The Thomann-Hanry gentle dry abrasive façade cleaning system, which is carried out from heavyweight cherry pickers, is expected to be used in New York to clean a 3,500-year-old granite Egyptian obelisk. 

In trials against other abrasive systems, chemicals and laser cleaning, it was the Thomann-Hanry ‘facade gommage’ system that most impressed the conservators of Central Park Conservancy. 

They are responsible for the $200,000 conservation of the obelisk, around $35,000 of which is for the cleaning.

After several months of planning, Thomann-Hanry UK Director Mark Styles and Jean Delaporte took part in the cleaning trials on the obelisk before Christmas. 

Four small areas were cleaned on a bright clear day under the watchful eyes of half a dozen Conservancy staff. Those watching the test were able to examine the cleaned areas and immediate feedback from the conservationists on Thomann-Hanry’s work was extremely positive.

Since returning to the UK, Thomann-Hanry has been invited to quote for the project, which is due to start in the spring.

Mark Styles says: “While we are used to working on historic and ancient buildings, a monument like this obelisk is a unique opportunity to showcase our expertise.”

If Thomann-Hanry is awarded the job it will mark a welcome return to the US for it. Work dried up in New York after the 9/11 attack on the World Trade Centre. A big advantage to the system in city centres is that scaffolding is not required and disruption is kept to a minimum.