Diagrams and how intensively stock is used

[IanXC]

I've just been reading this document (http://www.125group.org.uk/diagrams-GC.pdf) which lists that GC have 2x HST diagrams and 3x 180 diagrams. They actually have 3 HSTs and 5 180s, giving an overall usage of 63% (or 66% on HSTs and 60% on 180s).

Some of you might have seen my mention of earlier comment on Hull Trains diagramming - they have 4 180s and use 3 daily 75%.

I'm guessing that the key factors are the fault free miles on the unit type and whether units end up in many different locations. Is that right or are there other key factors in this? Also its much harder to work out intensity of stock usage for larger franchises, anyone have any ideas of what levels there are out there?

 

[rail-britain]

Although you have "spare" sets, these may not be available

For a small TOC like Grand Central the ratio is very high
2 diagrams : 3 sets available (assume spare at Newcastle)

When you then get to a larger TOC you want to have more spares spread strategically
For example Virgin Trains with spares at Wembley (for London), Birmingham, Manchester, Liverpool, and Glasgow
5 sets as a ratio is very low

Then finally add those sets that are out of service for maintenance
Out of 52 sets, 5 spare, plus 1 maintenance, this leaves 46 for diagrams
I suspect there are 45 diagrams for 46 units (leaving 1 for contingency)
Therefore the PVR is 45 at 86%

 

[tbtc]

This (locked) thread from last summer may be of interest regarding some of the percentages etc http://www.railforums.co.uk/showthread.php?t=33981

For example C2C need 95.9% of units in service (at the busiest time of the day), but as they only operate one type of train and run a relatively short self contained franchise there's less to go wrong (and no need for "hot-spare" units to be available at many locations).

On the other hand, Northern have a wide set of routes and many different types of train, so there's more need to have some spare stock (at more locations). For example, Northern only use two of "their" 180s each day (66.7% compared badly with C2C, but it's not comparing apples with apples)

 

[37402]

XC need 52 out of 57 voyagers per day. 91%. That is availability not intensity.

To study intensity (or should that be productivity?), you would need to look at each diagram and the amount of time the train is in traffic as opposed to sitting at depots, turnaround stations etc.

Of course, there will always be some element of inefficiency in diagrams (turnaround time, pathing etc) but the trick is to get it as low as possible.

 

[Pumbaa]

I suspect there are 45 diagrams for 46 units (leaving 1 for contingency)
Therefore the PVR is 45 at 86%

Fairly sure 47 units required each day on WC.

 

[Geezertronic]

Fairly sure 47 units required each day on WC.

That was my understanding too for VT to operate the weekday VHF services although I believe that is 390s only, not sure about their 221s

 

[Pumbaa]

Yes it's just 390. 221 is 17 out of 21 (but now following the removal of 144 it is now 17 out of 20?)

 

[NXEA!]

Yes it's just 390. 221 is 17 out of 21 (but now following the removal of 144 it is now 17 out of 20?)

Yes, 47 Pendo's, but I'm pretty certain its 18 Voyagers required out of 20.

 

[TheBigD]

Yes, 47 Pendo's, but I'm pretty certain its 18 Voyagers required out of 20.

Isn't there an extra Pendo's on a Friday?

The extra set does 1036(?) PRE-EUS and then replaces a Voyager on the 1430 EUS-LAN which is also extended to GLC. The Voyager then does a FO 1333 EUS-LAN.

 

[Philip Elliott]

And you're all wrong....

 

[northwichcat]

On the other hand, Northern have a wide set of routes and many different types of train, so there's more need to have some spare stock (at more locations). For example, Northern only use two of "their" 180s each day (66.7% compared badly with C2C, but it's not comparing apples with apples)

If you use figures for the Northern 323s it would should a lot higher intensity usage than the 180s.

 

[Pumbaa]

And you're all wrong....

Welcome to corrections

The diagrams I have in front of me show:

for 390s 47 diagrams, which includes number 35 as the spare at Euston after working in from Manchester in the morning, with 5 sets on maintenance, 2 at Oxley, 1 at Longsight, 1 at Wembley and 1 at Polmadie.

for 221s 18 diagrams with 3 on maintenance at CZ, but I do not know how this has been affected by the removal of 144.

 

[tbtc]

If you use figures for the Northern 323s it would should a lot higher intensity usage than the 180s.

Of course, much easier to have higher intensity when you have more vehicles (in a class) to play with; its one reason why I can understand the logic of splitting the Central Trains 158/170s up (even though it meant a worse service for where I live), its just a tricky balance between having a variety of trains for a variety of services and just concentrating on a couple of classes (to cover a variety of roles)