Having worked on films and TV as a set designer for maritime productions in
the past, anything is possible to get the atmosphere right for the plot.
What you describe sounds very like the the setup used for the very early
Torpoint Ferry. Save that it was connected to a rope across the river.
Verticle boilers were often used, Highland Puffers are an example, where
space was limited.[African Queen] and a simple 'Mill engine'type was used to
drive a shaft either to a paddle or a winch.[ The BD1 Bristol dock scraper
dredger.] why not make a model of it? be unusual..Best Regards ..... Mike
Mayhew
33 Kenn Moor Drive,
Clevedon.
North Somerset. BS21 5AR
http://www.waverleymodels.co.uk