Out of the "go anywhere do anything" engines of The Big 4 + a few extras, which one was better at different things?

[Tetragon213]

They certainly had a favourable axle load and, on the flat, put in a good turn of speed with heavy loads.
Their tendency to slip upon starting and up hills, leads me to think they face a challenge on this remit of "go anywhere, do anything".

I like them, I'll admit. Tangmere put in a fine performance up Folkestone Harbour branch's 1 in 30 in January 2009. 10 on, with a 47 shoving very hard at the back; but 34067 sent up a volcanic exhaust.
Oliver Cromwell, 2 months later, arguably took the same load a little more easily up the same climb.

Iirc, the BoB/WCs operated from Exeter St Davids up to Exeter Central, as part of their regular duties in hauling trains to the West Country via Salisbury as well as while operating the ACEs. The climb through St Davids Tunnel is something on the order of 1 in 38, so not much flatter than Lickey Incline. The wheelslip was certainly an issue, however; I've heard people say that they would spin their wheels while running as a light loco!

Ah, the light pacifics. Not sure of the RA rating, but indeed, they went across west country branches.

That is, when they went.

The trouble is, they didn't went enough.
Alas, their aesthetic beauty was inversely proportional to their availability for revenue-earning service.
Plus they had a death wish through self-immolation.

Heart over head, I fear. There was a very good reason why more than half the class was rebuilt after a dozen or so years of service - and this at a time when BR modernisation was already underway.

I believe the rebuilding (notably replacing the chain driver valve gear with a more conventional setup) made a world of difference for them, although a handful remained unmodified as the rebuilding somehow added about 4 tons to the weight, making the rebuilds unsuitable for Withered Arm duties.

It may be heart over head, but I still remain convinced that the power and relatively light axle loading of the WC/BoBs at least warrants a mention on a "go anywhere do anything" locomotive list.

 

[Sun Chariot]

Iirc, the BoB/WCs operated from Exeter St Davids up to Exeter Central, as part of their regular duties in hauling trains to the West Country via Salisbury as well as while operating the ACEs. The climb through St Davids Tunnel is something on the order of 1 in 38, so not much flatter than Lickey Incline.

Indeed, the climb from St David's to Central is brutal: slippery pointwork straight out of the down main platform, tight curve with the Waterloo line on the sharper radius, plus damp rails through St David's tunnel. No wonder trains were, in the main, banked.
Even in BR days, my younger self was delighted at the Sulzer racket made by a still-blue 47484 "Isambard Kingdom Brunel" and a 33/0 thrashing the collective guts out, with a long load from Meldon.

 

[75A]

I'd say that was a rare combination.
Was it double headed or top & tail?

 

[Sun Chariot]

I'd say that was a rare combination.
Was it double headed or top & tail?

IKB at the front, little Crompton banking. It was summer 1983 and my 110 camera photograph is even more blurry than my middle 50's memory.

 

[75A]

Thanks for that

 

[davyp]

As a slight aside, how did the Caprotti valve gear Black 5s and Standard 5s compare with the basic models?

 

[Threepea51]

A few thoughts:

Class V Schools - not designed as mixed traffic, but express passenger. 3 Cylinders = exp to maintain. No relevant to thread, IMO.

I'd like to say that the Schools were pretty damn powerful for their size and tractive effort. They could Hall a 9 coach train of Maunsell or Bulleid coaches up to speeds of or above 90 mph. They were slow starters, but when they got going, boy did they move. If anything, they were better performers than the N15s. The only reason they didn't have more success or use in more prestigious expresses was due to their Axle load and lack of adhesion

 

[matchmaker]

A few thoughts:

Class V Schools - not designed as mixed traffic, but express passenger. 3 Cylinders = exp to maintain. No relevant to thread, IMO.
Gresley V4s - surely were a passenger tank loco, 3-cylinders, expensive. Ditto above. I liked their aesthetics, but I strongly suspect post war BR preferred the cheaper LMS 2-6-4T rival - hence the 80xxx standards.

H-15s? I don't think so. The SR was a bit of an odd one out here. I think they didn't really have a Cl 5 MT in the class of the Hall, Black 5 or B1.
I'd say the U and N were the closest equivalent (if relatively underpowered compared to the 5s) - and the S15 was kind of comparable in the other direction, even though it was officially a freight loco.

The Halls had a good reputation for fast running on the GWR, I'm not sure if that was part of the GWR 'glamour' PR - that is to say, I don't know if they were any better than a Black 5 or B1 for faster running.
On maintenance costs, that would be an interesting comparison - but I suspect they were all pretty close.

On the Black 5 vs B1 (I think I've written this previously): Sometime in the mid-60s, our school railway society had a guest speaker. He was a fireman originally based at Aylesbury LNW sub shed, who then transferred to the GC when that shed closed. I remember two things from that talk:

1) He had fired both B1s and Black 5s on GC duties. He said that on lighter duties, there was no difference, but that on heavier trains - he may have mentioned 8-9 coach loads or so - the Black 5 had significantly better haulage power.

2) When working the Aylesbury - Cheddington branch, crews would not infrequently stop to pick up a dead pheasant hit by a train to take home for supper

V1/V3, not V4.

 

[Threepea51]

the V4s were the one-off 2-6-2 prototypes Gresley created

As a slight aside, how did the Caprotti valve gear Black 5s and Standard 5s compare with the basic models?

I believe the Caprotti ones steamed better at higher speeds and saved some coal at that speed, but they were pretty slow starters getting up to speed. However I believe that was remedied when 44686 and 44687 were fitted with outside shafts

 

[Bevan Price]

Ah, the light pacifics. Not sure of the RA rating, but indeed, they went across west country branches.

That is, when they went.

The trouble is, they didn't went enough.
Alas, their aesthetic beauty was inversely proportional to their availability for revenue-earning service.
Plus they had a death wish through self-immolation.


Heart over head, I fear. There was a very good reason why more than half the class was rebuilt after a dozen or so years of service - and this at a time when BR modernisation was already underway.

The main problem with the Bulleid pacifics as built was, I understand, their chain-driven valve gear, and associated oil baths - very unreliable and expensive to maintain. As rebuilt, they were fine machines, but possibly a little too heavy to go anywhere, and probably uneconomical when used on light trains on branch lines.

(Can anyone working on a heritage railway comment of costs of operating a Pacific versus a Class 2, 3 or 4 steam loco ?)

 

[778]

Good call, that would get my vote.
An exceptional heritage too: [Fowler]/Stanier/Fairburn/Riddles... No wonder they were some of the best!

The BR 4MT 4-6-0 should be included as well. Basically a tender version of the 2-6-4 tanks.

 

[Sun Chariot]

The BR 4MT 4-6-0 should be included as well. Basically a tender version of the 2-6-4 tanks.

Inferior Tractive Effort versus Thompson's B1.
Route Availability was dependent on which tender used.
BR1B tender locos were limited to a RA7.
BR2 tender locos were a lighter RA4.

 

[AM9]

the thing is that a steam engine (adhesion permitting) can apply full boiler pressure to the pistons for their whole travel on starting, whereas a diesel of that era can only supply as much current to the traction motors as will avoid overheating them - not a lot as a proportion of the maximum power, as that can't be applied until the back-EMF has built up to limit the current flow.

Hence the diesel driving technique of winding up the engine revs until the amps are at the max allowed, waiting for them to fall as the speed rises then increasing the engine speed again. and again. and again. You get to full power eventually...

It's torque that is required to accelerate from standstill, - and DC traction motors do just that. The power comes in as the speed increases.

 

[The Crab]

A few thoughts:

Class V Schools - not designed as mixed traffic, but express passenger. 3 Cylinders = exp to maintain. No relevant to thread, IMO.
Gresley V4s - surely were a passenger tank loco, 3-cylinders, expensive. Ditto above. I liked their aesthetics, but I strongly suspect post war BR preferred the cheaper LMS 2-6-4T rival - hence the 80xxx standards.

H-15s? I don't think so. The SR was a bit of an odd one out here. I think they didn't really have a Cl 5 MT in the class of the Hall, Black 5 or B1.
I'd say the U and N were the closest equivalent (if relatively underpowered compared to the 5s) - and the S15 was kind of comparable in the other direction, even though it was officially a freight loco.

The Halls had a good reputation for fast running on the GWR, I'm not sure if that was part of the GWR 'glamour' PR - that is to say, I don't know if they were any better than a Black 5 or B1 for faster running.
On maintenance costs, that would be an interesting comparison - but I suspect they were all pretty close.

On the Black 5 vs B1 (I think I've written this previously): Sometime in the mid-60s, our school railway society had a guest speaker. He was a fireman originally based at Aylesbury LNW sub shed, who then transferred to the GC when that shed closed. I remember two things from that talk:

1) He had fired both B1s and Black 5s on GC duties. He said that on lighter duties, there was no difference, but that on heavier trains - he may have mentioned 8-9 coach loads or so - the Black 5 had significantly better haulage power.

2) When working the Aylesbury - Cheddington branch, crews would not infrequently stop to pick up a dead pheasant hit by a train to take home for supper

Are you mixing up the V4 withe V1/V3?

 

[Harvester]

Are you mixing up the V4 withe V1/V3?

It seems so. The V4 class were 2-6-2 tender engines, with only two built. (BR numbers 61700 and 61701). The first carried the name Bantam Cock.

 

[Magdalia]

For me, this discussion reinforces my view that most steam locomotives were designed for quite specific purposes, the very opposite of what the OP calls "go anywhere do anything". This is well illustrated by the BR Standards, with so called standardisation still requiring a plethora of different classes.

For example, however a good a 2-6-4T is at hauling a 12 car commuter train, it isn't going to be much good on a main line express train or a hauling a heavy freight train over long distances.

Furthermore, there is a trade off between going anywhere and doing anything. A loco that hits the sweet spot of being able to go almost anywhere and do almost anything will be particularly useful to operators. Any railway will build lots of such versatile locomotives, so an indirect but good way of measuring "go anywhere do anything" is fleet size. Black Fives, B1s, Halls: there were literally many hundreds of all of them. I'm yet to be convinced that the Southern had anything similarly versatile.

Amongst the Standard classes, the 5MT 73xxx is the second biggest fleet after the 9Fs, and, if the Modernisation Plan had not intervened, there would probably have been many more of them.

So I'm still not looking beyond those 4 classes.

 

[Rescars]

For me, this discussion reinforces my view that most steam locomotives were designed for quite specific purposes, the very opposite of what the OP calls "go anywhere do anything".

The clear differentiation between passenger and goods engines goes back at least as far as the 1840s.

 

[Harvester]

The GWR Halls were competent, capable of good performances, but due to the width over the cylinders meant they were too wide to "go anywhere".

Yes, like the Granges, they would be out of gauge outside GWR and GCR metals. A good example is 6858 Woolston Grange‘s trek north on a SO Bournmouth-Leeds train in August 1964. After leaving Sheffield Victoria, disaster struck, when it took the Penistone branch.

 

[norbitonflyer]

The clear differentiation between passenger and goods engines goes back at least as far as the 1840s.

There were several factors determining what made a good freight engine or a good passenger engine

Gearing - essentially a steam locomotive has a fixed gear, determined by the driving wheel diameter and piston stroke. For speed you need a high gear (large wheels, long piston travel) but that makes it difficult to get a heavy load started. Hence the frequent use of banking engines to get expresses started out of stations like Euston.

Stability versus adhesion - a front bogie or pony truck helps guide the loco into curves but, being unpowered, reduces the weight over the driving wheels

That said, many freight locos were pressed into service on passenger services on high days and holidays, although one would hope only in the milder seasons of the year as another distinction between them was the lack of the necessary pipework for steam heating.

The differentiation was reflected particularly in the Midland's, and LMS, classification and numbering policies.

Midland - passenger tender 1-1199, tank 1200-2299, freight tender 2300-4999.

The LMS adopted similar blocks for the locos from its other constitiuents: further differentiating passenger and freight tank engines

LNWR (5xxx, 6xxx, 7xxx, 8/9xxx),
LYR (10xxx, 11000-11199, 11200-11999, 12xxx)
Scottish (14xxx, 15xxx, 16xxx, 17xxx) locos

Within each group starting with the lowest power rating.

(The LMS later cleared large blocks of 4-digit numbers for its new standard types like the Black Fives and 8Fs).

The GWR Halls were competent, capable of good performances, but due to the width over the cylinders meant they were too wide to "go anywhere".

Well, they were pretty much "go anywhere" on the network of the company they were built for.

 

[Rescars]

Well, they were pretty much "go anywhere" on the network of the company they were built for.

Thanks to Brunel and his works for his generosity of loading gauge!

 

[Dr_Paul]

Stability versus adhesion - a front bogie or pony truck helps guide the loco into curves but, being unpowered, reduces the weight over the driving wheels

Does this explain the various classes of 0-8-0 freight locos with a large overhang at the front, which made them look as though they were 2-8-0s missing their pony truck?

 

[AndrewE]

It's torque that is required to accelerate from standstill, - and DC traction motors do just that. The power comes in as the speed increases.

Maybe, but back-EMF comes into it (in older motors.) You can't put full power through a stationary electric motor without blowing it up. So you can't get 5000 HP, let alone 10, out of an electric or diesel-electric loco from standing. Whereas a steam engine piston will take full boiler pressure when stationary...

 

[Rescars]

Does this explain the various classes of 0-8-0 freight locos with a large overhang at the front, which made them look as though they were 2-8-0s missing their pony truck?

Maximum adhesion was useful both for getting trains started and for stopping them too - especially those without continuous brakes.

 

[Sun Chariot]

Does this explain the various classes of 0-8-0 freight locos with a large overhang at the front, which made them look as though they were 2-8-0s missing their pony truck?

I'd hazard a guess that it ensured the weight of the boiler and firebox, was over the driving wheels to maximise adhesion.

 

[norbitonflyer]

I'd hazard a guess that it ensured the weight of the boiler and firebox, was over the driving wheels to maximise adhesion.

The weight would be transmitted through the wheels however it was distributed. However the large overhangs front and rear made room for bigger cylinders and firebox, at the price of less stability. For faster running, a pony truck or bogie (with smaller wheels) would be needed, but that took some of the weight off the driving wheels.

 

[Sun Chariot]

The weight would be transmitted through the wheels however it was distributed. However the large overhangs front and rear made room for bigger cylinders and firebox.

The firebox was often over the rear set of drivers (certainly in the case of 0-6-0 and 0-8-0 tender classes, within the LNER's constituent pre-grouping companies).
Your point about the cylinder placing makes sense; that was a logical place for them anyway - to create space for pistons and the coupling rod to second set of drivers.

 

[norbitonflyer]

The firebox was often over the rear set of drivers (certainly in the case of 0-6-0 and 0-8-0 tender classes, within the LNER's constituent pre-grouping companies).
Your point about the cylinder placing makes sense; that was a logical place for them anyway - to create space for pistons and the coupling rod to second set of drivers.

Quite so - however one reason for the Atlantic and Pacific configurations (4-4-2, 4-6-2) was to allow a bigger firebox without too great an overhang behind the rear axle

 

[Tetragon213]

Quite so - however one reason for the Atlantic and Pacific configurations (4-4-2, 4-6-2) was to allow a bigger firebox without too great an overhang behind the rear axle

Having fewer driving wheels also gives you space for larger wheels, which allows for a higher top speed at the same number of revs. Iirc this was a major issue on the Standard 9F 2-10-0s, where the small drivers, while allowing for phenomenal leverage and traction, also limited their speed.

If it wasn't for the actual mass of the Standard 9F, I'd have thrown its hat into the ring for "go anywhere do anything" owing to the light axle loading (and I was shocked to discover it has a lighter axle load than a 5MT!), but the nearly 90-odd tonnes of loco itself are a bit of a mark against.

 

[Sun Chariot]

Quite so - however one reason for the Atlantic and Pacific configurations (4-4-2, 4-6-2) was to allow a bigger firebox without too great an overhang behind the rear axle

Absolutely. And yet I always wondered how Vincent Raven made such a monstrosity of his NER A2, with the carrying axle under its firebox and the large overhang under its cab. Ungainly lines, unimpressive performance.

Having fewer driving wheels also gives you space for larger wheels, which allows for a higher top speed at the same number of revs. Iirc this was a major issue on the Standard 9F 2-10-0s, where the small drivers, while allowing for phenomenal leverage and traction, also limited their speed.

9Fs, coincidentally, put in many fast runs - with fitted freights and passenger workings. 70+ mph recorded on several turns.
92220 Evening Star did the 9F class proud, on its SLOA turns in the 1980s.
I've a wonderful audio recording by Peter Handford, of a 9F. It absolutely belted past Barkston Junction (nr Grantham).

 

[coppercapped]

Having fewer driving wheels also gives you space for larger wheels, which allows for a higher top speed at the same number of revs. Iirc this was a major issue on the Standard 9F 2-10-0s, where the small drivers, while allowing for phenomenal leverage and traction, also limited their speed.

Hmm!

I went to the naming ceremony of 92220 Evening Star at Swindon in March 1960 with a group from school. A day of mixed emotions.

Purely by chance I was at Reading station at the end of June or beginning of July that same year when Evening Star rushed through at the head of the down Red Dragon express. In those days the line limit was 75mph and it looked like it was going like the wind, all that outside motion spinning...

Sometime later word started to circulate that they had been timed at 90mph on both the Capitals United and Red Dragon expresses and this gave some senior people in the BTC palpitations and so it was taken off the express turns.


The top speed of steam locomotives in the latter days had much more to do with steam circuit layouts, valve design and events and how the locomotives were balanced than purely to do with driving wheel diameter.