Is this the thinnest balance beam on the waterways?

Not only does the Stort have the craziest footbridge (see previous post), I reckon it also has the thinnest balance beam on a full size lock. OK I know the Stort locks aren't as big as normal double width locks, but they're still bigger than the single locks found all over the midlands.

Anyway, this one is at Harlow, just by the railway station if my memory serves me right. I don't have a clue why it was made this thin. I suppose it was about four inches square. I thought balance beams were supposed to counteract the weight of the gate, and the gate was normal size. I remember the gates were easy to open and close, so it works OK.

If you've seen a slimmer one, I'd be interested to know of it.