"You really think I'm this hypothetical human fail-safe device?"

He undoubtedly fitted them with a fail-safe device.

"There is, of course, a fail-safe device built into it all," he continued.

Not enough fail-safe devices were ever built in for a situation like this.

So he added a fail-safe device: a safety chain that clips onto a bag's main strap.

Magnets may be used to serve as a fail-safe device for some cable connections.

Apparently the captain had installed some sort of fail-safe device to prevent exactly what we were intending.

Should not fail if any fail-safe related to safety device fails.

Much remains unknown about the failure of this ultimate fail-safe device.

A complication is that the reactor's fail-safe devices may hold longer than we want them to.