Let's get cracking!

I just said this to some students and, thanks to the PF, found myself asking,"What is the origin of this phrase?"
Any ideas? SR

I can't help you with the origin of the phrase, but here's what the OED says. "b. Colloq. phr. to get cracking: to get started; to 'get a move on'. Cf. GET v. 32b. Also with noun or pronoun (or other object) interposed between get and cracking. 1937 PARTRIDGE Dict. Slang 324/1 Get cracking, to begin work.

c. to get going: to begin; to start talking, acting, etc., vigorously; to get into full swing; to 'get a move on'. Also trans., to start; to render (someone) excited, talkative, etc. See also to get cracking s.v. CRACK v. 22b.

1897 O. W. HOLMES Pollock-Holmes Lett. I. 77 He is really fine when he gets going on the Church of England." SS

I imagine it's related to the expresions, "To crack on more sail" or "to crack on more speed", maybe even "the crack of dawn". However, I draw the line short of "Cracking good toast, Grommet"!

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