I'm looking for a word (or phrase) to describe mechanisms that are perfectly functional even when they aren't functioning as expected.
Examples of these include:
- Escalators & Electric Walkways: Even when they aren't powered these systems still function as perfectly adequate stairs or sidewalks
- Mopeds: Even when out of gas, the owner can still pedal along
- Electric Toothbrushes: One can still brush their teeth without turning it on
I've considered using engineering and management terms such as redundant mechanisms, enhanced systems, or fault-tolerant machines that come close, but those terms refer to very specific technical concepts that don't apply to my needs or the the examples.