There are a few placards at the Museum which relate the secret history of Casa Loma during the Second World War, but this website (
visit link) provides a more thorough account:
"The Asdic Sonar Device
Magical Castle became hub of secret war actvites
World War II was marked by cunning espionage on both sides. Knowledge of batle plans and
new devices was the currency of the day. It is doubtul however that enemy spies would have
thought to look in the stables of the fabled Casa Loma for a magic sonar device called ASDIC.
ASDIC, named for its inventors, stands for Ant-Submarine Detecton investgaton Commitee.
This early sonic apparatus was invented around 1941. It was a predecessor to today's sonar
systems. ASDIC could detect a U-Boat at a distance of fve miles. At even the distance of miles
the device could calculate 4 the sub's depth to a foot, its distance to within a few yards, its
speed to within a fracton of a knot and its course to a degree. Such technology enabled Allied
navy vessels to search and destroy feets of enemy submarines.
William Corman viewed fantasy castle as perfect site.
The original producton site for the ASDIC device in London, England had been bombed during
the blitz. The Canadian producton of the device was placed into the hands of William Corman
Engineering Company Ltd. Sabotage was a real danger so Corman had to choose and assembly
site that would not be suspected by the enemy. The site also had to have high ceilings and
ample foor space. Casa Loma which was a well-known tourist atracton presented itself as the
perfect spot.
"Sorry for the inconvenience"
Security experts today would have shuddered had they seen the one dollar padlock which was
all which stood between the public and the secret operatons. Stragglers from Casa Loma tours
were kept away from the carriage room by a polite sign which read "Constructon in progress.
Sorry for the inconvenience." Litle did anyone, including the City of Toronto, know just what
was being built. When Corman made his clandestne arrangements with the Kiwanis Club of
Casa Loma, it was with the understanding that the local government was not to be made aware
- the project was too crucial to the Allied war efort to be placed at risk.
Many Canadian vessels were outited with an ASDIC device during the second World War.
HMCS Haida that is now docked in the Toronto harbour near Ontario Place was one such ship.
Today visitors to the HMCS Haida can see the basic components of the ASDIC device on display.
Casa Loma has its own tribute to he ASDIC device on the third foor of the Castle along with
other noteworthy military displays and the Queen's Own Rifes Regimental Museum.
The ASDIC project contnued in Casa Loma from 1941 untl the end of the war. Sir Henry, ever
the loyal military man, would have been proud had he known the integral part that his dream
castle played in the World War II victory of the Allied Forces."