What does moving 28 million specimens actually mean? | Katy Hudson and Ellie Clark, Collections Move Team Leaders

Katy and Ellie collecting data on some of the 28 million specimens that will be on the move.

In 2021 the Museum revealed plans to relocate 28 million specimens (approximately a third of the collection) from our stores to a new, purpose-built science and digitisation centre, to ensure their safety and accessibility for future generations. This mammoth undertaking has been enabled through a £182m investment from the Government Department for Digital, Culture, Media and Sport. So, with funding secured, how do you set about planning not only our largest ever collections’ move, but arguably one of the largest collections’ moves ever carried out worldwide?

It’s an exciting time for the Museum and the collections, but of course it doesn’t come without its challenges! Whilst we know what and how many things we’re moving (to put the 28 million into perspective, the next largest collection in the UK is at the British Museum which has about 8 million objects in total), this doesn’t currently tell us much about their physical dimensions and characteristics, which is key to planning the move. For example, can we really count an elephant skull the same as a worm?

Because of this we first needed to answer a number of questions to understand more about the collections moving, how they are organised and their future requirements. The collections on the move contain everything from taxidermy mammals to tiny microfossils, but how many different types of specimens are we moving? Are they organised by taxonomy? Stratigraphy? Collector? How much space do they take up? Do they need more room than they currently occupy?

Step 1

One of our first goals was to calculate the total volume and footprint of collections moving to the new centre. This required thinking not only about specimens, but the furniture and storage conditions in which specimens currently live. Some of the collections are stored in cabinets which may once have been state of the art (hello, beautiful bespoke Victorian mahogany!) but can now be improved upon. The Natural History Museum at Harwell is a fantastic opportunity to enhance storage conditions, collections management and physical access to the collections so it was important to consider not only how collections are stored currently but also how we might want them to be stored in the future. Do some areas of the collections require more space to be stored optimally? And how much space do we need to allow for future acquisitions of new specimens and collections?

After a lot of cross-museum discussion, the required data was agreed and phase one of data collection was almost in motion.

How to measure a collection, from mammoths to microinvertebrates 

Before we could begin, we needed to develop and trial workflows for collecting the data. This isn’t as easy as it may sound… How exactly do you measure a museum storage cabinet and all its drawers and boxes of objects? How do you assess how full a drawer of fossil molluscs is? And how might this compare to how full a drawer of recent mammal skulls is? All collections are different and come with their own individual storage requirements and nuances which must be taken into consideration when making such assessments.

Measuring up a drawer of fossil molluscs currently housed at the collections store in South London. Invertebrates will make up the majority of specimens moving to the new centre.

As mentioned, moving collections to a new storage facility requires not only consideration of the current number and volume of specimens, but the potential future volume required for collections expansion, as it is the nature of collections to expand!  This may occur through curation (or re-curation) of collections resulting in specimens taking up more space, or through acquiring new specimens to fill gaps and strengthen our collections. For example, a museum scientist may return from fieldwork with a box of unprocessed sediment, which once picked through for tiny vertebrate remains, prepared, and curated, may fill an entire cabinet!

We developed a workflow for assessing the current and future storage needs of a collection, at drawer or shelf level. Data could then be used to calculate how much space collections currently occupy within their storage units (drawer, shelf, etc.), and how much additional space would be necessary to ensure specimens are stored according to their ideal storage requirements.

To take advantage of the wealth of knowledge the curation teams hold, we consulted with curators to discuss the storage requirements of their collections and developed a guide to assist staff carrying out the exercise in assessing the ideal storage scenario for a particular collection. Then, the work could begin!

Over several months, two teams of Collections Assistants in the Life and Earth Sciences collections gathered data on external (e.g., cabinets) and internal (e.g., drawers and shelves) furniture measurements, drawer and shelf occupancy or “fullness”, as well as other collections’ details such as item type and number of specimens. With thousands of collections locations, this was no mean feat, and was interrupted at various points by lockdowns and guidance to work from home. As a result, we’re still going! Recently, the Moves project recruited nine new Collections Move Assistants to join the team, who are assisting in a final effort to complete this data collection exercise across Life and Earth Sciences. We hope to complete this in the Spring.

Collections Assistants are gathering a range of data from across thousands of collections to enable effective planning for the move. This involves peering into a lot of drawers!

Just how big are the collections moving to Harwell?

So, what does 28 million specimens look like in reality? From the data collection exercise we can now estimate that the footprint of collections moving to the new centre equals around 13,000m2. This is the equivalent of around two football pitches, fifty tennis courts, five Wembley arenas, three and a half Wembley IKEAs (the largest IKEA in the UK), or one Trafalgar square! The volume of collections moving is estimated at 17,000m3, which is comparable to seven Olympic swimming pools, fifty Boeing 767 passenger decks, or around three and a half Elizabeth Towers (aka Big Ben).

Additionally, this data collection exercise has enabled us to discover other fun facts about our collections. For example, if you laid out every drawer from our Palaeontology collections end to end, they would stretch for just over twenty miles, the distance from the Museum to Windsor! All this information will be used to inform various aspects of planning, such as the design of the new building and collections furniture specifications.

Some of the largest fossilised mammal specimens include these Megaloceros antlers. Megaloceros is an extinct genus of deer which lived throughout Europe until around 10,000 years ago. Its largest species, M. giganteus, is commonly known as the Irish elk and would have been around 2 metres tall with antlers spanning up to 3.5 metres across.

How Long is a Piece of String? More Like How Long is a Python?

Through a massive team effort and the help and knowledge of curators, we have been able to collect huge amounts of data to enable us to understand the space and storage requirements of the collections moving to Harwell. Out of this exercise has come some answers, but also some more questions! Our next consideration is oversized specimens. Just how big is a “big” specimen? What constitutes oversized? This is important for planning of the new site and to ensure these huge items are stored so they are secure and accessible.

To help us define this, we spent time taking measurements of our largest known specimens, including the tallest taxidermy giraffes, sizeable sperm whale skulls, and massive Megaloceros antlers. This got us thinking about how on earth these items got into their current storage locations in the first place…how do you get a seven-metre-long taxidermy python up several flights of stairs? Or around a corner? Or in a goods lift? What about a five-metre-long taxidermy caiman? Or an articulated elephant skeleton? We’re not sure of the answers yet but hope that collecting data about these items will help in planning their next move!


This data collection is the first step on a long journey to prepare for the move. In fact, we won’t actually start moving collections until at least 2025. In the meantime, we’re lucky enough to be getting a unique insight into the collections, in many cases uncovering specimens and drawers that may not have been opened for decades and rediscovering some of the real wonders of nature!


To find out more about the Natural History Museum at Harwell and to sign-up for email updates, including information on collections closures, visit our website . If you enjoyed this blog, why not share with your networks or on social media? You can also follow the project on Twitter and LinkedIn.

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