No longer in use. Some BPB security do have cuffs, I understand they are only for extreme circumstance. The police come in where needed, have seen it a few times.In the Blackpool Pleasure Beach documentary you see that they have (or had) holding cells in the park so wouldn’t be surprised if other parks at least used to have similar.
There have been police hovering on Towers Street (as in, the place, not here!) on 'those' days in the past, particularly during Scarefest