Why Canada nationalised struggling railways

Why did Canada nationalise struggling railways around the First World War?

The railways depended on British bank finance, but wartime government borrowing absorbed the capital they needed to keep operating.

Canadian railway policy was tied to the financial structure of the wider British world. Canadian companies relied on British banks for operating capital. During and immediately after the war, large British government loans drew heavily on those same institutions and left less money available for overseas borrowers. Nationalisation was therefore a response to a financing crisis, not simply an abstract preference for state ownership.