What lies beneath: dusting and documenting the blue whale skeleton | Conservators

The team have been busy in the 3 weeks since my last post, studying the blue whale skeleton and documenting its condition. The first stage was to record the initial condition of the skeleton, including the coating of dust that has accumulated over time, and to start to identify areas which would require attention prior to dismantling.

Photo showing the dusty vertebra close up

Thoracic vertebrae coated in dust and also showing an area where a metal support has failed.

Dust particles that are deposited on museum objects will typically consist of fibrous material (aka “fluff”) and non-fibrous particulates. Dust is hygroscopic and can accelerate biological, chemical and physical deterioration of specimens and even though it is over 6 metres above the ground, the whale skeleton is a dust attractor so a regular cleaning schedule is important where practicable. On this occasion, over 1.3 kilos of dust was removed from the blue whale skeleton during this initial clean.

The dust will contain both organic and inorganic material and it will be deposited from a variety of sources including the building fabric, skin and clothing from staff and visitors, and various airborne pollutants. Dust deposition is the result of a complex interaction of physical and chemical processes, influenced by environmental variables and it will accumulate at differing rates over time.

Photo showing dust layers as they're being removed

Thoracic vertebra with top layer of fibrous dust and base layer of particulate dust. Note the 2 screws that have been revealed!

As conservators we are interested in the dust on our blue whale skeleton so samples have been taken for analysis for further identification, chemical composition and also to check for microorganisms. We are fortunate enough to have access to a wide range of analytical facilities and expertise at the Museum so if you want to know more check out our web pages for our core research labs.

Photo showing one of the conservators swabbing a vertebra

A swab being taken from the whale skeleton to check for microorganisms

Confocal micrograph of dust

Initial evaluation of the dust using confocal microscopy. The molecules are fluorescing at different wavelengths reflecting the different chemical compositions present.

Dust removal

With a surface area of approximately 110.4 m2 to clean the method needed to be safe but efficient. Special wearable vacuum cleaners were used to help with access alongside face masks and disposable gloves to protect the team during cleaning. Soft brushes were also used, which encouraged the dust to leave the bone surface with minimal disruption. No clouds of dust could be seen while we worked!

This is sometimes very satisfying work to perform as our #WhaleWednesday series on Instagram has shown…

A short #WhaleWednesday clip shows how our conservation team are carefully removing the layer of dust gathered on our blue whale skeleton. A note from our #NHM_Conservators: It is important from a conservation perspective to remove as much dust as possible. Firstly, this helps us to see the surface and structure of the bone to properly assess its condition. Secondly, dust is hygroscopic – which means that it attracts moisture. This could be detrimental to the stability of the porous bone structure over time because it could lead to expansion and contraction which would cause damage. #conservation #NHM_Conservator #BlueWhale #whale #skeleton #bones #BlueWhaleSkeleton #whalemove #animal #BehindTheScenes #science #Naturalhistory #NHM #Museum

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Once the surface dust had been removed further condition reports could be completed for each individual bone. Initially, though, there was time to look and reflect on the mounted skeleton as a whole. This involved lots of whale watching, or in our case whale skeleton watching and discussion with colleagues. We already know so much more about this specimen since working on the scaffolding and it was useful to take the time to review once again our plans for de-installation.

Photo of the conservators and curator discussing the state of the whale skeleton in situ

Team whale discussing the proposed method for removal of the vertebrae

Photo showing conservators investigating the inside of the whale's mouth parts

Inspecting the left mandible and its existing metal mount. Some parts of the skeleton required us to climb inside so we could really see the extent of the challenge. 

There has been a long-standing tradition for specimen preparators and sometimes even conservators to discreetly “leave their mark” somewhere on any significant specimen they have worked on. So we were pleased – but not too surprised – to discover that some signatures had been left by the original team that placed the skeleton in the gallery back in 1934.

Photo showing the 3 signatures plus date

Signatures left on the underside of the skull and dated February 1934

Condition reporting

The condition of each bone has now been documented while the whale is in-situ. This has involved photography and a detailed assessment of the bone surface. As well as written descriptions, features of interest were mapped onto diagrams to show areas such as loss, cracking, delamination, staining, leaching lipids, old fillers, metal supports and inserts.

A standardised system was developed  so we had a consistency in what was being recorded and the vocabulary being used. This is the first significant part of the condition recording process. The second more detailed evaluation will take place once the whale has been de-installed and in the laboratory.

Photo showing two conservators inspecting the vertebrae

Condition reporting the caudal vertebrae

Each bone has now been labelled and the next stage is to remove each one from the existing metal mount. This will be done in phases starting from the smallest caudal vertebrae which measures barely 100mm at its widest point and ending with the 6 metre long skull. The challenge increases as we move along the skeleton in terms of complexity, volume and weight.

A short time-lapse showing the labelling of the vertebrae in preparation for removal:

Our final part 3 of 3 for this week's #WhaleWednesday is the next step after the initial dusting – labelling with gusto! "Our #NHM_Conservator team is not only responsible for ensuring the safety and stability of the specimen, but must also retain information about how the skeleton is mounted. This includes taking measurements, photographs and even labeling the individual bones with anatomical directions. In this case we are using conservation grade PTFE tape and writing directly on the tape. This will help us to ensure that the bones are re-mounted in the correct positions." #Wildlife #Animal #Gallery #Conservator #BlueWhale #Whale #Skeleton #BlueWhaleSkeleton #BehindTheScenes #MarineMammal #Mammal #NaturalHistory #NHM #Museum

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