BT CT22A Trial Blue Payphone - I8100331
This is an example of the first properly "modern" payphone in the UK. They were the first to replace the old "Pay On Answer"/"pips"rotary dial phones that had been in service for some twenty years.
BT introduced the Blue Payphone in 1980, installing a trial batch of Swiss made Autelca AG AZ33 phones, which BT called the CT22A. The trial phones were put in high usage locations, such as airports and main railway stations.
The trial was deemed successful and soon these went into production for several years in a slightly updated version made in the UK by AGITELCO, the CT22B. The trial CT22As had LED credit readout and white on blue instructions (from which the name Blue Payphone was derived, its said) whereas the production CT22Bs had an LCD credit readout and blue on silver (bare stainless steel) instructions.
As a student I first encountered one of these on Waterloo station, a typical trial site, some time in 1980 or 81.
This particular example, serial number 207, reportedly spent its service life in York station. It still carries its original, and possibly only, number label. It was taken out of service in 1985 or 6 and saved by a collector who ran it up once or twice and then stored it... until now.
It has clearly been repaired several times, only one of the three coin mechanisms has the same serial number as the phone. It is more or less complete but needs work on the locks - only one is present and that doesn't have a key - and the coin tray is missing. It is fully operational, though it cannot currently be put on a wall as the bolts that hold the phone to its backplate are missing. That, though, should be fixed soon.
They were slow and clunky: literally. They had a painfully slow Intel 4040 microprocessor which clocked at a maximum of 750kHz at which it processed a whopping 62,000 instructions per second. You had to wait a couple of seconds after lifting the receiver while it chuntered through the three coin mechanisms resetting them one by one before it would allow you to put in 8p, in four 2p coins, before you could dial. While it had a keypad it was actually pulse dialling, so it took a while after you had dialled to actually connect a call. The later Blue Payphone 2/payphone 500/600 was half and half: pulse to dial, then switching to tone during the call!
One advantage of the new technology, one that I remember featured heavily in BT's advertising of the time, was that this was the first payphone to give change. Well, it sort of did. It actually returned coins that you hadn't used. Woe betide anyone that put in a single 50p for a 8p local call expecting to get 42p change - that 50p was gone! That's where the Follow On Call button came in: to use up credit left from a previous call.
I am not sure how many CT22As were made. BT ordered an initial trial batch of 100. This is serial number 207, made in Switzerland on 24th September 1980, so the first batch was not the only one. Some of the replacements, possibly field spares or maybe taken from other phones, have serial numbers around 380-394. CT22A number 390 has also been preserved, though not by me. It was sold off as part of a BT Museum liquidation auction in 2002. There can not be many of these still around, though to be fair they were built like tanks, and weigh almost as much (36.5kg, and that's empty of coins!) so, who knows?
BT CT22A Trial Blue Payphone - I8100331
This is an example of the first properly "modern" payphone in the UK. They were the first to replace the old "Pay On Answer"/"pips"rotary dial phones that had been in service for some twenty years.
BT introduced the Blue Payphone in 1980, installing a trial batch of Swiss made Autelca AG AZ33 phones, which BT called the CT22A. The trial phones were put in high usage locations, such as airports and main railway stations.
The trial was deemed successful and soon these went into production for several years in a slightly updated version made in the UK by AGITELCO, the CT22B. The trial CT22As had LED credit readout and white on blue instructions (from which the name Blue Payphone was derived, its said) whereas the production CT22Bs had an LCD credit readout and blue on silver (bare stainless steel) instructions.
As a student I first encountered one of these on Waterloo station, a typical trial site, some time in 1980 or 81.
This particular example, serial number 207, reportedly spent its service life in York station. It still carries its original, and possibly only, number label. It was taken out of service in 1985 or 6 and saved by a collector who ran it up once or twice and then stored it... until now.
It has clearly been repaired several times, only one of the three coin mechanisms has the same serial number as the phone. It is more or less complete but needs work on the locks - only one is present and that doesn't have a key - and the coin tray is missing. It is fully operational, though it cannot currently be put on a wall as the bolts that hold the phone to its backplate are missing. That, though, should be fixed soon.
They were slow and clunky: literally. They had a painfully slow Intel 4040 microprocessor which clocked at a maximum of 750kHz at which it processed a whopping 62,000 instructions per second. You had to wait a couple of seconds after lifting the receiver while it chuntered through the three coin mechanisms resetting them one by one before it would allow you to put in 8p, in four 2p coins, before you could dial. While it had a keypad it was actually pulse dialling, so it took a while after you had dialled to actually connect a call. The later Blue Payphone 2/payphone 500/600 was half and half: pulse to dial, then switching to tone during the call!
One advantage of the new technology, one that I remember featured heavily in BT's advertising of the time, was that this was the first payphone to give change. Well, it sort of did. It actually returned coins that you hadn't used. Woe betide anyone that put in a single 50p for a 8p local call expecting to get 42p change - that 50p was gone! That's where the Follow On Call button came in: to use up credit left from a previous call.
I am not sure how many CT22As were made. BT ordered an initial trial batch of 100. This is serial number 207, made in Switzerland on 24th September 1980, so the first batch was not the only one. Some of the replacements, possibly field spares or maybe taken from other phones, have serial numbers around 380-394. CT22A number 390 has also been preserved, though not by me. It was sold off as part of a BT Museum liquidation auction in 2002. There can not be many of these still around, though to be fair they were built like tanks, and weigh almost as much (36.5kg, and that's empty of coins!) so, who knows?