About Us

Thomas Crame · February 21st 04, 09:31 PM posted to uk.transport.london

wrote in message ...
In article ,
(Peter Smyth) wrote:

"Thomas Crame" wrote in message
om...

The circle and H&C have a shared number series, I think.
The picc numbers were in the following series (in 1999):
250 - 257, 260 Cockfosters to Rayners Lane
261 - 267, 270 - 272 Cockfosters to Uxbridge
273 Spare at Acton Town (midday)
274 - 277 Northfields Midday Stablers
300 - 307, 310 - 317, 320 - 327, 330 - 337, 340 - 343 Cockfosters to
Heathrow
347 Acton Town Overnight stabler
351 - 357, 360 - 366 Arnos Grove to Northfields
371 - 373 Cockfosters Midday Stablers

Is there a reason why the don't use numbers ending in 8 or 9?

Peter Smyth

I think this started on the Northern Line, with the introduction of
programme machine working in the 1950s, and other lines followed suit. On
the programme machine rolls, the information for that train is stored in a
row of punched holes. Binary Coded Decimal is used a lot with the
programme machines and the various remote control of the IMRs etc. and
describers.

In BCD the decimal number is represented by the digits 0 and 1. The number
4 is represented by 100, 5-101, 6-110, 7-111, 8-1000, 16-10000 and so on.
This means an extra wire etc. for each extra digit. I suspect that this is
the reason. I have the info. on it somewhere, but not to hand.

The dutys (on the Northern Line anyway) also do not use 8 or 9. I can't
remember when it changed. It was a long while ago, but mot at the same
time as the programme machine introduction.

Roger

The programme machines use octal numbering, which is why they don't
use 8s or 9s. It's also impossible to have a train number beginning
with a number higher than 3 on a programme machine signalled line.

A few train numbers you won't see:
375 - This is used as the "Start of service" by a programme machine.
376 - Used for "End of service"
377 - Indicates the programme machine roll has come off the carrier,
as all contact fingers are made.

[email protected] · February 21st 04, 10:08 PM posted to uk.transport.london

In article ,
(Thomas Crame) wrote:

wrote in message
...
In article ,
(Peter Smyth) wrote:

"Thomas Crame" wrote in message
om...

The circle and H&C have a shared number series, I think.
The picc numbers were in the following series (in 1999):
250 - 257, 260 Cockfosters to Rayners Lane
261 - 267, 270 - 272 Cockfosters to Uxbridge
273 Spare at Acton Town (midday)
274 - 277 Northfields Midday Stablers
300 - 307, 310 - 317, 320 - 327, 330 - 337, 340 - 343 Cockfosters
to
Heathrow
347 Acton Town Overnight stabler
351 - 357, 360 - 366 Arnos Grove to Northfields
371 - 373 Cockfosters Midday Stablers

Is there a reason why the don't use numbers ending in 8 or 9?

Peter Smyth

I think this started on the Northern Line, with the introduction of
programme machine working in the 1950s, and other lines followed
suit. On the programme machine rolls, the information for that train
is stored in a row of punched holes. Binary Coded Decimal is used a
lot with the programme machines and the various remote control of the
IMRs etc. and describers.

In BCD the decimal number is represented by the digits 0 and 1. The
number 4 is represented by 100, 5-101, 6-110, 7-111, 8-1000, 16-10000
and so on. This means an extra wire etc. for each extra digit. I
suspect that this is the reason. I have the info. on it somewhere,
but not to hand.

The dutys (on the Northern Line anyway) also do not use 8 or 9. I
can't remember when it changed. It was a long while ago, but mot at
the same time as the programme machine introduction.

Roger

The programme machines use octal numbering, which is why they don't
use 8s or 9s. It's also impossible to have a train number beginning
with a number higher than 3 on a programme machine signalled line.

A few train numbers you won't see:
375 - This is used as the "Start of service" by a programme machine.
376 - Used for "End of service"
377 - Indicates the programme machine roll has come off the carrier,
as all contact fingers are made.

I stand corrected, thanks for the info.

Roger

Thread Tools	Search this Thread
Show Printable Version	Search this Thread: Advanced Search
Display Modes
Switch to Linear Mode Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
ELL Train Reporting Numbers	Jack Taylor	London Transport	0	May 15th 10 02:46 PM
Direct phone numbers to WAGN stations	M Patrick	London Transport	6	December 8th 04 08:36 PM
Trivia: Declining passenger numbers	Troy Steadman	London Transport	13	October 25th 04 05:04 PM
Oyster card slot numbers	Dave Newt	London Transport	5	June 29th 04 07:57 PM
Chingford line passengers numbers	Jason Hobbs King	London Transport	2	August 16th 03 07:32 AM

Menu

About Us