The AMPETCO was a Belgian oil tanker built in 1926 as the URANIA She was however owned by the Standard American Oil co. (Esso)
She was in a collision in 1944 and was later sunk 4/45 as a torpedo target.
I am sure if you post on Siri's Ship Forum
you would get a more detailed answer.
AMPETCO was in several Atlantic convoys see
As regards your father I think I am corect in saying, some his Merchant Navy records are in the British National Archive as follows
BT 372/2740/131 R844210 CATARAHIAS J M 03/03/1914 BELGIUM
You can obtain these records at a cost from the archive.
hope this is of help