Help with a signalling question please.

[edwin_m]

The OP appears to be a photo of a photo in a magazine. Apparent curvature may just be the magazine not lying completely flat.

 

[Rescars]

The symbol that looks like a cleared stop signal represents a slot. On this particular diagram, the slotting of a distant arm by the stop arm above it is implicit, and no symbol is shown. The symbol here indicates that the distant arm is additionally backslotted by the next stop signal beyond.



An underbolt is a form of mechanical release on a lever, as distinct from a slot which is on the signal.

Many thanks for your explanations. Much appreciated. Would an underbolt be operated electrically, or would there have been a mechanical connection between the two boxes in question.

 

[Railsigns]

Many thanks for your explanations. Much appreciated. Would an underbolt be operated electrically, or would there have been a mechanical connection between the two boxes in question.

An underbolt is a mechanical release. There's a drawing of one on the HMRS website.

 

[edwin_m]

The symbol that looks like a cleared stop signal represents a slot. On this particular diagram, the slotting of a distant arm by the stop arm above it is implicit, and no symbol is shown. The symbol here indicates that the distant arm is additionally backslotted by the next stop signal beyond.



An underbolt is a form of mechanical release on a lever, as distinct from a slot which is on the signal.

This distant is actually operated by North - it clears if any of North's three distants on the gantry approaching the platforms is clear, so indicates that an approaching train has clear signals through the station and at least as far as North's intermediate block signals beyond. This is somewhat surprising as one of these is for a low-speed divergence into the platform loop, so the South signaller should only be clearing the junction signal once the train is seen to be approaching at a suitable speed, by which time it would have passed the first distant anyway.

 

[MoleStation]

Also starting trains on the up line in those steam days were usually pushed over the viaduct by a banker and they had to return through to North Durham to wait for the next push up the hill to Neville's Cross/Crossgate Moor, so I'm guessing they would have to be signalled individually as well