On 4月25日, 上�8時46分, Steve Fitzgerald ] wrote:
In message
,
D7666 writes

On Apr 25, 12:39Â*am, Steve Fitzgerald ] wrote:

The Piccadilly still run them today in 3 car sets from Cockfosters to
the T4 loop for turning. Â*They are only the 'double ended units' only
though (8xx numbers) Granted they are out of public service but run
through the centre.

Please explain why a double ended unit needs to be turned especially
on a railway that would turn them with normal traffic anyway.

73 stock are made up of 2 3 car units making the 6 car train. Â*They are
handed; A ends and D ends (A are even numbers and D are odd numbers). Â*A
double ended unit can match with either but has to be coupled A to A or
D to D.

If one of the double enders that has been matched with a D end unit now
needs to be reformed to match with an A end unit it will need to be
turned first, hence the little trip to T4.
--
Steve Fitzgerald has now left the building.
You will find him in London's Docklands, E16, UK
(please use the reply to address for email)

It is impressive to see how LUL saves depot space (?) by taking an
empty little train round a full trip, clearly wasting a lot of
electrical energy if I must say.

On Apr 25, 11:06Â*am, Patrickov wrote:
On 4月25日, 上�8時46分, Steve Fitzgerald ] wrote:





In message
,
D7666 writes

On Apr 25, 12:39Â*am, Steve Fitzgerald ] wrote:

The Piccadilly still run them today in 3 car sets from Cockfosters to
the T4 loop for turning. Â*They are only the 'double ended units' only
though (8xx numbers) Granted they are out of public service but run
through the centre.

Please explain why a double ended unit needs to be turned especially
on a railway that would turn them with normal traffic anyway.

73 stock are made up of 2 3 car units making the 6 car train. Â*They are
handed; A ends and D ends (A are even numbers and D are odd numbers). Â*A
double ended unit can match with either but has to be coupled A to A or
D to D.

If one of the double enders that has been matched with a D end unit now
needs to be reformed to match with an A end unit it will need to be
turned first, hence the little trip to T4.
--
Steve Fitzgerald has now left the building.
You will find him in London's Docklands, E16, UK
(please use the reply to address for email)

It is impressive to see how LUL saves depot space (?) by taking an
empty little train round a full trip, clearly wasting a lot of
electrical energy if I must say.

But how often does this actually need to be done? Having a turning
triangle in your depot that you very rarely use is going to wase a lot
of space, which is a significant cost. I imagine the number of
occasions on which a unit that needs to be turned, but can not be in
some way marshalled into a service train going round the Heathrow loop
is likely to be quite small, given lots of trains go round it every
day, so there will be routine turning of most of the fleet.

Robin

On 4月25日, 下�5時43分, bob wrote:
On Apr 25, 11:06Â*am, Patrickov wrote:









On 4月25日, 上�8時46分, Steve Fitzgerald ] wrote:

In message
,
D7666 writes

On Apr 25, 12:39Â*am, Steve Fitzgerald ] wrote:

The Piccadilly still run them today in 3 car sets from Cockfosters to
the T4 loop for turning. Â*They are only the 'double ended units' only
though (8xx numbers) Granted they are out of public service but run
through the centre.

Please explain why a double ended unit needs to be turned especially
on a railway that would turn them with normal traffic anyway.

73 stock are made up of 2 3 car units making the 6 car train. Â*They are
handed; A ends and D ends (A are even numbers and D are odd numbers). Â*A
double ended unit can match with either but has to be coupled A to A or
D to D.

If one of the double enders that has been matched with a D end unit now
needs to be reformed to match with an A end unit it will need to be
turned first, hence the little trip to T4.
--
Steve Fitzgerald has now left the building.
You will find him in London's Docklands, E16, UK
(please use the reply to address for email)

It is impressive to see how LUL saves depot space (?) by taking an
empty little train round a full trip, clearly wasting a lot of
electrical energy if I must say.

But how often does this actually need to be done? Â*Having a turning
triangle in your depot that you very rarely use is going to wase a lot
of space, which is a significant cost. Â*I imagine the number of
occasions on which a unit that needs to be turned, but can not be in
some way marshalled into a service train going round the Heathrow loop
is likely to be quite small, given lots of trains go round it every
day, so there will be routine turning of most of the fleet.

Robin

Maybe I am just stimulated by the statement of "Cockfosters to T4".
Had I seen something like Northfields then I'd say it's very much
reasonable. Thanks for your insight.

On 25/04/2012 10:06, Patrickov wrote:
On 4月25日, 上�8時46分, Steve ] wrote:
In message
,
writes

On Apr 25, 12:39 am, Steve ] wrote:

The Piccadilly still run them today in 3 car sets from Cockfosters to
the T4 loop for turning. They are only the 'double ended units' only
though (8xx numbers) Granted they are out of public service but run
through the centre.

Please explain why a double ended unit needs to be turned especially
on a railway that would turn them with normal traffic anyway.

73 stock are made up of 2 3 car units making the 6 car train. They are
handed; A ends and D ends (A are even numbers and D are odd numbers). A
double ended unit can match with either but has to be coupled A to A or
D to D.

If one of the double enders that has been matched with a D end unit now
needs to be reformed to match with an A end unit it will need to be
turned first, hence the little trip to T4.
--
Steve Fitzgerald has now left the building.
You will find him in London's Docklands, E16, UK
(please use the reply to address for email)

It is impressive to see how LUL saves depot space (?) by taking an
empty little train round a full trip, clearly wasting a lot of
electrical energy if I must say.

Plus, the cost of crew time.