Ore roasting Charcoal making

SU-7022 SU-7020

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Ore roasting and forgeEnriquecimiento del mineral (tostado) y fragua

Bifid tuyere Ubication/ Ubicación de la pieza de insuflación bífida

Draw.: J. Morer, A. Rigo; Photos: J. M. Gallego

Ore enrichment structure (roasting))/Estructura para el enriquecimiento del mineral (tostado)

Forge/ Fragua

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TuyeresToberas

Draw.: M. Renzi; Photos: J. M. Gallego

17


Bifid tuyeres/Piezas de insuflación bífidas

Photos: N. Molist/ J. M. Gallego

Free- breathing furnace physical dynamics

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Draw.: A. Alarcos

Chimney effect/ Bernoulli effect:(V2 (Id - Ed)/2 + P + (Id - Ed) g h = constant) Gas acceleration Fluids Law:

(A1 · V1 = A2 · V2)

Air absortion through tuyeres Air absortion through tuyeres

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Free- breathing bloomery furnace ELBUITEHorno de reducción directa de tiro natural ELBUITE

Draw.: J. Morer, A. Rigo; Photo: J. M. Gallego

ELBUITE (SU- 7235)- 0’9 m. Ø, 2 m. H, 430 l. Volume (aprox.)- 100 kg. natural ore/ 85 kg. dehydrated ore- 269 kg. charcoal: 45% Olive tree (Olea Europaea), 55% Ilex tree (Quercus Ilex). - 82 hours combustion- 1283 ºC/ average temperature 850 ºC- Ore/ charcoal ratio: 1/ 3’1

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Hybrid bloomery furnace ELNOBEHorno híbrido de reducción directa ELNOBE

Draw.: J. Morer, A. Rigo; Photos: J. M. Gallego

ELNOBE (SU-7348)- 0’65 m. Ø, 1’30 m. H, 140 l. Volume- 41 kg. natural ore/ 16 kg. dehydrated ore- 90 kg. charcoal: 50% Olive tree (Olea Europaea), 50% Ilex tree (Quercus Ilex). - 26 hours combustion- 33600 l. of air/ hour- 1090 ºC/ average temperature 700 ºC- Ore/ Charcoal ratio: 1/ 5’6


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Results and preliminary conclusions/ Resultados y conclusiones preliminares


ELBUITE’s RESULTS- High quantity of non- altered or half- melted ore.- Low quantity of bloomery stuff.- Inlays melt on the tuyeres.- Low thermal alteration of the internal walls of the furnace.- Very little iron blooms, impossible to compact by hammer.

PRELIMINARY CONCLUSIONS- Insufficient thermal increasing effect due to the low height of the chimney (ratio bowl/ chimney: 1/2) - Position of tuyeres too high.

FUTURE MODIFICATIONS- Increasing chimney height (20 cm.)- Re- ubication of the tuyeres

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Resultados y conclusiones preliminares/ Results and preliminary conclusions


ELNOBE’s RESULTS- High quantity of non- altered or half- melted ore- High quantity of slags- Inlays melt stuff on the tuyeres. High thermal alteration.- Low thermal alteration of the internal sides walls of the furnace

PRELIMINARY CONCLUSIONS- Inhomogenous temperature inside the furnace.- Very low quantity of ore.- Internal extreme dissemination of the ore.- Short time.- Position of the induction tuyere too high.

FUTURE MODIFICATIONS- Increase ore quantity- Re- ubication of the induction tuyere.

23Photos: J. M. Gallego

Conclusions concerning Iron making methods and its technological, social and economic implications.

Indirect archaeological documentation

Peripheral elements

Direct archaeological documentation

Experimental interpretation

of integral iron chain

References in Classics

Synthetic ideal concept scheme

Experience goals/ Objetivos de la experiencia

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With special thanks to:Aida Alarcos, Pablo Aparisi, Georgina Castells, Natxo Fuertes, Francesc Luchetti, Pablo

Martínez, Saulo Pujoles, Sergi Segura, Toni Villazán.

With special thanks to:Aida Alarcos, Pablo Aparisi, Georgina Castells, Natxo Fuertes, Francesc Luchetti, Pablo

Martínez, Saulo Pujoles, Sergi Segura, Toni Villazán.

openarch presentation by the iberian citadel of calafell, burgos may 2014 and kierikki june 2014

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