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Diagram Naming

M

MerlinRail 804

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There’s probably a really obvious answer to this which I’ve missed, but I’ll ask anyway:
What is the format for names of diagrams? Is there a specific kind of unique code for each or something? Also, where are these names found (for example on RTT or Network Rail)?
If there’s no specific system, what’s the most common way, or are they just like “diagram 1, 2, etc?
 
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Javelin_55

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Are you talking about unit/loco diagrams, or train crew?
Either way, I imagine the naming conventions are left up to each individual operator.
My TOC has an internally produced document that sets out the letter/number combos for train crew diagrams which help you determine at a glance what depot the crew is from, what day of the week it's for, whether it's a composite or spare turn, or if it's for a bank holiday/strike day/other day with an amended timetable. Some diagram numbers might even tell you what routes are covered.
 
Horizon22

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It is somewhat operator dependent.

Often something along the lines of XXX## for crew and unit diagrams. So as a (completely made up) example, a unit out of Wimbledon depot might be WM101. A train crew diagram might be slightly different e.g. WD2001. The numbers might be different for weekend working (e.g. WD9002 on a Sunday).

You won't see them on public-facing info like RTT.
 
Andy1673

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The common case is the unit diagram looks like this <main depot code><2- or 3-digit number>. Those numbers depending on type of rolling stock (class). SWR class 158s diagram numbers 101 and so on (e.g. SA101). 159s -201 and so on (e.g.SA201). 444s - NT301 and so on (Northam), 450s - NT401 up to NT520 (Northam), 455s - WM601 and so on (Wimbledon), 458s - WM801 and so on (Wimbledon), 707s were 901-..., 456s were 701... Southern 2-car 171s diagrammed as SU701-... 3-car 171s as SU801-..., 377/3 as SU301-..., 377/2 were as SU251-..., 377/1/4 - BI101 up to 23*, 377/6/7 - SU601-..., 387s (GatEx and Southern services) as SL (or BI) 051 and so on. 313s were BI701-... 455s were SU501-... Within each class number of a diagram rises alphabetically depending on the name of the starting point of this particular diagram. e.g. diagram starting at Barnham has lower number than that starting at Eastbourne.
 
306024

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The general principle is as described by others, as that's the format most diagramming software accepts, two letters for depot the units or crews are allocated to, then numbers as appropriate. Different TOCs will allocate those numbers according to what suits them. The only thing you have watch is that the diagram number for units should not be the same as the painted number on the unit, to avoid obvious confusion. So Crossrail unit diagrams for example are OC1xx, because the unit numbers are 345 0xx
 
Andy1673

Andy1673

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306024 said:
The general principle is as described by others, as that's the format most diagramming software accepts, two letters for depot the units or crews are allocated to, then numbers as appropriate. Different TOCs will allocate those numbers according to what suits them. The only thing you have watch is that the diagram number for units should not be the same as the painted number on the unit, to avoid obvious confusion.
Click to expand...
Why not? Unit 377101 can work on diagram BI101 and 377301 can on SU301. Where number of a unit matches the nunber of a diagram...
 
306024

306024

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Andy1673 said:
Why not? Unit 377101 can work on diagram BI101 and 377301 can on SU301. Where number of a unit matches the nunber of a diagram...
Click to expand...
Just avoids any misunderstanding when, for example, a shunter / depot driver or whoever is reading over unit allocations to Control, or vice versa. I've done both unit controlling and diagramming, so have been on both ends of such communications.
 
Andy1673

Andy1673

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306024 said:
Just avoids any misunderstanding when, for example, a shunter / depot driver or whoever is reading over unit allocations to Control, or vice versa. I've done both unit controlling and diagramming, so have been on both ends of such communications.
Click to expand...
Well it`s clear and logical
 
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CyrusWuff

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To use an example that's been uploaded to the SimSig website to accompany a Marylebone timetable, Chiltern's unit diagrams are numbered as follows:
  • 601 - 628: 2-car Class 165 (165001 - 028)
  • 631 - 641: 3-car Class 165 (165029 - 039)
  • 651 - 659: 2-car Class 168 (168321 - 329)
  • 671 - 679: 3-car Class 168 (168 - 113, 168214, 168218 and 168219)
  • 681 - 690: 4-car Class 168 (168001 - 005, 168106 - 107, 168215 - 217)
  • 801 - 804: Class 68 + 6 Mk3s + DVT
 
Wilts Wanderer

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306024 said:
The only thing you have watch is that the diagram number for units should not be the same as the painted number on the unit, to avoid obvious confusion. So Crossrail unit diagrams for example are OC1xx, because the unit numbers are 345 0xx
Click to expand...

In the TOC I’ve had direct experience of, this is not a consideration in the numbering of diagrams. In fact the opposite has been true, as with a diverse fleet it makes things clear and obvious as to what the intended type of unit is for a particular set of workings.

(As you say, each TOC to their own! Maybe operators with a very homogenous fleet have the opposite view; provided everyone involved is clear on the local conventions then neither principle is wrong.)
 
Horizon22

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Gaelan said:
For the publicly-owned operators, diagrams are available under FOI, if you're curious what they look like:
LNER
Northern
ScotRail (under "Class 2: How we deliver functions and services")
TfW
TPE
Southeastern
Caledonian Sleeper
Click to expand...

Probably all out of date unless they're from the Dec '23 timetable. Even if a timetable barely changes, you can bet there's a lot of diagram changes in the background especially for crew.

Wilts Wanderer said:
(As you say, each TOC to their own! Maybe operators with a very homogenous fleet have the opposite view; provided everyone involved is clear on the local conventions then neither principle is wrong.)
Click to expand...

Indeed. Somewhere like Crossrail / Elizabeth line that now has 70 345 units all formed of 9-cars and one maintenance depot it's pretty simple! Many others will have very different conventions but which would all be logical once explained.
 
Gaelan

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Horizon22 said:
Probably all out of date unless they're from the Dec '23 timetable. Even if a timetable barely changes, you can bet there's a lot of diagram changes in the background especially for crew.
Click to expand...
With the exception of CS, I believe they all are from Dec 23.
 
306024

306024

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Wilts Wanderer said:
In the TOC I’ve had direct experience of, this is not a consideration in the numbering of diagrams. In fact the opposite has been true, as with a diverse fleet it makes things clear and obvious as to what the intended type of unit is for a particular set of workings.

(As you say, each TOC to their own! Maybe operators with a very homogenous fleet have the opposite view; provided everyone involved is clear on the local conventions then neither principle is wrong.)
Click to expand...
Of course, I was only mentioning what I was told was best practice forty years ago. The bigger TOCs will have more complex permutations. Didn’t imagine it would start a debate!
 
Wilts Wanderer

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306024 said:
Of course, I was only mentioning what I was told was best practice forty years ago. The bigger TOCs will have more complex permutations. Didn’t imagine it would start a debate!
Click to expand...

Its always interesting and informative to hear different ways of doing things :smile:
 
B

Big Jumby 74

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Andy1673 said:
The common case is the unit diagram looks like this <main depot code><2- or 3-digit number>. Those numbers depending on type of rolling stock (class). SWR class 158s diagram numbers 101 and so on (e.g. SA101). 159s -201 and so on (e.g.SA201). 444s - NT301 and so on (Northam), 450s - NT401 up to NT520 (Northam), 455s - WM601 and so on (Wimbledon), 458s - WM801 and so on (Wimbledon), 707s were 901-..., 456s were 701...
Click to expand...
I can confirm this. I can not now remember what the situation was last century, although I did use the references in place at that time, but with the 2007 franchise change and the plans for the 10 car suburban railway, there was a need for additional diagram number sequences.
It was a simple case of keeping unit class numbers in numerical order (commencing 158, 159, 444 etc and working upwards), with the diagram number range increasing in increments of 100 accordingly for clarity. Obviously with any fleet type with more than 100 diagrams (class 450 in SW terms) the diagram number range exceeded 100, and so the next unit class commenced with the next available 100 numerical range (if that makes sense). It was just simple logic to arrange it that way, albeit the Depot codes were not in alphabetical order.
 
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