the great 6

[60157]

Hi is it me or has Hornby lost out on doing the great 6 in live steam as I think it would have been quite simple to do them as they have the running gear for all and would have to change to tops as required these would have looked good they would only

 

have to do 4 as they have flying scots and mallard any one think this would have been a good idea

 

thanks

 

60157

[60157]

sorry not flying scot but Dwight d Eisenhower

[walkingthedog]

As they don't make live steam any more it would cost them a lot to start production again. It costs a lot to buy the ordinary set, the price of the live steam versions would be huge.

[The son of Triangman]

As WTD has said it would cost a lot to restart production. It's no tthe right time either as the UK still isnt really out of recession, it's tough trading out there.

 

The "Great" Gathering never really inspired me, it was good to see all six surviving

 

A4's together for a while but two important LNER locos were missing from the line up as they had long ago been scrapped by BR. There was no Silver Link and the unofficial legendary 155mph rebuilt W1 "Super A4" 10000 (BR 60700)(Pegasus) was missing(it never

 

carried it's name in service). Without these two important legends it was less inspiring.

 

 

[PlanesTV]

The OO Live Steam Club are taking some renamed renumbered Locos To Shildon to meet up with their big brothers. Watch for the pictures on our website.

 

[OOLiveSteamClub]

The plan is to take the 6 models to Shildon on Feb 19 just for an unofficial non running photo.

 

Yes it would be nice to see Hornby release new versions but they are not that hard to rename and renumber. In addition to UOSA I also have Kingfisher

 

and Lord Faringdon. BR Sir Niger next that I cabbed at Doncaster in 1963.

 

Maybe there is hope for a short new production run when we see a used Papyrus going for £850!

[OOLiveSteamClub]

Infernal predictive text. Sir Niger indeed!

[Go_West]

[reply]OOLiveSteamClub said:

 

I have 2 renumbered LS A4 engines but at the end of the day an A4 is an A4 and not in my mind a new loco an LMS or a GWR or SR engine would be great but as has been said will not be put back into production any time

 

soon and as i think hornby have like many companies to watch the pennies till things improve. but I have been working on an idea which is almost finnished which i think hornby could go into production with so watch this space?

[Go_West]

Hi LS

 

I do not think a model of the dynamometer car has been made yet and this is one item that goes well with the A4 Mallard 126mph record loco so Horby get going and make one it would look good even in a display case, but till then have a look

 

at mine if you want,

 

[Raven_Electric]

Hi gowest

 

I enjoyed your dynamometer car. In fact it is the bees knees because it is a real one ! Train load AND speed, just imagine what O. S. Nock would say if he could see your model, his eyes would pop out of his head!

 

I don't think there

 

would be much demand for a model of the "Hush Hush" W1 4-6-4 though The_Son_of_Triangman - certainly in its original form. Indeed with the possible exception of Ford's Edsel it is, in my view, the ugliest thing that ever ran on wheels!

 

Water tube steam

 

locomotives are interesting. All credit to Gresley for having a go and sticking at it for years - and he had the best brains in the steam boiler business helping him. In truth fire tube boilers are glorified Scotch boilers hence the critical safety need to

 

keep the water level high and the steam volume low. Quite a few clever designers had a go at water tube locomotives and they were the holy grail but there never ever was a really commercially successful one as far as I know. A history of the various attempts

 

would be a very interesting read though.

 

As for 155mph the only LNER streamliner that ever saw that was the plasticene one in the wind tunnel! Another speed limiting factor on the Hush-Hush in both forms was the conventional trailing four wheel bogie,

 

ideal for weight distribution but it did nothing for stability, Gresley's use of the cunning rear axle suspension design for the Pacifics played a big part in their ability to go where the tracks went and ride well to boot. But at 155mph on 6'8" wheels there

 

would have been con rods all over the place from Kings Cross to Waverley and the vibration would have brought down the Royal Border Bridge.

 

The Yarrow water tube boiler was easily good for 600psi and far more later. Now that fed through a turbine

 

set and geared transmission would have been something else.

 

What has always amazed me about all the high speed runs was that the LNER Civil Engineers Department at the time was always adamant their lovely railway was only good for 90mph. I often wonder

 

if they all travelled by bus!

 

[The son of Triangman]

Gresley's trailing pony truck on the big baltic was more of a 4-6-2-2 design although officially classed as a 4-6-4, the pony truck was designed for stability and weight bearing on10000, the baltic wheel arrangement has long been recognised as the optimum

 

for steam mainline locos but pacifics were cheaper to build.

 

155mph was unofficially done down stoke bank with the rebuilt 10000(BR 60700) on more than one occassion, rummours circulated in the railway world at the time. I remember speaking to a retired

 

driver of the loco in the 1970's on King's Cross station, he had just been up to the cab of one of his old mates HST's. The guy swore the "old girl touched 155mph down stoke and I thought I had better ease her back as she had started see-sawing back and forth".

 

 

 

Rummours from crews of A4's reaching 140mph were also known, how much of this was bravado and how much is really correct is anyones guess. A rocking back and forth motion seems to set in at these speeds causing drivers to slow the locos back down to quickly.

 

Mallard is the fastest recorded A4, but that's just the officially recorded record. SNG himself is on record stating he felt Mallard could have gone at least 10-15mph faster.

 

Mallard was let down by essendine curves and the middle big end design and

 

after the record much work was done to sort the middle big end problem out.

 

Interestingly the original hush hush high pressure boiler outlived the rebuilt loco, the boiler being used as a works heating and steam boiler until 1965.

 

Certainly we

 

will never know for sure but it is very likely the record was well and truly broken on more than one occasion by the rebuilt W1 and some A4's.

[The son of Triangman]

The Great Gathering was more like the great wimpering without a Silver A4 and rebuilt W1. It only serves to remind us of what we lost to the scrapman,

[Raven_Electric]

Gresley certainly didn't use radial axle box suspension for cheapness because it wasn't! Think of a boat with rudder on the end, or an aircraft tailfin, as the craft yaws the leverage from the rudder brings it back on course. Equally, with radial axle

 

boxes, when the locomotive yaws there is sideways resistance from the axially deployed springs and the locomotive has to "climb" up the spring so to speak so the weight and sideways momentum of the locomotive itself is used to automatically centre it. By adjusting

 

the spring rate carefully the system can be made to offer the maximum correction at the speed at which the oscillation is greatest. A very elegant solution in Gresley's Pacifics.

 

Although wheel weights statically balance a locomotive Gresley's three

 

cylinder setup was not fully dynamically balanced, to say the least, and the radial rear axle would have helped to mitigate oscillations and frame flexing from this too.

 

The same idea was often used in luxury cars where a leading link was employed.

 

The result of this was that when you braked the nose of the car didn't dip, indeed by adjusting the springs you could make it go up! The top end British Daimlers such as the Majestic (proper Daimler, 1955 and pre Jaguar) were good examples of this and there

 

are many more.

 

A negative roll centre is equally unnerving, if a car is configured in this way when it turns into a corner it leans into it and that gets us back to some interesting train suspensions!

 

More wheels mean more friction and more

 

unsprung weight and less power transfer if they are not coupled wheels. However, this is rather less expensive than heavier rails!

 

There were, and I understate, quite a few good steam locomotive designers (for the world) in the UK and not one of them

 

used a 4-6-4 arrangement for their mainline express locomotives because in many later, faster cases the rear axle of a 4-6-2 was working as a rudder.

 

With much bigger American and Continental loading gauges and train loads track loadings even on heavier

 

mainlines were more of a problem so more axles were required for freight locomotives and as speed and therefore locomotive weights increased additional axles were resorted to on a few high speed passenger locomotives too. Adding more smaller coupled wheels

 

for high speed running was no solution as piston speed became a serious issue and these things were not engineered by Cosworth. Also, the much bigger loading gauge allowed for other solutions to torsional vibrations etc, many French locomotives providing good

 

examples of this.

 

The W1 had a similar weight and axle loading to the A4s but perhaps the boiler/firebox arrangements made it tail end heavy or possibly with well over 400psi piston hammer was an issue with the civil engineers. There was only one,

 

it was experimental and the suspension on it certainly wouldn't have been uppermost in Gresley's mind. The extra vertically sprung axle would unquestionably have reduced the effectiveness of the radial springing but as is usually the case with experiments

 

where the main point lies elsewhere it possibly just got tacked on as a fix to solve some problem or other.

 

I can quite understand drivers imagining 155mph on the footplate of those locomotives but I would never accuse them of bravado. They were a

 

breed apart I think. It is beyond my ken how anyone could have good enough nerves to drive one at even 100mph on a sunny afternoon let alone thunder down from Coldingham Moor into the dark and wet of a Borders easterly gale. I travelled on them often enough

 

and they certainly did. I have a vivid memory from boyhood standing frozen to the bone on Fort William station on a filthy freezing February evening waiting for the last Queen St train. It arrived off Rannoch Moor tender first for some reason with a couple

 

of feet of snow and ice in front of it and the driver still managed a smile. How could anyone have stood that? A breed apart goes nowhere near doing those guys justice.

 

 

 

[The son of Triangman]

The Rebuilt W1 boiler wasn't 400 psi but the same in pressure terms as an A4. The pacific wheel arrangement was cheaper to build, no extra axle to make. Some very good baltics were built in the country including some big baltic tank locos down south. They

 

proved to be very stable at speed and in service. It was recognised that the pacific wheel arrangement was cheaper to build and adequate for the jobs needed. 4-6-4's have been sued succesfully for express work overseas so it may have just been possible. The

 

loco certainly had the power and legs over an A4's, wether you would have wanted to be on the footplate of such a loco at speed that's another question?

 

Some tech stuff about rebuilt W1.

 

Boiler Pressure Rebuilt W1 250psi

Heating surface 3346.5

 

sq ft

Grate Area 50ft

Tractive effort at 85% 41.437lbs (more TE than an A4, Duchess or King!)

Tender water capacity 5000 gallons

Coal Capacity 9 imperial tons

Axle loading 22 Tons

 

A4 Techy Stuff

Boiler Pressure 250psi

Heating Surface

 

3325.2 sq ft

Grate area 41.25 sq ft

Tractive Effort at 85%, 35,466lbs

Tender Water Capacity 5000

Coal Capacity 8 Tons

Axle Loading 22 tons

 

 

 

 

 

 

 

 

 

[Go_West]

[reply]Raven_Electric said:

 

the 2 bits put in these pages is most interesting and great reading i like the what if from you both and many steam engines had lots of improvements i think the dynamometer car was old when it was linked to the A4's run

 

what year was it made?

[Raven_Electric]

Hi there gowest

 

The clerestory roofed dynamometer car which Gresley used extensively for locomotive testing was ex NER and was made in 1906 and is now part of the National Railway Collection. I must add it was also used extensively by Sir Vincent

 

Raven in developing his electric mainline traction. Electric motors loose torque with speed and Raven's breakthough was to manage high torque at low speed for heavy goods trains linked with sufficient torque at high speed to have made pulling a 16 car train

 

at well over 100mph a doddle had his mainline electrification gone ahead.

 

Equally, Gresley sought high power with low weight and good balance in his designs, and was prepared to pay the price for this, the centre big end design being one of a good few

 

examples. His attempt to apply the much more advanced and very much safer and reliable water tube boiler to locomotives was research he continued for nearly ten years and although success eluded him it would have been the single most important advance that

 

could have been made to steam locomotives. Double acting reciprocation would gone, in itself a major limitation to speed and reliability, with appalling loadings on frames and track damage through piston hammer. Instead, in would have come multi stage high

 

pressure steam turbines and geared transmission. Gresley was a always an innovator and he certainly saw this future because even by 1927 he well knew the ultimate limitations of the existing technology and that he was very close to it. In my mind it stands

 

as one of his greatest achievements that he tried so hard when so many others with greater resources at their disposal didn't. This above any other consideration is the importance of the W1 "Hush Hush".

 

For an understanding of the way Gresley's design

 

philosophy evolved one has to go back to his original, startling, Pacific design, The Great Northern for the GNR where he was Chief Mechanical Engineer before grouping. O S Nock's "The Gresley Pacifics" published by David & Charles is a superb introduction

 

to a detailed study of Gresley's design thinking if you can find a copy. Nock discusses Gresley's commitment to flexible frames and the importance he placed in the so called "Cartazzi" arrangement which he developed and refined in conjunction with his flexible

 

frames to achieve a degree of stable running that was exceptional. Ever growing vibrations from resonant frequencies was of great concern in marine shafting and Gresley would have been well aware of work on this from his visits to Armstrong Whitworths who

 

with other Tyneside works were involved with this.

 

The final result was unquestionably the A4s where weight balance, springing, frame design and a whole host of details had been combined so that a large collection of what appeared minor inconsequential

 

changes led to the whole being greater than the sum of the parts - always the sign of great engineering of which today a fine example is the Porsche 911.

 

Gresley was not an easy man, but neither was Thompson and the difference in their backgrounds,

 

Thompson's being more academic, probably played a part in what appeared to approach mutual loathing. Poor old Thompson should have gone down in history as the man who moved carriage design into a safer era with steel construction replacing the carnage of wooden

 

carriages in accidents, but of course his mangling of Great Northern in 1944 can only be explained as a nasty vindictive act and has left him a condemned man in the eyes of enthusiasts. It was Peppercorn and later BR engineers who really sorted out some of

 

 

Gresley's detail design failings in his conjugated valve arrangement and the centre big end that The_Son_of_Triangman rightly drew attention too.

 

There is an interesting postscript. It was a suitable and appropriate end to the A4s that they provided

 

such sterling reliable service, often through Stirling, on the Aberdeen Glasgow run on both former Caledonian and NBR tracks in BR times. Service engineers at Darlington and Doncaster were known to have criticised Gresley's lack of interest in feedback from

 

service failings and one wonders if he ever travelled the tracks to Aberdeen before coming up with the P2 2-8-2. Hornby's eagerly awaited model of this breathtakingly beautiful locomotive only makes one wonder why on earth Gresley came up with such a design

 

for these bendy, short hilly tracks on the NBR Edinburgh Aberdeen run. They were an absolutely dismal failure on the tracks they were designed for with broken frames being a regular event. Why on earth didn't he use derivatives of The Great Northern which

 

would have been much more appropriate for those conditions and absolutely thrived on them in their twilight years?

 

 

 

[Go_West]

[reply]Raven_Electric said:

 

Hi

 

Thanks for that, all my work on my engines and mods i write up with text and pictures so have copy and pasted the Dynamometer history into my book thanks

[Raven_Electric]

Hi gowest

 

Considering all the work you have put into your Dynanometer car it more than justifies decent documentation.

 

A bit like the Queen's Consort it is always there in the pictures but playing second fiddle!

 

There is plenty about

 

it online to fill a pleasant evening's browsing - starting with the National Railway Museum website. I have also come across references in quite few publications over the years. I am afraid I cannot remember the details (If I do I'll post again) but somewhere

 

I came across extensive documention about it's early equipment aand calibration and then later modification. Obviously, Worsdell and then Raven had an abiding interest in haulage measuring with so much coal to shift! I could be mixing this recollection up

 

with something else but I think Armstrong's produced a hydraulic train load measuring system for it that fed into a barograph style paper reel chart recorder that had a second pen charting inclines and a third, speed. If you do come across the details of this

 

please post. All of it is surely a must for your records.

 

I am assuming in all this there was only one car but the NER also had a crane callibrating car too but whatever documentation exists on that is probably thin on the ground and I have never seen

 

a picture but when I was young I had an old relative who had worked for Lloyds British Testing and he had some early experience on it.

 

Almost certainly the dynamometer car would have been commissioned by Wilson Worsdell, Locomotive Superintendent (Chief

 

Mechancial Engineer) to the North Eastern Railway in 1906. (Confusingly, he followed his brother Thomas in the job). The NER was dripping with cash and was far and away the most financially successful British railway company with the huge Tyne Dock staithes

 

and many others up the Tyne and Amble, Blyth, Sunderland, Seaham, Hartlepool and the mighty Newport, now TeesPort. Worsdell came up with some interesting locomotives with the emphasis on seriously heavy haulage, not just for coal but iron ore up the arduous

 

climb to Consett Ironworks. He was also responsible with Raven for the NERs automatic train protection system (later scrapped by Gresley).

 

Gresley too had a go at heavy haulage. His P1 2-8-2 could laugh at 1600 ton trains and came with a booster engine

 

on the rear "Cartazzi" axle. Like something from America, the freight trains it could pull were just too long for signalling sections so only two ever got built. A mighty beast well worthy of Hornby's consideration for a model.

 

It is fitting that one

 

of the finest and most sophisticated steam locomotive to ever run on British rails, Riddles 9F, could be seen to the very end (amazingly often double headed and what a sight) hauling huge auto tipping ore trains from Tyne Dock up to Consett Ironworks.

 

And

 

Riddles work saw them all out because his humble little wartime J94 0-6-0 WD austerity engines were snapped up by the NCB and private operators when BR abandoned steam.

 

 

[The son of Triangman]

Totally agree about the A4 desgin being refined, SNG and others did heaps of work on the locos. The W1 was used as a test bed for the kylchap blastpipe arrangement that later became standard on the A4's.

 

The rebuilt W1 probably did smash Mallard's

 

record into bits, it had a reputation of being a real speed machine, and there is little doubt that some A4's did too. Claims of 140mph with A4's was known but hushed up. Recently a comment by a respected olden days A4 driver came forward in the magazines

 

suggesting he had an A4 up to 140mph. SNG was on record as saying that Mallard should have gone another 10-15mph faster and a second run was planned for june 1939 but world events stopped this, a run with the rebuilt W1 was also planned for that year but again

 

world events stopped the race for speed. 155 mph with the rebuilt W1 begins to look possible, certainly the power and stability was there in the loco and with all the work SNG did on it in rebuilt form and the A4's, who knows for sure. We shall never know

 

for sure, Mallard is the official record holder for now unless the yanks have a go as they say they are going to.

 

As for the rebuilt W1, it passed almost without recognition in 1959 at Donny works, forgotten by rail enthusiasts, being the BR modenisation

 

era and being a non-standard loco and a one off the loco it was doomed as anything non-standard on BR was getting the chop. Interestingly the original high pressure boiler soldiered on as a heating boiler until 1965.

 

A class of "Super A4" W1 baltics

 

was propossed by SNG but war stopped this happening, partial plans for a production rebuilt W1 super A4 apparently are supposed to be with the NRM archives. People maligned this superstar of steam in rebuilt form as when it went for big overhauls it spent

 

a lot of time out of service, this was down to the boiler being a one off, today such things are taken for granted as a lot of steam survivors are now sole examples of their kind and long overhauls are common place. It's accident at Peterborough is well remembered

 

too when the main bogie frame broke and derailed the loco at 15-20mph putting the loco and tender on it's side but it was repaired and put back into service, lesser locos at that time would have been chopped up for scrap onsite.

 

Certainly it is possible

 

the real record holder may well have got the chop at Donny works in 1959. The W1 in rebuilt "Super A4" form was I feel Gresley's masterpiece, every lesson learnt with the unrebuilt W1 and the A1's and later A3's rebuilds, and A4's went into it's redesign.

 

All those refinements and improvements. I agree Gresley was near the limits of design for the technology and I also agree steam turbines and high pressure boilers were a good way forward for steam.

 

Onto P1's and P2's.

 

The P1's were impressive

 

machines, but were too powerful as has been said, totally agree. They eventually became worn out and weren't replaced. They were surefooted haulers, used on the Peterborough area brick works trains where long trains of wagons needed plenty of grunt. There

 

were like an A3 in looks but much more impressive. A model would be most welcome.

 

P2's, well I have to agree, they were track bashers, very heavy on flange wear and frame breakers, not ideal for the lines they were used on and usage of the new ones

 

will be limited in which preserved lines they can run on, in Thompson rebuilt A2 form they were just as troublesome with frames breaking behind and in front of the cylinder blocks.

[Raven_Electric]

Hi Son_of_Triangman

 

Your mention of the Kylchap system brings a reference to one of those physical principles that can be difficult to get your head around. The idea is of course is that as airspeed increases the pressure drops so air surrounding

 

secondary apertures is at a higher pressure and forces itself in. The same principle applies to air passing over the longer top of an aircraft's wing where having to speed up causes a reduction in pressure and results in lift from the higher pressure under

 

the wing. The Kylchap system looks a bit like, but is not the same as a certain vacuum cleaner design where spinning air goes up a cone so speeding up and centrifuging the heavier crud to the outside walls.

 

Gresley was a friend of the French genius

 

engineer Chapelon who brought the rigour of scientific method to steam locomotive design. He had studied fluid dynamics carefully (his books are a worthwhile read) and he refined and perfected the Kylchap system. Not only did Gresley adopt that, he also adopted

 

the streamlining that Chapelon had pioneered on some of his trains and railcars with his friend Ettore Bugatti. People often said the Gresley streamliners were a marketing stunt, the B17/5s certainly were, but stick your arm out of a car at 70mph and then

 

read the figures Gresley came up with and it, with carriage end streamlining on some rakes certainly helped. So there you are, the rebuilt W1 is really a Bugatti so it had no excuse, it had to be fast!

 

Stephenson's wonderful High Level Bridge over the

 

Tyne has a triangular approach from both west and east on the south end. The Gateshead shed's turntable was short and probably clapped out when I was young and the drivers turned the Pacifics on the Bridge triangle through Gateshead's unique (and now gone

 

sadly) completely wooden up in the air station on two sides. Of course they often had some sport and opened the things up the second they stopped and the sound from the Kylchap exhaust hurt your ears if you were standing on the Gateshead platforms, a great

 

thick jet of solid ash shot skywards and the station roof was about a foot thick in the stuff. They didn't need the ash pit after the two stops and starts.

 

And that brings up another point. Before any ex Northumbrian pitman shouts me down I appreciate

 

there was (and still is) lots of quality coal in the Durham and Northumberland coalfield but in the main it is power station coal and you need a nuclear reactor to get it to start burning at all as anyone who collects washed ashore stuff from some beaches

 

can testify. The GWR and LMS had access to superb "steam coal", Welsh anthracite. Gresley in the main was stuck with this poor quality stuff with difficult burning characteristics and lower calorific value. As far as I know the Fife and Lothian fields weren't

 

much better. Had the W1 water tube boiler fullfilled expectations the potential furnace demand could have been huge and the provision for that in the bigger firebox possibly explains the need for the extra axle to meet some track loading restrictions as it

 

did run north. I am certain though that Gresley's production models would have employed his axial springing arrangement on both axles because Chapelon adopted it on some of his designs.

 

Those high speed express steam locomotives really were filthy,

 

dangerous things though. Persil white was unknown for folk who lived near the NER tracks, most places, until they had gone. Hornby's models are much nicer!