On Apr 3, 1:14*am, Charles Ellson wrote:
On Sun, 1 Apr 2012 12:33:21 -0700 (PDT), Stephen Furley





wrote:
On Apr 1, 6:15*pm, wrote:
On Apr 1, 6:20*am, wrote:

*Letters on dials were originally to aid in dialing exchange names, eg
PEnnsylvania 6-5000 instead of 736-5000. *The US gradually
transitioned to "All Number Calling" by 1980.

I wrote a reply to this, but for some reason Google Groups won't allow
me to send it. *I'll try to send it as a reply just to you, which may
be better since it's quite long, and off-topic for this group.-

The above came through fine. *Not sure why google rejected your other
reply.

An email won't work. *This thread has already gone way off topic, so
it probably won't hurt to post it publicly. *Others may find it of
interest. *Maybe break it up into parts. *Thanks.

(Trains and telecommunications have many 'connections' in that they're
both common carriers, some of telephone technology is used for
signalling, and trains always have been heavy users of
telecommunications, including development of their own networks.)

Your post which I was trying to reply to is on Google Groups, in both
uk.railway and misc.transport.rail.americas, but does not appear in
either group in Giganews; I don't know what's going on.

The reply which I tried to send earlier was:

Somewhat different here. *0 was not used for the operator, at least
not in my time, the operator was 100. 0 was used for subscriber trunk
dialing. *I think 0 may have been used for the operator in the early
days, but that was before my time. *Normal GPO dials did not have the
word 'Operator' on them.

Older (pre-1950s?) ones did.

That's interesting, I've got serveral No. 10 dials which must be
pre-1950s, but none have the word 'Operator', and I don't think I've
seen one which did; how common were they? Most American dials do have
'Operator', including the WE dials on the 500, where it's printed in
such a way that it looks backwards.


0 is still used to call the local operator on PABX systems.

On small systems, larger systems sometimes used 01 (02 etc. being used
for inter-PBX calls) or 100 to extend the available numbering range.

Leaving aside some very early dials, and special ones for pre-payment
callboxes, test instruments etc. there were four main GPO dials, the
10, 12, 21 and 54a. *The 10 was used on candlesticks and early
Bakelite 'phones and was available in L (etter) and F (igure)
versions. *The L dial plate, *had only M and N on the 6 hole; O was on
the zero hole; there was no Q and no Z, *Later dials added the Q in
the zero hole.

Dials 10, 12 and 21 all used the same three-point fixing and could be
interchanged. Dials 54 (and 51) were manufacturers' designs with
simplified mechanisms which used a clamping ring to hold them (thus
could be replaced by the earlier types).

That's right, all could be mounted in models from the 150 candlestick
to the 300 series by this means. When mounted in the 706 a different
system was used, with a metal ring which clamped around the body of
the dial, held it place in the plone by two 'feet' fitting into slots
at the bottom, and a single screw at the top.

The 21 dial could also be fitted with a steel fingerwheel, with a
thicker spacer on the back of it, of the type used on the 10 and 12,
so it looked more like them when used as a replacement. The metal
fingerwheel was also used, always with a green dial plate, on the
standard payphone of the time.

The 21 was introduced for the new thermoplastic 706 'phone in 1959.

Early T.706s also used Dials No.12 which continued to be used for many
telephones supplied for railway use and optionally with PAXs.

A few very early 706s used the No. 12 dial, and also straight cloth
cords rather than the vinyl ones. One of these turned up on Ebay last
year, and was bought by somebody on the Classic Rotary Phones group
for a very good price. They also appear in some manufacturer's
literature of the time, but the vast majority of 706s were fitted with
21 dials.

Was the 51 the very similar lightweight plastic dial to the 54a, but
by a different maker? I've got the early dial version of the
ambassador, the bright yellow one, which is fitted with one of these
dials and that is fitted by means of four screws into the back of the
flange, so a different model of dial could not be fitted, unless you
drilled four small holes in it.

I've also got the (No. 25?) radioactive dial in a Trimphone, which
still has the glass tube in it, but I can no longer tetect any
radioactivity. I had three of the model 280 engineer's 'phones, with
the small dial mounted behind the receiver. I had to scrap one of
these when the rubber body turned to sticky black goo, so I've got a
spare dial, and various other parts. The other two 'phones of the
same model are still in good condition.