Loholmen
Marinarkeologisk förundersökning
Långared 2:1 och 2:2, Långareds socken,
Alingsås kommun
Delia Ní Chíobháin
Bohusläns museum Rapport 2010:53
Loholmen
Marinarkeologisk förundersökning
Långared 2:1 och 2:2, Långareds socken, Alingsås kommun
Bohusläns museum Rapport 2010:53
ISSN 1650-3368
Författare Delia Ní Chíobháin
Grafisk form Gabriella Kalmar
Layout och teknisk redigering Lisa K Larsson
Omslagsbild Foto taget av Delia Ní Chíobháin. Fotot visar undersökningsområdet från sydost.
Tryck IT Grafiska AB, Uddevalla 2010
Kartor ur allmänt kartmaterial, © Lantmäteriverket medgivande 90.8012
Kartor godkända från sekretessynpunkt för spridning Lantmäteriet 2010-09-22. Dnr 601-2010/2371
Bohusläns museum
Museigatan 1
Box 403
451 19 Uddevalla
tel 0522-65 65 00, fax 0522-126 73
www.vastarvet.se, www.bohuslansmuseum.se
Innehåll
Svensk sammanfattning........................................................................................................... 5
Background..................................................................................................................................................... 5
Landscape........................................................................................................................................................... 5
Natural landscape.................................................................................................................................. 5
Cultural environment........................................................................................................................ 8
Fornlämningsmiljö................................................................................................................................. 8
Ancient monument environment and...........................................................................
previous investigations.................................................................................................................... 9
Method................................................................................................................................................................ 10
Results. ...................................................................................................................................................................11
Långared 2:2 - permanent fishing trap (A1).................................................11
Långared 2:1 - cultural layers (A2). ............................................................................11
Documented finds............................................................................................................................. 12
Discussion....................................................................................................................................................... 13
Conclusion and recommendations.................................................................. 13
Referenser....................................................................................................................................................... 14
Litteratur......................................................................................................................................................... 14
Otryckta källor........................................................................................................................................ 15
Tekniska och administrativa uppgifter....................................................... 16
Appendices................................................................................................................................................... 17
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Bohusläns museum 2010:53
Figure 1. Section of GSD-Property map with the location of the investigation area marked.
Figur 1. Utsnitt ur GSD-Röda kartan/Fastighetskartan med platsen för undersökningen markerad.
Loholmen
Svensk sammanfattning
På uppdrag av Antens Kommunikationsmuseum utförde Västarvet
genom Bohusläns museum i augusti 2010 en marinarkeologisk förundersökning i anslutning till fornlämning Långared 2:1, vilken utgörs av
ruinen efter Loholmens medeltida borg. Undersökningen utfördes med
anledning av planerna på att uppföra en brygga på den nordöstra delen
av ön Loholmen. Arbetet omfattade okulär besiktning av ett 1 500 kvadratmeter stort bottenavsnitt samt grävning av ett mindre antal provgropar. Inom området framkom ett tunt kulturlager med bland annat tegel,
huggspån, keramik och bearbetat trä, vilket visar att utbredningen av
Långared 2:1 kan utsträckas mot nordost. I den norra delen av området påträffades en trolig fiskeanläggning. En 14C-analys visar att denna
sannolikt uppförts någon gång under 1700- eller början av 1800-talet,
och den är således inte samtida med borgen. Eftersom inga fynd eller
anläggningar av antikvariskt intresse framkom inom själva etableringsområdet för den planerade bryggan har museet inga synpunkter på den
föreslagna exploateringen.
Background
In August of 2010 Västarvet through Bohusläns museum, in cooperation with Vänermuseet, carried out a preliminary underwater archaeological investigation in an area of water off the south-west of Loholmen
in Loviken, Långareds socken, Alingsås kommun (figure 1–3). The preliminary investigation was undertaken by request of the client, Antens
Kommunikationsmuseum, who plans to construct a jetty on the north
face of Loholmen to facilitate the mooring of a tourist steamer at the
site (figure 4). The jetty will be moored in place using concrete anchors.
The purpose of the preliminary investigation was to determine the presence and extent of submerged archaeological remains in the area and
to limit potential damage to sites by the development. Registered monuments on the island include Långared 2:1, the ruins of a medieval
castle dating from the early 1300s and Långared 330:1, the foundations
of a bridge which connected the island to the mainland which date to
1301 or shortly thereafter (Bergstrand 2003).
Landscape
Natural landscape
Lake Anten is located 50 kilometers north east of Göteborg and 30 kilometers to the south of lake Vänern. The lake covers an area of 18 square
kilometers and has an average water depth of 30 meters. An outlet to
the south connects Anten to Ålandsjön and onto Mjörn. Loholmen island is situated in the northeast of the lake, within Loviken, circa 200
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Bohusläns museum 2010:53
Figure 2. Section of GSD-Property map with the location of the investigation area marked. Scale 1:20 000. Permission for
distribution approved by the Security Officer. Lantmäteriet 2010-09-22. Dnr 601-2010/2371.
Figur 2. Utsnitt ur GSD-Fastighetskartan med platsen för undersökningen markerad. Skala 1:20 000. Godkänd ur
sekretessynpunkt för spridning. Lantmäteriet 2010-09-22. Dnr 601-2010/2371.
Loholmen
Figure 3. . Section of GSD-Property map, sheets 7A 5j, 7A 5a, with the investigation area and nearby ancient remains
marked. Scale 1:10 000. Permission for distribution approved by the Security Officer. Lantmäteriet 2010-09-22. Dnr 6012010/2371.
Figur 3. Utsnitt ur GSD-Fastighetskartan, blad 7C 8b, med översikt över undersökningsområdet samt närliggande fornlämningar markerade. Skala 1:10 000. Godkänd ur sekretessynpunkt för spridning. Lantmäteriet 2010-09-22. Dnr 6012010/2371.
7
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Bohusläns museum 2010:53
Figure 4. Investigation area towards the southeast. Photo Staffan von Arbin. Bohusläns museum.
Figur 4. Undersökningsområdet mot sydost. Foto Staffan von Arbin. Bohusläns
museum.
meters from the shore. The water between the northern extent of the
island and the shore measures at most four meters deep and the bottom
consists of sandy sediments.
Cultural environment
Västergötland had the most number of castles from the medieval period until 1530, largely due to its borders with Denmark and Norway.
Most early castles, from the early medieval period, were built purely for
defensive reasons and were used as royal residences. During the 1100s
bishops had begun to build castles and by the 1200s wealthy individuals were constructing castles for their own use (Ekre 1992).
The earliest written evidence of Loholmen castle is from 1312, when
Gudmar Magnusson and Margaret Ulfsdotter of the Hjorthuvud dynasty
resided there during the early 1300s. Margaret was given Loholmlen by
her relative Eskil, a brother of Birger Jarl. Gudmar served as a knight, as
a judge in Västergötland and was also in the privy council (riksråd). In
the late 1400s Loholmen came into the hands of Erik Abrahamsson of
the Lejonhuvud house and Ebba Eriksdotter of the Vasa dynasty. Erik was
executed at the Stockholm bloodbath of 1520, after which Ebba and her
six children moved from Ekeberg to live in Loholmen castle. One of their
children, Margaret, married King Gustav I (Vasa) after he came to Loholmen for courtship following the death of his first wife Katarina in 1535.
Loholmen
Figure 5. Plan of the archaeological finds and features in the water surrounding
Loholmen, located by MASG in 2002. Björn Dahrén, MASG (permission granted from illustrator for publication).
Figur 5. Plan över arkeologiska fynd och lämningar i vattnen kring Loholmen,
lokaliserade av MASG år 2002 (Björn Dahrén, MASG).
The last owner of Loholmen castle was their second eldest son, Sten
Eriksson Lejonhuvud and Ebba Månsdotter from Upplo. Following
Sten´s death from a sword wound in Stockholm’s stortorget in 1568, his
wife Ebba moved to Gräfsnäs castle, located on the mainland two kilometers northwest of Loholmen. Gräfsnäs castle was constructed in late
Renaissance style using building material from Loholmen castle (Dahrén
& Fransson 2004:7).
Ancient monument environment and
previous investigations
Earlier research in the area includes a limited archaeological survey of
Loholmen in 1936 by the former county antiquarian Harold Olsson.
Known ancient monuments in the area include Långared 2:1 which are
the remains of the aforementioned medieval castle on Loholmen and
Långared 330:1. The latter was located during a marine archaeological
survey conducted in 2002 and 2003 by Marinarkeologiska sällskapet,
Götheborgskretsen (MASG).
The survey focused on the remains of what was interpreted as a bridge
which connected Loholmens western extent to land, 200 meters across
the strait (figure 5). The remains consisted of twelve stone caissons and
a bridge head constructed using wooden frames with dove-tail joints
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Bohusläns museum 2010:53
Figure 6. Timber with construction joint
(Långared 330:1). Photo taken in September
2003. Photo Staffan von Arbin. Bohusläns
museum.
Figur 6. Timmer med ok-konstruktion
(Långared 330:1). Foto taget i september
2003. Foto Staffan von Arbin, Bohusläns museum.
Figure 7. Stones from a stone caisson
(Långared 330:1). Photo taken in
September 2003. Photo Staffan von
Arbin. Bohusläns museum.
Figur 7. Stenar från en av stenkistorna
(Långared 330:1). Foto taget i september 2003. Foto: Staffan von Arbin,
Bohusläns museum.
and filled with stones (figure 6 and 7). The caissons measure approximately from 5 × 3 meters to 5 × 5 meters in size while the individual stones
range in sizes from 0.4 × 0.4 meters to 0.8 × 0.8 meters. Other features
recorded during the survey were the remains of a pier on the western
face of the island; cultural layers and several stray finds consisting of
construction timbers and boat components which were located to the
north and west of the island. Dendrochronological analysis in 2003, in
association with Bohusläns museum, was conducted on several oak and
beech timbers from the stone caisson frames. The analysis yielded a date
of 1301 or shortly thereafter for the bridge construction. One stray timber returned a date after 1495 and was not thought to have been part
of the bridge construction (Bergstrand 2003).
Method
The area investigated measured 1 500 square meters and the diving was
carried out in water measuring at most three meters deep (appendix 1).
The area was visually inspected by diving archaeologists, which revealed a
number of finds (appendix 4). Based on the results of the visual investigation three test trenches were dug with the use of a water dredge, the
contents of which were then sieved for archaeological finds (appendix 3).
All diving was carried out with tethered surface-supplied diving and
diver-surface communications in accordance with the Work Environment Authority’s (Arbetsmiljöverkets) regulations of commercial diving
(AFS 1993:57) and the diving standards of Bohuslän museum. All positions were recorded using DGPS.
Figure 8. Fragments of tile from the shoreline. Photo Staffan von Arbin. Bohusläns museum.
Figur 8. Tegelfragment från stranlinjen. Foto Staffan von Arbin. Bohusläns museum.
Loholmen
11
Results
The visual inspection of the area and its surroundings revealed a number of finds and features as noted on the site plan (appendix 1) and as
listed in appendix 3 and 4. Within the inspection area a concreted metal object (F1) and a plank of timber (F3) were located. Outside of the
investigation area five timber poles (A1) were located protruding from
the sediment, the possible remains of a fishing trap, and to the south of
the investigation area two substantial pottery shards, from the same vessel, were discovered (F2). The pottery has been preliminarily dated to
the 1400s. Furthermore, several worked oak timbers, possibly remains
from the above mentioned bridge foundations, were located, and along
the shore of Loholmen bricks and brick fragments were observed (figure 8). Three test trenches were dug in the vicinity of the proposed jetty.
The trenches yielded evidence of cultural layers in the form of fragments
of bricks, wooden chips, and charcoal fragments.
Långared 2:2 - permanent fishing trap (A1)
A group of at least five wooden stakes were located to the east of the
investigation area (figure 9 and 10) and were interpreted as having formed part of a permanent fishing trap. The stakes, of uncertain species,
measured 4–6 centimeters in diameter and were partially eroded where
exposed. Three of the stakes were heavily eroded and protruded some
decimetres from the sediment while two stood at a height of circa one
meter. The stakes surrounded four large stones, measuring on average
50 centimeters, as there were no other features on the sediment in this
area it is thought that they may have been associated with the poles.
Carbon dating of a timber fragment was conducted at Ångströmlaboratoriet, Uppsala University (appendix 2). The 14C analysis was conducted on a sample from one of the stakes and yielded a result of 190±30
BP, which calibrated (2 sigma) provides a dating range from 1640–1960,
with a greater probability of the period 1720–1820 (53.5%). The feature has been registered as an ancient site, Långared 2:2.
Långared 2:1 - cultural layers (A2)
The results of the visual survey and test trenches have led to the extension of the Långared 2:1 in the form of cultural layers (A2) which are
associated with the castle settlement. The test trenches revealed whole
bricks, wooden chips, and coal fragments (appendix 3). The finds and
objects located during the visual inspection are also within the extent
of the cultural layer (appendix 1). The layer is thin and is present throughout the extent of the survey area.
Figure 9. Wooden pole interpreted as part of a
permanent fishing trap (Långared 2:2). Photo
Staffan von Arbin. Bohusläns museum.
Figur 9. Påle tolkad som del av fast fiske
(Långared 2:2). Foto Staffan von Arbin. Bohusläns museum.
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Bohusläns museum 2010:53
Documented finds
A concreted metal object, F1, was located in the western extent of the
survey area and measured 28 centimeters in length and 8 centimeters
in width (figure 11). It is thought to be part of the cultural layer associated with Loholmen castle, Långared 2:1.
Two ceramic shards from a redware jug, F2, were recovered during
a visual survey dive to the northwest of the survey area (figure 12). Of
the larger fragment a part of the rim, the entire handle and a portion
of the shoulder remained in tact, while the smaller shard formed a part
of the rim. The jug has a zig-zag pattern on the shoulder with circular
decorations at the corners of the pattern. Similar types of ceramic finds
can assert a preliminary date of 1200–1300 to the jug (cf Wahlöö 1976).
An eroded oak timber, F3, was located near the centre of the search
area (figure 13). It is thought to have been a construction timber, possi
bly from the bridge construction Långared 330:1. The timber measured two meters long, eighteen centimeters at its widest part, and circa
nine centimetres thick.
Figure 10. Wooden pole interpreted as part
of a permanent fishing trap (Långared 2:2).
Photo Staffan von Arbin. Bohusläns museum.
Figur 10. Påle tolkad som del av fast fiske
(Långared 2:2). Foto: Staffan von Arbin. Bohusläns museum.
Figure 11. Concreted metal object. Photo
Staffan von Arbin. Bohusläns museum.
Figure 12. Fragments of a redware jug (F2). Photo Delia Ní Chíobháin. Bohusläns museum.
Figur 11. Korroderat metallföremål. Foto
Staffan von Arbin. Bohusläns museum.
Figur 12. Fragment av kanna i äldre rödgods (F2). Foto Delia Ní Chíobháin.
Bohusläns museum.
Loholmen
Discussion
The cultural layers discovered within the investigation area contain artefacts which are contemporaneous with Loholmen castle, in particular
the brick finds, worked timbers and the ceramic shards which can be
dated to the period that Loholmen castle was in use. Since the history
of the castle is not very well known, the layers can contribute to the
present knowledge of the site.
While permanent fishing traps have been used over a long period of
time throughout history, few sites have been investigated archaeologically. However, Bohusläns museum has conducted research on permanent fishing traps in several locations around Sweden including Åsunden
lake, Ulricehamns kommun (von Arbin 2006), in the sound outside
Arvika (von Arbin & Wallbom 2004) and in the estuary of the Tidan
river in Mariestads kommun (von Arbin & Lindström 2005), which
have all been dated to the medieval period. Archaeological excavations
conducted in Motala river in Östergötland have revealed fishing traps
from the early medieval period and modern times (von Arbin, forthcoming). The varying nature of fishing trap construction is dependant on the
environment in which they are placed but all share the same characteristics of a barrier construction with a pointed entrance, leading the fish
into some form of trapping chamber (Eriksson 1993). The condition of
most remains however are too eroded to identify their precise design but
fishing traps from the historical period could potentially be compared
to contemporary written sources (Gainsford 2009). While the 14C-date
from one of the stakes of 1720–1820 is not contemporary with the use
of Loholmen castle, the remains consist of an ancient monument and
contribute to the growing knowledge of this type of maritime feature.
Conclusion and recommendations
The archaeological survey revealed further evidence of cultural remains
in the vicinity of Loholmen and have resulted in the extension of the
Långared 2 site. The discovery of the redware ceramic finds positively
date the cultural layer to the 1200–1300s, the earlier occupation period
of the castle. The later date range provided for the permanent fishing
trap (1720–1820) indicates continued use of the area up to the modern era. As the visual survey and test trenches revealed remains of low
archaeological importance in the immediate area of the proposed jetty
site, Bohusläns museum have no archaeological comments to make on
the proposals.
Figure 13. Eroded oak timber (F3). Photo
Staffan von Arbin. Bohusläns museum.
Figur 13. Eroderat ektimmer (F3). Foto
Staffan von Arbin. Bohusläns museum.
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Bohusläns museum 2010:53
Referenser
Litteratur
von Arbin, S. 2006. På Åsundens botten. Arkeologisk utredning inför planerade vattenverksamheter Ulricehamns stad och kommun. Bohusläns museum Rapport 2006:43. Uddevalla.
von Arbin, S. & Wallbom, B. 2004. Arkeologisk utredning: Del av sundet.
Arvika socken och kommun, Värmlands län. Bohusläns museum Rapport
2004:44. Uddevalla.
von Arbin, S & Lindström, J. 2005. I Tidans mynning – medeltida
fiskeanläggningar och en 1800-talspråm. Bohusläns museum Rapport
2005:60. Uddevalla.
von Arbin, S. (i tryck). Motala kungsfiske – fiskeplats med kontinuitet.
Bottnisk kontakt XIII. Båtdokgruppen. Skärhamn.
Bergstrand, T. 2003. Loholmens borgruin Raä 2, Långareds socken, Alingsås
kommun. Dendrokronologiska dateringar. Bohusläns museum Rapport
2003: 31. Uddevalla.
Dahrén, B. & Fransson, S. 2004. Sägenomspunna Loholmen. Marinarkeologisk tidskrift 1/2004, (7–9).
Dykeriarbete. AFS 1993:57. Arbetarskyddsstyrelsen. Stockholm.
Ekre, R. 1992. Västergötlands medeltidsborgar. Borgar från forntid och
medeltid i Västsverige. Arkeologi i Västsverige 5 (108–120). Göteborgs
arkeologiska museum.
Gainsford, M. 2009. Spillvattenledning i Alingsås, Gärdska ström, Gärdsken, Forsån och Lilla Färgen. Frivillig arkeologisk utredning, Alingsås
socken och kommun. Bohusläns museum Rapport 2009:34. Uddevalla.
Wahlöö, C. 1976. Keramik 1000-1600. I svenska fynd. Arcaeologica
Lundensia. Investigationes de antiqvitatibus urbis Lundae VI. Lund.
Loholmen
Otryckta källor
Eriksson, M. 1993. Fasta fisken. B-uppsats i arkeologi. Arkeologiska institutionen. Stockholms universitet.
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Bohusläns museum 2010:53
Tekniska och administrativa uppgifter
Lst dnr:
Västarvet dnr:
Västarvet pnr:
Fornlämningsnr:
431-2344-2010
NOK 877-2009
10005
Långared 2:1, 2:2
Län:
Kommun:
Socken:
Fastighet:
Västra Götalands län
Alingsås
Långared
Vattenområde nordväst om Loholmen
Ek. karta:
Läge:
Vattendjup:
Koordinatsystem:
7C 8b
X: 6442699, Y: 1307530
0-3 meter
RT90, 2,5 gon V
Uppdragsgivare:
Ansvarig institution:
Projektledare:
Fältpersonal:
Konsulter:
Antens Kommunikationsmuseum
Bohusläns museum
Staffan von Arbin
Staffan von Arbin
(Bohusläns museum)
Delia Ní Chióbháin (Bohusläns museum)
Roland Peterson
(Vänermuseet)
Ångströmlaboratoriet, Uppsala Studio Västsvensk Konservering, Göteborg
Fältarbetstid:
Arkeologtimmar:
Undersökt yta:
11 augusti 2010
24
1500 m2
Arkiv:
Fynd:
Bohusläns museums arkiv
Keramikkannan (F2) kommer efter konservering att överlämnas till Lödöse museum
Loholmen
Appendices
Appendix 1. Plan över undersökningsområdet med provgropar, anläggning-
ar och fynd markerade. Utsnitt ur GSD-Fastighetskartan, blad 7C 8b. Skala
1:1500. Godkänd ur sekretessynpunkt för spridning. Lantmäteriet 2010-09-22.
Dnr 601-2010/2371
Appendix 2a. Resultat av 14C -analys av trä från Alingsås kommun, Väs-
tra Götalands län. Ångströmlaboratoriet. Uppsala universitet. Labnummer Ua40456. Göran Possnert och Ingela Sundström
Appendix 2b. Resultat av 14C -analys av trä från Alingsås kommun, Väs-
tra Götalands län. Ångströmlaboratoriet. Uppsala universitet. Labnummer Ua40456. Göran Possnert och Ingela Sundström
Appendix 3. Provgropar och fynd
Appendix 4. Inmätta fynd
17
Appendix 1. Plan över undersökningsområdet med provgropar, anläggningar och fynd markerade. Utsnitt ur GSD-
Fastighetskartan, blad 7C 8b. Skala 1:1500. Godkänd ur sekretessynpunkt för spridning. Lantmäteriet 2010-09-22. Dnr
601-2010/2371
Appendix 2a. Resultat av 14C -analys av trä från Alingsås kommun, Västra Götalands län. Ångströmlaboratoriet. Uppsala universitet.
Labnummer Ua-40456. Göran Possnert och Ingela Sundström
Appendix 2b. Resultat av 14C -analys av trä från Alingsås kommun, Västra Götalands län. Ångströmlaboratoriet. Uppsala universitet. Labnummer Ua-40456. Göran Possnert och Ingela Sundström
Appendix 3. Provgropar och fynd
Beskrivning
Fynd
PG 1
Provgrop ID
Vattendjup/meter
2
50 x 50 cm stor, 50 cm djup
Träflis, tegelsten, träkolsfragment
PG 2
2
50 x 50 cm stor, 50 cm djup
Inga fynd
PG 3
2
50 x 50 cm stor, 50 cm djup
Tegelfragment, träkolsfragment,
små träfragment
Appendix 4. Inmätta fynd
Beskrivning
Koordinator (x/y)
RT 90 2,5 gon V
2
Metallföremål
6442688 / 1307504
2
Keramik
6442695 / 1307498
2
Konstruktionstimmer
3442690 / 1307529
ID
Vattendjup/meter
F1
F2
F3
Loholmen
Marinarkeologisk förundersökning
Långared 2:1 och 2:2, Långareds socken,
Alingsås kommun
Delia Ní Chíobháin
Bohusläns museum Rapport 2010:53