Sunderland was (and to some extent still is) a source of steel (and 'rails'), as well as coal' shipping. It was a very important port in the 19th C.

What is wrong with shipping from the Wear and Sunderland to Bilbao (or anywhere else for that matter)?. The poem only mentions Sunderland; nothing is said about Portsmouth.

The ferry from Portsmouth has nothing to do with shipping from Sunderland. I mentioned the Portsmouth ferry because it is popular with trippers for a short cruise to a Spanish port, and uses the port facilities at Getxo for Bilbao; the maps of the harbo(u)r are good if one googles Getxo. I was looking for a possible location of the "bar."

(Charley, I excuse myself for losing my grasp because of my age. What is your excuse- he, he, he)?