Carrier Catapault Hold-Back Bar ?

Hi,

Have always been interested in catapults on carriers, but have never been
able to find any good drawings or diagrams showing how the hold-back
mechanisms work.

I remember in the "old days" that they used breakable/frangible bars, but I
doubt that these are used anymore.
Are they ?

Anyone know of any links or pix/diagrams showing details of how they are
constructed, and used, these days ?

Looked pretty exhaustively, but cannot come with any.
Am a retired mechanical engr., and have always been interested in this
component.

Thanks,
Bob