As part of the Missenden Railway Modellers summer retreat, I was lucky enough to be invited to see the Princes Risborough North Box, which is now in the custody of the Chinnor and Princes Risborough Railway Association.

The box had lain derelict for many years, since its closure in 1991.  Somewhat peculiarly, it was a break in by vandals during this period that potentially saved the box as it identified how seriously affected by water penetration and rot it was.  This lead to the preservation society being able to convince Network Rail to let them in to stabilise it and they feel that had this not have occurred, when the building’s distress subsequently became apparent to Network Rail they would have merely ripped it down.

The box is substantial and is apparently the largest remaining GWR signal box in the country.  It originally controlled the north end of Princes Risborough station but its size was determined by the complicated junction at this end of the station with three branch lines splitting from the main-line to Bicester and beyond.  The branches it served were Aylesbury (still part of the national network), Oxford (closed in 1963) and Watlington (closed in 1957 but now reopened to Chinner as part of the preserved railway).  The Railway Clearing House map is below and just to prove the complexity the box diagram too!

As would be imagined, there is a fairly extensive array of levers although in the various rationalisations that occurred through the GWR and BR eras have reduced the extent of these significantly.  The preservation association have, however, reinstated many of the missing levers even though they are not yet connected to anything.

At present, the preservation society only have a temporary connection into the Princes Risborough bay platform but the intention will be to make this a permanent link onto their line, signalled via the box.  However, given that this will still only be one of the lines that the box formerly served, there will only be a limited amount of it in use.  Apparently the plan therefore will be to separate off the bulk of the box to create an interactive museum where visitors can play the part of a signalman.

The treat for me (and many of the others on the visit) was to go into the frame room to take a look at the locking frame.  Although I had seen this in model form before, I had never seen a full sized locking frame – even though this is only a shadow of its former self as it only covers that proportion of the box that was in use at 1991, it is still very complicated as you can see.

The Chiltern line is now really quite busy, far more so than when I used it to get to Solihull on business regularly.  In addition to the procession of class 168 DMUs, there were class 68s on the trains for Birmingham and Wrexham plus a pair of trips each day with class 66s on spoil trains from the Thames Tideway sewer project.

And finally, this is what the box looked like in the days of steam.  This photograph was taken in 1960 by Christopher Bomken when he was still in his shorts – it even won him 2 shillings and sixpence in a school photographic competition.  Recognition at last Christopher it has made the interweb!