Imaginary Locomotives

[Corbs]

OOH!

Do tell us then what parts go into making it!

[WD0-6-0]

OOH!

Do tell us then what parts go into making it!

Ok, so cab and boiler are from a mainline STD 4.

Boiler front ring, smokebox, chassis and front running plate are all from a Bachmann STD 4 tank.

Rear truck frames are two Hornby brittania rear frames chopped and stuck together around the existing Bachmann bogie.

Finally the upper Firebox is from a GBL 8F while the lower sides and wide bottom are all from a GBL Princess.

 

My original intention was to use the mainline STD 4 body to produce a BR STD 2-6-2 but I couldn't justify a narrow Firebox prarie against the existing STD 4 and 5 so I lengthened the boiler and gave it a wide Firebox. It appears to have a slight American hint to it but thats no bad thing as the stds drew from best practice around the world. I think perhaps it could have been a low class 6 but I've no idea. Still lots left to do but the main things are finish the running plate, source clackvalves, a double chimney and screws for the crankpins

Edited September 8, 2018 by WD0-6-0

[Gibbo675]

What with the recent discussion of non-standard BR standards, I thought it might be time to share my own time waster.

I've not done any research into it's power or put much effort into justifying it, I had some spare parts and too much time on my hands.

I imagine it being mixed traffic but ultimately used mostly on fast fitted freight. Just for fun the only part that's not off a spare br standard model is the Firebox, the rest genuinely is standard parts!

Mainly just a little project though, the BR STD 2-6-4, 5/6mt?F?

I haven't got a tender yet but I would like to use a BR1F or BR1H

20180908_090452.jpg

Hi WD,

 

I think it's a "Crazy Clan", where perhaps when it was built they got the bogie and truck mixed up !

 

Likely a fast freight 6F by the look of it, might go better than a Clan due to smaller driving wheels and supply more steam than a class 5. It has the arrangement of a stretched V2 and they went well.

 

Thinking about you tender options I think it will look best with the BR1F, they suit seem to suit the class 5's well enough. Here is a good link for easy comparison of tenders,

 

https://preservedbritishsteamlocomotives.com/5mt-73000-73171-4-6-0-br-standard-class-5/

 

I considered a Vanderbilt tender for my contraption but went via the lazy option and made the BR1 styled centipede type.

 

 

Gibbo.

[RedGemAlchemist]

What with the recent discussion of non-standard BR standards, I thought it might be time to share my own time waster.

I've not done any research into it's power or put much effort into justifying it, I had some spare parts and too much time on my hands.

I imagine it being mixed traffic but ultimately used mostly on fast fitted freight. Just for fun the only part that's not off a spare br standard model is the Firebox, the rest genuinely is standard parts!

Mainly just a little project though, the BR STD 2-6-4, 5/6mt?F?

I haven't got a tender yet but I would like to use a BR1F or BR1H

20180908_090452.jpg

Wow that's a bit of a beast. Look forward to seeing the result. Passenger or mixed traffic? Because 2-6-4 isn't particularly suited to goods in my experience.

[WD0-6-0]

Hi WD,

 

I think it's a "Crazy Clan", where perhaps when it was built they got the bogie and truck mixed up !

 

Likely a fast freight 6F by the look of it, might go better than a Clan due to smaller driving wheels and supply more steam than a class 5. It has the arrangement of a stretched V2 and they went well.

 

Thinking about you tender options I think it will look best with the BR1F, they suit seem to suit the class 5's well enough.

Hi Gibbo

 

Thanks, it's funny you should mention the Clan as that's similar to how I considered it. I was thinking a class 6 goods loco to allow the Clans to be focused onto passenger workings.

The V2 was certainly in mind when I originally dreamt this up!

 

I agree, just have to track one down, I have one behind my 9F but that's firmly staying put haha!

 

I really liked your loco, it was seeing that on here inspired me to share mine.

 

Wow that's a bit of a beast. Look forward to seeing the result. Passenger or mixed traffic? Because 2-6-4 isn't particularly suited to goods in my experience.

That's interesting RedGem as I'd originally thought of it as a freight biased mixed traffic loco but perhaps not if they weren't so well suited, is your experience on tanks tenders or both? Perhaps as a tender loco it would be better?

[RedGemAlchemist]

That's interesting RedGem as I'd originally thought of it as a freight biased mixed traffic loco but perhaps not if they weren't so well suited, is your experience on tanks tenders or both? Perhaps as a tender loco it would be better?

Fair. Mine was on tank locos. Edited September 8, 2018 by RedGemAlchemist

[The Johnster]

Given that the boiler of the (Swindon designed) Std 4 4-6-0 was based on the GWR no.14 used on the Manor, the next stage is clearly a Manor based GW 2-6-4 tender engine, perhaps with Hawksworth type plate frames, continuous splasher, and a new flush sided all welded 3,500 gallon tender.  The key to the loco's usefulness, of course, is that the axle loading would be very light, but it might be a bit light footed compared to a 4-6-0; how about boosters for the trailing axles?

 

Can't see it being much more than power class 4MT, though; there's only so much you can get from that boiler and cylinder combination without upping the pressure drastically, and even then you've got to persuade the wheels to grip.

Edited September 8, 2018 by The Johnster

[Corbs]

20180908_090452.jpg

 

May I make a suggestion? When I was photobodging staniers, someone pointed out that the rear bogie should be taking the weight of the firebox and that with the rearmost wheelset under the cab, it wasn't doing its job properly. What I ended up doing was flattening the bottom of the firebox and moving the bogie forward. With the 2-6-4T it is supporting the bunker but the tender does this job.

A bit like the US locos with a rear bogie, wide firebox with the bogie in the middle - rearmost wheelset under the front of the cab (and thus the back of the firebox).

Edited September 8, 2018 by Corbs

[WD0-6-0]

The boiler is the same diameter but it's a full ring longer with a distinctly bigger Firebox, as to the difference that would make I'll leave to someone else to tell me.

You're right Corbs, the bogie is a little too far back, not only is the weight distribution in the wrong place but it's giving me a headache regarding the tender coupling! I'm reluctant to lengthen the Firebox more but perhaps a small increase in the Firebox and move the bogie forward a little will balance the looks and realism a little!

What I can't fix will get a generous amount of rule 1 haha!

Edited September 8, 2018 by WD0-6-0

[LNWR18901910]

What with the recent discussion of non-standard BR standards, I thought it might be time to share my own time waster.

I've not done any research into it's power or put much effort into justifying it, I had some spare parts and too much time on my hands.

I imagine it being mixed traffic but ultimately used mostly on fast fitted freight. Just for fun the only part that's not off a spare br standard model is the Firebox, the rest genuinely is standard parts!

Mainly just a little project though, the BR STD 2-6-4, 5/6mt?F?

I haven't got a tender yet but I would like to use a BR1F or BR1H

20180908_090452.jpg

It reminds me of those American O-Gauge trains from the 1950s (I think).

[Gibbo675]

May I make a suggestion? When I was photobodging staniers, someone pointed out that the rear bogie should be taking the weight of the firebox and that with the rearmost wheelset under the cab, it wasn't doing its job properly. What I ended up doing was flattening the bottom of the firebox and moving the bogie forward. With the 2-6-4T it is supporting the bunker but the tender does this job.

A bit like the US locos with a rear bogie, wide firebox with the bogie in the middle - rearmost wheelset under the front of the cab (and thus the back of the firebox).

 

Hi Corbs,

 

The connection of a bogie or truck to the main part of a locomotive frame is in the vertical plane and for the purposes of weight distribution via mathematical calculation considered solid.

 

Locomotive frames are considered beams that are classed as having distributed loads applied to them. These loads are as connections downward onto the frame of the smoke box, fire box, cylinders and motion brackets and upward through the spring links from the axle boxes. That said, the boiler as a whole may also be considered a beam and does effect the behavior of the frame especially so in bar framed locomotive designs, less so with plate frames but this is rather beyond the scope of this discussion.

 

To say that a bogie supports a fire box is not strictly true, the frame supports the fire box and the bogie supports the frame with the axles and suspension via static equilibrium orienting the frame in a level azimuth. The bogie would assist in balancing the couple applied to the centre of mass of the frame by the mass that the fire box constitutes to the whole system.

 

When weighing a locomotive the first thing to do is tho check that the running heights are correct with respect of tyre thickness and that the gaps in the horn guides are correct, the wheels are then "floated" on the weighing device. The weighing device will shew how much weight is on any particular wheel and the adjustment of the suspension will distribute the forces (weight) into the frame until the desired weights over each of the axles are achieved.

 

It is possible to put most of the weight into the bogie and truck and severely reduce the weight upon the drivers and vice versa by altering the suspension links. In the first case the locomotive would slip due to lack of adhesive weight over the driving wheels and in the second case, the locomotive would be prone to derailment traversing sharp curves and point work especially as it may be possible for the side control springs to overcome the axle loading upon those guiding wheels.

 

Bogies and trucks very often have removable shims to take into account differences in tyre thickness between bogie, truck and driving wheels so that the position of the axle boxes are correct within their hornguides.

 

Have a watch of this;

 

 

 

The boiler is the same diameter but it's a full ring longer with a distinctly bigger Firebox, as to the difference that would make I'll leave to someone else to tell me.

You're right Corbs, the bogie is a little too far back, not only is the weight distribution in the wrong place but it's giving me a headache regarding the tender coupling! I'm reluctant to lengthen the Firebox more but perhaps a small increase in the Firebox and move the bogie forward a little will balance the looks and realism a little!

What I can't fix will get a generous amount of rule 1 haha!

 

Hi WD0-6-0,

 

Corbs is correct about the bogie being a bit to much under the cab although extending the firebox would put it right visually, then so too would truncating it into a 2-6-2. 

 

For the sake of aesthetics I would go to the 2-6-2 route for the boiler might look a bit skinny if it were to be further lengthened, however, that would be your call.

 

 

I hope that was of assistance to both of you.

 

Keep it up chaps !

 

Gibbo.

[WD0-6-0]

Taking into account everything contributed so far I'm thinking that reverting to a 2-6-2 is the way to go, I agree further lengthening the boiler is out of the question and there simply isn't the room to move up the bogie (I tried)

I'm still not sure exactly how powerful it would be but rule one still says it was a class 6.

 

Can only give one rating Gibbo but I'd like to say that was also friendly and informative! Very interesting about how loco weight distribution works and how they're balanced!

Edited September 8, 2018 by WD0-6-0

[runs as required]

Flitting past here on the way to bed, I stopped at memories of structural calcs 'taking moments' from long ago in Gibbo's post.

 

Presumably loco design is dynamic, and not static as the example. Can one design a Pacific loco say, to afford adjustable loading on wheels to counter slipping? Perhaps a variation of the 'balancing beam' distributing weight equally between wheels? Presumably additional weight, and complexity would negate any benefits.

And how did a self-weighing tender work? They must have been complicated, there were very few of them.

Hey Ho! Its off to bed we go..

dh.

[The Johnster]

Self weighing tenders used sky hooks; simple...

 

Ok, I'll get me coat.

[Mr_Tilt]

 

And how did a self-weighing tender work? They must have been complicated, there were very few of them.

 

 

Back in the day they had the coal bunker manufactured as a separate 'box' from the rest of the tender and it was attached to a balance beam arrangement so that the coal load could be weighed after each test run by adjusting the balance weight and reading off the coal weight.

 

It'd be a lot easier these days as the supports of the coal bunker would be strain-gauged and calibrated. It'd even be possible to weigh the coal as the loco was moving, which wasn't possible with the balance bar arrangement. 

[melmerby]

Here's one or two:

 

https://www.flickr.com/photos/holycorner/13544846485

https://www.flickr.com/photos/holycorner/8255903450

https://www.flickr.com/photos/52467480@N08/6435903435/in/photolist-aNHFSk-aNHG2g-ecZhZo

 

 

Keith

 

Found in this topic:

http://www.rmweb.co.uk/community/index.php?/topic/91016-black-5s-with-coal-weighing-tender/

Edited September 10, 2018 by melmerby

[Gibbo675]

Flitting past here on the way to bed, I stopped at memories of structural calcs 'taking moments' from long ago in Gibbo's post.

 

Presumably loco design is dynamic, and not static as the example. Can one design a Pacific loco say, to afford adjustable loading on wheels to counter slipping? Perhaps a variation of the 'balancing beam' distributing weight equally between wheels? Presumably additional weight, and complexity would negate any benefits.

And how did a self-weighing tender work? They must have been complicated, there were very few of them.

Hey Ho! Its off to bed we go..

dh.

Hi DH,

 

After overhaul locomotives are weighed to see that the loadings upon the axles are correct to diagram, should they not be then the suspension is adjusted accordingly. As you might expect this is done in a static situation and so as with the example it is correct when the locomotive is weighed. That said, when the locomotive is running then due to track irregularities such as dropped joints and twist due to elevation change in curved track the loadings will shift about between axles. The amount by which this occurs is generally slight but at its greatest well within the design limits of the the locomotive, its suspension and its axle box dimensions.

 

There are usually about four inches of travel in a horn guide, from running height about one and half inches up and two and a half down. I may be wrong (Per Way help me out here) but I think that allowable twist on a running line is half an inch per eight cribs with cross levels being one sixteenth of an inch per crib. Half an inch on an adjuster can easily represent a couple of tons over just one wheel at weighing but this unlikely on the running lines except where the track defects are beyond allowable tolerances.

 

There are various methods by which the loading of the springs are adjusted, there are nuts that screw up and down the spring pillars, cotters of different depths that are exchanged for either deeper or shallower ones, spring links with different hole centres and shim stacks on the tops of axle boxes. I much preferred screw adjust because all that is required is a big spanner to put things where you wanted them.

 

I have ridden upon locomotives that when passing over rough rides at speed have bottomed out upon their suspensions when the axle boxes have contacted the bump stops at the tops of the horn guides and it is known that tyres may occasionally lose contact with the rail head. The latter is far more rare than the former, Chat Moss was always good for rough rides. !

 

As for shifting weight around there are various designs of what are know as adhesion trucks that have air or steam operated pistons that act upon the equalising beams of the suspension to relieve weight from the trucks allowing transfer to the driving wheels. These are employed when starting heavy trains and are released when in motion as the driving wheels will be over the design axle loading and the trucks will be prone to derailment due to being lightly loaded. I don't know of any British locomotives that employed this feature but there are various Chinese, American and South African locomotive that did have.

 

I can still do all those boring sums but prefer not to have to !

 

Gibbo.

[melmerby]

There is the tale (maybe apocryphal?) about the GWR "King" class locos that were nominally 22.5 Tons each driving axle which was right on the civil engineers limit but the actual locos really weighed more than officially stated and never had such a well balanced set-up.

The tale goes that sometimes some driving axles had as much as 25T or more on them!

 

It could be true.

 

Keith

[Gibbo675]

There is the tale (maybe apocryphal?) about the GWR "King" class locos that were nominally 22.5 Tons each driving axle which was right on the civil engineers limit but the actual locos really weighed more than officially stated and never had such a well balanced set-up.

The tale goes that sometimes some driving axles had as much as 25T or more on them!

 

It could be true.

 

Keith

Hi Keith,

 

The trouble with a King is that there is no truck to shove the weight onto, when setting up 34067 we used to do the opposite and lighten the truck by a three quarters of a ton and shift it to the centre and rear sets of drivers.

 

It is said that the Swindon built Ivatt class 2, 2-6-0's were nearly two tons heavier than the Crewe and Darlington built examples.

 

Gibbo.

[melmerby]

 

It is said that the Swindon built Ivatt class 2, 2-6-0's were nearly two tons heavier than the Crewe and Darlington built examples.

 

 

Built to last

 

Keith

[JimC]

There is the tale (maybe apocryphal?) about the GWR "King" class locos that were nominally 22.5 Tons each driving axle which was right on the civil engineers limit but the actual locos really weighed more than officially stated and never had such a well balanced set-up.

The tale goes that sometimes some driving axles had as much as 25T or more on them!

 

It could be true.

 

Keith

 

I've wondered about this, and I asked someone who maintains a King now and was told that they do come in on the specification. I think the tale originates with Gibson, who is not always completely reliable, if not gifted with such a powerful imagination as Tuplin.

[Dr Gerbil-Fritters]

Anything worth knowing about GWR notional axle weights and so on - A E Durrant's your man.  'Swindon Apprentice' is the book.

[runs as required]

Here's one or two: Found in this topic:

http://www.rmweb.co.uk/community/index.php?/topic/91016-black-5s-with-coal-weighing-tender/

Thanks for those - one can see clearly how the coal bunker is suspended inside the welded tender shell.

Are they actually all pics of the same LMS tender ! Two photos at Carlisle, the other at Springburn ?

The Southern Pacifics all ran with an LMS s/w tender attached in the 1947 exchanges - perhaps there was only one !

dh

[melmerby]

According to a post on another site the LMS had 4 & the LNER 2

 

Keith

[JimC]

Given that the boiler of the (Swindon designed) Std 4 4-6-0 was based on the GWR no.14 used on the Manor, the next stage is clearly a Manor based GW 2-6-4 tender engine,

I can't make that work with standard components. The boiler just isn't long enough. Even if you close the wheels together like the Bear the rear axle doesn't clear the firebox. I suppose you could give it an extended smokebox. It might work with a Std 1 boiler, but it works far better as a 2-8-0. But that wouldn't have any better RA than a Manor. A lightweight go anywhere 2-8-0 might work with 4'7 wheels. What you'd end up with would be something that bore the same relationship to the 45 as the 28 does to the bigger 2-6-2Ts. It might be a useful piece of kit on preserved lines... However if one figures preserved lines then plenty of fuel and water capacity and a tank engine might be a good idea, so one follows an apparently logical train of thought to reach this ludicrous conclusion...

 

 

Manor boiler with extended smokebox and Manor front bogie migrated to rear. Most of the rest is lengthened 4575. 4MT in BR terms I imagine, but if you gave it 28xx wheels and Manor cylinders it would probably go to 5MT, at the cost of platform clearances.

Edited September 11, 2018 by JimC