1891 English Census indicates that Patrick was aged 33, so born about 1858. Occupation given as a dock laborer. 1911 Census indicates he was born in Tartarachan, Co. Armagh (properly Tartaraghan).
There are a few possibles for his father in Tartaraghan in Griffiths -- for the most part, the surname has been spelled as Tennison in these records. Noted in Derrylard and Gallrock.