Handling heritage objects

Physical forces

Breaks, cracks, chips, losses, deformation and surface abrasion are all evidence of dropping, knocking or even improper placement of hands when lifting fragile objects. The extent of damage depends on the type of materials and their condition. Typically, more brittle materials suffer more damage than flexible ones, but the weight of objects and the height from which they are dropped all have an influence in that regard (further details about physical forces as an agent of deterioration can be found under Agent of deterioration: physical forces).

Objects may appear to be strong to the untrained eye, but they may conceal weaknesses or unanticipated deterioration:

• Materials might have become fragile due to their aging and subsequent deterioration, e.g. some historical black-dyed leathers and furs can be extremely degraded to the point of tearing under their own weight (Figures 2a and 2b).
• Visually intact surfaces can hide very fragile interiors, such as a piece of wood that has been tunnelled by insects but has an intact skin, or outer layer. A surface that fools the eye has potential to fool the hands. Even when carefully handling an object, pressure, albeit minimal, is applied at the point of contact, which can cause damage if the object is very fragile in this area.
• Joints, ties, adhered components, etc. may be damaged, worn or loose. Often, weaknesses at joints and points of assembly are not conspicuous until closely inspected (Figures 3 and 4).

Lifting objects without adequate support can cause damage. For example, a ceramic vessel with incipient cracks may break apart if not properly supported when handled. Weakened materials in an object may no longer be able to support their own weight or the weight of attachments and protruding components. For example, an ornate silk object may be too weak to support the weight of attached decorative elements when lifted without a support; the elements will pull at the point of attachment and cause the fabric to tear (Figure 5). The object needs complete support to prevent damage when being moved.

Wheeled transporting devices, such as dollies or carts, are commonly used, but they can jostle unsupported objects, which may cause damage to very fragile objects, e.g. weakly bonded paint layers (Figure 6) or adhesive joints may separate. Cracks already present on an object may extend, or there may be movement of loosely attached components that stress the point of attachment, such as weak hinges on doors. Padding, securing ties and other possible solutions to these problems are discussed under Support, lift and move objects.

Contaminants

Natural salts and oils from hands can mark clean surfaces, even though this may not be immediately noticeable.

Objects particularly sensitive to damage from this type of contamination when handled with bare hands include:

• metal surfaces: polished silver, copper and brass (Figures 7, 9 and 10)
• gilded surfaces (Figure 8)
• photographs, which can easily be marred because most photographic surfaces are extremely absorbent and hygroscopic

Glossy surfaces, such as glass or highly polished stone, may hold fingerprints. Even though the salts and oils may not react unfavourably with these surfaces, additional and otherwise unnecessary cleaning or polishing will be needed to improve the appearance.

Applied pressure to unclean surfaces (dusty, soiled) can cause dirt to be forced more deeply into a substrate. If the pressure is applied by hands, the perspiration and oils fix the dirt in place, especially on porous or rough surfaces.

Provide supports

Permanent supports for storage and handling provide the best solution; they will serve as long-term protection and will reduce the hazards of handling and the preparation time required for moving objects (Figures 28 to 31). The object will be fully supported, and the handler may never need to touch the object.

Be aware of attachments, handles, old repairs

Attachments as well as protruding parts of an object that were intended as handholds to move or lift it might have been weakened by extensive use or a poor repair prior to the object being collected. They may no longer be able to support the weight of the object if used to grasp or lift it. If a break occurs while lifting, the rest of the object may be damaged if it drops to the ground. Convenient handholds, used frequently in the past to lift the object, should always be suspected of being fragile. For example, chairs should be lifted at the seat rail and not at the back or arms (Figures 32 and 33). Lifting by any projection attached to the top of an object will result in all the weight being concentrated at this point, thus risking fracture (Figure 34). The weight of objects should be supported from the base (Figure 24).

Multiple handlers

Objects should always be lifted, never dragged, which requires having enough personnel on hand for the lifting. One person should act as the lift leader to talk through the lift and move, ensuring that safe handholds are known by everyone, and that all handlers are ready to carry out instructions at the same time. Movements need to be coordinated, and the object needs to be monitored as it is being moved. This is especially important if the object cannot be moved on a cart or trolley (e.g. if stairs must be used).

Lifting specific types of objects

When handling wet objects (e.g. objects affected by leaks or floods), allowances must be made for absorbed liquids that increase the weight of the object. The material may not be able to support the additional weight, and the water might weaken the material or structure. Support the object as much as possible, preferably using a solid support.

Lift heavy or large objects, such as a piece of furniture or a sculpture, near the base using strong and solid areas as handholds (Figure 35). Bend the knees and hold the object close to the body. A heavy object should only be lifted for a brief period, so ensure that a cart or dolly is standing nearby. Very heavy objects should be moved with appropriate equipment (forklift, pump truck or small crane) and by experienced handlers.

When lifting bagged objects, the layout, weakness and shape of the contents should be determined and a solid handhold established (Figure 36). Bare hands or close-fitting plastic gloves should be used when lifting bagged objects, as the surfaces of the bags may be slippery.

Any flat surface that has loosely attached components, such as poorly bound pigments or flaking paint, should be carried and stored horizontally to prevent loss.

Moving objects a short distance

Good building design can simplify the safe movement of objects enormously. Highly desirable features include level floors, separate freight elevators, ramps, loading docks with dock levellers, wide doors and adequate space for movement within storage areas.

For short trips, a tray is useful for moving one or several smaller objects with low centres of gravity. The interior of the tray should be padded with a foam sheet that provides cushioning as well as a surface that prevents sliding. Small objects with high centres of gravity are better carried by hand or in padded boxes.

A cardboard box or a plastic container with padding around each object may be useful as temporary housing during a move. If several objects are moved in one container, it is important that each be separated with padding to prevent damage through contact (Figure 37). Objects should not be placed one on top of the other.

Flat objects, such as paintings or framed items, can be placed vertically in a box and separated from one another by a stiff sheet spacer (cardboard, corrugated plastic, etc.) slightly larger than the objects it separates.

Selecting wheeled equipment for moving objects

It is easier and safer to use a cart or a flatbed trolley, unless an object has to be carried when negotiating stairs or if it cannot tolerate even the small amount of movement caused by wheeled equipment. Many styles of carts are available for specialized applications, including the A-frame cart with a high, slanted support for objects that need to be transported vertically (Figure 38). Carts are more manoeuvrable if all the wheels swivel caster-fashion. This is important in areas where movement is restricted. Movement of objects on a cart due to the cart rolling over imperfections in a floor should be avoided. The use of padding materials will restrict the movement of objects and dampen vibration.

If objects have been well wrapped and padded, they can be placed on unpadded carts, provided that they are secured in place to prevent movement. In most cases, padding the cart is more convenient. A robust, low-cushion padding material, such as carpet, will withstand heavy loads. Additional padding, such as soft foam (up to several centimetres thick, depending on the weight of the object) may be used to absorb vibration. All objects must be separated from each other by padding materials or rigid sheets.

The type and size of wheels will influence the smoothness of movement; larger wheels (127 mm [5 in.] in diameter) will go over cracks and defects in the floor more smoothly than smaller wheels. Pneumatic tires will reduce vibration (Figure 39) (Esser 2011).

Ensure security

Moving objects, even within a building, creates a certain security risk. To ensure maximum security:

• Move objects from one secure area to another and supervise at all times to prevent theft, vandalism or damage.
• Update the object file by indicating the new location.

Consult Agent of deterioration: thieves and vandals for more strategies on strengthening security measures for heritage collections.

Report damage

Reports should be made of any damage, preferably with photographs, and the appropriate staff member should be informed (e.g. collections manager, registrar, conservator, curator). Box or bag all pieces that come loose, identify the package and keep it with the object (e.g. box or bag the object together with the bag or box containing the detached pieces). If pieces are sharp or fragile, wrap each piece in tissue before packaging it. If breaks are in danger of being snagged and lifted, a cloth tape can be bound around the break, or a warning label tied or placed near the object.