Recently we visited a local, home-based business that sits on the Liphook Road just after Shottermill Ponds in Haslemere. We were intrigued by the blue plaque on the wall of their property. Commemorating Robert Lochner, we were fascinated to find out more about both the man and the history of the house. First thing first, we asked the current owner, Sarah (who is the owner of Sarah Bakes Cakes), what she knew.

The house itself was originally called Vine Cottage but the name was changed in the early twentieth century to the name it still has today - Rats Castle. When asked about the origins of the name, Sarah told us, ‘We’ve heard a story that prisoners were marched from London to Portsmouth, with our house being a mid-point stop. We assume this perhaps created lots of ‘waste’ and I guess led to a lot of rats…!’‘

The history of the property goes back long before that though. Historical records suggest that the house was built in the 16th century but there is a beam above the inglenook fireplace which is engraved with the date 1367, so it may well be even older than records suggest. There certainly used to be a Paper Mill there and then the trout fisheries, of which Sarah and her family still have the top pond.

More recently, Robert Lochner brought the house back in 1939. Lochner was a scientist, qualified engineer and mathematician. He worked for Crompton Parkinson for a number of years before moving to Laurence, Scott & Electromotors Ltd. Signing up to join the navy in 1939, Lochner had to forego active service due to poor eyesight. Perhaps we should be thankful for that as he focused on research and invention instead.

Robert Lochner was the Inventor of the Mulberry Harbour floating breakwaters that supported the D-Day landings in June 1944. Sarah told us how his daughter had described him coming up with the idea for the invention by chance whilst in the bath one day in 1943. ‘Swirling around the bath was a flannel which was stitched to make a pocket, and Lochner noticed its floating properties. He mocked up a larger version using an old rubber lilo which he tested in the pond and this eventually became the mulberry harbour.’Incidentally, that same bath still sits in the house today!!

The Mulberry Harbour was, in essence, a floating breakwater securing the concrete landings that were towed across the English Channel. Following his initial eureka moment, a mathematical theory to support Lochner’s idea was in place by July of the same year and experiments began in Portsmouth by the August of 1943. Full scale trials of the floating breakwater then commenced in April 1944 and they subsequently played a crucial role in the D-Day landings.

Whilst the Mulberry Harbour is the invention Lochner is most well-known for, he did play a key role in coming up with other solutions to combat the threat posed by Germany. For example, together with others, he also invented the degaussing girdle. This countered the threat posed by Germany’s magnetic mines which, until then, could attach themselves to the hulls of allied ships, sinking them in quick succession. This invention therefore secured the future of the vital north Atlantic convoys on which Britain depended.

Another key figure in the Second World War was Barnes Wallis, inventor of the Bouncing Bomb used for the Dambusters Raid. Wallis and Lochner were certainly good friends and Wallis would, most certainly, have been a frequent visitor to Rats Castle. It’s probably not surprising that the two men got on so well – both had similar naval backgrounds which they both had to give up due to poor eyesight. And, of course, both showed incredible intellect and a dogged determination to invent technology that had a major impact on the outcome of the Second World War.

Following, Robert Lochner’s premature death in 1965, the house passed to his daughter. She in turn, sold it to Sarah and her family in 2022. Sarah now runs Sarah Bakes Cakes from Rats Castle. She has been in business in Haslemere for 15 years. Her partner also runs his Construction company - Acorn Brickwork - from the house too. What with work, six children aged between 13 and 18 and the two spaniels that also live at Rats Castle, it’s a busy household these days!

In total there are currently 17 official blue plaques in Haslemere, all managed by the Haslemere Society. Some other notable people commemorated include Sir Arthur Conan Doyle, George Eliot and Field Marshal Montgomery. As stated on their website, the Haslemere Society exists to ‘protect and enhance Haslemere, nearby villages and the surrounding countryside, by encouraging the interest and support of residents and members.’ It has a long and illustrious history. The group’s roots actually go as far back as 1884 when Sir Robert Hunter (one of the co-founders of the National Trust) founded the Haslemere branch of the Commons Preservation Society. This eventually became the Haslemere Society that we know today.

You can find out more about the Haslemere Society on their website including the history of Robert Lochner and the other holders of the blue plaques. If this story has piqued your interest, we can definitely recommend joining this local organisation – membership is a bargain at just £15 a year for an individual. Find out more.

And, if you want to see Robert Lochner’s blue plaque, then we can heartily recommend you order one of Sarah’s delicious cakes so you have an excuse to pop round!