Heavy

A 2 × 2 square of cells in a pattern is said to be heavy if, at any time during the evolution of the pattern, at least three of its four cells are alive in the same generation.

x = 9, y = 16, rule = B3/S23 bo2bo$5bo$o5bo$2o4bo$5bo$4bo$3b4obo$3bo3bo$bo3bo$ob4o$4bo$3bo$2bo4b2o$ 2bo5bo$3bo$4bo2bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ GPS 7 THUMBSIZE 2 ZOOM 16 HEIGHT 450 ]]

The block catalysts in 34P7 are considered heavy as they have at least 3 cells alive in the 2 × 2 region the block is for 6 out of 7 phases. (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here