Butts Junction treadle

A requirement in the early days of operations was an indication at Medstead signal box when the evening dining train left Alton station. It seems sometimes the train left with no one telling the signalman at Medstead whose first indication of the train’s arrival would be when it arrived at the down home signal.

A simple solution was developed which in different guises still works to this day.

At Butts Junction was a trackside treadle which operated a relay in the Alton telephone exchange which in turn sounded a buzzer in the station office.

An additional set of relay contacts activated an auto dialler relay set, shown below; this dialled a number connected to a relay set at Medstead signal box via the internal telephone system. This relay set would answer the call, sound a buzzer and send a signal back to Alton to release the call. The signalman could either cancel the buzzer or it would auto cancel after a delay.

It was not possible to have a direct circuit between the two stations due to a shortage of cable pairs.

The first attempt was a proper auto dialler which proved unreliable, this was replaced by a DIY set comprising of an electronic sender previously used in STD equipment, a type 4 uni-selector and a number of 3000 type relays completed the relay set.

Over 3000 calls a year were connected by this circuit, I was impressed with this figure only to be told in its previous life the sender would handle that number in a few days.

The circuit was provided on the understanding it was an indication only and not to be relied on, if the telephone circuits were busy between the 2 exchanges on other calls and the relay set activated the call would result in no connection.
Meters connected to the circuit indicated 95% of calls would be connected successfully.

With the introduction of the Norstar switches the Hotline facility was used, the old relay set has been retained for possible future use in the demonstration exchange.

It was taken out of service 5th March 2010 with the introduction of the Alton colour light signalling. 

Shown below is the first attempt - it proved unreliable and was replaced by the version above