"Reversible" vs "Bi-Directional" on WCML at MKC

[eMeS]

On a notice by a trackside access gate north of Milton Keynes Central station

M K Car Park North
London . . . . .Rugby
< - - . . . . . . - - ->
- - - > Down Fast
< - - > MK Reversible Fast
< - - > UP Fast
< - - > Bi-Directional Down Slow
< - - > MK Reversible Slow
< - - - UP Slow

Image
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I'm a total novice in these matters, but Googling suggested that "Reversible" and "Bi-directional" are interchangeable, so I'm confused, particularly as the UP Fast carries the same directional arrows as Reversible tracks.

- and do these recently added facilities get used?

With regard to track north of the platforms, why are some rails painted white?

Thanks

 

[Hydro]

Rails are painted white as a hot weather precautionary measure, so as to not absorb as much heat. It's only done in at risk areas, such as curves and S&C, though any site deemed to be at risk of heat related issues would be painted.

 

[AlterEgo]

On a notice by a trackside access gate north of Milton Keynes Central station

M K Car Park North
London . . . . .Rugby
< - - . . . . . . - - ->
- - - > Down Fast
< - - > MK Reversible Fast
< - - > UP Fast
< - - > Bi-Directional Down Slow
< - - > MK Reversible Slow
< - - - UP Slow

Image
-----------
I'm a total novice in these matters, but Googling suggested that "Reversible" and "Bi-directional" are interchangeable, so I'm confused, particularly as the UP Fast carries the same directional arrows as Reversible tracks.

- and do these recently added facilities get used?

With regard to track north of the platforms, why are some rails painted white?

Thanks

Hi

Platform 5 is used for a few fast LM services to Crewe, which change onto the slows and thence the Northampton Loop at Hanslope Junction, north of MKC. It's also used in times of disruption - both up and down Virgin trains stopping at MKC can be held here to allow faster trains to pass - in the interests of PPM presumably. I was on a Virgin train which died a few weeks ago about 300 yards north of MKC - we were reversed into Platform 5 and detrained.

Platform 2 is used for Southern and LM terminators only. I've never actually seen an up train use this platform on its way to London, but I assume it is theoretically possible.

 

[ole man]

i installed most of the ole at mk during the remodelling 2 years ago,think the paint is something to do with heat(please correct me if im wrong) and wear and tear

 

[Old Timer]

....I'm a total novice in these matters, but Googling suggested that "Reversible" and "Bi-directional" are interchangeable, so I'm confused, particularly as the UP Fast carries the same directional arrows as Reversible tracks.....

Google is incorrect technically.

A Bi-directional line is one that is used by trains in either direction in the normal course and by intention. A Reversible line is one which has a pre-determined direction, eg Down but is signalled to allow trains to travel in the reverse direction as and when required, hence the term "Reversible".

The definitions are quite important because during failure situations a Reversible line will be used in its primary direction, whereas a bi-directional will either have a nominated direction in the Signalbox Special Instructions, or will be worked bi-directionally by a Pilotman.

For the record the term "Reversible" is no longer preferred by the Industry, but what I have given is the history of it.

 

[thefab444]

Personally I would use "bi-directional" to describe a line which is regularly used in both directions and "reversible" to describe a line which is generally only used in one direction but is signalled for use in the other direction as well.

Which I think is pretty much what OT said.

 

[eMeS]

Thanks guys for your clarification.

Can I assume that the double headed arrow symbol for the "UP Fast" is a typo?

 

[cslusarc]

From the pic, it looks like to UP Fast is currently used exclusively in to London bound direction but may have some reversible signalling still in place.

 

[nr_signaller]

the up fast and down slow are bi directional but not reversible as such, you cannot come into mkc on the down slow and reverse to go back up slow, and the up fast you cannot reverse to go back north on the down fast. however the 2 reversible lines you are able to do so.