Were there any safety devices?

There was a safety device to keep the warhead on a Mark 14 or Mark 18 from exploding too close to the submarine which could damage the boat. It was an impeller on the front of the torpedo that prevented the torpedo from exploding until it had run about 400 yards. The impellor pulled out a safety screw. (An impeller is a device like a small propellor, but the water moves the impeller, not the other way around.)

After the Tang was lost, more work was done on an anti-circular run (ACR) device which would prevent the torpedo from exploding if it circled back at the submarine.

There was also a safety device to keep the torpedo from going below 100 feet. That is why the submarine was supposed to be at 150 feet or deeper.