Basil Jet wrote:
On 2015\06\20 22:03, Recliner wrote:
Roland Perry wrote:
In message , at 17:31:34 on Sat, 20 Jun 2015,
" remarked:
I wonder if they employ trippers on that stretch or if they fit the
test trains with AWS.

http://www.bbc.co.uk/news/uk-england-29110845

I've seen the tube trains under test at Old Dalby (last time I drove up
to the East Midlands a month ago). Unfortunately there wasn't anywhere
convenient for me to stop to take a photo.

The other odd thing about the line is the OHL a long way from any
electrified service lines. https://goo.gl/maps/Q70Uo

I think it's the only section of track, anywhere, with both fourth rail and
overhead electrification. I think that it's currently being used for both S
stock and IEP testing. Old Dalby is also where the currently surplus S7
stick waiting to enter service is being stored.

One unusual location for ex-LU stock the BBC missed is Long Marston:
http://www.railtechnologymagazine.co...e-this-anymore

IIRC Drayton Park has both fourth rail and overhead,
although obviously not for much distance.

The fourth rail isn't operational. It was disconnected when the overhead
was installed. It does have a short length of third rail and overhead, but
that's not uncommon.

On 2015\06\21 02:45, Recliner wrote:
Basil Jet wrote:

IIRC Drayton Park has both fourth rail and overhead,
although obviously not for much distance.

The fourth rail isn't operational. It was disconnected when the overhead
was installed. It does have a short length of third rail and overhead, but
that's not uncommon.

This seems to imply that overhead + 4th rail is in some way harder to do
than overhead + 3rd rail... I would have thought it would be the other
way around.

Basil Jet wrote:
On 2015\06\21 02:45, Recliner wrote:
Basil Jet wrote:

IIRC Drayton Park has both fourth rail and overhead,
although obviously not for much distance.

The fourth rail isn't operational. It was disconnected when the overhead
was installed. It does have a short length of third rail and overhead, but
that's not uncommon.

This seems to imply that overhead + 4th rail is in some way harder to do
than overhead + 3rd rail... I would have thought it would be the other way around.

I think it just so happens that no fourth rail DC trains normally share
tracks with any overhead line AC trains.

On Sun, 21 Jun 2015 02:04:13 +0000 (UTC), Recliner
wrote:

Basil Jet wrote:
On 2015\06\21 02:45, Recliner wrote:
Basil Jet wrote:

IIRC Drayton Park has both fourth rail and overhead,
although obviously not for much distance.

The fourth rail isn't operational. It was disconnected when the overhead
was installed. It does have a short length of third rail and overhead, but
that's not uncommon.

This seems to imply that overhead + 4th rail is in some way harder to do
than overhead + 3rd rail... I would have thought it would be the other way around.

c.313s don't use the fourth rail so it is redundant.

I think it just so happens that no fourth rail DC trains normally share
tracks with any overhead line AC trains.

Not since the DC line was converted to 3rd rail.

In message
-septemb
er.org, Recliner wrote:
This seems to imply that overhead + 4th rail is in some way harder to do
than overhead + 3rd rail... I would have thought it would be the
other way around.

I think it just so happens that no fourth rail DC trains normally share
tracks with any overhead line AC trains.

I can't think of any instances: I'm fairly sure the tracks are
segregated throughout at Barking and Upminster.

Euston used to have shared 4th rail and AC; that section was converted
to 3rd rail at some point in (IIRC) the 1980s.

Not sure if the Willesden TMD entry road is shared 4th and AC or just
shared 3rd and AC.

--
Clive D.W. Feather | Home:
Mobile: +44 7973 377646 | Web: http://www.davros.org
Please reply to the Reply-To address, which is:

On Sat, 27 Jun 2015 23:43:43 +0100, "Clive D. W. Feather"
wrote:

In message
-septemb
er.org, Recliner wrote:
This seems to imply that overhead + 4th rail is in some way harder to do
than overhead + 3rd rail... I would have thought it would be the
other way around.

I think it just so happens that no fourth rail DC trains normally share
tracks with any overhead line AC trains.

I can't think of any instances: I'm fairly sure the tracks are
segregated throughout at Barking and Upminster.

Euston used to have shared 4th rail and AC; that section was converted
to 3rd rail at some point in (IIRC) the 1980s.

Not sure if the Willesden TMD entry road is shared 4th and AC or just
shared 3rd and AC.

It would have been converted at the same time as the rest of the DC
line (and the 4th rail has since been removed) so the same as the
shared lines into Euston. While the sectional appendix instructs that
non-LU trains are not to enter Stonebridge Park depot or Queens Park
sheds under any circumstances there seems to be no converse
instruction preventing a disabled LU train or vehicle from being
shunted into Willesden TMD if necessary.

In article ,
(Charles Ellson) wrote:

On Sat, 27 Jun 2015 23:43:43 +0100, "Clive D. W. Feather"
wrote:

In message

-september.
org, Recliner wrote:
This seems to imply that overhead + 4th rail is in some way harder to
do than overhead + 3rd rail... I would have thought it would be the
other way around.

I think it just so happens that no fourth rail DC trains normally share
tracks with any overhead line AC trains.

I can't think of any instances: I'm fairly sure the tracks are
segregated throughout at Barking and Upminster.

Euston used to have shared 4th rail and AC; that section was converted
to 3rd rail at some point in (IIRC) the 1980s.

Not sure if the Willesden TMD entry road is shared 4th and AC or just
shared 3rd and AC.

It would have been converted at the same time as the rest of the DC
line (and the 4th rail has since been removed) so the same as the
shared lines into Euston. While the sectional appendix instructs that
non-LU trains are not to enter Stonebridge Park depot or Queens Park
sheds under any circumstances there seems to be no converse
instruction preventing a disabled LU train or vehicle from being
shunted into Willesden TMD if necessary.

And 4th rail provision exists south of Queen's Park towards Kilburn High
Road to allow for LU trains, surely?

--
Colin Rosenstiel