About to redesign a submarine (5)

I believe the answer is:

uboat

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'a submarine' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.

'about to redesign' is the wordplay.
'to redesign' indicates anagramming the letters (I've seen this in other clues).
'about' with letters rearranged gives 'UBOAT'.

Can you help me to learn more?

(Other definitions for uboat that I've seen before include "What convoy tried to avoid" , "Sub" , "Warship" , "Vessel" .)

I've seen this clue in The Daily Express.

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