A Return Ticket to Buckingham – Part 3, the Automatic Crispin

Peter Denny’s Buckingham branch was very much an operational layout; for many years Peter’s children – Stephen and Crispin – were his chief assistant operators.  However, as his children grew up they weren’t always available and Peter found himself operating short-handed.   He found this frustrating as the need to cover the missing person interfered with the remainder of the operators.

This provoked the creation of the Automatic Crispin, one of the more famous parts of the layout.  Long before the use of DCC, micro-processors or automatic shuttles, this was an electromechanical computer – and very ingenious (and mind bogglingly complicated) it is too.  This was designed by Peter’s other son – Stephen – and took the place of Crispin to operate a portion of the layout automaticaly, in response to requests and commands from the other operators.

The heart of the system are a pair of disks and a paper chart with holes in it; all powered by motors and the enivitable mechano!  The disks contain a series of metal studs or runners, each of which is connected to either the bell, the block instrument, the track or turnout relays.  Running across these were a series of wiper blades of brass that connected power to the studs or runner as required.


The operation of the disk was initiated by Grandborough Jct’s signalman.  As he sends a bell code, this sends a pulse of power to initiate the motor to rotate the disks or the paper chart on one segment; this first segment sends power to activate a bell code reply (each stud giving a ping).  When this is answered by Grandborough Jct, in addition to acknowledging the offering forward of a train with a further bell code, it sets the block instrument.  The acknowledgement of the latter being the next command to operate the correct route into the fiddle yard and power up the track in order to allow the train to arrive.  The arriving train would hit a dead portion of track at the end of the fiddle yard to stop it running away, but in the process would send the “train out of section” bell code back to Grandborough Jct to allow the line to be cleared.


The story always told by Peter was that the Automatic Crispin was required when the real Crispin went to University but I think it is time to share with the world that this was a white lie.  Crispin’s more prosaic explanation was that he had discovered girls at the time and all of a sudden, playing with Daddy’s trainset didn’t seem quite so interesting…….

As can be seen in the pictures, at present the Automatic Crispin is presently in bits, but is all beleived to be complete.  It is part of Tony’s master plan to reassemble this; its orignator Stephen is apparently up for assisting to, so who knows?

To conclude the last of these three posts on Buckingham Central, a few photographs and to give you a chance to see the Automatic Crispen in action, take a look at this link to the BBC News article on Peter’s death and some video from circa 1980 of the layout – enjoy!


It is fair to say that Peter Bond and myself were not as proficient as Peter and his sons in this, sounds like we need some more practise Peter……..





About highlandmiscellany

Just playing trains; my weekday life is a bit more serious though!

Posted on January 23, 2017, in Buckingham Central and tagged , , , , , , . Bookmark the permalink. 7 Comments.

  1. The automatic Crispen sounds like a development of Walker’s train describer, used amongst possibly others, on the lines into London Bridge, Cannon Street and Charing Cross. To advise the signalmen in the box in advance of the destination of the train about to pass from the control of one box to another, Charles V Walker, Telegraph Engineer to the South Eastern Railway had invented as early as the 1870s a train describer, which required for its operation only a single wire between boxes. One or more train describers per track were provided in the box at each end of the section, together with sometimes on intervening station platforms for the information of station staff. Both transmitting and receiving instruments consisted of circular glass fronted dials annotated around the circumference with the various descriptions, mounted on white discs, to describe the route and type of the next train. Generally there were twelve possible descriptions available on each instrument, one of which was ‘Cancel’, although twenty four position instruments were subsequently also used. Behind the face of the transmitting instrument was a circular disc upon which were mounted twelve pins, while around the outside of the face of the instrument was a series of small levers, one opposite each description. By pulling one of these forward, the signalman dispatching the train would release the previous lever and initiate the rotation of the pointer, driven by clockwork. As each pin was passed an electrical impulse was sent to the receiving box. Each step resulted in an audible click as each pin was passed and caused the pointer in the receiving instrument(s) to follow suit, until they both (all) came to rest at the appropriate description.

    By 1957 the limitations of this equipment led to the SR/SReg’s worst accident on 4 December, see “St John’s Lewisham, 50 years on, Restoring traffic”, The Oakwood Press (now Stenlake), 2007.

  2. Thanks to Tony Gee for preserving Buckingham Great Central. It is good to know that visitors are continuing to enjoy operating the layout. The photos are excellent. Buckingham was designed to be viewed from operating distance and the taking of close up shots was discouraged. However, I think the photo of the Goods and Grain Warehouse really captures the atmosphere of a railway.
    On operating the railway to the timetable and keeping pace with the speeded up clock – I can tell you the clock is part of the Automatic Crispin. The speeded up clock is sometimes referred to as scale time. When fully functioning with the Automatic Crispin the clock advances the punched hole paper tape every 10 scale minutes. In turn the paper tape sets the storage sidings points, bell code etc. in line with the timetable. At the entrance/exit to the storage sidings there is a detector that identifies if a scheduled movement has taken place. In the event that a scheduled train has been delayed by more than 5 scale minutes the clock will stop until the train passes the detector. Reference is made to the clock stopping in the online BBC video.
    Interestingly, Bond is Peter Denny’s middle name and the maiden name of his mother. How apt it was to see another Peter Bond at the Buckingham controls.

  3. Always loved reading about Buckingham, its operational correctness and variety. The news that it was being preserved was such a wonderful thing to hear about a few years ago. Tony is doing God’s work for the entire hobby by taking it on and curating it. As I grew up I hankered after some day seeing it for real – so these blog entries are the next best thing! Thanks for posting them.

    My current work in progress is an attempt to channel the Buckingham operational characteristics but using a later period (early 60s) and moving to the west by a few hundred miles to a fictional terminus on the Welsh coast. My blog about it and its relationship to Buckingham GC is at http://www.portdinllaenlines.com/. The layout itself is located some thousands of miles further west of that in (usually) sunny California!

    As part of that project, eventually I have the ambition to create an open-source software-based automatic Crispin on top of a system base like JMRI + DCC. The combo has the basic control primitives but today like track circuits and control of power but do not understand either block bells or the intricacies of the Buckingham style (realistic) timetable with all its different daily patterns and sub-options that Peter recorded in his books. It being software, I would hope to make changing the timetable and sequences a less onerous process.

    If I get there, probably it would be called a “virtual Crispin” in honour of both its immediate and grand-predecessors…

    • Adam Richards

      I read with interest your article where you commented on my father’s layout and the possibility of creating an updated Automatic Crispin. Being the original prototype I think father would be very pleased to think his idea could be carried forward into the 21st century in, what I hope would be, a more reliable system. In this regard I should add that replacing me was a tall order in that when I was at the height of my railway operating powers (sometime around 1969) Buckingham Central and the storage sidings ran like a smoothly oiled machine even if some of the shunting operations were carried out by rather rapidly moving station shunters.

      Good luck with Port Dinllaen and one day I hope to read of a fully working Virtual (I can hardly believe it) Crispin.

      Crispin Denny

      • Crispin,
        Thanks for chiming in, I’m sure your father did not think of the AC as your “replacement”, but rather a (probably poor and certainly less adroit) substitute for when you were otherwise occupied!

        The timetable that I have for Buckingham is the one in the Peco books and it is quite subtle and varied, so I can see it would keep you on your toes. For PD I am taking real WTTs for the LMR Afon Wen line and blending them with a set of services for the fictional port, both with WR trains from South Wales to the North and former ER trains from Marylebone (the timeframe being while Midlandification was occurring after the regional reorg).

        Well, I’ll soldier on and see what can be done, I’m glad you didn’t find the idea too offensive. What I have in mind would be more of a toolkit so that Virtual Crispins could be relatively easily created and “taught” via definition files how to operate defined parts of any layout in a prototypical fashion using block bells and instruments to a suitable timetable – also fed in as a file. These digital VC “clones” would be as reliable as the trains, sensors and electronics allow – the human element always being likely to gum up the works, of course!

        In fact we might even be able to cope with early/late running trains being sent into storage in the “wrong” order or with the wrong train class set by the human signalmen.. By sticking individual RFID “chips” like the ones used in pets under the locos, wagons and carriages, we can detect the contents of trains as they leave the human areas and so adjust the automated area’s response.

        Once I have got past some improvements I am doing for the XtrkCAD design program, I’ll be able to move over to JMRI and get started.

        Thanks again,

      • Adam

        My daughter found the following entry on Wikipedia. I thought you might be interested –

        A fictional branch of the Great Central Railway.

        Buckingham went through a number of major rebuilds over the years and was regularly featured in the modelling press.

        A feature of the later railway was ‘The Automatic Crispin’. This was a very early example of model railway automation using a form of drum sequencer. It responded automatically to signalbox bell codes, in much the son way that Denny’s son Crispin had previously done when operating the railway.

        Denny died at the end of 2009 but portions of the layout are still exhibited.

        Crispin Denny

      • Wikipedia – 21st century fame indeed!!

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