DFR - Miscellaneous Forms held as PDFs

DFR Internal Directory

Form used for Lineside Surveys

Lineside Work Party Briefing Form

Fault Log Form

Blank DP Card

Maintenance Record Forms

Norchard Selectors etc

Parkend Selectors etc

Norchard - Power, Ringing, Alarms

Parkend - Power, Ringing, Alarms

Lineside Cabinets


Norchard Signal Box Concentrator

Lydney Signal Box Concentrator

Parkend Signal Box Concentrator

Norchard Main Public Address Equipment

Lydney Junction Public Address Equipment

Clock System

DFR - Diagrams held as PDFs

Lydney Junction Exchange etc.

This is a simple uniselector 22 line exchange. The uniselector line finder extends a caller to Norchard and the Norchard first selector provides dial tone. Any one dialling a 6 is connected to a junction incoming to Lydney Junction and the two final digits are used to position a uniselector onto the called number's line circuit. Local calls on the Lydney Junction exchange are therefore connected via junctions to and from Norchard. This was known as trombone working.

Exchange Line Circuits

Line Finders

Line Finder Notes

Final Selectors

Final Selector Notes

Test Number

S & Z Generator

S & Z Generator Notes

Low Volt Alarm & Clock Pulse Reception

STARS Lydney Junction Alarm Relay Set

Ringer Start & Ring Distribution

MDF Terminations

Power Unit

Concentrator Line Circuits & Operator Circuit

Concentrator Timer Circuit

Concentrator Notes

Concentrator SPT Labels

Concentrator Internal Wiring and Connections in Head

Concentrator Line Circuits Relay Set U Points

Concentrator Operator's Relay Set U Points

Concentrator Timer Relay Set U Points

Norchard Exchange etc.

The exchange is basically a standard UAX13, however many locally designed selectors and relay sets have been added for various purposes over the years and these diagrams are listed below. The standard UAX13 diagrams are not shown here.

Ring Back Relay Set ex002a

Outgoing Junction R/S (ex004c)

Outgoing Junction R/S Diag Notes for ex004c (ex101a)

Outgoing Junction Regen R/S (ex120a)

Outgoing Junction Regen R/S (ex120b)

Outgoing Junction Regen R/S (mod ATW56160) (ex113a)

Wall Mounted Strips Bothway Junction Relay Set (ATW53010) (ex005a)

Final Selector Busying (Rack A1) (ex034b)

Final Selector Busying (Rack A2) (ex035b)

Junction Call Count Meters (ex056a)

Outgoing Junctions Distributor (ex065a)

Outgoing Junctions Distributor Notes (ex102a)

Incoming Junction 4000 Type Selector (ex066a)

I/C Junction 4000 Type Selector Notes (ex103a)

Level 0 Single Digit Final Selector (ex067a)

Level 0 Single Digit Final Selector Notes (ex104a)

Demo Direct Exchange Line 4000 Type Selector w notes (ex078a)

Demo Direct Exchange Line 4000 Type Selector (ex078b)

Demo Direct Exchange Line 4000 Type Selector ( ex078c)

Auto-Auto Regen Relay Set ( ex120c)

Auto-Auto Regen Relay Set ( ex120d)

Power Supply Arrangements (pe003c)

Power Supply Notes (pe008a)

Museum Signal Post Relay Set (mc007a)

Museum Signal Post Display (mc008a)

Museum Signal Post 6 Volt AC Supply (mc009a)

Museum Signal Post Notes (mc014a)

Museum Speaking Clock Relay Set (mc012a)

PW Tele to Tele Circuit (mc011b)

Main Overlay Point (MOP) (bt005a)

Overlay Network Circuits (bt007b)

Overlay Network Notes (bt008a)

Norchard Signal Box.

The signal box equipment is a stand alone concentrator of relay design providing all common services from its internal transistor equipment. These diagrams are listed below.

Concentrator Diagram Notes

Concentrator Line Circuits

Concentrator Operators Circuit

Concentrator Timer

Concentrator Tone Generator

Concentrator Ringing Converter

Concentrator Head Tester Keys

Concentrator Alarm & Clock

Parkend Exchange etc.

The exchange has been constructed mostly from PABX4 equipment, however many locally designed selectors and relay sets have been added for various purposes over the years and these diagrams are listed below.

Line Circuits & First Selector (ex021a1)

1st Selr Getting Dial Tone - Op & Rel Chart (ex021a2)

1sr Selr Dial Digit - Op & Rel Chart (ex021a3)

1st Selr Dial 9 - Op & Rel Chart (ex021a4)

1st Selr Release - Op & Rel Chart (ex021a5)

Local Final Selector (ex020c)

Incoming Final Selector (ex020b)

Final Selector Notes (ex105a)

Final Selector Call Distributor

Test Selector

Test Selector Access

AT5422 Tester

AT5422 Power Unit

Testing Arrangements Notes

Incoming Selector (Issue C)

Incoming Selector (Issue D)

Incoming Selector Notes

Multi Level Auto-Auto R/S with Regenerator (pages 1-4)

Multi Level Auto-Auto R/S with Regenerator Notes

Both Way Auto-Auto Relay Set

Both Way Auto-Auto Relay Set Notes

S & Z Generator

Ring Back

Spare Level NUT

Clock Pulse Reception

STARS Parkend Alarm Relay Set

Low Voltage Alarm Circuit

Ringer Control

Fuse Layouts

Rectifier Diagram

Power Plant Connections

Parkend North Exchange etc.

This 22 line uniselector exchange in Parkend Signal Box has been designed specifically to allow long lines to be connected to it and so will be available to service any lines going north from Parkend as the railway extends. It is very similar in circuit design to Lydney Junction Exchange but has been physically constructed somewhat differently. All outgoing calls are made via first selectors in Parkend exchange. Incoming calls arrive via junctions from both Norchard and Parkend.

Exchange Line Circuits

Line Finder & O/G Auto-Auto Relay Set

S & Z Generator and Allotter

30 Sec Pulse Generator

Final Selector

Test Number

NU Tone for Spare Numbers

Low Volt Alarm


Clock Pulse Reception

Ringer Control & Connections

Power Unit

Concentrator Line Circuits

Concentrator Operator's Circuit

Concentrator Timer Circuit

Concentrator Head Circuit

Concentrator Operator Phone

Concentrator Type 4 Uniselector Connections


STARS (Signals and Telecoms Alarm Reception System) collects alarms from around the railway and directs them back to Norchard. Any alarm is first displayed by the appropriate lamp lighting on a simple display at Norchard exchange. If the alarm persists for more than six minutes it then lights a lamp in a key and lamp display in the shop office. The appropriate officer can then be informed of the alarm condition. The system is notable for the way in which up to three alarm locations can be combined to transmit alarm signals over a single wire to Norchard.

STARS Norchard Circuit Notes

STARS Circuit Elements

STARS Reception Relay Set at Norchard

STARS Shop Display Relay Set

STARS Parkend Alarm Relay Set

STARS Lydney Junction Alarm Relay Set

STARS Norchard IDF Termination Strip Connection


The public address equipment is quite complicated as access to the amplifier is required from two microphone positions and from several telephones around the site. These telephones gain access to the amplifier by dialling a Norchard number and by also pressing a button which puts a loop on a control pair. The amplifier is also accessed on a high priority basis by the fire warning equipment to distribute a warning tone, and by a CD player with very low priority to provide background music when required.

PA Circuit Elements

Overall circuit (difficult to read)

Telephone Access circuit diagram

Audio Switching circuit diagram

IDF Terminations

Norchard Speaker Arrangements

Music Channel Equipment

PA Tele Access R/S U Points

PA Audio Switching R/S U Points

24V Supply

Microphone Connections

PA Diagram Notes


The Fire Warning equipment was designed as an interim system until a regular fire alarm system could be installed by our alarm contractor. The equipment is still in use. Essentially, if any one on the Norchard site dials a given number on an internal phone, then the warning system provides a warbling tone over the PA system for one minute. The originator can hang up and dial other numbers while the one minute tone is sounding. The two microphones connected to the PA system have priority over the warbling tone so that instructions can be issued over the PA.

Overall circuit diagram 254Kb

Diagram Notes

Shop Equipment 36Kb

Terminations on the IDF Local Block 60Kb


The Clocks at Norchard are controlled by a standard GPO pendulum master clock. A second master is available and can be switched in should there be a difficulty. We have three types of clock in use.

1) the usual 30 second pulse clocks that are connected in series within the main building.
2) clocks that are driven over separate pairs by a 50 volt supply that reverses every 30 seconds.
3) pulse clocks that are remote from the main building and need to be fed via separate pairs with a 30 second pulse.
4) the 30 second pulses are also fed to Parkend and Lydney Junction over the second wire of the alarm/clock pair.

Master clocks and main circuitry

Distant clock drivers circuitry

Diagram Notes

IDF Strip Connections

Clock Locations

Telecoms Office Clock Regenerator


Page provided by John Bathgate

This page was last updated on
28th July 2020