From evidences to facts. The Iberian siderurgy chain under an experimental perspective in the Iberian Citadel of Calafell. This presentation was given both at Burgos conference in May 2014 and later in Kierikki June 2014 during the OpenArch Conference.

1. 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

2. 2
Location/ Localización
Source: Google Maps
El Vendrell (Tarragona,
Catalonia, Spain)

3. 3
Photos: 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.

4. 4
Photos: Aucat; Draw: J. Morer, A. Rigo
Experience location/ Localización de la experiencia
Iberian Citadel of Calafell
Ciudadela 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.

5. 5
Direct archaeological evidences/ Evidencias arqueológicas directas
Ore extraction zones
Zonas 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

6. 6
Bloomery furnaces
Hornos de reducción directa
Drawing and photo.: J. Morer, A. Rigo
UE- 7438 (4th cent. BCE)
UE- 7235 (2nd cent. BCE)
Direct archaeological evidences/ Evidencias arqueológicas directas
UE- 7438

7. 7
Ore enrichment/ charcoal making trenches and forges
Rasas 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 carbónDraw.: J. Morer, A. Rigo
Direct archaeological evidences/ Evidencias arqueológicas directas

8. 8
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
Direct archaeological evidences/ Evidencias arqueológicas directas

9. 9
Photos: E. Allart, AFAN/ J. Morer y A. Rigo
Mound- kilns
Carboneras
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.)

10. 10
Evidencias arqueológicas indirectas/ Indirect archaeological evidences
Toberas
Tuyeres
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.)

11. 11
Indirect archaeological evidences/ Evidencias arqueológicas indirectas
Bifid tuyeres
Piezas 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 Olè rdola (S. Martí d’Olè rdola,
Barcelona), 3rd cent. BCE/ Pieza de insuflación
bífida de Olerdola (s. III a. C.)
Draw.: R. Jornet; Photo: N. Molist

12. 12
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)
Photos:J.Morer/J.M.Gallego

13. 13
Interpretation and reconstruction/ Interpretación y reconstrucción
Identification, extraction and washing of the ore: Rocabruna (Gavà, Barcelona)
Identificación, extracción y lavado del mineral (Rocabruna (Gavà, Barcelona)
Photos:J.M.Gallego

14. 14
Interpretation and reconstruction/ Interpretación y reconstrucción
Mound- kilns/ Charcoal- kilns
Carboneras
Photos:E.Allart,AFAN/J.M.Gallego
Ore roasting Charcoal making

15. SU-7022 SU-7020
15
Interpretation and reconstruction/ Interpretación y reconstrucción
Ore roasting and forge
Enriquecimiento 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

16. 16
Interpretation and reconstruction/ Interpretación y reconstrucción
Tuyeres
Toberas
Draw.: M. Renzi; Photos: J. M. Gallego

17. 17
Interpretation and reconstruction/ Interpretación y reconstrucción
Bifid tuyeres/
Piezas de insuflación bífidas
Photos: N. Molist/ J. M. Gallego

18. Free- breathing furnace physical dynamics
18
Interpretation and reconstruction/ Interpretación y reconstrucción
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

19. 19
Interpretation and reconstruction/ Interpretación y reconstrucción
Free- breathing bloomery furnace ELBUITE
Horno 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

20. 20
Hybrid bloomery furnace ELNOBE
Horno 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
Interpretation and reconstruction/ Interpretación y reconstrucción

21. 21
Results and preliminary conclusions/ Resultados y conclusiones preliminares
Photos: J. M. Gallego
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

22. 22
Resultados y conclusiones preliminares/ Results and preliminary conclusions
Photos: J. M. Gallego
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.

23. 23
Photos: J. M. Gallego
Conclusions
concerning Iron
making methods and
its technological, social
and economic
implications.
Indirect
archaeological
documentation
Peripheral
elements
Direct
archaeological
documentation
Experi
mental
interpr
etation
of
integra
l iron
chain
Reference
s in
Classics
Synthetic ideal concept scheme
Experience goals/ Objetivos de la experiencia

24. 24
With special thanks to:
Aida Alarcos, Pablo Aparisi, Georgina Castells, Natxo Fuertes, Francesc Luchetti,
Pablo Martínez, Saulo Pujoles, Sergi Segura, Toni Villazán.