Archaeology Underwater: The NAS Guide to Principles and Practice

ARCHAEOLOGICALCONSERVATION ANDFIRST-AID FORFINDS 155

• Bubble-wrap, plastic string, or cotton ties such as
  archival tape.


• Purpose-built pallets or large trays with holes in
  the base, plus handling ropes, to support multiple
  boxes of bags or larger objects for transfer to boats
  or the shore. (figure 16.6).
  
  
  • Block-lifts in surrounding burial sediment/context,
    for fragile or large objects, may result in potentially
    heavy loading but may retain enhanced amounts of
    archaeological data.
  
  
  
  

The exposure to air of all finds raised should be kept

to a minimum while handing finds from divers to

personnel on barges/boats/platforms etc. Handing over

(diver safety and surface conditions notwithstanding)

should be undertaken as slowly and as gently as possible,

given that potential loading and/or excess water run off

at speed, may cause considerable damage, particularly

to fragile or organic materials (figure 16.7).

Large objects: Large, heavy or complex objects, such as

guns, hull components and associated structures, despite

appearing robust, may be weak due to corrosion or

decay and may be too heavy to support their own weight.

Water may constitute much of the remaining mass, such

as in waterlogged wood, which should be supported

along the full length (e.g. by using planks of wood). Such

finds may also have soft and fragile surfaces, retaining

valuable archaeological detail (such as cut-marks) and

so should be covered during lifting using a cushioning

material such as bubble-wrap or polyether foam. They

should be strapped using ties such as strips of bandage

and splints, arranged so that they will not cut into the

surface on lifting and also so as to ensure that as much

of the loading as possible is carried on the supports

(plate 16.3). Containers (such as boxes, barrels or am-

phorae) should be recovered in their entirety and lifted

in an upright position (possibly using bandaging to help

support overall structures), with the original contents

Figure 16.5 Excavating a small fragile object. This leather
water-bottle from the Armada wreck La Trinidad Valencera
(1588) has been extracted by hand and placed on a sup-
porting board with a sheet of muslin fastened to one end.
When the object is in place the muslin will be secured around
the remaining sides with the plastic clothes pegs at the foot
of the board. (Photo: Colin Martin)

Figure 16.6 Raising a large organic object. This spoked
wooden wheel from the Armada wreck La Trinidad
Valencera(1588) weighs, with its associated concretions,
about half a tonne. Because it is no longer structurally
capable of bearing its own weight, a supporting frame
has been built around and beneath it prior to lifting. It is
seen here after its successful transfer to the conservation
tank. (Photo: Colin Martin)

Figure 16.7 The leather water-bottle shown in figure 16.5

is brought to the surface and handed to the waiting con-

servator. (Photo: Colin Martin)