Morning. Long time lurker, occasional poster here.
A brief observation from today's regular morning commute along the canal.
To the chap on the Boardman mountain bike: if you can't stop by the bridge at Harrison Park without locking up your back wheel and skidding for several metres, that is probably an indication that you are travelling about 3 times faster than is sensible, and not a problem which would have been solved by me ringing my bell. The fact that I had come to a gentle halt and was track standing to watch you career towards me / the canal indicated that I was a good deal more in control than you.
I don't have a bell on the bike I was using this morning as most of my bikes are used for racing at weekends, and I find that a combination of sensible speed, a noisy freehub when I coast and a cheery "on your right / thanks" avoids any problems on my daily commute. I also avoid the canal on sunny evenings and tend to be cycling in just before the worst of the morning rush hour, and a good bit after the evening rush hour. I don't claim to be perfect but I do go under the blind bridges at or close to walking pace until I can see clearly out the other side. For these reasons, my personal choice is not to use a bell, although I appreciate that others will take a different view.
Ringing a bell before piling under the canal bridges at 20mph doesn't do anyone any favours - it just means people will hear you coming before you fall into the canal out of control. At the speed you were travelling you wouldn't have heard my bell even if I had rung one anyway.