Theoretical Structural Archaeology - Thirty New Discoveries

 

1. Introduction 

1.1 What I study 

• I reverse engineer archaeological buildings & structures from posthole evidence.

• Using  traditional architectural technical drawing, CAD, and deductive reasoning to build functionally accurate models.

• Working with the complete scaled dataset to identify basic structural components.

• I started in 1990 [1] & published online here since 2008. {so they are not all new}

• Postholes are the most numerous archaeological features on certain types of sites.

• Thus, Theoretical Structural Archaeology represents a set of analytical techniques for understanding certain archaeological data sets.

1.2 What qualifies as a discovery 

• Insights & discoveries of potential national or international importance.

• Completely original & not copied from other scholars or site reports. 

• Outside of my primary work as a professional archaeologist. 

• Work done in my own time.

1.3 Wider context of Theoretical Structural Archaeology

• My basic methodology has been peer reviewed in the USA. [2]

• Theoretical Structural Archaeology is maths & science based where possible. 

• Models are refined by looking for errors, inconsistency and poor mathematical fit.

• To the best of my knowledge I am the only UK archaeologist working on the interpretation of timber built environments. 

• This was the basis of a PhD at Newcastle, but evidence based archaeology and science proved incompatible with image based post-processualism subjectivism.

1.4 Format - 30 page A4

Brief and concise summary of the insight, idea or discovery.

• Details, definitions & Implications - maximum of six.

• Summary or example illustration as space permits. {this is a very visual subject}.

• To Fit on A4 sheet, ie. 30 Pages {+ this one}, in 3 groups;

• Basic structural modelling {from c. 430 lecture / video slides} 1-7

• Advanced Structural Models & Case Studies 8 - 22

• Archaeology of Hadrian’s Wall { from 3 Videos + 120 lecture slides} 23 -30

2. Basic structural modelling 

2.1 Reverse Assembly Truss

The most important concept and the basis of any understanding of post built buildings is the difference between normal and reverse assembly. {sectional view}

• A Truss is composed of a rafter pair with a horizontal Tie across the bottom.

• This triangle is the basis of the roof as understood; a building is a roofed structure.

• Assembly is the detailed order in which the structural components are put together; i.e. foundations first to thatch last. 

• Normal Assembly; in a building with load bearing walls, the load of the roof is supported on a solid wall or timber frame, the roof truss and its tie sit on top.

• Reversed Assembly; in a building where the mass of the roof is supported on posts, it is practical to place the posts directly under the ties.

• This arrangement allows for;

• Offset posts which simplified jointing

• Lightweight wall construction

• Still present in Far Eastern tradition, {performance in earthquakes}.

2.2 The Offset Tie

Apparent irregularity in the layout of posthole foundations can be explained as a product of offset jointing, which simplifies construction and allows the rafter pair to be at right angles to the roof plate & ridge.

• This single observation explains the ground plan of reverse assembly structures.

• It is present in LBK Longhouses, roundhouses, & larger circular buildings {Classs Ei}.[3]

• Enables the distinction of structures such as floors from roof supports. 

• It probably originates in PPNA as it is present at Göbekli Tepe.

2.3 Relationship between postholes & trees

A long tradition of forestry and woodland management has developed a detailed understanding of trees which can be directly related to the remains of archaeological timber structures. Through data contained in species specific yield tables.

• DBH is diameter at breast height {4’},  is good approximation for size of the post pipe

• The key metric is the height of crown formation {c.⅔ top height }

• Larger trunks can be box sectioned

• Coppice is method of growing multiple stem on single root system

• Yield tables can form the basis of modelling

• The general parameters of buildings and structures are in part a product of the local availability of timber .

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2.4 Relationship between trees & buildings

tbc . . . . .

1. 'Excavations at the Orsett ‘Cock’ enclosure, Essex, 1976'. G. A. Carter (1998): East Anglian Archaeology Report No 86. [Illustrated by L.E. Collett]

2. Building the Past: Studies of Prehistoric Wooden Post Architecture in the Ohio Valley-Great Lakes Region, edited by Brian G. Redmond and Robert A.

3. Neolithic houses in northwest Europe and beyond, 1996, Neolithic Houses in North-West Europe and beyond (Oxbow monograph 57), T.C. Darvill , Julian Thomas (Eds).