Most reliable locomotive?

[100andthirty]

What exactly was the inherent design flaw with 86s that affected the track quality? The track doesn’t seem to be particularly good on the WCML now compared to some secondary routes but I assumed that was to do with the density of both fast and heavy traffic using it. Anything wrong with it is definitely felt more on a 195 than on a Pendolino.

Class 81-85 were fitted with bogie frame mounted motors with flexible couplings between the motor/gearbox and axle. This reduced the unspring mass. Someone decided that this feature was unnecessarily costly and provided a system where one side of the motor was coupled to the axle and the other side was supported on the bogie frame. This is called nose suspended, axle hung. It increased the unsprung mass significantly and they gained a reputation for pounding the track. This was eventually resolved by using resilient wheels and improved secondary suspension was fitted which was nicknamed Zebidee suspension after the Magic Roundabout character.

 

[43096]

What exactly was the inherent design flaw with 86s that affected the track quality? The track doesn’t seem to be particularly good on the WCML now compared to some secondary routes but I assumed that was to do with the density of both fast and heavy traffic using it. Anything wrong with it is definitely felt more on a 195 than on a Pendolino.

As built the locos had bogie mounted heavy motors, so there was a lot of unsprung weight, or more precisely partly sprung, and any jolting of the bogies on poor track meant the heavy weight effected a heavy hammer blow on the track.

The previous locos, classes 81-85 had been specified with body mounted motors and flexible drives to avoid this. Thus the motors weren’t part of the bogie mass. The bodies don’t bounce around as much as the short 4 wheel bogies so movement is softer to track. Adding resilient wheels eased some of the impact.

The 81-85 fleet had bogie frame mounted motors (not body). The 86s had axle-hung motors as a cost-saving measure, which were found to greatly increase track forces. The three locos I mentioned that were properly fixed were the three Class 86/1s, which were modified with Class 87-type bogies (which went back to bogie frame mounting of the motors).

 

[quattrohead]

Not locos but diesel engine, I think the Thumpers must have been super reliable. Simple and sturdy and still so many of them around.

 

[D1537]

The correct answer was in reply 2 (i.e. Class 59). It's a bit difficult to compare classes, though - is miles per casualty a suitable metric to compare (for example) a Class 25 pootling around on trip freights and a 47/7 being hammered for 16 hours on a 700-mile-a-day push-pull diagram? Or a Class 31 on the Norwich-Birmingham circuit versus a Deltic on the East Coast?

 

[MattRat]

As built the locos had bogie mounted heavy motors, so there was a lot of unsprung weight, or more precisely partly sprung, and any jolting of the bogies on poor track meant the heavy weight effected a heavy hammer blow on the track.

The previous locos, classes 81-85 had been specified with body mounted motors and flexible drives to avoid this. Thus the motors weren’t part of the bogie mass. The bodies don’t bounce around as much as the short 4 wheel bogies so movement is softer to track. Adding resilient wheels eased some of the impact.

What about the later locos, like 87, 90, and 92? 91 obviously only ran on the ECML, so we don't have to think about it.

 

[Swanley 59]

Just curious - is the Class 68 not considered reliable? I'm guessing not, given there is a separate thread about faults with the fleet leased by Chiltern.

 

[SolomonSouth]

Just curious - is the Class 68 not considered reliable? I'm guessing not, given there is a separate thread about faults with the fleet leased by Chiltern.

The 68 is not reliable. I suspect the 66 would blitz it.

 

[Deepgreen]

I'd suggest Bulleid pacific 35028 'Clan Line' is up there! I can't recall the last time it wasn't available when needed except for planned maintenance. My tongue is pushing the side out my face out, by the way!

 

[train_lover]

It's surely a 66 many of which are over 20 years old now. I spend my days driving the things and very rarely do they go wrong. What people don't realise is they are getting thrashed daily pulling heavy trains Monday to Friday then working engineering trains on a weekend and back out on heavy trains the following week. At my FOC the 66s are very rarely shut down and in some cases can be running for weeks on end.

You only have to look at how popular they've been not just in the UK but across the world.

 

[Jamesrob637]

In Switzerland, Re460 is bulletproof. This thread title didn't specify UK, to be fair!

 

[MattRat]

In Switzerland, Re460 is bulletproof. This thread title didn't specify UK, to be fair!

Come to think of it, it didn't specify gauge either, and there quite a few very old narrow gauge steam engines still running....

 

[47827]

Class 86s need a massive asterisk applied I'm afraid. I'm not for a minute saying many or indeed any diesel classes would touch them with ease though, but the different fleets seem to have had different levels of reliability. The Freightliner ones, up until their recent storage, have been second to none of those I can think of, whereas from direct experience the IC (later Virgin) XC fleet was possibly the worst. There was even a brief discussion in the 90s about reducing the use of 86s on XC down to little or nothing, which was abandoned given the then need for a huge number of extra diesels, poorer schedules on some services and potential implications it wasn't taken further than being on an options list (probably near the bottom). There could be a whole host of reasons, of course, why that one fleet lagged behind. I'm sure maintenance and the nature of their duties may have contributed although the diagrams were a great mix of slightly taxing and easy going. The train formations in later years were easy though for their capability, often being short formed toward the end too. If anyone thinks I'm lying, the hundreds of extra XC diesel workings under the wires I alone recall (on top of the many others listed) say otherwise. There wasn't anything like a monopoly of 86s booked on XC workings North of Birmingham (but it was the case mostly north of Preston) and the fleet had some contingency yet it was rare to go more than an odd day with every 86 diagram covered fully by 86s. On a real bad day there had occasionally been more vices than booked 86s out. Whilst 86s from other sectors or owners did show up, and 87s/90s dropped once in a while, diesel subbing was the norm (most commonly 47/8s and often the real reason why they were unavailable for their own trains). In fact there were periods where availability sunk so low there were double digits worth of workings North of New St in the same day and periods of common substitutions reaching Scotland. Occasionally they were pinched for other stuff on the WCML in or out of Euston, but it was commonly poor availability or failures during the day causing diesel subbing to be common (mostly except when it was my late running train home on a Sunday night due to swap at Birmingham).

 

[XAM2175]

Come to think of it, it didn't specify gauge either, and there quite a few very old narrow gauge steam engines still running....

The fact that an old loco is "still running" in preservation is no measure of its reliability, though.

 

[MattRat]

The fact that an old loco is "still running" in preservation is no measure of its reliability, though.

In Russia, that would be considered reliability.

 

[Whistler40145]

Definitely not 70s

I'd say 37s

 

[XAM2175]

In Russia, that would be considered reliability.

What's that got to do with it?

It's a fairly simple distinction - an old locomotive can be kept going in preservation quite easily if it's only running at low speeds for a couple of hours a month between weeks of being slaved over by emotionally-invested volunteers. It could be failing left, right, and centre for all you know.

I'd rate a 66 doing thousands of miles on the mainline stopping only for mandatory checks as a lot more reliable even if it's got far fewer years under its belt.

 

[MattRat]

What's that got to do with it?

It's a fairly simple distinction - an old locomotive can be kept going in preservation quite easily if it's only running at low speeds for a couple of hours a month between weeks of being slaved over by emotionally-invested volunteers. It could be failing left, right, and centre for all you know.

I'd rate a 66 doing thousands of miles on the mainline stopping only for mandatory checks as a lot more reliable even if it's got far fewer years under its belt.

Because in Russia reliability is about something being fixable and continuing to work, not never breaking down. Just thought it might make the topic more interesting.

Personally though, I'd still pick something electric. If not an 86, then the next logical answer is the 87.

 

[XAM2175]

Because in Russia reliability is about something being fixable and continuing to work, not never breaking down.

That's a secondary definition, surely. Not breaking down at all has to be the preferred status; leading to the ideal condition being that a vehicle very very rarely breaks down but is easy to fix when it does.

Personally though, I'd still pick something electric. If not an 86, then the next logical answer is the 87.

Why, though?

 

[MattRat]

Why, though?

Less parts to go wrong. That means less likely to break down. All that's needed is one bolt out of place to make things go wrong, so why not use less bolts?

 

[SolomonSouth]

It's surely a 66 many of which are over 20 years old now. I spend my days driving the things and very rarely do they go wrong. What people don't realise is they are getting thrashed daily pulling heavy trains Monday to Friday then working engineering trains on a weekend and back out on heavy trains the following week. At my FOC the 66s are very rarely shut down and in some cases can be running for weeks on end.

You only have to look at how popular they've been not just in the UK but across the world.

Agreed. You never hear of them breaking down.

 

[47827]

Agreed. You never hear of them breaking down.

I've heard of plenty and been caught up in the failure of an odd one over the years BUT 66s for the fleet size are one of the most reliable diesel designs ever run on UK soil much as I found them very unappealing in other respects. Have heard of a lot more failures of their ETH cousins, the 67s though.

 

[MattRat]

I've heard of plenty and been caught up in the failure of an odd one over the years BUT 66s for the fleet size are one of the most reliable diesel designs ever run on UK soil much as I found them very unappealing in other respects. Have heard of a lot more failures of their ETH cousins, the 67s though.

And the most reliable full stop? Presumably electric.

 

[Pigeon]

It's a fairly simple distinction - an old locomotive can be kept going in preservation quite easily if it's only running at low speeds for a couple of hours a month between weeks of being slaved over by emotionally-invested volunteers. It could be failing left, right, and centre for all you know.

Indeed. Look at Dolgoch: absolutely tatered and broke down all the time but they still kept it going because Talyllyn was too tatered to be used at all.

I do think we would all do well to adopt Ostbloc standards of fixability though.

 

[CBlue]

what do the 37s achieve now?

After the debacle with the Colas ones used on passenger service in Wales a few years back, they're definitely below par in terms of reliability.

Only reason operators keep them on is route availability and little more, at 60 years old any survivors have definitely earned retirement.

== Doublepost prevention - post automatically merged: 4 Feb 2022 ==

And the most reliable full stop? Presumably electric.

You say that, but the only example given up thread was the 86 which certainly hasn't been "reliable" in a multitude of ways?

 

[Ayrshire Roy]

I think it has to be the 59s and 66s.
The whole reason we have them is because no BR diesel could come close to the availability they offered.

 

[47827]

After the debacle with the Colas ones used on passenger service in Wales a few years back, they're definitely below par in terms of reliability.

Only reason operators keep them on is route availability and little more, at 60 years old any survivors have definitely earned retirement.

== Doublepost prevention - post automatically merged: 4 Feb 2022 ==



You say that, but the only example given up thread was the 86 which certainly hasn't been "reliable" in a multitude of ways?

37s were often only picked over the likes of a 47 as still powerful enough for certain sorts of jobs but cheaper to run and maintain (including on the amount of diesel one would use in service). Different fleets (same as most BR large fleets) have shown to often have different levels of reliability dependent to what area they were based and how they were used along with other loco specific factors. Most 37 surviving fleets, possibly ROG leased ones accepted, have suffered more with age as the old knowledge/competency dries up and they've suffered from gradual run down and reduced heavy maintenance. Certain older fleets also suffer poorer reliability from inactivity. 47s always been a class that didn't like being stuck out on a big job after weeks sat on shed in all weathers. Not what anything was designed for. GBRF learnt this recently with their EMU drag fleet which improved the moment they were in regular use, not that it was a company that was ever good at operating them for many years. The issue with spares shortage and long lead times for new parts tends to mean there's usually one out of traffic for long periods.

 

[MattRat]

You say that, but the only example given up thread was the 86 which certainly hasn't been "reliable" in a multitude of ways?

Well there are other electric locos, but I get the feeling most would rather talk about their diesel bias than let the spotlight go to a reliable electric loco, say, the 87.

 

[D6130]

After the debacle with the Colas ones used on passenger service in Wales a few years back, they're definitely below par in terms of reliability.

....not to mention the problems with the DRS ones on the Cumbrian Coast although, in fairness, they were partly to do with Northern driver unfamiliarity combined with the frequent stops and starts required on that service.

 

[ac6000cw]

It's surely a 66 many of which are over 20 years old now. I spend my days driving the things and very rarely do they go wrong. What people don't realise is they are getting thrashed daily pulling heavy trains Monday to Friday then working engineering trains on a weekend and back out on heavy trains the following week. At my FOC the 66s are very rarely shut down and in some cases can be running for weeks on end.

You only have to look at how popular they've been not just in the UK but across the world.

It doubtless helps that EMD has produced over 50,000 diesel locos for the North American market since 1936, plus around 10,000 for export (including ones built under licence or with EMD supplying power equipment only e.g. our class 67's are an Alstom Valencia design with EMD traction equipment).

(Production totals based on data from https://en.wikipedia.org/wiki/List_of_EMD_locomotives )

 

[colchesterken]

Thought here does anyone know how the 87 are getting on in there new home..are they well used?