Imaginary Locomotives

[toby_tl10]

4 hours ago, PhilJ W said:

They streamlined a couple of B1's as well but the streamlining was removed post-war.

Two B17s, not B1s. Streamlining removed in 1951.

[rockershovel]

11 hours ago, JimC said:

Not very surprised I suppose, there must be laws of physics factors around tube length. The relationship between number of tubes and flues is quite alien to UK practice though... 

About 21ft, in fact. More DIAMETER is valuable (which was also the point of the Beyer Garratt design)

 

I don't know about tubes and flues but last-generation American steam typically featured huge fireboxes and combustion Chambers, so I guess the gas flow dynamics would be quite different.

[Yarravalleymodeller]

3 hours ago, toby_tl10 said:

Two B17s, not B1s. Streamlining removed in 1951.

Think you can even get a kit for them in O gauge... they looked rather nice dare I say better proportioned than an A4. 

[rodent279]

10 hours ago, Ramblin Rich said:

I'm sure I've read that the nose end only contributed a small fraction of overall drag and a lot more benefit came from enclosing spaces under and between coaches.

In other words, streamlined rolling stock and a non-streamlined loco was worth almost as much aerodynamically as going the whole hog.

Did the record breaking duck managed its record with normal (i.e. non-streamlined) stock? I think SNG on its 1959 112mph run was using mk1 stock.

[Compound2632]

3 minutes ago, rodent279 said:

Did the record breaking duck managed its record with normal (i.e. non-streamlined) stock? 

 

It was a Coronation set wasn't it? But it included the ex-NER dynamometer car which was (is) a far from streamlined vehicle.

 

[john new]

2 minutes ago, rodent279 said:

In other words, streamlined rolling stock and a non-streamlined loco was worth almost as much aerodynamically as going the whole hog.

Did the record breaking duck managed its record with normal (i.e. non-streamlined) stock? I think SNG on its 1959 112mph run was using mk1 stock.

Well the Dynamometer Car on Mallard's record run was unstreamlined for starters. The SLS Special in 1959 was a normal set of coaches AFAIK.

[sncf231e]

11 hours ago, John Besley said:

 

Would look better with a 6 wheel tender I think

 

Like this?

 

Regards

Fred

[Yarravalleymodeller]

44 minutes ago, sncf231e said:

 

Like this?

 

Regards

Fred

How about as a 4-4-4 for a slightly longer boiler barrel and slightly bigger fire box. 

[Compound2632]

1 hour ago, sncf231e said:

 

Dinky!

 

18 minutes ago, Yarravalleymodeller said:

How about as a 4-4-4 for a slightly longer boiler barrel and slightly bigger fire box. 

 At that rate one might as well make it a 4-6-2 for greater adhesion...

 

Done in the US, though, of course:

 

 

[Embedded link to Wikimedia Commons.]

 

As a resident of Reading, I am conscious that I have not done enough reading about the Reading Railroad.

[rodent279]

31 minutes ago, Compound2632 said:

 

Dinky!

 

 At that rate one might as well make it a 4-6-2 for greater adhesion...

 

Done in the US, though, of course:

 

 

[Embedded link to Wikimedia Commons.]

 

As a resident of Reading, I am conscious that I have not done enough reading about the Reading Railroad.

I suppose if you didn’t need the power & adhesion properties of a Pacific,  but needed to burn low grade, high ash coal, a 4-4-4 might be the way to go.

[Compound2632]

17 minutes ago, rodent279 said:

I suppose if you didn’t need the power & adhesion properties of a Pacific,  but needed to burn low grade, high ash coal, a 4-4-4 might be the way to go.

 

On the other hand, my limited knowledge of the Reading Railroad does extend to the knowledge that the Philadelphia and Reading Railway was built to serve the anthracite coalfields of northeastern Pennsylvania.

[The Johnster]

3 hours ago, rodent279 said:

In other words, streamlined rolling stock and a non-streamlined loco was worth almost as much aerodynamically as going the whole hog.

Did the record breaking duck managed its record with normal (i.e. non-streamlined) stock? I think SNG on its 1959 112mph run was using mk1 stock.

Which begs the question of whether Mallard was able to achieve it’s record because of it’s shape or because of the Kylchap double chimney; I would tend to favour the latter explanation, and believe that streamlining on a steam loco serves no purpose other than passenger-attracting imagery for the publicity people (not knocking that, btw, it generates a lot of profitable income, but is irrelevant in engineering terms).  The A4s were required to haul 14-coach unstreamlined trains in service to timings that required speeds in the 90s, and were successful at that task; I doubt that the shape made much difference though as has been stated it was effective for smoke-lifting.  The Thompson A1s were pretty much on a par performance wise in service, and as near to slab-fronted as a sream loco gets!
 

[rodent279]

2 minutes ago, The Johnster said:

Which begs the question of whether Mallard was able to achieve it’s record because of it’s shape or because of the Kylchap double chimney; I would tend to favour the latter explanation, and believe that streamlining on a steam loco serves no purpose other than passenger-attracting imagery for the publicity people (not knocking that, btw, it generates a lot of profitable income, but is irrelevant in engineering terms).  The A4s were required to haul 14-coach unstreamlined trains in service to timings that required speeds in the 90s, and were successful at that task; I doubt that the shape made much difference though as has been stated it was effective for smoke-lifting.  The Thompson A1s were pretty much on a par performance wise in service, and as near to slab-fronted as a sream loco gets!
 

I think if the work of Chapelon etc tells us anything, it's that internal streamlining, i.e. streamlining of passages to & from the cylinders, is more important in getting the most out of the steam generated by the boiler.

[Flying Pig]

3 hours ago, sncf231e said:

 

Like this?

 

Regards

Fred

 

Clearly built for the GE section.  

[Gilwell Park]

How about this for model that has been built & actually works very well. Started life as a Hornby Railroad 9F with a mazak rotted tender. 

[Yarravalleymodeller]

1 hour ago, Gilwell Park said:

How about this for model that has been built & actually works very well. Started life as a Hornby Railroad 9F with a mazak rotted tender. 

https://www.stationroadsteam.com/5-inch-gauge-4-10-2-innovare-stock-code-5409/

 

Other people have had similar devious thoughts on a tank engine based on a 9f... your example reminded me of the existence of this work of the imagination. 

[bigd]

4 hours ago, Flying Pig said:

 

Clearly built for the GE section.  

I think the weight of that machine would have bee problematic on the GE section.

If the war had not intervened, I wonder if a 4-4-2 version of the V4 Bantam Cock would have emerged?

[Flying Pig]

23 minutes ago, bigd said:

I think the weight of that machine would have bee problematic on the GE section.

If the war had not intervened, I wonder if a 4-4-2 version of the V4 Bantam Cock would have emerged?

 

I think we need to save 2 tons per axle to match a Sandringham.  Will this do?

 

[Flying Fox 34F]

Dear All,

Gresley rebuilt the experimental 4 cylinder Ivatt large Atlantic with a high running plate and outside valve gear.  Another large Atlantic received a twin window cab when it’s frames were extended to accommodate a  Steam booster engine.  Combine these two together and this would be pretty close.

As for an Atlantic version of a V4, it’s a thought, but the boiler may look too small with large driving wheels.

 

Paul

[tythatguy1312]

6 minutes ago, Flying Fox 34F said:

Dear All,

Gresley rebuilt the experimental 4 cylinder Ivatt large Atlantic with a high running plate and outside valve gear.  Another large Atlantic received a twin window cab when it’s frames were extended to accommodate a  Steam booster engine.  Combine these two together and this would be pretty close.

As for an Atlantic version of a V4, it’s a thought, but the boiler may look too small with large driving wheels.

 

Paul

I more suspect an Atlantic V4 may look rather close to a Klondike with outside running gear. However this raises an interesting issue due to the Klondikes being withdrawn due to lack of suitable work, which causes me to doubt that such work existed in enough quantity to warrant construction of a V4 Atlantic. Maybe it'd exist if the LNER adopted a Midland style "small engine" doctrine but that would be completely nonsensical early-on and easy to fill with DMU's by, say, 1945.

Edited December 6, 2022 by tythatguy1312

[Yarravalleymodeller]

15 hours ago, rodent279 said:

I suppose if you didn’t need the power & adhesion properties of a Pacific,  but needed to burn low grade, high ash coal, a 4-4-4 might be the way to go.

The LNER inherited 2 batches of 4-4-4 tanks, both by all accounts capable fast suburban passenger engines though unpopular with crews for whatever reasons(humans are odd at just hating equipment instead of learning to work with it)

 

If you chucked a 3rd cylinder up the front you could get away with elongating the boiler and fire box just a bit and still come out with something that was balanced front and rear. You'd lose some weight and therefore adhession by moving to a tender but you'd claw some back by adding the extra cylinder etc. Then the problem becomes it being slip happy from the 3rd cylinder but once you got going it would probably perform quite well. 

[Compound2632]

2 hours ago, Yarravalleymodeller said:

The LNER inherited 2 batches of 4-4-4 tanks

 

A 4-4-4T is a very different thing to a 4-4-4 tender engine with wide firebox. It's an entirely conventional 4-4-0 with the firebox sitting between the coupled axles but with the addition of a large bunker over a trailing bogie.

Edited December 7, 2022 by Compound2632

[Yarravalleymodeller]

54 minutes ago, Compound2632 said:

 

A 4-4-4T is a very different thing to a 4-4-4 tender engine with wide firebox. It's an entirely conventional 4-4-0 with the firebox sitting between the coupled axles but with the addition of a large bunker over a trailing bogie.

Not really, the front end up to the rear drivers remains essentially unchanged unless as stated you want to add a 3rd cylinder but even then thats not a huge ask nor is simply counterweighting any extra load added to the rear by the new bigger fire box, a new frame extention/redesign of the frames and slap a wide fire box in there with a drag box for the tender and jobs done. 

 

The GWR could have gone down this same route to get a wide firebox atlantic out of the 2900 class examples that were built as atlantics. It's no great engineering challenge. Had they had the idea of the wide fire box way back when they could have experimented with this on planet type locos when they were busy converting those from 2-2-0s into 2-2-2s by simply adding a frame extension.

 

You're only having a fiddle with 30% odd of stuff that makes up the design and none of it seriously in depth in order to achieve one from the other. 

[Compound2632]

2 hours ago, Yarravalleymodeller said:

Not really

 

Yes really. The firebox position relative to the coupled axles is completely different. Likewise if one compares a 4-4-2 and a 4-4-2T or a 4-6-2 and a 4-6-2T.

[melmoth]

I was reading E.S. Cox's 'Locomotive Panorama, volume 1' last night and came across this passage regarding LNWR locomotives in 1922, which underlines the point made somewhere above regarding ashpans on some early 460s.