1. Moving from intuition to data

For a long time, loan and transport decisions relied mainly on experience, empirical feedback, and best practices. For certain fragile or iconic works, this approach is no longer sufficient: it is becoming necessary to have measured data that can be reused from one project to another.

A data-driven approach allows you to:

• objectify the risk for each work;
• document decisions for management, scientific committees, insurers, and authorities;
• capitalize on experience: each instrumented transport enriches the knowledge of the mechanical behaviors of the works.

2. Assessing risk before transport

2.1. Diagnosis of the work

Before any movement, a thorough examination of the work constitutes the basis for the decision:

• detailed condition report (support, paint layer, varnish, fixings, restorations);
• identification of highly sensitive zones (cracks, lifting, unstable elements, fragile old restorations);
• classification of the work according to its presumed sensitivity to vibrations (low, medium, high).

Based on this diagnosis, several options can be envisaged:

• transport possible with a slightly adapted standard crate;
• transport conditional on a specific crate, a reinforced damping system, and/or monitoring;
• deferred or refused transport, if the mechanical risk is deemed too high regarding the work’s current state.

2.2. Analysis of the route and logistical context

In parallel, analyzing the transport context is essential:

• total distance, duration, and type of roads (highway, secondary roads, urban areas, cobblestones);
• number and nature of vector changes (truck, loading dock, freight elevator, trolley, etc.);
• schedule constraints, installation windows, co-activity on site;
• presence of critical zones (slopes, thresholds, stairs, construction sites, diversions).

This analysis makes it possible to anticipate the segments potentially most stressful for the work.

3. Designing an adapted crate and damping system

3.1. Transport crate

The crate is the first level of mechanical and climatic protection:

• rigid, stable crate, with a structure sized around the work
• integration of thermal and hygrometric insulation elements according to the duration and context of transport
• design of holding and cushioning points defined with conservation-restoration, relying on mechanical knowledge of the support.

3.2. Mechanical damping

Between the work (or its support) and the crate, the role of damping materials is crucial:

• foams selected for their mechanical behavior (density, thickness, viscoelasticity)
• damping interfaces (pads, spring systems, high-damping materials)
• vibration isolation solutions aiming to filter potentially damaging frequencies.

Two extremes are to be avoided:

• cushioning that is too rigid, which transmits almost all shocks and vibrations to the work
• cushioning that is too loose, which allows the work to gain momentum inside the crate.

The goal is to reach a mechanical compromise: hold the work firmly, while leaving the system the capacity to dissipate energy.

4. Choosing the right carrier, vehicle, and route

4.1. Specialized Carrier

The choice of carrier conditions a large part of the risk:

• use carriers specialized in works of art, familiar with preventive conservation constraints
• verify the existence of written driving and handling procedures
• involve the carrier in the upstream reflection on the specific constraints of the work.

4.2. Vehicle and driving

A few points of attention:

• selection of adapted vehicles (suspensions, crate holding systems, climate control if necessary)
• sensitization of drivers to smooth driving (progressive acceleration, anticipated braking, adapted speed)
• limitation of transfers from one vehicle to another, as each handling operation is a potential source of shocks.

4.3. Route

The route can be optimized with a risk reduction logic:

• prioritize the smoothest and most regular axes, even if the trip is slightly longer
• avoid, as much as possible, cobblestone roads, heavily degraded roads, or those with a succession of speed bumps
• anticipate construction zones and diversions that could impose unfavorable conditions.

5. Organize Handling and On-Site Procedures

Many of the most intense stresses occur during handling, sometimes over just a few meters:

• Limit the number of transshipments (truck → loading dock → freight elevator → forklift → room)
• Systematically use tail lifts, ramps, and gantries to overcome differences in level
• Prohibit stepping over stairs with heavy or bulky crates
• Write simple and clear procedures, shared with all stakeholders
• Organize operations to avoid rushed situations (delays, reduced staff, unanticipated concurrent activities).

6. Implement Appropriate Monitoring: Sensors and Data

6.1. Which sensors to use?

Depending on the artwork and the level of risk, several configurations are possible:

• Vibration sensors/accelerometers (often tri-axial, X-Y-Z) measuring accelerations along the entire path
• Shock recorders detecting and storing acceleration peaks exceeding a certain threshold
• Multifactorial monitoring systems combining vibration, shock, temperature, relative humidity, and even light.

Sensors can be:

• Integrated into the crate,
• Mounted on a mechanical support attached to the artwork, when possible,
• Located in the immediate vicinity of critical areas, after approval by the conservation department.

6.2. Leveraging Data: Towards Predictive Conservation

The value of monitoring lies not only in having graphs, but also in the ability to interpret them and use them to inform decision-making:

• analysis of vibration levels during transport (average values, peaks, exposure time)
• identification of critical events (shocks, specific road sections, handling phases)
• comparison with internal reference data and research data
• production of transport reports that can be integrated into loan, restoration, or research files.

As projects progress, this data feeds into an increasingly personalized and predictive approach to conservation: each artwork can be tracked over time, throughout its exhibitions and transports.

7. Going Further: From Understanding to Action

Understanding the problem is the first step. The next step involves concretely mitigating risks: designing shock-absorbing crates, selecting the vehicle and route, implementing handling procedures, and installing sensors and monitoring platforms to analyze data over time.

1. Why vibrations are a major risk for works of art

Vibrations and shocks associated with transport can:

• cause micro-cracks in paint layers and varnishes;
• accentuate detachment between the paint layer, ground, and support;
• weaken wood joints (panels, frames, sculptures, furniture);
• contribute to mechanical fatigue in aging materials;
• destabilize old or heterogeneous fastening systems (nails, screws, pegs, old glues).

Particularly sensitive are:

• panel paintings with splits, joints, or old restorations;
• large-format paintings on canvas that are loosely tensioned or on weakened stretchers;
• polychrome wood sculptures or composite objects;
• mounted objects, with added elements or cantilevered parts;
• any work already showing cracks, lifting, losses, or extensive restorations.

In these cases, transport is never neutral: it is a matter of quantifying and qualifying the actual risk incurred.

2. Where do vibrations come from during artwork transport?

During a journey, a work does not undergo a single uniform vibration, but a succession of mechanical stresses from various sources:

• Vehicle motion: road condition, potholes, cobblestones, speed bumps, rails, bridge joints, etc.
• Suspension and truck type: unadapted vehicles, inadequate settings, over- or under-loading.
• Handling: crossing thresholds, curbs, ramps, moving on pallet jacks or trolleys, freight elevators.
• Loading/unloading operations: small drops, jolts, sudden rotations, point loads.

Schematically, we distinguish:

• continuous vibrations linked to driving, over a wide frequency range;
• punctual shocks (speed bumps, curbs, sudden braking, impact), capable of causing immediate damage.

For the artwork, what matters is not just the isolated event, but the entire vibrational spectrum to which it is exposed: amplitude, frequencies, duration, repetition, and directions of the stresses.

3. How Vibrations Damage Heritage Materials

The effect of vibrations on a work of art depends on its structure, materials, and history:

• Structure: panel, canvas, sculpture, furniture, composite object, etc.
• Materials: wood, canvas, animal glues, ground layers, binders, fillers, varnishes, composite materials.
• State of conservation: cracks, lifting, old restorations, weakened areas.
• Resonance frequencies: certain parts of the artwork can resonate with external stresses.

Several damage mechanisms can be observed:

• Mechanical fatigue: a large number of cycles, even of low amplitude, can cause progressive breakage, the slow opening of a crack, or the reactivation of a fragile area.
• Friction and micro-slipping: between poorly secured elements or at interfaces (for example, paint layer/ground), generating slow wear and micro-gaps.
• Local amplification by resonance: frames, cantilevered elements, and added parts can vibrate more strongly than the rest of the artwork.
• Reopening of old cracks: cracks stabilized under stationary conditions can reopen under repeated stress.

The actual risk always results from a combination of factors: vibration level, frequencies, exposure time, the object’s intrinsic fragility, and its history of previous transport.

4. Typical Risk Scenarios for Collections

Some situations combine several unfavorable factors:

• Long international road journeys with vehicle changes, sections of highway, followed by degraded secondary roads.
• Transport in a refrigerated truck, where the refrigeration unit adds a level of vibration specific to the system.
• Very fragile artwork (cracked panel, lifting paint, unstable sculpture) entrusted to standard transport, without crate modifications or monitoring.
• Multiple loans over a short period, without cumulative monitoring of mechanical stresses.
• Imposed routes (roadworks, detours) including very degraded roads, cobblestones, or roads with numerous speed bumps.

In these situations, relying solely on intuitive criteria (“it’s gone well so far”) is no longer sufficient: the decision to lend, reinforce a security measure, or refuse transport must rely on objective elements.

5. When should a work of art be considered “at risk of vibration”?

Several criteria, often combined, indicate that a work requires special attention regarding vibration:

• Documented fragile state of preservation (cracks, lifting, significant restorations);
• Structural complexity (composite object, added elements, cantilevered areas);
• History of damage or warnings during previous transports;
• Complex route and logistics (long distance, poor road conditions, numerous changes of transport, tight scheduling constraints).

Identifying these criteria in advance allows us to:

• Classify works according to their sensitivity to vibration;
• Prioritize protective measures (specialized crate, damping systems, monitoring);
• Better justify decisions to management, partners, and insurance providers.

6. Glossary – Vibrations and the Transport of Works of Art

7. Going further: from understanding to action

Understanding the problem is the first step. The next is to concretely limit the risks: designing shock-absorbing crates, choosing the vehicle and route, implementing handling procedures, and setting up sensors and monitoring platforms to analyze data over time.

Transformation Mask

2022

We are working in collaboration with members of the museum team such as Eleonor Kissel, as well as with the team at Summum 3D for their three-dimensional scan of the mask.

Wooden sculptures of the Isnard organ

2022

Our team is conducting a study on two wooden sculptures from the Isnard organ of the Madeleine Church in Aix-en-Provence.

This study aims to study the hygromechanical effect of a freezing pest control treatment. The monitoring device operates before, during and after the treatment in order to understand the impact of such a climatic shock on massive wooden sculptures.

Presentation video

La Sainte Trinité couronnant la Vierge

2021

This research has been performed by:

• the Fabre Museum,
• the Mechanics and Civil Engineering Laboratory (LMGC, University of Montpellier),
• l’institut P’
• theUniversity of Florence (UNIFI),

In collaboration with:

• Joseph Gril,
• Gilles Tournillon,
• Danièle Amoroso,
• Philippe Hazael Massieux,
• Cécilia Gauvin.

More information about this research:

• a research article:
  “Experimental study of the hygromechanical behavior of a historic painting on wooden panel: devices and measurement techniques”.
• a conference paper:
  “Mechanical behavior of a painted wooden panel from the heritage subject to hygrothermal variations: role of the reinforcement”.
• a video (in French, see below).

Presentation video

The Bayeux Tapestry

2021

We had the privilege to work on the Bayeux Tapestry, in Bayeux in Normandy, France.

This study aimed at setting preventive conservation recommendations. We enjoyed bringing in our expertise of mechanical engineering, by setting-up full-field monitoring of strain and stress on tapestry mock-ups (as shown on the right-hand side picture). Besides our monitoring, we helped design conservation solutions and characterise the sensitivity of the Tapestry to its surrounding climate.

We teamed up with a great team of conservators and ergonomists:

• Thalia Bajon-Bouzid,
• Raphaëlle Déjean,
• Élodie Aparicio-Bentz,
• Vanpoulle Christophe,
• Bourgeois Fabrice;

And in association with:

• the Bayeux Museum,
• the DRAC Normandie
• La Fabrique de patrimoines in Normandy.