Every set of points will have means to be manually secured. Traditionally in the tunnels they would be housed in a small grey box on the tunnel wall as close to the points as possible normally one box per set of points, whilst in the open they would be in larger bin-type containers somewhere nearby.
This may sound lovely and simple, however there’s always been a perennial issue of the clips and scotches going missing. These are supposed to be used by operating staff only, however the culprits for the disappearances are always suspected to be the p-way, who frequently need to secure points when carrying out work, or other overnight staff when running certain forms of engineers train. In reality the clips and scotches get “borrowed” and then simply dumped on the track somewhere. A variation on the theme is the boxes being broken open.
To counter all this, there’s been moves to provide more conspicuous boxes, in more conspicuous locations, where they can be checked easily - so a move to put them on platforms where conveniently possible, and with a glass front so missing equipment can be more readily identified. Likewise more secure locks. Needless to say now less convenient for the staff who are actually supposed to use them, but avoids the problem of turning up in the middle of a major failure to find an empty box!
Remote securing is the preferred means, however this isn’t universally fitted, and can only be used if the points have full detection and indication reported by the signalling system.