On 2 Apr, 12:19, "Recliner" wrote:
"rail" wrote in message







In message
* * * * *"Recliner" wrote:

"Chris Read" wrote in message

Thanks all. I had thought that DOO on the tube was a 1980s
phenomenon.

The Victoria stock uses a very simple 1960s system that's quite
different to that used in modern ATO trains. From memory, trains run
at either a standard restricted speed, or flat out, with no finer
controls.

There were four control codes used:

420 ppm up to line speed
270 ppm up to 25mph
180 ppm coasting up to 25mph
120 ppm used in connection with signalling

for the 270 code there is a governor that regulated the speed between
21 and 23 mph. *Over 25mph and the emergency brakes would come on
automatically.

A seperate 15kHz signal indicated points where power could be shut
off and the train allowed to coast. *As it approached the next
station there were a succession of command codes to slow the train
down. *Codes were calculated at 100Hz/mph so 35mph had a code of
3.5kHz. *There were 3 rates of breaking providied by mercury retarder
switches down to 4mph at which pont a constant pressure control took
over to ease the braking to a smooth stop.

Very sophisticated for the time; remember, practical ICs were a
decade or more in the future.

OK, that's a bit more sophisticated than I remembered. *And, yes, I
agree that it's very impressive, and reliable, for mid 1960s technology.
Mid/late 1960s car or airliner designs would feel a lot more antiquated
compared to today's products than do those elderly 1967 stock trains.
And, unlike those trains, which remain in heavy daily use, such cars and
planes would almost all have been retired long ago.- Hide quoted text -

- Show quoted text -

We are now on the third generation "Auto driver" box as well.

Also to go to a further depth of nitpicking, it wasn't just "Shut the
Doors" and "Press two (sic) start buttons", the drivers window also
had to be fully closed (prevented beheadings at the tunnel headwalls!)

Cheers

Puffernutter

On Thu, 2 Apr 2009 04:28:52 -0700 (PDT), puffernutter
wrote:



We are now on the third generation "Auto driver" box as well.

Also to go to a further depth of nitpicking, it wasn't just "Shut the
Doors" and "Press two (sic) start buttons", the drivers window also
had to be fully closed (prevented beheadings at the tunnel headwalls!)

Unusually for the time, there were no side doors to the drivers cabs
on 1967 TS, probably for similar reasons (press the buttons, train
starts moving, try to get out for some reason and wind up half inside
and half on the platform at Seven Sisters). ISTR that when 1960TS
units were fitted with ATO they had the side doors welded shut (or
otherwise securely locked).

On Thu, 02 Apr 2009 13:03:13 +0100
Uncle Toby wrote:
Unusually for the time, there were no side doors to the drivers cabs
on 1967 TS, probably for similar reasons (press the buttons, train
starts moving, try to get out for some reason and wind up half inside
and half on the platform at Seven Sisters). ISTR that when 1960TS

Presumably they credit the current central line drivers with a bit more
self preservation instinct. Either that or the cab doors are interlocked
with the ATO.

B2003

On Apr 2, 1:36*pm, wrote:
On Thu, 02 Apr 2009 13:03:13 +0100

Uncle Toby wrote:
Unusually for the time, there were no side doors to the drivers cabs
on 1967 TS, probably for similar reasons (press the buttons, train
starts moving, try to get out for some reason and wind up half inside
and half on the platform at Seven Sisters). ISTR that when 1960TS

Presumably they credit the current central line drivers with a bit more
self preservation instinct. Either that or the cab doors are interlocked
with the ATO.

B2003

Sliding cab doors came in with 1973 stock I think. Before that
(including 1960 stock) it was door handles and hinges, so nothing to
interlock.

"MIG" wrote in message
...
On Apr 2, 1:36 pm, wrote:

Sliding cab doors came in with 1973 stock I think. Before that
(including 1960 stock) it was door handles and hinges, so nothing to
interlock.

C69 stock has sliding doors and pre-dated the 1973 tube stock..

On Apr 3, 8:09*am, "J Lynch" wrote:
"MIG" wrote in message

...
On Apr 2, 1:36 pm, wrote:

Sliding cab doors came in with 1973 stock I think. *Before that
(including 1960 stock) it was door handles and hinges, so nothing to
interlock.

C69 stock has sliding doors and pre-dated the 1973 tube stock..

Ah true, but nothing at the time of 1960 and 1967 stock. I was only
thinking tube.

wrote in message ...
On Thu, 02 Apr 2009 13:03:13 +0100
Uncle Toby wrote:
Unusually for the time, there were no side doors to the drivers cabs
on 1967 TS, probably for similar reasons (press the buttons, train
starts moving, try to get out for some reason and wind up half inside
and half on the platform at Seven Sisters). ISTR that when 1960TS

Presumably they credit the current central line drivers with a bit more
self preservation instinct. Either that or the cab doors are interlocked
with the ATO.

There does not appear to be any sort of circuit for the cab doors on Central
Line trains as I have seen drivers depart with them open many a time. I
would believe that drivers close them as soon as they enter the tunnels ,
despite there being little to no danger, because of the noise and dust.

I imagine that it;s nice to have the cab door open in the spring when
running on surface level, but then drivers probably risk having something
thrown at them. Either that or operating rules require it to be closed.