On the DH8, in case of an engine failure after V1, the affected propeller is triply feathered.
Whenever such a thing happens, it triggers memory items. Firstly, maximum takeoff power is set on the good engine, then the absence of a fire warning and the correct working of the autofeather system is verified. If it has done its job (and no fire is indicated), there is no further action until acceleration and cleanup is completed. If however the autofeather has not worked for some reason and the propeller is still running at windmilling speeds (about 200-300rpm), the memory items continue with a full shutdown of the affected engine; this contains two other attempts at feathering the propeller. Firstly, the power lever goes to flight idle, then the condition lever will go to Fuel Off (#2 attempt at feathering). Whether or not this has worked, the Alternate Feather switch will be selected thereafter (#3 feathering attempt).
After that, there are only very few freak failures that can leave the propeller unfeathered - some blockage/rupture of the oil passages in the governing mechanism maybe. But nevertheless, it is well possible to fly a DH8-400 with an unfeathered failed engine and even coerce it to climb at a low rate. One can compare the climb performance of a -400 in this situation to that of a -300 with the failed engine properly feathered. The -300 is a wholly different beast though; there always was a lot of fun in the simulator when the PNF only casually proceeded to feather the dead engine.