One modification was made that removed the need for a routing digit if the call was for Ropley and not a tandem one. If seized via level 4 a NO relay would operate (Number Only), this caused the stored digits to be sent without a routing digit.
At Ropley level 3 from the incoming 1st selectors gave direct access to the final selectors, the first stored digit on a Ropley local call being 3.
This facility later caused minor problems when several years later calls needed to be switched to the new exchange at Alton, the Alresford sets would send a routing digit of 6 instead of 3, at Ropley level 6 of the incoming first selectors was teed to level 3 of the local first selectors to give access to the Alton junctions.
The 0 and 1 sets at Alton and Medstead had the same feature on calls to Ropley.
Due to the limited number of junctions unanswered calls would be subject to a "time out" if the call was not answered within a specified period, the caller would get a short period of Number Unobtainable tone before being force released after around 4 seconds. The timer used was the SU1 timer from a type 5 STD Register.
In the early days, due to a lack of circuits between station, junctions were "bothway working" able to handle calls in either direction. The disadvantage of this arrangement was if the circuit went faulty (too frequently due to the overhead pole route) the equipment at either end had no indication and the circuit would still be free for traffic and the call would fail. There were ideas for a junction guard arrangement on the bothway circuits but the idea was not developed.
Later, with the introduction of underground cables, most junctions became uni-directional and junction guard equipment fitted, when the outgoing junction relay set was idle a high resistance relay was connected across the line. This relay, designated JG with a 15000 ohm coil, would operate to the line current from the A relay in the distant incoming selector, the low current prevented the A relay from operating. If a fault developed JG would release and the junction would be busied out of service and raise an alarm. There was also an advantage that the incoming selector could be removed for maintenance purposes, the far end equipment being automatically busied.
Initially four both way junctions were provided between Alresford and Ropley using four UAX 0 and 1 relay sets - these sets had 2 parts, later changes were made to allow a narrower rack to be installed and a second route was provided between Alresford and Ropley for local calls between these two stations, with two junctions from Alresford and Ropley, this being the busiest telephone route on the system. The original route handling tandem traffic was reduced to two junctions from Alresford and Ropley, if the local route to Ropley became busy calls could overflow to the tandem route. Four junctions were provided Ropley to Alresford. The original 4 foot 6 inch rack at Alresford was replaced by a 2 foot 6 inch rack to give space for a Carrier rack, the new rack only had space for two 0 and 1 sets on a shelf, the two spare sets were used at Medstead. The new Ropley local route relay set was much smaller.
During a year 20 to 30,000 calls would be switched between exchanges, no count was made of own exchange calls.
Above is a rough diagram made a number of years ago to show how the linked numbering applied to Ropley, Medstead and Alton.
As there are incoming relay sets at Ropley for the Medstead junction it dates to the time that exchange was the GEC 5100 PAX.
At the time there were plans for a big development at Butts Junction and level 5 at Alton was reserved for a small exchange there, the plans came to nothing and no equipment was ever obtained for there.
Each exchange had a test number on XX99 giving multi line reversals and XX98 with a single line reversal on answer. XX being the local first and second digits, at Alresford thetest numbers were 2298 and 2299.
An indication was given if there was an exchange fault by altering the cadence of the NU tone the caller heard, a signal was applied to operate the AP relay, possibly flicker earth. This gave five short bursts of NU tone then silence instead of the normal test number tone.
Ring back was provided on X8 and X0, (Alresford 28 and 20) the later was used as there were a few party lines in remote locations where line plant was scarce, these extensions were always in the numbering range XX0X, the phones shared a pair of wires but the ringing was down one leg to earth depending on which half was called, the 0X code ring back gave reversed ringing to the 8X one.
Another modification made was to reduce the apparent post dialling delay.
As mentioned earlier on the junction routes to the tandem unit pulse regenerators were used to store the number dialled, the junction relay sets would insert a routing digit before the stored number was sent introducing a delay between finishing dialling and hearing a tone. When the final selector connected ring tone there could a 2 second delay in hearing the tone depending of the cadence, the modification connected a short burst of continuous ring tone when the final selector H relay operated then the normal ring tone would be heard, the ring tone sounded similar to a digital exchange.
Junction relay sets at Ropley, the sets in positions 3 and 4 were the incoming part of the Medstead linked number working. Relay set 10 was for a Printer Meter Check.
Two bothway circuits to Alresford, two bothway to Alton, two outgoing to Medstead and one spare set, originally a third circuit to Alton but traffic did not justify it.
A problem was noticed on calls through the tandem equipment; it was not practical having a person originating a call at one exchange and another in the tandem noting what was happening.
A modification was made to allow one to make an originating call from a distant exchange, a small relay set was connected to XX80 of the final selector multiple, connected to this relay set was a line circuit.
When XX80 was dialled from a remote site the relay set would seize the line circuit, additional digits could then be dialled via the final selector, the relay set counted digit trains, dialling a fifth digit would release the line circuit allowing another outgoing call to be made.
This allowed one person to make calls from one site while being at another to observe progress, using this system the fault previously mentioned was quickly found.
Brief description of operation
KA operates when seized by the Final selector, trips ringing and connects NU
tone to caller. After a delay SL seizes line circuit and removes NU tone. Caller hears dial tone, dialled digits via D lead pulses AA relay, CD operates a start of pulse train and releases at the end of it stepping PC uniselector.
Caller dials required number and monitors progress, dialling a fifth digit PC steps and operates RL relay, this causes the release of SL and the circuit is restored for another call if required.
The D lead was spare in the ordinary Final selectors for the dialled digit path at Alton and Medstead exchanges but Alresford and Ropley had 2-10 PBX Final selectors and used the D lead for the PBX marking conditions. To overcome the problem Normal Post springs were fitted on level 8 which changed over the circuit from the PBX testing circuit to the pulsing path for the Test Access Relay Set.
September 2010 - while looking for something totally unrelated the following notes were found, dating from Summer 1980, they refer to ideas before the LNS was planned.
Interesting to note there are no plans for an exchange at Medstead, the station had been badly vandalised and it was thought the station building would be demolished.
The station was restored and is now home to the Building Department, Permanent Way, S & T , Wagon Group and Telecoms.
The following notes detail proposals for the future development of the automatic telephone system in conjunction with the extension of the railway to Alton.
Past experience has shown the need for a comprehensive telephone system on the Mid Hants and the following will allow full inter dialling between the 3 main stations, it will be important to introduce it from the start of the railways operation to Alton and so prevent the need to install an interim system which would mean complications to staff at a later date when changing to the new network. The design of the Alton network has taken into account the need not to introduce changes to the present telephone operating procedures, dialling codes or major alterations to the existing exchanges, the basis of the plan involves the installation of an automatic exchange at the Alton end of the line.
The distance from Alton to the exchange at Ropley prevents the direct connection of telephones unless special long line equipment is used, however each telephone would require one pair of wires back to Ropley, assuming a minimum of four lines – booking office, station inspector, signal box, platform telephone means four pairs of wires Alton to Ropley. By providing an exchange at Alton only two junctions would be required, two pairs Alton to Ropley (a minimum of two junctions to be provided to prevent exchange isolation in the event of a junction fault)
One must bear in mind that the number of lines installed far outweighs original estimates, it was originally thought that Ropley would have requirements for around six lines but now has over twice that number connected.
There are 3 main ways of interconnecting the exchanges.
a) direct junctions between exchanges, single digit dialling codes (two codes per exchange) but increased number of junctions, including four between Alresford and Ropley.
b) existing Ropley exchange to switch Alresford to Alton calls but will cause increased wear and possible congestion of Ropley exchange plus mixed one and two digit dialling codes.
c) The most suitable method is to introduce extra equipment at Ropley termed a tandem exchange, this will be used to switch calls between Alresford, Ropley and Alton.
The advantages of using a tandem exchange are as follows, number of junctions reduced, all dialling codes single digit (only one code for outgoing calls per exchange)
Ropley exchange will not have to switch Alresford to Alton tandem traffic.
Alresford and Ropley local exchanges will be modified in conjunction with the opening of the tandem exchange which will reduce wear and tear on these exchanges and therefore extend their life.
Equipment for the Alton exchange exists in store along with some of the equipment for the tandem exchange, the remaining items are being obtained at present.
The tandem exchange can be installed and placed in service pending the opening of Alton exchange.
In view of the amount of spare land at Four Marks and possible future development allowances have been made for a possible exchange at this station.
Next to be considered is the connection between Ropley and Alton for signal and telephone circuits.
On the present section of line the overhead wire has caused considerable difficulties and it is well known of the problems should one of these circuits go faulty also the time taken to locate and repair overhead faults.
A minimum of four circuits will be needed to Alton, signal box code telephone, block and two Alton to Ropley junctions.
In view of the high fault liability of drop wire the time that would be taken to run four drop wires seven miles and the disrepair of the pole route a polythene jelly filled cable (multi pair) is suggested.
The cable can be mole ploughed along side the track and will overcome the problems of erecting overhead multi pair cable or laying it on the surface where it can be damaged or stolen, also overhead cable is dearer.
As four circuits will be required at the outset a 10 pair cable will be required, this will allow a second pair for the block if needed, plus an alarm circuit (also Four Marks junctions) also spare pairs for future developments or any faults.
Any circuits to distant signals for lamp repeating will use drop wire via the telephone pole route.
Thought should also be given to the eventual replacement of the existing overhead wires with a buried cable between Alresford and Ropley.
Conclusion
The scheme details the most straightforward and cost effective method of providing communications with Alton and if provided ready for when services commence will overcome the problems which were found when communications were established from Alresford to Ropley.
Since the previous notes were written (Summer 1980) the railway has had donated the Plessey exchange and with the equipment acquired from Brockenhurst this year we now have the chance to replace the telephone system with more modern equipment, the two existing exchanges are approximately 40 years old and obsolescent, the replacement equipment is only about 15 years old and the type is still in every day use and spares are easy to obtain.
Work on the new telephone system has started with the replacement of Alresford exchange, the new unit opening, hopefully, Autumn 1981.
If the existing room can be reused at Ropley the old exchange can be taken out during the 1981/2 winter and a new exchange ready for the 1982 season.
When the new system is completed every phone will have a 4 digit number, therefore to call any phone from any other phone only the four digit number is dialled, no junction dialling codes needed, the automatic equipment will determine call routing.
Typical Mid Hants telephone numbers (new system)
Alresford 21XX Ropley 43XX Alton 44Xx Four Marks 30XX
In view of the number of calls handled at present between Alresford and Ropley a third junction may be required between these two stations to cater for the extra traffic to Alton.
February 1981.
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