Return to the high definition surveying seas

Mary Rose museum and Leica Geosystems’ involvement

By 2005, plans were being developed to create a new flagship museum in which to house the Mary Rose hull and her unique collection of artefacts, and to tell the story of her crew. These plans were realised when the new Mary Rose Museum opened in May 2013. Prior to opening the new museum, the wax spray was turned off and the drying process began, keeping the Mary Rose in a controlled environment, called the “hotbox”, with a 54 per cent relative humidity and 19 degrees Celsius. Once dried, the PEG will stop the cells from collapsing and will hopefully help to preserve the ship for hundreds of years to come.

In 2013, Leica Geosystems was asked to assist with the conservation project and help to monitor the ongoing drying process of the Mary Rose in the confines of its “hotbox” within the new museum. The system provides vital data to enable the Trust’s conservation team to understand the effects of the controlled drying process on the 500 year old timbers and will be involved in the project for four years, after which time, the majority of the timbers will be dry. As the timbers dry, they can move and understanding the magnitude of this movement and in which direction is significant to this unique scientific research. Once dried, all the black ventilation tubes aiding the drying process will be removed from around the timbers, opening up unhindered views. The ship is also supported with scaffolding and braces to provide extra support and protection and to slow down the movement of the ship, preventing both damage to this unique historical artefact and also safety-of-life for those working on the 500-year-old timbers.

To accurately measure the hull’s movement, a Leica Nova MS50 MultiStation was initially installed with optimal line-of-sight coverage onto the hull along with 36 reflector targets attached to the timbers in key locations. The MultiStation automatically calculates its position and orientation prior to each measurement cycle to militate against any movement itself. Five widely distributed control reference targets mounted in stable locations away from the timbers form the basis of the resections. Measurement cycles run three times a day.

Leica Geosystems, with more than 25 years of automated monitoring expertise, has supplied the hardware, software and consultancy for this prestigious project.

Involved from the early stages of the drying phase, Leica Geosystems Account Manager Mark Francis commented; “Leica Geosystems is proud to be involved in offering the latest state-of-the-art measurement solutions to assist in the research of such a prestigious and unique project, and we look forward to further collaborations.”

In May 2015, Leica Geosystems’ Steven Ramsey and Francis also assisted with a High Definition Survey (HDS) using the newly released, state-of-the-art ScanStation P40. This technique produces a point cloud of billions of points to accurately model every millimetre of the structure, far beyond the 36 discrete monitoring points. The intention is to re-laser scan in 2016, post construction of the opened viewing galleries for an updated model.

As with any continuous monitoring project, in addition to the sensors, power and communication are key components of the system architecture for the reliability and success of the complete solution. At the Mary Rose Museum, main power and an ethernet cable connected to the site LAN ensured the continuous operation, control and data transfer with a computer in the museum connected to the network server. Leica Geosystems’ renowned GeoMoS monitoring software controls the measurement cycles three times a day. Additionally, the data is extracted to a spreadsheet format from the open SQL database and automatically emailed to key stakeholders on a regular basis for continued analysis.

“The incorporation of the MultiStation into our conservation plan provides us with invaluable information, which will greatly enhance our understanding of the drying hull. This will allow us to develop a strategy that will ensure the future of this unique piece of cultural heritage,” said Dr. Eleanor Schofield, conservation manager.

The data from the MultiStation is delivered by email to doctoral students from the University of Portsmouth’s Civil Engineering and Surveying Department. They are then able to analyse the movement data, identifying trends and correlating to other lines of research including the dryness of the timbers.

Explore next chapter: Future of the Mary Rose

Story: Return to the high (definition surveying) seas
Chapter 1: Mary Rose's excavation
Chapter 2: Mary Rose museum and Leica Geosystems' involvement
Chapter 3: Future of the Mary Rose