The Dean Forest Railway (The DFR) is situated just off the A48 at Lydney in the Forest of Dean in Gloucestershire. It runs for just over four miles from its junction with Network Rail in the south to its northern terminus at Parkend.
Its main centre is at Norchard in the middle of the line.
This is well sign posted from the centre of Lydney. Norchard has a large free car park, a very well stocked shop, an attractive museum (with a selection of telecoms exhibits among the railwayana), a cafe and workshops, sheds etc. It is usually best to come to Norchard to join the trains as you may catch a train going in either direction and so have the least waiting time.
The main telephone exchange, a UAX13, is housed in the museum at Norchard and is situated behind a glass wall allowing customers to view the apparatus.
Telephones are provided so that calls may be made through the exchange and the progress of the calls can be watched through the glass. The selectors have been equipped with "In Use" lights to help visitors follow the progress of the call.
Norchard also provides Public Address, control of the sites clocks, a speaking clock, museum announcements etc.
There is a second Strowger exchange situated at Parkend but this is not visible to passengers. This has been constructed from recovered PABX4 equipment.
A third, quite small, uniselector exchange has been constructed at Lydney Junction Signal Box and was brought fully into service on the 10th July 2013.
Similarly a fourth small exchange at Parkend Signal Box has been installed which will be used for any phones required on the possible rail extension to the north.
These exchanges provide a service to the railway's staff and to this end there is a cable network covering the length of the railway. The cable work needed to connect the exchanges together and provide a linked numbering scheme for the whole railway was completed in September 2010.
Running in the same cables are local battery telephone circuits connecting the signal boxes to each other. These are quite independent of the circuits running from the telephone exchanges and provide a back up should there be any difficulty with the dial phones. There are also signal post telephone (SPT) CB circuits that terminate on line concentrators at Norchard, Lydney Junction and Parkend signal boxes.
As a final back up, BT lines are installed in the signal boxes and at the main centre at Norchard.
The cable network is also used to distribute 30 second clock pulses and public address speaker connections around the site at Norchard. Equipment alarms at Parkend, Norchard signal box and Lydney Junction signal box are extended back to Norchard. The signal and telegraph group (S&T) also share the cable network with circuits that control and monitor signals, points, treadles etc.
As the staff available to maintain the strowger equipment are getting older and we find it difficult to locate replacements, we are now installing a digital system based on raspberry pi computers running Asterisk software as an alternative. The digital and strowger networks are interconnected at Norchard so that all telephones on the railway can reach each other.
Site edited by John Bathgate
This site was last significantly updated on
16th January 2020
This is issue 148