  In 2003, Hammond and Lewis defined a statistic on partitions into 2 colors
which combinatorially explains certain well known partition congruences mod 5.
We give two analogs of Hammond and Lewis's birank statistic. One analog is in
terms of Dyson's rank and the second uses the 5-core crank due to Garvan, Kim
and Stanton. We discuss Andrews's bicrank statistic and how it may be extended.
We also generalize the Hammond-Lewis birank to a multirank for multipartitions
and the Andrews bicrank to a multicrank for extended multipartitions. These
both give combinatorial interpretations for multipartition congruences modulo
all primes t>3.
