He was educated at Luggs School on the Headland, near St Hilda's church, and at the age of fifteen entered the drawing office of the Hartlepool shipbuilders Edward Withy & Co.

In 1907 he left Lloyd's to join the board of the shipbuilders R. Craggs & Sons of Middlesbrough, but soon returned to London to practise as a naval architect.

The Americans also gave Isherwood their own version of Commendation and Honour with a Testimonial Dinner at the Waldorf Astoria Hotel in New York with over a hundred of the great and good from the North American shipbuilding scene and a eulogy which began: “When God intended that we should ultimately harness Jupiter and utilize the unseen forces of the ether for the benefit of mankind, He created Benjamin Franklin.

When He intended that the peoples of the earth should come in closer communication with one another He created Morse and Alexander Graham Bell; and when it became His will that a greater safeguard be thrown about the lives of human beings on board ships at sea, he created Joseph William Isherwood.” More than seven different International Governments adopted Isherwood’s designs and patents, including Japan.

Isherwood was a valued member of Lloyd’s Technical Committee; he was also a Freeman and a Liveryman of the Worshipful Company of Shipwrights, having joined in April 1917.

After Alberta's death, her parents presented St Mary's church, West Acklam, with a silver chalice, paten and wafer box.

In 1914, after the death of Arnold, they commissioned and gave the church hall (designed in the Arts and Crafts style) in memory of their children.