Do the slow lines have a new Name

[Windcutter]

Having been to Nuneaton today, do the up and down slow lines have a new names these days.
Why ?, the speed on these lines with the freight trains through the station was unbelievable, you expect the fast lines to be just that, but I was surprised at what I saw today.
So can they be renamed.

 

[MidnightFlyer]

Wouldn't that just be change for change's sake? Most of the time there is a speed difference between the two...

On the Western Region though, they do have a separate name, and have done since construction - 'Relief'.

 

[route:oxford]

Having been to Nuneaton today, do the up and down slow lines have a new names these days.
Why ?, the speed on these lines with the freight trains through the station was unbelievable, you expect the fast lines to be just that, but I was surprised at what I saw today.
So can they be renamed.

Yes, let's call them "relief lines" instead.

Matt got in there first.

 

[Harlesden]

Surely two lines running parallel in the same direction can, in the majority of instances, both accept fast moving traffic. It is only the pattern of service and customary use that deems one line to be slow and the other line fast.

 

[MidnightFlyer]

Surely two lines running parallel in the same direction can, in the majority of instances, both accept fast moving traffic. It is only the pattern of service and customary use that deems one line to be slow and the other line fast.

And in most cases speed differences...

 

[Old Timer]

Yes, let's call them "relief lines" instead.

Matt got in there first.

That is a GW term used only because they didn't go fast enough to justify calling any additional lines "slow" lines.

 

[matchmaker]

That is a GW term used only because they didn't go fast enough to justify calling any additional lines "slow" lines.

 

[LNW-GW Joint]

On the Western Region though, they do have a separate name, and have done since construction - 'Relief'.

When I first showed up in Reading in the 60s I was intrigued by buses indicating they were going to somewhere called "Relief", which seemed to be very well served so must be a big place.
It took quite a while to realise it was a local term for what oop north we called a "Duplicate".

There were also buses to another bizarre place called "Nettlebed", but that turned out to be real...

 

[wensley]

I've been beaten to my intended 'relief' response!!
There is normally a speed difference, take the UF and US from Thirsk to Skelton Jn, 125mph on the F, 90 on S.

 

[Eagle]

Having been to Nuneaton today, do the up and down slow lines have a new names these days.
Why ?, the speed on these lines with the freight trains through the station was unbelievable, you expect the fast lines to be just that, but I was surprised at what I saw today.
So can they be renamed.

If you think traffic on the slows at Nuneaton is fast, you should see it on the fasts! I've stood at the edge of plat 3 as a Pendolino sped past my face at 110+... I fell over.

 

[ChrisCooper]

Of cource "slow" is relative. In many places the "slow" lines are 90 or 100mph, for example at places on the ECML, WCML and MML (and the GWML reliefs). This though is alongside 110 (current MML) or 125mph fast lines. They are also used for "slow" services, i.e all stations. On the other hand in some places the "fast" lines are hardly fast, hardly much faster than the "slows", especially in busy suburban areas. I think there are even a few places where the "fast" lines have a lower speed limit than the "slow" lines. Some places they have the same limit. Of cource if HS1 had been built with 4 tracks then there is a good chance that alongside the 186mph Fasts there would have been 140mph "slow" lines.

 

[Nym]

Or you have the likes of Manchester or Leeds that have G, DS, US, DF, UF, DE, UE or A, B, C, D, E, F...

 

[Smudger105e]

These terms are quite often historical, and why change them if everyone knows what a line is called?

Sidings often have historical names too. At Stewarts lane, the sidings between the fuel point and the yard accomodation was called the Steam Shed, even though there had been no roof or steam locos there for 30+ years. The New Sidings at Toton have been there for 30 or so years, but are still called the New Sidings...

 

[The North Briton]

Out of interest, why is the linespeed lower on the slow lines on a four-track section? Is the P/way maintained to a lower standard?

 

[Old Timer]

Out of interest, why is the linespeed lower on the slow lines on a four-track section? Is the P/way maintained to a lower standard?

Quite simply yes in most cases, as the higher the standard the more that it costs.

There may also be other factors which do not allow the speed to be higher, such as the clearance in bridges or the physical way the track is installed where there may be sharper curves for example or the construction of the track itself, wooden sleepers, etc..

 

[jopsuk]

Lower-speed rated points used as well perhaps?

 

[LNW-GW Joint]

Two fast/slow oddities I know of:

At Reading the Relief (slow) lines through the station have a higher line speed than the Main (fast), because of the straighter alignment.
Might have changed or will change with the rebuild but at one time is was 75 slow and 50 fast.

And on TV4 (new Trent Valley 4-track section Amington-Lichfield) all four lines are rated at 110/125EPS, despite being named fast/slow.
Perversely, where the 4-track becomes 2 at Colwich the down slow carries on at 90 towards Stafford because it is the straight route, whereas the down fast has an awkward 65 turnout to reach the Stafford line.

 

[The Planner]

And on TV4 (new Trent Valley 4-track section Amington-Lichfield) all four lines are rated at 110/125EPS, despite being named fast/slow.

Not quite, it is the Lichfield side of Tamworth before that happens, probably because of the bend.

 

[ChrisCooper]

Alignment is often a factor. The fast lines in most cases are the original lines so have the best and most straight alignment, but when the slow lines were added later they were less straight and curve away at points where the lines need to be seperated. A good example is stations, on a straight track the fast lines will be straight, but the slow lines will have curves to allow them to move away from the fast lines to provide room for the island platform/s and then return alongside them. Tunnels too, the slow lines will often curve away to pass through a tunnel, whilst the fast lines will be straighter.

At the end of the day the majority of traffic on the slow lines will be travelling slower. With the exception of Mail (which is rare these days), all freight is restricted to 75mph or less, most 60mph or less. Many suburban trains running on the slow lines are also restricted to 75mph. Due to the short distances between stations it's usually not worth having them going faster than that. You put a lot of energy in to accelerate them to higher speed, but even with regenerative braking (which is a very new thing) you loose most of it and over short distances you get very little advantage. Even where fast trains run on the slow lines, such as diversions, the lower speed doesn't make a massive difference, and if they were running faster they would just catch up with the stopping trains anyway. As had also been said, maintenance costs are higher where speeds are higher.

 

[Legzr1]

Out of interest, why is the linespeed lower on the slow lines on a four-track section? Is the P/way maintained to a lower standard?

The ECML from Longlands - York is 3 aspect signalling on the slow,4 aspect on the fast.

Maybe that makes a difference

 

[Old Timer]

The ECML from Longlands - York is 3 aspect signalling on the slow,4 aspect on the fast.

Maybe that makes a difference

Not really as signal spacing is related to linespeed.

 

[hairyhandedfool]

The impression I am given is that the number of aspects relates to capacity of the line, not the speed of it.

 

[Tomnick]

The signal spacing on the slow lines is constrained by the positioning of the four-aspect signals on the fast lines - the Standards say somewhere that signals on adjacent lines should be located adjacent to each other where possible. That being the case, and assuming that the signal spacing has been designed to provide the optimal capacity on the fast lines, I could well imagine that the signal spacing is a limiting factor on the linespeed on the slow lines.

 

[barrykas]

Don't forget the Main and Local lines on the Great Central & Metropolitan Joint Line, and the Suburban, Main and Electric lines out of Liverpool Street...

 

[northwichcat]

Do the slow lines have a new Name

Yes. They used to be the slow lines when less trains were using them, they've now become the very slow lines now that more trains are using them.

 

[Legzr1]

The signal spacing on the slow lines is constrained by the positioning of the four-aspect signals on the fast lines - the Standards say somewhere that signals on adjacent lines should be located adjacent to each other where possible. That being the case, and assuming that the signal spacing has been designed to provide the optimal capacity on the fast lines, I could well imagine that the signal spacing is a limiting factor on the linespeed on the slow lines.

My point exactly (and this is the way the signalling is implemented on the section of line I mentioned).

Max permissible speed on the fast (4 aspect) : 125mph
Max permissible speed on the slow (3 aspect) : variable between 40mph (up slow at Thirsk) and 90mph.

It really isn't safe having HST's travelling at 125mph to meet a single yellow round the corner

 

[Nym]

Although in clear weather, a 221 can stop from 125 on two aspect signalling, everyone is up against the cab door, but it can be done

 

[Tomnick]

Although in clear weather, a 221 can stop from 125 on two aspect signalling, everyone is up against the cab door, but it can be done

If the linespeed's 125mph and you've got two-aspect signalling, then you're always going to have braking distance to each stop signal from its associated distant signal - and everyone can remain seated for the duration.

 

[Railsigns]

It really isn't safe having HST's travelling at 125mph to meet a single yellow round the corner

HSTs are running safely every day at 125 mph on three aspect signalling on parts of the East Coast Main Line between Newcastle and Berwick.

 

[Legzr1]

HSTs are running safely every day at 125 mph on three aspect signalling on parts of the East Coast Main Line between Newcastle and Berwick.

Absolutely.

But can you guess the difference in braking distance when getting a single yellow at Belford and getting the same aspect at Sessay on the Up Slow?


By the way,Newastle is 4 aspect - the 'on the cheap/implementing SIMBIDS' doesn't start until Benton Jcn.