Is the NYMR's 9F unique?

[LMS2968]

45 minutes ago, Paul_sterling said:

 

Though that's the first time I've heard about double chimneys increasing consumption at low outputs, it sounds feasible, if they dropped off the efficiency curve for the drafting, and didn't pull the fire as well as a single. As 9F's were built to be driven hard, I suspect it was seldom an issue in their operating days, and reduced coal consumption at higher outputs, was no double more desirable on the whole, than increases at low outputs. 

 

On the same vein, I think that there would not be much difference in performance between any of the 9F's at sub 25mph due to the draughting (drafting?) and any variations in performance would be more likely down to locomotive condition, firebox, tubes, passages, valves, pistons, valve timing etc rather than how many pots it has on top. 

 

Re. the 9F being the most powerful, contentious comment as it was (and I suspect just to give some drama to the commentary) it depends in what context you define as most powerful I guess, hauling an express over Shap for example requires a markedly different "powerful" locomotive, to one which hauls Iron ore trains from docks to Consett, or 2000 plus tonnes at Foster Yeoman, the DBHP/IHP etc. figures are probably not even comparable. however.............. given the 9F's could hit 90mph, if there was any one locomotive that could haul an express up Shap, and drag and slog a heavy freight train up a steep incline, I would like to suggest it would be the 9F. 

 

Also, I've shouted at the TV so many times whilst watching that TV programme, my wife is concerned for my mental health, but it is a programme that is largely targeting non-enthusiasts, and that most definitely is a good thing for luring new folk into the fraternity, even if it does drive the rest of us nuts! Stuff like Shed and Buried does the same to me, particularly when they rope in "experts"................

Although the Nines did get some very heavy jobs, I doubt that the majority of their work was in that category, and much of it was within the capacity of the 2-8-0s from three of the Big Four groups, and in that case their muscle power was rather wasted. They did in these cases have a reserve of power to meet potential problems, but you could run only so fast with a heavy, loose coupled train, no matter how many d.b.h.p's the engine could develop: you soon reached a point where stopping the thing became the main concern and brakes were not a 9F strong point.

 

As to their speed potential, yes, they were timed at 90 m.p.h., but you'd need to ignore the potential damage to both engine and track if you were to use this on a regular basis, say on the Elizabethan or Caledonian. But the ability to reach 90 m.p.h. and haul 1,500 ton trains did not happen at the same time, and you need to consider at what speed the peak power occurred, and how rapid the fall off above that. I don't know the answer; I rather doubt that anyone else does either.

 

I'll agree that the 9Fs were probably the best of the Standards, but I'll take a bit of convincing that they were mixed traffic engines in the full sense.

[Paul_sterling]

17 minutes ago, LMS2968 said:

Although the Nines did get some very heavy jobs, I doubt that the majority of their work was in that category, and much of it was within the capacity of the 2-8-0s from three of the Big Four groups, and in that case their muscle power was rather wasted. They did in these cases have a reserve of power to meet potential problems, but you could run only so fast with a heavy, loose coupled train, no matter how many d.b.h.p's the engine could develop: you soon reached a point where stopping the thing became the main concern and brakes were not a 9F strong point.

 

As to their speed potential, yes, they were timed at 90 m.p.h., but you'd need to ignore the potential damage to both engine and track if you were to use this on a regular basis, say on the Elizabethan or Caledonian. But the ability to reach 90 m.p.h. and haul 1,500 ton trains did not happen at the same time, and you need to consider at what speed the peak power occurred, and how rapid the fall off above that. I don't know the answer; I rather doubt that anyone else does either.

 

I'll agree that the 9Fs were probably the best of the Standards, but I'll take a bit of convincing that they were mixed traffic engines in the full sense.

 

One of the references I saw some time back (and may well have been O.S. Nock) was that the driver behind the design of 9F, seemingly in a category where much of the demand was already well catered for in 2-8-0's as you noted (and even the 2-10-0 Aus), was that rather than work alongside of them, the idea was to create a locomotive which could do long distance haulage within the standard working shift, which required increased speeds and greater power output over the 8F's and such like, hence the 5' diameter wheels. I don't really know what rolling stock they intended to use for these higher speed freight services, but I suspect fitted freights rather than loose coupled, which probably also adds more  to your mention of their brakes not being that strong, perhaps chiefly because they weren't intended for loose freights where powerful brakes would have been needed.  They ironically ended up on some slogging jobs, and did well at them, particularly Tyne Dock.

 

Anyway, to be clear, when I said a Locomotive which could do 90, I agree, they were capable of doing it, just as my car is capable of 140mph, it doesn't mean it can do it continuously, but as has been generally shown in the timings of the Crack LMS and LNER expresses, they didn't sit as those speeds continuously either. I don't think there is an Engine which could do everything, but I do think the 9F was about the closest we ever got to it.

 

As an aside, I would think the 9F 2-8-2 might have leaned slightly closer to speed, rather than slog, again, because the driver behind the design was for increased freight speed. 

 

Paul.  

[Sheffield]

It is pleasing to think that the last main line loco design built for use in the UK was also probably one of the best. Steam went out on a good note.

[Bomag]

15 hours ago, Sheffield said:

It is pleasing to think that the last main line loco design built for use in the UK was also probably one of the best. Steam went out on a good note.

 

The last UK mainline steam loco design was 71000 Duke of Gloucester (Designed 1953), the 9F was designed in 1951.

[Paul_sterling]

On 17/11/2020 at 12:15, Bomag said:

 

The last UK mainline steam loco design was 71000 Duke of Gloucester (Designed 1953), the 9F was designed in 1951.

 

Quite a long time between designing the 9F and building beginning then, unless of course the design process started in 1951, and was not completed till 1953/4, certainly the design cycle for Diesel Engines I was involved with was around 3 to 4 years. 

 

Paul. 

 

 

[Bomag]

3 hours ago, Paul_sterling said:

 

Quite a long time between designing the 9F and building beginning then, unless of course the design process started in 1951, and was not completed till 1953/4,  

 

 

 

Steel was in short supply so they had to delay construction of some of the larger locos, the second batch of 6MT/Clans never got built.

[Arun Sharma]

On 17/11/2020 at 12:15, Bomag said:

 

The last UK mainline steam loco design was 71000 Duke of Gloucester (Designed 1953), the 9F was designed in 1951.

Wouldn't the last steam design have been the redesign of the MN and WC/BB engines?

[Sheffield]

As I said, the last loco built for BR to use in mormal service was a 9F; the design may have been older than that D of G or the MN rebulds, but a 9F was the last built.  Pleasing that the last built was, all round, one of the best.

[Titan]

On 16/11/2020 at 09:48, PenrithBeacon said:

It's been my contention for at least the last two decades that the 9F was by far the most successful mixed traffic engine built in the UK, an argument let down by the fact that non had steam heating.

 

I thought the ones that worked passenger trains over the S&D on a regular basis had steam heating fitted?

[PenrithBeacon]

They weren't fitted with  carriage heating, they ran only in the summer months.