4644 may refer to:
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4-6-4-4
In Whyte notation, a 4-6-4-4 is a railroad steam locomotive that has four leading wheels followed by six coupled driving wheels, a second set of four driving wheels and four trailing wheels.
Other equivalent classifications are:
UIC classificat ...
, a Whyte notation classification of steam locomotive
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4644 Oumu, a minor planet
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