A Queer Ferry

https://en.wikipedia.org/wiki/Widnes-Runcorn_Transporter_Bridge

It seems to have had lasted for a good while. I was wondering why not just build a bridge in the first place?
It seems cost and letting large ships pass were the factors

A few transport bridges still going:

http://www.newport.gov.uk/heritage/Transporter-Bridge/Transporter-Bridge.aspx

https://www.middlesbrough.gov.uk/parking-roads-and-footpaths/tees-transporter-bridge

https://www.pont-transbordeur.fr/rochefort-transporter-bridge

This is one of those engineering projects where the "most practical" option wasn't doable, and they had to resort to the "least impractical" solution.

Thanks to Phideaux and S. Norman x 2 for enlightening info on "trasnporter bridges." WEIRD UNIVERSE has the smartest and most forthcoming patrons!

A bridge would cost way more, due to the inclines needed on either side to get to the elevation. And they may have needed miles for these, as the bridge was designed for waggons having only two real horse-power. Clever contraption, I'd say, but forget it for high volume traffic crossings.

I'm no engineer, but it seems to me the deck of a bridge weighs a whole lot. By eliminating the deck, they can build a much less robust structure at a much lower price. The weight of conventional bridge decks is why some bridges (especially draw bridges) have steel decks.

Darn, I visited cousins in Middlesbrough many years ago and nobody told me about the transporter bridge.

Another advantage to this system is that it apparently supported pedestrians, which a bridge built for cars or trains wouldn’t do very well.