Imaginary Locomotives

[Mr_Tilt]

I'm waiting for the Crosti version............... 

[Gibbo675]

 Sorry to say, you would never get it in that light. There's circa 18 tons to add for factors like the boiler frame, stoking machine, extended live and exhaust steam runs..

 

For appearance, if you can find or make a suitable item, you want either a larger d/c offering 50% greater aperture area than the 9F, or a triple chimney arrangement at 9F apertures.

Hi There,

 

The 9F has a maximum 15 ton axle load with 9 tons on the truck, I have allowed an extra ton on each axle which is another sixteen tons.

 

Should you allow one ton for the steam reversing gear, two tons of stoker, ten tons for the second set of cylinders and extra motion and two tons for extra steam pipes that comes to 15 tons with a ton to spare.

 

I know for a fact that a black five cylinder weighs less than four tons because I have picked one up with a crane to place it on my boring machine before now and five good men can pick a 9F con rod so that's about 700lbs maximum. The locomotive is not equipped with air brakes and so saves another ton and a half of pipes and clutter.

 

Therefore, 122 tons it is,if for nothing else because Horwich works say so !!!

 

As for what you term "boiler frame" I suggest you study the photographs within following links because the ones used by the Union Pacific Railroad are of extreme light weight. The front end of the boiler is supported by a sliding saddle on top of the front engine unit and the smoke box, being cylindrical is self supporting.

 

 https://www.up.com/aboutup/community/inside_track/steam-update-08-25-2017.htm

 

https://www.up.com/aboutup/community/inside_track/steam-update-10-12-2016.htm

 

https://oldmachinepress.com/2016/12/20/union-pacific-4-8-8-4-big-boy-locomotive/

 

Gibbo.

[Gibbo675]

I'm waiting for the Crosti version............... 

Hi Kit,

 

My Garret from the class 4 kit might go down that silly route as there is unhindered area under the boiler to fit it all in that the Mallet type precludes.

 

Gibbo.

[melmerby]

Next:

 

A Mallet-Garratt?

https://www.cumberlandmodelengineering.com/images/SG2.gif

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwjf3puw45zdAhVJlxoKHcWNAXkQjRx6BAgBEAU&url=https%3A%2F%2Fwww.deviantart.com%2Fdpuo%2Fart%2FGC-class-Garratt-175502127&psig=AOvVaw2fOz163PLUy9aO605BjuHi&ust=1535993329435686

 

Keith

Edited September 2, 2018 by melmerby

[Gibbo675]

Next:

 

A Mallet-Garratt?

https://www.cumberlandmodelengineering.com/images/SG2.gif

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwjf3puw45zdAhVJlxoKHcWNAXkQjRx6BAgBEAU&url=https%3A%2F%2Fwww.deviantart.com%2Fdpuo%2Fart%2FGC-class-Garratt-175502127&psig=AOvVaw2fOz163PLUy9aO605BjuHi&ust=1535993329435686

 

Keith

Hi Keith,

 

I like that but you can build your own !

 

Gibbo.

[Budgie]

A Mallet-Garratt?

https://www.cumberlandmodelengineering.com/images/SG2.gif

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwjf3puw45zdAhVJlxoKHcWNAXkQjRx6BAgBEAU&url=https%3A%2F%2Fwww.deviantart.com%2Fdpuo%2Fart%2FGC-class-Garratt-175502127&psig=AOvVaw2fOz163PLUy9aO605BjuHi&ust=1535993329435686

Will models of those go round second-radius curves?

[brack]

Will models of those go round second-radius curves?

The fixed wheelbase is about the same as a 45xx small prairie.

[melmerby]

Will models of those go round second-radius curves?

Going around sharp curves was one of the reasons for the Beyer Garratt design in the first place.

 

Keith

[Budgie]

Going around sharp curves was one of the reasons for the Beyer Garratt design in the first place.

It's not the Beyer-Garratt bit I'm worried about, but the Mallet bit.

[The Johnster]

What I'm worried about is finding loads for such beasts on a railway with loops, refuge sidings, and signalling clearances that restrict the train lengths to 60 10' wheelbase wagons and a van.  Even where greater lengths were permitted (mostly the coal trains from Severn Tunnel Junction, Toton, and Peterborough to the London yards) the existing locos were able to cope.

 

But, please, don't let this spoil the fun!

[scots region]

What I'm worried about is finding loads for such beasts on a railway with loops, refuge sidings, and signalling clearances that restrict the train lengths to 60 10' wheelbase wagons and a van.  Even where greater lengths were permitted (mostly the coal trains from Severn Tunnel Junction, Toton, and Peterborough to the London yards) the existing locos were able to cope.

 

But, please, don't let this spoil the fun!

 

Could always just use the 'one off experiment excuse'.

 

'Yes, Mr Riddles, I understand your point about Iron Ore from Tyne dock, I'm just not sure a... a twenty four wheeled.... double fairy? Fairlie? was it? Is quite in our budget, or anyone else's for that matter. Also what is a 'Leander'?'

[PhilJ W]

Going around sharp curves was one of the reasons for the Beyer Garratt design in the first place.

 

Keith

It's not the Beyer-Garratt bit I'm worried about, but the Mallet bit.

I was thinking of the transition from straight track sharply curved track on a model railway layout.

[34theletterbetweenB&D]

..., 122 tons it is,if for nothing else because Horwich works say so !!!

 

As for what you term "boiler frame" I suggest you study the photographs within following links because the ones used by the Union Pacific Railroad are of extreme light weight. The front end of the boiler is supported by a sliding saddle on top of the front engine unit and the smoke box, being cylindrical is self supporting...

 Well, Horwich... It's simple enough, 1930s onwards high power UK mainline types run at 2.25 ton/ft frame length in working order, and that's at least a 63ft frame. I am well aware of the engineering of the final generation US superpower, and 'light weight' is not a term that springs to mind. The sliding saddle support for the front end of the boiler, and the standard UK safety factor in boiler construction are going to make weight saving a real challenge on a UK design.

 

But why do you want it light anyway? High factor of adhesion is very desireable for a heavy mover of this type, and as it is a loco with power potential only ever worth operating on 22T axleload rated main lines, you may as well have it.

 

I was thinking of the transition from straight track sharply curved track on a model railway layout.

 It was a factor on the real thing. Major multiple track realignments were required to ensure the overhang wouldn't clout other traffic on parallel running lines.

Edited September 3, 2018 by 34theletterbetweenB&D

[Gilwell Park]

Hi.  This is my attempt at the BR Standard Garratt proposed by Beyer Peacock in the 50's. Still unfinished after several years in the shops it has a Kitmaster boiler/frame with 2 Hornby Railroad class 5 chassis. Only one motor in the coal bunker, runs well with pick ups on both units. I can't really think of a use for it in East Anglia but it was always a bit of fun. Hopefully I will show the completed model in due course.

[Satan's Goldfish]

I think this has been mentioned elsewhere, but Question; why are Garratt cylinders orientated as far away from the boiler as possible? I'm sure there's a reason, but very basic logic would suggest less losses would be incurred if the cylinders were close to the boiler.

 

Ta

[Northroader]

You’ve got the centre unit projecting well over the two engine units, as the pivots are inboard of the inner drivers on each engine unit. This wouldn’t leave much clearance for cylinders, etc. Then having the weight of the cylinder unit at the outer ends allows the pivot points to be kept further back on each engine unit than otherwise, keeping an even weight distribution.

[Satan's Goldfish]

You’ve got the centre unit projecting well over the two engine units, as the pivots are inboard of the inner drivers on each engine unit. This wouldn’t leave much clearance for cylinders, etc. Then having the weight of the cylinder unit at the outer ends allows the pivot points to be kept further back on each engine unit than otherwise, keeping an even weight distribution.

 

Cheers, that makes sense.

[Gibbo675]

 Well, Horwich... It's simple enough, 1930s onwards high power UK mainline types run at 2.25 ton/ft frame length in working order, and that's at least a 63ft frame. I am well aware of the engineering of the final generation US superpower, and 'light weight' is not a term that springs to mind. The sliding saddle support for the front end of the boiler, and the standard UK safety factor in boiler construction are going to make weight saving a real challenge on a UK design.

 

But why do you want it light anyway? High factor of adhesion is very desireable for a heavy mover of this type, and as it is a loco with power potential only ever worth operating on 22T axleload rated main lines, you may as well have it.

 

 It was a factor on the real thing. Major multiple track realignments were required to ensure the overhang wouldn't clout other traffic on parallel running lines.

Hi There,

 

The loco scales at 56' 6" over buffing planks and is therefore 2.15 ton/foot compared to the 9F which is 2.18 ton/foot measured by the same parameters. From these figures it is therefore within 4% of your given average, ie. bang on weight. This means that by your own parameters of 2.25 ton/foot over 63' the loco would be 141t 15cwt.

 

Using 2.25 ton/foot the locomotive is 127t 3cwt, you could loose that amount up by using 3% nickel steel for the boiler which is a possibility not only for weight saving but for strength.

 

One thing you may not have factored in is that it has a welded steel fire box and boiler shell which saves on lapping of plates, butt straps and the material contained within the rivet heads.

 

Do also take into account that a steel firebox is of only 3/8" thick juxtaposed to a copper one equivalently pressed which would be 5/8" thick, further compounding the weight saving gain would be the density of steel at 7700kg/m³ over copper at 8960kg/m³, this would be without the utilisation of 3% nickel steel.

 

As for a moderate all up weight, that assists in the civil engineers bridge load bending curve very nicely. Both Oliver Bullied and Dr Porta were strong proponents for light weight locomotives for efficiency reasons.The locomotive was designed at Horwich not Swindon.

 

As for the strength of the boiler it is a thin walled tube, that being self supporting, without the non existent "boiler frame" that you have completely failed to address within your answer, saying that you are, "well aware of the engineering of the final generation US superpower" doesn't tell any one that there is no such thing as a "boiler frame" !!!

 

Three other things are;

1. I designed it and engines on my railway do as they are told.
2. Its imaginary.
3. I lost my bet with myself that you would pick me up on the tractive effort rounding errors.

 

Glad you are a good sport,

 

Gibbo.

[Gibbo675]

Hi.  This is my attempt at the BR Standard Garratt proposed by Beyer Peacock in the 50's. Still unfinished after several years in the shops it has a Kitmaster boiler/frame with 2 Hornby Railroad class 5 chassis. Only one motor in the coal bunker, runs well with pick ups on both units. I can't really think of a use for it in East Anglia but it was always a bit of fun. Hopefully I will show the completed model in due course.

Hi G P,

 

Is this a model of the Garrett drg. no.127114/A shewn as a diagram on page 95 of E S Cox's Locomotive Panorama Vol I ?

 

It certainly looks like it by way of the shape of the bunker and tanks, if it is, its a long way from Scotland as the diagram states its intended area of use was to be.

 

Great looking model.

 

Gibbo.

[Gilwell Park]

Hi G P,

 

Is this a model of the Garrett drg. no.127114/A shewn as a diagram on page 95 of E S Cox's Locomotive Panorama Vol I ?

 

It certainly looks like it by way of the shape of the bunker and tanks, if it is, its a long way from Scotland as the diagram states its intended area of use was to be.

 

Great looking model.

 

Gibbo.

Hi. Yes it is, but the wheels are 6' instead of 5'8" and the boiler is a bit different. However it looks the part. I will base details on the Rhodesia Railways 15 class 4-6-4 + 4-6-4 when I can make time available.  Roger

[Satan's Goldfish]

I still have a bit of a thing for 2-8-2 locos at the moment. Not helped by seeing the huge Finnish monster now loitering at Fengate farm near Brandon at the Weeting steam rally a few weeks ago. (google '1060 2-8-2 Finnish Loco')

 

I know a few pages ago I tackled the GWR 2-8-2 crackpot dictator class, but in a similar vein here's another. This time it's GWR Grange wheels, stretched GWR King boiler, and LMS Princess firebox and very big smoke deflectors. I actually first tried it without the smoke deflectors and a slightly longer boiler but it didn't look quite right, and that's why the first ring spacing is a bit short. Standard GWR King tender.

 

 

I think I prefer this to my first effort

 

Feel free to start pointing out all the errors and flaws...

Edited September 3, 2018 by Satan's Goldfish

[brack]

I think this has been mentioned elsewhere, but Question; why are Garratt cylinders orientated as far away from the boiler as possible? I'm sure there's a reason, but very basic logic would suggest less losses would be incurred if the cylinders were close to the boiler.

 

Ta

K1, the first garratt built, has its cylinders inboard. In addition to the other reasons given apparently the cab floor can get rather hot with the cylinders directly beneath it.

[RedGemAlchemist]

I still have a bit of a thing for 2-8-2 locos at the moment. Not helped by seeing the huge Finnish monster now loitering at Fengate farm near Brandon at the Weeting steam rally a few weeks ago. (google '1060 2-8-2 Finnish Loco')

 

I know a few pages ago I tackled the GWR 2-8-2 crackpot dictator class, but in a similar vein here's another. This time it's GWR Grange wheels, stretched GWR King boiler, and LMS Princess firebox and very big smoke deflectors. I actually first tried it without the smoke deflectors and a slightly longer boiler but it didn't look quite right, and that's why the first ring spacing is a bit short. Standard GWR King tender.

 

GWR Mikado.jpg

 

I think I prefer this to my first effort

 

Feel free to start pointing out all the errors and flaws...

I like that. Very smart. Edited September 4, 2018 by RedGemAlchemist

[melmerby]

Feel free to start pointing out all the errors and flaws...

Smoke deflectors.

It's the GWR after all.

 

Keith

[Satan's Goldfish]

Smoke deflectors.

It's the GWR after all.

 

Keith

Got to upset people somehow

Yeah I know, I just like them. Something about them makes it look more balanced.

 

Think I'll try it on smaller drivers next so it can loose the splashers. 8f wheels too small for a mixed traffic loco?