I have asked Mother about this song,
The "Alley" is the Manchester ship Canal.
The date used was the day the canal was opened.

The big ship sails on the Alley Alley Oh,Alley Alley Oh,Alley Alley Oh, Rpt.
On the last day of September.

The Captain said this will never never do.ect

The big ship sinks in the Alley Alley Oh.----

We all drown in the Alley Alley Oh.----

We all jump up in the Alley Alley Oh.----
This is what she can remember of the Chester version of this song.