How small a fleet is a "micro-fleet"?

[61653 HTAFC]

Something that comes up a lot in discussions on here is the issue of micro-fleets. It's been cited as an issue with the 230s (as they'd likely have very limited operating areas, so not many units needed) and with many other proposals...

Yet BR at times didn't seem overly concerned about such things, so we saw Leeds-Doncaster served by a fleet of three 321s among other examples. Even after privatisation Silverlink had three 508s for the DC lines out of Euston, and Northern is retaining the seven 155s (albeit moving them to Hull) despite losing the similar 153s at some point in the near(ish) future.

So my question is this: how large does a fleet of a particular unit type need to be before it isn't considered a micro-fleet with all the issues that entails?

(EDIT: realised I've posted in the wrong section, not sure how that happened but I've self-reported )
(2ND EDIT: Thanks to the moderator who corrected said error. Apologies again!)

 

[TRAX]

3-4 units.

 

[Bletchleyite]

Marston Vale will be a microfleet of 3 230s, so this isn't necessarily something that bothers every TOC.

 

[D365]

Sometimes the necessity is borne out of unit length restrictions on a particular route, a diesel “island” in an otherwise electrified network, or simply passenger growth meaning new or cascaded units were required.

 

[NorthernSpirit]

A microfleet to me is anything that contains less than nine units, so the 155's, the 321/9's and the since withdrawn Thumpers on the Lymington? branch would be regarded as such.

Saying that, the 150 prototypes are formed of three coaches so they could, in a way, be regarded as a microfleet - all depends on how you'd view it.

 

[hexagon789]

The Blue Pullmans were definitely a micro-fleet even when the 2 LMR units joined the 3 WR units. So I would say potentially just 2 units constitutes a micro-fleet.

 

[swt_passenger]

A few LO 508s sounds on the face of it like a micro fleet, but how different are they to the 313s in use at the same time? Would they have a large enough technical overlap, cos they all look the same to me...

 

[43096]

A microfleet to me is anything that contains less than nine units, so the 155's, the 321/9's and the since withdrawn Thumpers on the Lymington? branch would be regarded as such.

Saying that, the 150 prototypes are formed of three coaches so they could, in a way, be regarded as a microfleet - all depends on how you'd view it.

Don’t think you can put a number on it: SWR see the 458s (36 sets) and 707s (30 sets) as small, non-standard fleets that are best replaced by the large Aventra order.

 

[noddingdonkey]

Does it not also matter if it can be rescued by other stock in the area? They couldn't run all three 321/9s at the same time to make sure one was available for Thunderbird duty. Now that the 322s are in traffic with Northern in assume that's no longer an issue.

 

[61653 HTAFC]

Marston Vale will be a microfleet of 3 230s, so this isn't necessarily something that bothers every TOC.

Vivarail did promote the 230s as ideal on routes remote from a depot, due to the ability to do basic maintenance with a fitter in a transit van; and the engine modules easily swapped out using a forklift.

A microfleet to me is anything that contains less than nine units, so the 155's, the 321/9's and the since withdrawn Thumpers on the Lymington? branch would be regarded as such.

Saying that, the 150 prototypes are formed of three coaches so they could, in a way, be regarded as a microfleet - all depends on how you'd view it.

An extra car won't necessarily make a difference, with the 150/0s there are other things which are non-standard due to them being prototypes. I'm not sure they're even the same as each other, this was certainly an issue in the past due to 002's former life as 154001- the 158 test-bed. I think there has been some effort to standardise them, at least with each other.

A few LO 508s sounds on the face of it like a micro fleet, but how different are they to the 313s in use at the same time? Would they have a large enough technical overlap, cos they all look the same to me...

Does it not also matter if it can be rescued by other stock in the area? They couldn't run all three 321/9s at the same time to make sure one was available for Thunderbird duty. Now that the 322s are in traffic with Northern in assume that's no longer an issue.

Both the above pairs will no doubt share a significant amount of commonality which will lessen the effects of having a micro-fleet.
I imagine one of the deciding factors will be how significant the differences are. For example whilst maintenance staff might see no difference, crews may require a conversion course. Or vice-versa.

A "true" micro-fleet would be where there are no similar units with the same TOC or in the same area, particularly if there's also no units nearby able to rescue. In terms of numbers I suppose it will vary based on how many units are required in service, therefore how many spares (if any). In the case of Marston Vale the inability to keep a spare at Bletchley is also an issue.

Whilst Marston Vale is 'gaining' a micro-fleet with the 230s, in reality it already operates with one due to its remoteness from the home depot. One could also argue that it's essentially a micro-fleet within a micro-fleet, as WMR or whatever they're called don't have a large fleet of either 150s or 153s.

 

[WatcherZero]

It depends a lot on how large the rest of the fleet is, having 150 of one class and 12 of another is a microfleet, having 12 of one and 15 of another isn't.

 

[xc170]

It depends a lot on how large the rest of the fleet is, having 150 of one class and 12 of another is a microfleet, having 12 of one and 15 of another isn't.

This is how I see it also. I've seen the 175 fleet described as a microfleet a few time but it just isn't.

 

[AM9]

Its just an word that's popular at the moment. Was 71000 ever described as a micro fleet, or turbomotive, the Deltics etc., although they would have presented their own logistic issues, there's always been odd minority deployments on National Rail. Now LU is something different. With the possible exception of the W$C with it's 2-car '92 stock, each line has homogenous stock allocations. But even the W&C (in its own right) has a single type so I wouldn't even call that a 'micro' fleet.

 

[43096]

Now LU is something different. With the possible exception of the W$C with it's 2-car '92 stock, each line has homogenous stock allocations. But even the W&C (in its own right) has a single type so I wouldn't even call that a 'micro' fleet.

The 92 stock on the “Drain” is almost identical to the Central line stock, so not really a micro-fleet as such.

 

[AM9]

The 92 stock on the “Drain” is almost identical to the Central line stock, so not really a micro-fleet as such.

They are NOT interchangeable with the Central Line stock without time in a shop for modifications and subsequent testing, (ignoring the fact that there isn't a rail link between the two lines). It does represent 100% of the W&C fleet so isn't what some call a 'micro' fleet.

 

[sprinterguy]

...and the since withdrawn Thumpers on the Lymington? branch would be regarded as such.

Not strictly relevant to the conversation, but they weren't Thumpers, they were 3-CIG electric units.

 

[swt_passenger]

It depends a lot on how large the rest of the fleet is, having 150 of one class and 12 of another is a microfleet, having 12 of one and 15 of another isn't.

At the other extreme we get people suggesting SWR might bin their 733 Desiro vehicles as they are out of line with the future 750 Aventra vehicles...

 

[DarloRich]

Surely it doesn't matter on the size of the fleet but more that they are concentrated somewhere where maintenance and operational staff are familiar with their foibles.

A microfleet to me is anything that contains less than nine units, so the 155's, the 321/9's and the since withdrawn Thumpers on the Lymington? branch would be regarded as such.

Saying that, the 150 prototypes are formed of three coaches so they could, in a way, be regarded as a microfleet - all depends on how you'd view it.

why 9? why not 3 or 7 or 21?

 

[mark-h]

A "true" micro-fleet would be where there are no similar units with the same TOC or in the same area

I think there would need to be more than one to count as a fleet.

 

[61653 HTAFC]

I think there would need to be more than one to count as a fleet.

True . I didn't actually mean one unique unit, just a situation where an operator didn't have anything fairly similar (so no shared spares float for example).

 

[randyrippley]

well...........BR during its 1970's standardisation policies obviously was thinking in terms of "hundreds".
Anything less than a hundred or so went - but its clearly not as simple as that as the Hymeks went even though they totalled 101 - but nothing else used that transmission. The various smaller BRCW fleets stayed -but they shared the electrics and much of the diesel with other classes so mechanically weren't unique.
You have to look at the overall commonality of the parts used and their interchangeability.
e.g. Deltics were a microfleet. But arguably the 50s, especially after the rebuild weren't because they shared so many parts with other EE designs.
But thats just looking at it from an engineers point of view, if you wanted to look at it from the point of operational interchangeability then you've a completely different set of parameters

 

[507021]

I personally think ten units or less is a micro fleet.

 

[randyrippley]

I suppose one way of looking at it is:
A microfleet is any fleet that has been built or modified in such a way that it cannot realistically be used elsewhere on the nextwork

 

[Clansman]

I'd perhaps define this a couple few ways, given the term 'micro-fleet' is used in different contexts in regards to how small it actually is.

TOC & ROSCO Definition
a) 'A rolling stock fleet that comprises of under 10% of a TOC/ROSCOs overall fleet of trains, to which they are of the minority, of a different[1] manufacturer or build, and/or incompatible with the other rolling stock they operate'

General Definition
'A rolling stock fleet that is of a low quantity, from a unique and/or purpose built variation[2];
i) that hasn't been extended beyond the initial order of the fleet'
ii) that is operationally incompatible[3] across the rail network


[1] 'Different' in the context of in comparison to units of their operators
[2] 'Variations' in the context of the classification or mechanics of the train, rather than the family they belong to, for example; Junipers
[3] 'Incompatible' in multiple contexts;
i) incompatible with other rolling stock across the UK without the aid of barrier vehicles
ii) incompatible with the general infrastructure across the entire UK network, or purpose built for the sole accommodation of a particular infrastructural area on the network; for example the 374s

 

[The_Engineer]

The problems with a micro-fleet must surely be the disproportionate costs spent in training train-crew and maintenance staff, not to mention spares holdings......

 

[61653 HTAFC]

The problems with a micro-fleet must surely be the disproportionate costs spent in training train-crew and maintenance staff, not to mention spares holdings......

The spares thing might be the biggest one, as once your crews are trained they stay trained (as long as it doesn't lapse) as do fitters. The spares float is an issue throughout the life of the stock.

 

[northwichcat]

Surely it depends on the type of class. For instance, the 5 x 322s wouldn't exactly be a microfleet if they were at Anglia.

 

[WatcherZero]

Particularly as a small production run may mean sourcing (and where no longer in production) commissioning bespoke spares is extremely difficult. Its a lot easier to justify a bespoke spares order (that may require hundreds of units that result in years of spares as a minimum production run) if you can use it on the majority of your fleet rather than the minority.

E.g. You have 6 vehicles but the minimum order is enough spare bespoke door pistons to last you a decade whereas on your main fleet of 60 that same quantity would see you through 1-2 years. May even incentivise you to order even more for the unit cost savings.

 

[craigybagel]

Here's a weird one - ATW have only 8 153s, out of a fleet of 125 units plus 2 MkIII rakes in service. But traincrew at 8 different depots still need to sign them....

 

[LNW-GW Joint]

Surely the main driver is lease and maintenance costs?
There comes a point when the ROSCO will not be interested in maintaining a small and increasingly obsolescent fleet.
Just like Microsoft won't support a Windows version after 10 years or so.
Economies of scale and all that, and resistance in the market (if replacement is cheaper/better value).
The Deltics were a micro-fleet (22 units), but they had first class and (expensive) maintenance.
But there was no future for them anywhere else when the 125mph HSTs came in.
The Class 91s seem to be heading in the same direction after IEPs roll out on the ECML.