RailWest

Indeed, the ringed arm read into the goods yard on the right. The current Swanage Railway have a different version of that signal (seen here in 2009) and here the ringed arm reads into the run-round loop on the left.

No wonder I could not find anything 'interesting' when I went there at a later date :-)

>>>..to help obscure the joint between the scenic boars... Yes, such things can be a pig to hide :-)

Nor was it unusual for LQ arms to survive well into the 1960s anyway on place such as the ex-L&SWR and S&DJR.

IIRC - but I would need to check and that could take some time - there was the normal set of AB instruments for Down trains on the Down line and Up trains on the Up line, plus another instrument for trains going wrong-direction on the reversible line.

In all the above new examples, the 'Up Starter' at the START of the platform IMHO is superfluous, as all moves into the platform could be controlled by the stop signal in rear or a shunt signal at the Down line end of the crossover. Likewise in C1 and C2, as there appears to be no pointwork or other potential obstructions between the Down Home and Down Starter, then one of those is superfluous also.

>>>Double slip on a running line at a wayside station? Most unlikely... Generally I would agree, but such things were not unknown eg Marston Magna.

What about the alternative, where the block section is actually the stretch of line past the platform? In other words, the 'Home' at the entrance to the platform is West's 'section signal' for the line to East, and the 'Starter' at the exit from the platform is actually East's Home signal. Neither signal would be slotted by both boxes.

Different railway companies had different colour schemes, and also at different times. For example, level-crossing locks were blue on some lines at one time, but then became brown in later years. Could the OP be more specific about his chosen period please?

It is certainly the case AFAIK - and from all the examples which I have seen - that GWR block bells used for block working on double-track lines did contain relays driven by the line wire circuit, which switched current to the bell coils from a local circuit. The block bells used with electric train staff or electric key token circuits had no tappers (worked by the plunger in the staff/token instruments) and no relays of their own, usually being controlled from relays in the instruments instead. AIUI the bell coils local circuit was usually about 6V.

Now, here's a puzzle.... The signal-box at Burnham had a door and two windows in the end nearer the pier. The end near Highbridge had merely two windows (as seen in this photo dated 1960 https://thetransportlibrary.co.uk/index.php?route=product/product&product_id=166290&search=Burnham-on-Sea) and appears like that in all the pre-BR pix which I have seen. BUT...this photo is dated 1952 and clearly shows 3 windows !https://thetransportlibrary.co.uk/index.php?route=product/product&category_id=65&page=1876&product_id=70637 so unless the image date is wrong, was the box altered from 2 to 3 and then back to 2 ?? Just to confuse the issue, after the box was sold to the Yieldingtree Museum they converted that end to a door + one window (of different pattern) and when eventually it ended up in the hands of the S&DRT they converted it back to 3 windows.

A BR-era job with a frame put in the former Porter's Office on the Up Platform

Corfe Castle is on the site of the FIRST, not the second, box at that station. Again, it is a modified version of the original and about a 1/3rd longer in length.

>>>The signal box at Swanage is a preservation copy of the original that was demolished, built on the same site as the old one - and you would be hard pressed to tell the difference. No, you won't :-) because (a) it is NOT on the same site as the original , but on the opposite side of the line with its frame back-to-track and (b) it is a modified version of the previous Type 3 style.

The Scottish lines originally were traditional LH running, but AIUI changed to RH running when RETB was introduced as it was easier then (for some reason) to deal with access to the sidings. The (recently) new 'dynamic' loop at Axminster was indeed RH running originally , apparently AIUI because this fitted better with the geometry of the points at the loop ends by enabling departing trains to leave the loop at speed. Exactly why and when they changed to LH running - and whether that is still the case - is not known to me. Certainly as a 'customer' I found the RH running b***** confusing when waiting for a train at a station that was different from all the others on the line :-(

>>>>...and only applies to the local geography such that other places still exist as normal (Exeter, Bristol, Bath.....) That is comforting to know :-)

AIUI the terms 'Direction Lever' and 'Acceptance Lever' relate to different methods of block working over single lines - sadly I can never remember the precise difference between the two :-( Certainly from a GWR/BR(WR) perspective the term 'Interlocking Lever' was often used for levers which controlled one of a number of different functions, say (for example) GF releases or 'switching out' at single-line passing-loops or 'wrong direction' running on AB lines such as at Exeter St Davids etc, so not exclusively related to block working in any way.

It might be worth asking the Exeter West Group about the arrangements for the Interlocking Levers which worked between the Middle and West boxes - it's been a very long time since I dabbled with them to remember now :-(

Which would suggest that it is physically possible to pull both levers?

Surely part of the set-up for the Interlocking levers at East and West must be that they lock each other, which presumably would have been done electrically. Otherwise, what is to stop both boxes pulling their levers and releasing the signals at both ends at the same time?

One important thing to remember, which does not seem to have been mentioned so far, is that - regardless of whether traps are provided or not, and whatever 'the rules' may say - it depends also upon what the interlocking does - or does not - allow. In a 'typical' simple passing-loop with no traps, then the opposing Home signals would be interlocked so that it would be impossible physically to pull them both 'off' at the same time, thereby enforcing the relevant rule about 'only one train at a time'.

Actually, there are two now :-) The layout at Crowcombe Heathfield (on a summit) with traps at each end replicates what was there in GWR and BR days until the line closed. The layout at Williton (much more on the level-ish) used to be similar until modified in the 1960s by BR. It has now been reinstated with traps at both ends again. The ability to admit trains simultaneously certainly helps to cut down on possible delays.

In the case of single-lines, with the exception of the S&DJR (who always managed to be just that little bit different from normal L&SWR practice), I would be hard pressed to think of more than one or two examples of SA arms on the Western Section. On the other hand, with the GWR it seemed be almost de rigeur to have one, usually under an Advanced Starting to boot :-)

Simple - at a loop with trap points at the exit ends, if an incoming train over-runs the Starting signal then (hopefully) it just ends up 'in the dirt'. If no trap-traps, then it might go head-on into the train waiting at the opposing Home (or, even worse, if trains could enter simultaneously, into the side of the carriages :-( ).

>>>I've looked up a few signalling diagrams for single track line stations with passing loops, and it appears (though I can't be 100% sure) that quite a few have the Home signals close up to the point at the beginning of the loop..... I would suggest that was the normal practice, for one simple reason. Once a train has started to pass a Home signal which has been 'off', you do not want the signalman to be able mistakenly to replace that signal, unlock the the facing point ahead, and then move the point under the train. The necessary 'route holding' used to be provided by the 'lock bar' for the FPL, which would extend from the point back to the Home, but clearly not the length of a 10-coach train! Where the Home is some considerable distance back from the facing point, then usually there would either be a track-circuit between the Home and the point that would lock the FPL and point levers and/or a 'running shunt' at the point itself (the latter can be seen at the Minehead end points of the loop at Blue Anchor, although it's a WSR adaption of it original use).