Waterfront archaeology and vernacular.pdf

15 Waterfront archaeology and vernacular

architecture: a London study

G Milne

Abstract

The recording of well-preserved timber structures on waterfront excavations enables characteristics of the vernacular

carpentry of a particular period to be identified and assessed. This is of crucial importance to the study of periods

for which few or no examples of timber buildings survive on dry-land sites. This paper reviews evidence from the

medieval London waterfront (examined in more detail in Milne 1985a, 155-76), arguing that the implications of such

a study extend well beyond problems concerning the construction of riverside revetments. By way of an example,

the date and manner of the initial introduction of fully framed buildings to London is examined.

Introduction

The process of reclamation or extension on the urban

waterfront is now well known and the importance of the

excavation of such sequences appreciated, as the

proceedings of the first two waterfront conferences

make clear (Milne & Hobley 1981; Herteig 1985c).

Apart from the major topographical implications, work

on the waterfront has provided other wider archaeologi-

cal benefits, ranging from the recovery of large, closely

dated finds groups to the study of changing styles of

wharf construction (Milne 1987). It is an aspect of the

latter subject that this paper attempts to summarise.

Intensive archaeological work on the London water-

front began in 1972 (Milne & Milne 1979) and is still

continuing. A remarkable series of well-preserved

timber structures has been recorded, ranging in date

from the 1st to the 17th century (eg, Milne 1979; Milne

& Milne 1982; Milne 1985b; Tatton-Brown 1974;

Miller et al 1986). Although all of the riverfront revet-

ments shared the same function, each was different. It

is argued that the differences observed reflect changes

in contemporary building practice, once the structural

attributes particular to the waterfront situation are dis-

counted. A study of the medieval waterfront installa-

tions of 11th to 15th century date may thus be used to

illuminate the development of timber buildings in

general, in a period which witnessed the change from

earthfast post structures to box-frame buildings.

There is little evidence to suggest that London's

riverfront revetment construction was the work of spe-

cialist carpenters. The only named carpenter known to

have built revetments in the city is Richard Cotterel,

who was employed not only to rebuild the timber face

of Broken Wharf in 1347, but also to construct the jetty,

fence, and sheds (Salzman 1952, 435). The three car-

penters engaged to work upon a Southwark wharf in

1389 were required to rebuild two watermills and the

millhouse as well (Salzman 1952, 467-9), while two

carpenters employed to work on the roof of Westmin-

ster Abbey were also mentioned in a contract for a

wharf at Vauxhall in 1476-7 (Woodward-Smith &

Schofield 1977, 284).

The evidence from urban excavations where water-

front installations and contemporary buildings have

been found supports the general proposition that the

construction of both types of structure, although clearly

different in function, utilised the same range of techni-

ques. That this approach differs from the methods

employed by other specialist carpenters, such as boat-

builders, is also apparent. The most cursory examina-

tion of the Scandinavian material makes this point

emphatically: the solid lafted (half-lapped) block-house

tradition of house building is obviously reflected in the

form of the waterfront kar structures, and contrasts

starkly with the graceful planked form of the contem-

porary shipping.

It is therefore argued that the waterfront installations

in medieval London were erected by the same men who

were responsible for timber building elsewhere in the

city. Since so few examples of their craft survived the

ravages of fire, the Blitz, and the pressures of urban

renewal, one of the only ways that general changes in

London’s timber building traditions can be recorded,

studied, and appreciated is through the waterfront

material.

Vernacular timber building traditions

in medieval London

Consideration of medieval London revetments and the

reused timbers they incorporated demonstrates that

three main techniques or traditions are represented:

earthfast post; stave; framed. For convenience, the

ensuing discussions will be conducted under these

heads, but how discrete the techniques actually were in

practice is a question that will be considered later.

Earthfast post building, in which the principal posts

of the structure are set into the ground. On the water-

front or in well construction, the technique is recorded

from at least the 11th century into the 13th century.

The technique is also known to have been used in

10th-12th century buildings in the city (Horsman et al

& 1988), although the evidence for these only survives in

the form of post-holes. The types of planked cladding

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London, waterfront archaeology and vernacular architecture

117

Fig 15.1 London: stave-wall construction techniques re-

presented on the waterfront: A staves butted flush; B

staves joined with false or free tenons; C staves joined with

dowels; D rebated staves; E vee-edged boards

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Milne

associated with the earthfast waterfront structures

include planks set in grooves cut into the edges of the

upright posts and planks fixed to the face of the posts

with wooden pegs.

Stave building, in which vertical timbering provides

both the structural rigidity for the building and also the

wall cladding (Fig 15.1). Examples of this technique

from the London waterfront date from as early as the

11th until the 15th century, and therefore represent a

technique of considerable longevity. Wall types

recorded include the use of vee-edged boarding; staves

butted flush; staves joined with dowels; staves joined

with false or free tenons; and staves joined with rebates

cut on opposing edges. All but one of the London

examples of stave walling incorporate a baseplate,

usually with a groove cut along its length into which the

feet of the staves were set. It is now clear that the

buildings incorporating baseplates which were con-

structed in London before the Norman Conquest were

stave structures, not fully framed buildings (Horsman

et al 1988).

Framed buildings, in which the structural carcass

comprises an integrated framework of timbers which

relies on its site for no more than the support of its

weight (Hewett 1980, 57). In buildings of this distinc-

tive type, the principal posts are set in baseplates, after

which the wall-cladding is applied to, or infills the

framework. On the London waterfront, baseplates

accommodating vertical posts are introduced into revet-

ment and river-stair construction in the early 13th

century, showing that the general technique would have

been in use elsewhere in the town by that date.

Introduction of framed buildings in

medieval London

The introduction of the fully framed building could

only occur after the development of a number of specific

structural attributes, including:

Fig 15.2 London: A & B pre-Conquest square through-

mortices from the Billingsgate Lorry Park site (BIG82);

C 13th century rectangular through-miortices (BIG82);

D 14th century standard rectangular mortices, Trig Lane

site (TL74)

a the use of timbers of squared, uniform scantling

b the introduction of well-cut, closely fitted joinery

c the use of a baseplate

d the adoption of the mortice and tenon with two

shoulders to form the basic articulation at the head

and foot of principal posts

e the adoption of the chase-tenon as the basic articula-

tion for diagonally set braces integral to the frame.

Evidence to support this suggestion is found in a

number of hybrid structures of that date recently

recorded on the London waterfront. For example, at

Sunlight Wharf (site code SUN86), a stave wall was

found in which the staves were set in a series of basepla-

tes separated by braced earthfast members; on the

Thames Exchange site (site code TEX88), massive

earthfast posts were braced with squared timbers

articulated with well-cut pegged joints, reminiscent of

the remarkable early 18th century hybrid of earthfast

post and framed building at Cedar Park (Hobley 1982,

fig 24).

The cutting of, and preference for individual joints

also changed. The standard mortice and tenon, the joint

which is basic to all fully framed building, is unknown

in London before the Norman Conquest. Square

Since none of these elements is required of necessity

in an earthfast structure, it could be argued that framed

buildings represent a new building tradition, imported

into London, fully developed, some time after the

Norman Conquest. However, a recent study of the

well-preserved riverfront structures allows a different

interpretation. It is suggested that the technique of

framed building was gradually developed following a

fusion of attributes taken from the otherwise quite

separate stave and earthfast traditions, which were

themselves developing independently. From the list

above, it seems that c and d were attributes taken from

the stave-building tradition, while the other attributes

(a, b, and e) were all being developed and used in

earthfast structures in the 12th and early 13th centuries.

London, waterfront archaeology and vernacular architecture

119

Fig 15.3 London : range of mortice-and-tenon types represented on the waterfront: A

splayed recess (BIG82); B chase tenon (TL74); C standard tenon (TL74); D spurred

tenon (TL74); E bare-faced tenon (TL74); F tusk tenon (TL74)

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Milne

Fig 15.4 London: range of lap-joints represented on the waterfront: A halved (TL74); B diagonal (TL74); C notched

(TEX88); D secret notched (TEX88); E lap dovetail (TL74)

through-mortices were used initially, and the stages

through which the joint developed in the 11th and 12th

centuries until it reached its more familiar form, can be

traced (Fig 15.2). The front braces used in the earthfast

revetments and the earliest baseplated structures

articulate with the posts by means of a splayed recess,

into which the crudely shaped head of the brace was

wedged (Fig 15.3). By the end of the 13th century, the

joint selected for such a position was invariably a well-

cut chase mortice and tenon. Again, there is plenty of

evidence for notched lap-joints from the 12th to the mid

13th century in situations where later the chase tenon

would be used. Lap-joints can always be used in earth-

fast building or similar structures in which the principal

posts are raised first, and the bracing subsequently

applied to them (Fig 15.4). However, in fully framed

structures in which post and braces are raised in

integrated units, such lap-joints cannot be employed,

and the mortice and tenon must be used.

techniques used in the construction of the medieval

riverfront revetments were varied and subject to con-

siderable change. The significance of the changes

recorded is considered to be wide ranging, for the struc-

tures represent a remarkable sample of truly vernacular

building: as such they may be compared profitably with

other studies based solely on surviving higher-status

structures, such as tithe barns, cathedral roofs, and

manor houses (eg Hewett 1969; 1980). It has been

shown that there were two main traditions in evidence

in London in the pre-Norman-Conquest period, earth-

fast-post building and stave building. However, these

two traditions did not exist in isolation, for not only was

there development of a tradition, but there were also

development between traditions (Milne forthcoming).

As a consequence, the box-frame building was gradu-

ally perfected in London in the period between the mid

12th and the late 13th centuries. Although this new

tradition completely superseded the earthfast techni-

que, stave building continued to develop until at least

the 15th century. How representative this picture is of

developments in vernacular building elsewhere in the

country awaits the excavation and study of similar large

groups of well-preserved vernacular timber structures

in other regions.

Conclusion

The recent study of well-preserved structures on the

city waterfront summarised here has shown that the

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