Niels

On 24/05/2019 at 11:36, Traintresta said:

It’s the cylinder arrangement I dislike, but it looks like a civil engineers nightmare!

 

very nice model though, somehow the lion and wheel suit that tender.  

 

There is also this: 

Compagnie Nord made something like it in1912

https://commons.wikimedia.org/wiki/Category:Nord_3.1151_–_3.1170_→_SNCF_2-231.A?uselang=fr#/media/File:Early_Nord_Pacific.jpg

1 hour ago, Clive Mortimore said:

Getting back to using imagination, a Stanier Baltic class 5 P, a Stainer 2-6-0 Class 4MT and a Fowler 2-6-0 class 4MT.

Can You please also make a 2-8-4 t based on WD austerity and put it in same picture as the Baltic?

A gentleman with driving expirience on another site stated that 2-6-4t s were best riding loco he had driven.

2-8-4 must be better still.

Building costs would have been low and track damage from four sets of 4feet 8 would have been less than three 6 feet two

7 hours ago, melmerby said:

And nobody mentions hammer blow!

 Hammerblow is not nessecary on  three cylinder engines.

Bulleid proved it by modifying a Schools

5 hours ago, 34theletterbetweenB&D said:

Because it is fixed gear, for any given stroke rate, the larger the wheel the faster the loco will go if adequate power is available.

 

What is true is that a wheel diameter of 2m/6'6" +, once thought essential for express speed (typically in the range of  110 - 140 km/h or 70 to 90mph in the steam traction era) can be achieved with smaller diameter wheels with superior valve arrangements. But this knowledge arrived rather late in steam development, as it was about to be displaced from its position as principal power for rail traction.

Nope

Dutchmen in Indonesia rebalanced and revalved a class of 2-8-0 gauge 1067mm  with 1105mm drivers sustaining 90 km/h earning money and doing 105 on test run before ww2 and after Chapelon.

7 hours ago, Traintresta said:

This is certainly an interesting proposal, I wonder if you could provide larger drivers to make them a more mixed traffic loco. 

 

Larger drivers are counterproductive when three-cylindered.

The Schools class for example  will be a  better locomotive if rebuilt with five feet wheels and wide firebox.

After Chapelon and mr Diamond it was common knowledge that power and speed was limited by valve area more than anything else.

Just like car engines

It is the poor balancing of two cylindered engines that made it nessecary to employ big wheels for going fast.

Try to look at the power curve of the very succesfull SNCF 2-8-2

30 years small wheeled high power.

And step 13 pages backwards

Higher power at speed than any UK locomotive and 1550mm wheels and two cylinders.

This was possible due to big Cossart valves and the two funny looking connecting rod look alikes.

Try this link instead

Caso masterpiece

On 16/04/2019 at 23:40, rodent279 said:

What about a subtle twist on what's already there?

How about a 9F, but with 3 cylinders, slightly smaller so no need to be inclined? Smoother starting, smoother at speed, maybe even with British Caprotti gear? Is that a useful beast?

There is another phantasy way.

WD locomotives came around  850 as 2-8-0 and 150 as 2-10-0.

They were built without reproci etc balancing and that is good on lousy tracks and tolerable at speeds below say 25 mph.

Coming home they were not really liked.

The distance between center of leading wheel and second driver was 13 feet and11inches.

On a B16 (made by my Hero mr Raven) the distance between front boggie wheel and driver is 14 feet.

Take the austerities and remove the first driver  and leading wheels.

Put in a three-cylinder compound machine over a boggie and drive unto the now first driver.

It will now have balance and riding like an A4 and better fuel economy.

After say 100 years of experiments the swedes found their ideal locomotive.

Twenty of these three-cylindered beauties:

Best Swedish lokomotive

UK could have had almost 1000 for nothing.

UK loading gauge makes drive unto first set of driver nessecary and connecting rods will be as short on A2/2s

Photoshopping anyones?

1 hour ago, 298 said:

Cafés, the Diner is lit with cool white LED strip but the Coffee Shop uses warm white 3mm LEDs with a touch of Tamiya clear red to balance the light to the same colour as the filament bulbs in the globe streetlights outside.

 Your american ligth is fantastic

Formidable

On 14/04/2019 at 16:35, SteamedLyons said:

Interesting this cut and weld.

Try it on a LNER P2 and get something like:

Surburban LNER P2

1 hour ago, Clive Mortimore said:

Hello Tony

 

Your assumption is correct. This is quite an interesting read, it has a section on Kernwek grammar. https://en.wikipedia.org/wiki/Cornish_language

 

It is all Edward VI's fault it died out as a living language.

Interesting.

Zasawzneck in Cornish meaning saxon speaking.

Any relation to sassernach that I once heard in Scotland?

It was no praise.

On 03/04/2019 at 14:43, MarkC said:

Thanks too for clarifying the point about cylinder blocks - this morning's claim about common castings was the first I had heard of that theory.

My morning claim was that Raven A2 (4-6-0),Q7(0-8-0) and B16(4-6-0) shared cylinder blocks.

Bradley writes that Q7 and B16 had inter-changeable cylinders ,boilers and motion.

That A2 used same cylinder casting is likely, but not confirmed.

The B16 had conrods outside coupling rods as had A2s and Q7

27 minutes ago, MarkC said:

 

 

Regarding the connecting rods - they were actually mounted inside the coupling rods on the driving axle, as they were on the S3/B16 and D/H1(later A8). As an aside, what was the reasoning for this?

If You look at pictures in Yedon for B16 it is not true.The connecting rods are further away from center than coupling rods

It would have been a better arrangement reversed but was not possible due to using the complicated cast in one three-cylinder block from mineral Q7.

10 minutes ago, drmditch said:

 

 

Perhaps the final verdict on the 'congested' leading crank axles should come from someone who had to maintain them?

 

 

The common inside cylindered locomotive had two crankthrows and four eccentrics between frames.

The A2 with one throw and six eccentrics sounds easier to me.

Especially as they are more accesible due to front wheel drive

1 hour ago, MarkC said:

 

Then there was the issue of minimum radii trackwork. By using the front end from the S3/B16, which was similar to other Raven locomotives such as his Class D (later H1) 4-4-4T and his Atlantics, there were clearance issues to consider between the bogie wheels and the cylinders. (As we modellers know only too well...). Bad enough on the Atlantics, but VERY limiting on the Pacifics. This won't have helped their case either when being compared to the Gresley Pacifics. Indeed, there is a story (and possibly a photo) of an Atlantic having a wheelset jammed against the cylinder, and I fancy that it won't have happened just once.

 

The Raven A2s were impressive looking machines, but to me they were very much a 'near miss' when compared to the Gresley Pacifics.

The A2 had outside connecting rods sitting outside the coupling rods at a centerdistance of ,let me guess 6 feet 9inch.

If built as 100000 american front driven 4-4-0 with conrods inside coupling rods at say 6 feet three inch, there would have been no clearance problem.

A2 and B16 and Q7 shared same cylinder block and on Q7 it was imposible to drive first wheelset so the idea of standartisation was the culprit.

35 minutes ago, micklner said:

The NER hung all their big Locos valve gear on the front axle , so presumably it worked ok for them, as well as the inside motion did for the GWR.

And all the Midland compounds.

One crankthrow and six eccentrics on leading driving wheelset

1 hour ago, Tony Wright said:

 Could anyone see the the Raven A2s surviving for a further 25+ years? I don't think so. 

 

Regards,

 

Tony. 

The B16s had  same machinery and crankshaft .(more or less)

Did a lot of revolutions during a very long life.

There is a picture of a Raven B16

https://www.gracesguide.co.uk/images/1/15/Im1921EnV131-p014bba.jpg

and of a Raven A2

https://transportsofdelight.smugmug.com/RAILWAYS/LOCOMOTIVES-OF-THE-LONDON-NORTH-EASTERN-RAILWAY/LOCOMOTIVES-OF-LNER-ORIGIN/i-72m2bMq/A.

The ultimate Pacific in my universe is a shortened A2 boiler on B16 machinery with a trailing wheel  or a set of driver more.

It can surely be photoshopped but the A2 picture is copyrigthed.

It will be of great value to mankind and keep me from mischief if  readers here , who has built these two locomotives, will photograph them with long focal length lens and connecting rods in same position

45 minutes ago, micklner said:

Just found some pictures a NER Loco with six drivers !!

 

Lovely locomotive that was deemed out by Gresley

Machinery was like B16 that was better than Sandringhams.

Sandringhams had same machinery lay out as  Thompson/Peppercorn pacifics .

These pacifics were built after Gresley pacifics and was better or management made an error.

Same applies to the V2s that was built as A2/1.

If the Raven Pacific had received same loving care that the Gresleys got after loosing to GWR 4-6-0s,some nice locomotives had resulted.

It would have been even better if it had had 5feet8 wheels (B16) rather than the 6feet 9 it got.

Just dreaming

19 minutes ago, Corbs said:

From a while ago, this was my take on the 2-8-4

 

I modified the ashpan and lower firebox a fair bit, think it has less of a slope to it now.

 

Lovely and can it easily be made roundtopped?The trailing truck wheels need not be same size

2 hours ago, Satan's Goldfish said:

Ok, so trying to work out the best solution here; Am I right in thinking there are advantages to having a leading 2 axle bogie rather than a leading single axle at higher speeds? 

Unite the leading single axle with the first driver in a Zara or Krauss-Helmholtz truck and it will be just as good at speed as a 2 axle .

This means the first driver shal have 1 inch freedom side to side and this will only be possible within UK loading gauge if You use three or four cylindes.

The 9F has cylinders one inch further out than Britanias.

Bang went standartisation.

New cylinder patterns.

Reason was conflict between front coupling pin and croshead.

Brittanias are 8 feet 8,25 inches wide and 9Fs 8feet 10.25 over cylinders.

18 hours ago, Satan's Goldfish said:

I like revisiting things as I find out more, so I went back to one of my favourites that'd I like to attempt to actually build (as I have some of the parts already) which is the unstreamlined LMS coronation Mikado. My previous effort used an 8f chassis, but I thought I'd try again with the slightly larger drivers of a 9f chassis.

 

I don't know if I've messed up my scaling of the source images slightly, but as you can see, it doesn't really sit right as a Mikado using the 9F chassis and cylinders, but there was enough room to keep the leading coronation bogie and cylinders and turn it into a mountain.

 

 

 

 

(Edit - Just done some quick maths, and 3x 6'9'' drivers = 20'3'' on the standard coronation. 4x 5' drivers from the 9F = 20' so it would fit...)

Why not move the Coronation boiler a little forward ,omit aft  9F wheelset and put a boggie under firebox?

A 2-8-4 that was more or  less the swan song for american steam freigth

2 hours ago, Corbs said:

Have a look at the link, it's part of a much bigger proposal they worked up

 

Today's nonsense.

 

An Ivatt Super-8F 4-8-0

3 cylinder front end similar to Royal Scot/Jubilee etc. Double chimney

Bigger firebox than an 8F - wheelbase has been enlarged to accommodate this.

Ivatt style cab

Very close to a real engine

SJ E10

null

On 12/03/2019 at 22:14, Gibbo675 said:

Hi Niels,

I do like the 2-8-0, I might bash a Dapol kit now that I have looked at it !

Gibbo.

 You aint seen nothing yet.

https://i.imgur.com/RqN3dGA.jpg

Steam locomotive drivers was sometimes more than five feet because two cylinder locomotives shake themself to death and destruction with  number of rpm squared.

Three  cylinder locomotives are inherently well balanced so five feet drivers would have been big enough for most trains.

Based on 9F wheels and boiler form tools.And was nice to dream on a rainy day like today.

http://

40 minutes ago, Satan's Goldfish said:

 

Ok, dropped the Princess on some 5'6'' drivers, so a couple of inches bigger than a 4f. I'll agree, it looks better. Cylinders needed moving forward to accommodate the chassis.

 

Lovely,but can be even more extreme.

Tests made by BR Rugby showed that 9F boiler was as least as effective as Brittania boiler (that compared very well with LNER V2) as long as it was  at or under 3000 lbs coal per hour,one fireman limit.

Narrow fireboxes would  not have been  worth the trouble on British railways if five feet drivers could have  been made to turn fast enough.

To make five feet drivers fast enough they can be three cylinder driven or by two and then some artificial balancing.

With two outside cylinders and a crankshaft and a dummy conrod inside it will still be ligther than the moving parts of Kings,Royal Scotts and Class 5/B1 .

And just as fast in daily use.

To show it a Photoshop session from a WD 2-10-0 picture will be easy due to the cylindrical round top boiler.

Is there sush a picture somewhere?

Something like:

WD 2-10-0 side picture

Maybe Leaders should have been  Heislers.

There is a lot of similarity between Hymeks and Heislers,and the Heislers did not need the hydraulics.

A V2 compound steam engine is a very smooth engine.