C Tube hydrophone rubber bulb. Collection of Boyd A. Propert. Thanks to his son, David Propert for submitting the photo scan.
The C Tube hydrophone was one of the listening devices on the chasers. These images, from the service of Boyd A. Propert, a Listener on SC 322, are from his son, David Propert.
An extremely rare artifact from a chaser, the rubber bulb from a C Tube Hydrophone. The version of the C Tube installed on the chasers was called the S.C. C Tube, but was typically called the SC Tube. The device was in the shape of a large, inverted tee. At each end of the horizontal part, a rubber bulb transmitted sound waves to the tube. A Listener inside the boat used a stethoscope-type headset to listen for sounds.
See also the photograph of SC 322, from the same collection.
A complete description of the C Tube and images of the device are included in the book, Hunters of the Steel Sharks: The Submarine Chasers of WWI