GWR & LNWR Pre-grouping 4mm locos workbench

[Brassey]

On 09/01/2022 at 13:15, Regularity said:

...But using this system of 3-point suspension means half the mass (if evenly distributed) might be on the leading bogie...

 

I have arranged the beam so that 2/3rd of the that weight is on the front driving wheel and 1/3rd on the bogie.  The rear fixed wheel carries weight too.

 

Other issues with twin beam is that you get a pivot right where the gearbox is.  You can either use various drive stretchers on the gearbox to work round this or split the pivot.  I have done this but found the pivot ended up too slack so reverted to the previous method.  However, on the 2 Finney chassis I have on the go at the mo,  there are some clever tabs that fold up into a box that hold the loose end on the pivot wire.

 

You can make them out in the pic between the drivers on these two 4-4-0's.  Top is the City and the Duke is below:

 

 

The other issue with an unfixed axle is torsion and the need to restrain the gearbox in some way.  The Finney chassis have this covered but for the Portescaps they were designed for.  It's built into High Level chassis using his gearboxes.

 

The wheels for these two are now in the paintshop drying...

[Regularity]

4 hours ago, Brassey said:

Other issues with twin beam is that you get a pivot right where the gearbox is.

How did you manage that?

With twin beams on the drivers, they go down either side, adjacent to the frames resting on the tops of the axle boxes. The gearbox goes on the driven axle between the axle boxes.

 

A single beam pivot, with one point on the inner driven axle and the other on the bogie pivot, does require all sorts of complications if that axle is the driven one, rather than the fixed outermost driver.

 

You might think that the rear bogie will take 50% of the weight, via the bogie pivot point, but that is only the case if the weight is equally/evenly distributed, but if the centre of gravity is slightly to the front of an 0-4-4 or the rear of a 4-4-0, then taking moments will show that more weight will be born by the drivers.

 

 

[Methuselah]

On 08/01/2022 at 19:33, Brassey said:

For those interested in mixed formations, here's another image of a 4-6-0 possible taken at the same location.  The image came from an acquaintance with the caption ".2941 Easton Court with the 5.25 p.m. Shrewsbury to Bristol Express on 18th July 1914"

 

Very appropriate - almost passing his Lordship's front-door....!

[Brassey]

On 16/01/2022 at 22:12, Regularity said:

How did you manage that?

With twin beams on the drivers, they go down either side, adjacent to the frames resting on the tops of the axle boxes. The gearbox goes on the driven axle between the axle boxes.

 

A single beam pivot, with one point on the inner driven axle and the other on the bogie pivot, does require all sorts of complications if that axle is the driven one, rather than the fixed outermost driver.

 

You might think that the rear bogie will take 50% of the weight, via the bogie pivot point, but that is only the case if the weight is equally/evenly distributed, but if the centre of gravity is slightly to the front of an 0-4-4 or the rear of a 4-4-0, then taking moments will show that more weight will be born by the drivers.

 

 

Yes, as I stated previously above, I have used and trialed this method of splitting the pivot.  But in 4mm, the nuts and bolts I used were 14ba.  After a while the bolts/screws started to rotate in their holes and soon worked loose and the whole thing became slack which inhibited good running.  I doubt that I could have used bigger bolts as in 4mm kits there is not much meat in a compensation beam for such a hole.  Luckily in that chassis I could just take the nuts and bolts out and run a brass wire straight through right across the chassis without dismantling it.  That is because I used a High Level Road Runner plus with a drive stretcher which avoided the shaft.  Performance greatly improved.

 

In the Finney City and Duke I am using HL Road Runner without any stretcher and plan to solder the split pivot shaft to the tabs provided as per the pic.  I am not convinced of the longevity of this solution but will see.  It will be interesting to compare the two City chassis when complete to see how they peform in comparison.  The wheels are in the paintshop so it won't be long before they are on.

 

Edited January 18, 2022 by Brassey
correction

[Regularity]

1 hour ago, Brassey said:

I doubt that I could have used bigger bolts as in 4mm kits there is not much meat in a compensation beam for such a hole. 

Just make the beam a bit deeper, if not along the whole length, then around the hole.

[Coal Tank]

Looking good 

[Coal Tank]

Hows the layout going 

[Brassey]

12 hours ago, Coal Tank said:

Hows the layout going 

At some stage I concluded to move it to the loft which was always the initial plan.  That would require min radius curves of 4ft to make it work as a roundy.  For that reason the LNWR Experiment leapfrogged other builds as, being the largest loco I plan to build, it might be the most challenging to get round the corners. For the same reason my C Class 0-8-0 is now also on the workbench. 
 

I had planned to add a scenic extension but might, in the end, move the layout into another bedroom as an end to end. Either way, I need to do work that will be a lot easier when it is dismantled rather than shoehorned tight into a corner as now.  Such things as cosmetic chairs… I also plan to replace the boundary with hedging rather than fences as per prototype. 
 

Don’t hold your breath for any action anytime soon. 

[Coal Tank]

Hi, how far have you got with the C 

John 

[Brassey]

1 hour ago, Coal Tank said:

Hi, how far have you got with the C 

John 

Just starting but I have all the components 

[Brassey]

Herewith chassis progress for my Finney GWR Duke.  As stated before, the twin beams are retained by tabs through the frames.  No too convinced of the longevity of this solution but time will tell.   There's just enough room in P4 to get a High Level RoadRunner gearbox between now. 

 

Next, do they same on my Finney GWR City:

 

 

The beams sit just below the footplate. 

 

[Brassey]

Despite the lo-tech fixed wheel compensation, the City, 3401 Gibraltar, seems to run ok.  Probably aided by the weight of the whitemetal boiler.

 

 

[Brassey]

On 09/01/2022 at 21:20, Compound2632 said:

 

Jenkinson, LNWR Carriages, is oddly silent on the birdcages, moreover his photo of a D240 doesn't appear to show them... 

 

Here's some more, double-ended and single-ended: https://lnwrs.zenfolio.com/p909960545/h6e6f0655#h6e6f0655

 

Another: https://lnwrs.zenfolio.com/p990703580/h9346ab9b#h9346ab9b

 

And the glazed end of one: https://lnwrs.zenfolio.com/p882833506/h4f09edb0#h4f09edb0

 

Here's another in the background that the Peaky Blinders have taken to Walsall:

 

[Brassey]

The GWR Duke is now up on its wheels.  This is to be 3328 Severn as seen at Hereford.  Being one of the last batch, it has a BRO boiler ansd 2500 gal tender.  This variant is not catered for in the Finney kit, so a bit of kit mingling/scratch building is required.  The 1224 Mashima should fit straight up into the raised firebox.

 

 

[Mikkel]

Looks good, lovely curves.

 

In the prototype photo I notice two ladders on the lamp. Hardly something the GWR would have come up with, it seems the Midland double-heading theory applied to ladders too!

[Compound2632]

18 minutes ago, Mikkel said:

it seems the Midland double-heading theory applied to ladders too!

 

I don't think so. The Midland infrastructure at Hereford was confined to places the Great Western would not run:

 

 

If you must apportion blame, I'd try the LNWR. Though as it's on the Joint Line perhaps there's one ladder for the North Western and the other for the Great Western?

 

I can see that you might mistake that hipped-roof signal box for a Midland one, but the curved bracket supporting the eves gives it away - it's one of the Saxby & Farmer-derived designs erected as part of the Barrs Court resignalling in 1884 - though the contractor was the Railway Signal Co. [R.D. Foster, A Pictorial Record of LNWR Signalling (OPC, 1982) p. 237].

[Mikkel]

Interesting, thanks Stephen. The tops of the ladders don't look GWR to me.  

[Regularity]

5 hours ago, Compound2632 said:

I can see that you might mistake that hipped-roof signal box for a Midland one, but the curved bracket supporting the eves gives it away - it's one of the Saxby & Farmer-derived designs erected as part of the Barrs Court resignalling in 1884 - though the contractor was the Railway Signal Co. [R.D. Foster, A Pictorial Record of LNWR Signalling (OPC, 1982) p. 237].

There is also an example of what George Dow called “the LNWR’s elephantine” signal arms there.

[Brassey]

1 hour ago, Regularity said:

There is also an example of what George Dow called “the LNWR’s elephantine” signal arms there.

 

 

 

Not to mention the telegraph pole...

[Brassey]

The Duke is slowly progressing.  I haven't found a source for that transparent solder others seem to use.  Next stage is to progress the chassis as the outside frames and buffer beams are attached to this rather than the body on this kit!

 

 

A repaint is due for the waiting hut following discussion on my layout thread about chocolate coloured windows.

[Brassey]

Cab roof and interior.  Buffer and drag beams and outside frames all fitted.  Outside cranks made up, quartered and soldered on.  Rods fitted and bogie levelled up and it runs complete with tender.

 

Steps to be added next and other fittings such as sandboxes and handrails before the paintshop beckons.

 

[Mikkel]

Looks nice and neat. And unmistakeably Great Western! 

[Brassey]

Bulldog Bird class of 1909 work in progress.  The basis of this is a Falcon Brass etch that I acquired last year.  Had to wait a while for the gearbox (High Level) and wheels (Ultrascale):

 

[Coal Tank]

That looks nice Peter 

[Asterix2012]

Was this one of the ones with only half the chassis etches?