This is a ramp for horses to escape if they fell into the canal between Froghall and Consall. It was added when this section of the canal was repaired following a breach in the 1980s. At that time there was a horse drawn trip boat operating out of Froghall Wharf so the decision to add this feature is presumably connected.
We asked on our facebook page, if you remember more details please let us know. And we received this information:
The boat was Birdswood, which was run by Bill and Jackie Young and her mother Peggy St. Clair. The horse was called Badger.
The boat was sold a couple of years ago and now works on the canal at Cromford mostly driven by motor but once a month it is horse drawn. - Alison, June 2015