BR 4MT 2-6-4T - resource material

Dog Star

Western Thunderer
I think I might have got to the bottom of the story re spring hangers. When originally designed both top and bottom of the spring hanger had a collet arrangement with various thickness wedges inserted to alter the spring rate and hence weight distribution. This was a mighty faff to alter or change a spring so someone came up with the idea of converting the lower end to be retained by a nut and locknut, much as a Black 5. What is important to know is that this happened in the preservation era and didn't pertain to locos when withdrawn by BR.

Thank you Martin,

From what you have written, I think that these photos show the original form of spring attachment - all photos are courtesy of Jonpaul (@lnerjp) and each of the three photos are copyright Jonpaul Venus. I understand that the photos were taken about seven or eight years back and are of 80135 on the NYMR hence the images record what was then rather than what might be now.

Spring hanger block 1.jpg

Spring hanger block 2.jpg

Spring hanger block 3.jpg

The first photo show that the bottom of the suspension cup / block is flat (relatively so) with a recess (of what shape?) to contain the bottom end of the spring hanger "bolt". The other two photos illustrate the way in which the spring sits inside the spring hanger bracket and give glimpses of the top end of the suspension fixings.

Anyone have photos of the top and bottom fixings as alluded to in Martin's post earlier? Or a description of how springs are changed / axle weight adjusted? Ok, modelling might not be impacted by the questions and answers, personal interest could be satisfied.

thanks, Graham
 

Martin Shaw

Western Thunderer
Ok last lot

IMG_0442.1.jpg

Front left buffer.

IMG_0443.1.jpg
Bogie frames.

IMG_0444.1.jpg
Bogie again. It was cold and raining at this point and I wasn't inclined to hang about, I'll take some better ones another time.

IMG_0445.1.jpg
Drivers side cab interior.

IMG_0446.1.jpg
LH tank side.

IMG_0447.1.jpg

RH tank top.

IMG_0448.1.jpg

LH tank top.

IMG_0449.1.jpg

Crosshead again, why?

IMG_0454.1.jpg
Set up on the surface table to establish centres.

IMG_0453.1.jpg
The slot where the cotter goes to hold the piston rod in.

IMG_0452.1.jpg IMG_0452.1.jpg
The other crosshead showing wher the drop link is attached.

IMG_0450.1.jpg

Slidebars.

IMG_0451.1.jpg
Slidebars 2, They are big and heavy.

IMG_0455.1.jpg
Valve and cylinder casting.

I think that's enough from me, I hope that the pictures give some useful detail of the bare bones of the loco. If I can get over there on a decent day I'll take more detailed pics of the bits currently lying outside. If anyone wants something better pictured just ask.

Regards
Martin
 

Martin Shaw

Western Thunderer
Graham

As you can readily see ours is in bits and I didn't see any of the spring hanger components. I think I know where they are so I'll see what I can do in due course.

Mike

Haven't forgotten about AWS, from memory it was bolted to the rear of the bogie, again with more clement weather I'll have a poke about.

Regards
Martin
 

lnerjp

Western Thunderer
Hi All & Graham

Got some pictures of spring hangers yesterday.
SL550045.JPG

Hanger from 76079

SL550047.JPG

The block that sits on top of the spring with the slot in that the key sits in come in different thicknesses and is how you adjust the spring tension and therefore the axle weight. (if that makes sense?)

SL550048.JPG

Spencer block from underneath.

SL550049[2305843009216211786].JPG

And again.
 

Dog Star

Western Thunderer
After seeing how those BR springs are fitted I am glad that my days of changing springs are over..

Thank you Jeanpaul, very helpful in understanding how the suspension was designed (and still is on some of the Std 4 MT tanks).
 

Martin Shaw

Western Thunderer
Indeed I concur with Graham, ours are different and I will take pics when I can get to the railway. My understanding is that it was a modification to the spring hanger design by the Std loco owners group to make spring changes and subsequent weighing easier and was approved by one of the Vehicle Acceptance Bodies, presumably for all standard classes, but I may be wrong on this last point. Were they all the same?
Regards
Martin
 

farnetti

Western Thunderer
Graham, Martin,

Having recently started a MOK kit of the 4MT I find this thread very helpful. Grahams post 27 describes the kit as supplied and I am building 80064 as it was at Watford in 1959. There are several photos of the preserved loco but none I can find of the relevant spring blocks, modification would be relatively easy if needed.

The Bluebell is a long way from here, anyone have an answer.

Thanks,

Ken
 

markjj

Western Thunderer
Do they have a Facebook page for 80064? It might be worth asking there for photos if they do. A lot of preserved loco's have very active Facebook pages.
 

lnerjp

Western Thunderer
Having recently started a MOK kit of the 4MT I find this thread very helpful. Grahams post 27 describes the kit as supplied and I am building 80064 as it was at Watford in 1959. There are several photos of the preserved loco but none I can find of the relevant spring blocks, modification would be relatively easy if needed.

The Bluebell is a long way from here, anyone have an answer.

Ken, unless anyone knows any better, I would accept that the spring set up was as in my photographs above, any other set up you see would have been done in preservation to make axle weight adjustment quicker/easier.

J.P.
 

Riefler

Member
Ok last lot

View attachment 82568

Front left buffer.

View attachment 82569
Bogie frames.

View attachment 82570
Bogie again. It was cold and raining at this point and I wasn't inclined to hang about, I'll take some better ones another time.

View attachment 82571
Drivers side cab interior.

View attachment 82572
LH tank side.

View attachment 82573

RH tank top.

View attachment 82574

LH tank top.

View attachment 82575

Crosshead again, why?

View attachment 82576
Set up on the surface table to establish centres.

View attachment 82577
The slot where the cotter goes to hold the piston rod in.

View attachment 82578 View attachment 82578
The other crosshead showing wher the drop link is attached.

View attachment 82579

Slidebars.

View attachment 82580
Slidebars 2, They are big and heavy.

View attachment 82581
Valve and cylinder casting.

I think that's enough from me, I hope that the pictures give some useful detail of the bare bones of the loco. If I can get over there on a decent day I'll take more detailed pics of the bits currently lying outside. If anyone wants something better pictured just ask.

Regards
Martin


Hi Martin,
Having been pointed in this direction by Graham on my MOK build thread, I have now down loaded the photos into my prototype file for future reference. What a brilliant set of photos, so let me add my thanks to you for having gone to the trouble of taking and posting them.

I took a whole load of photos of 80002 stored out of service but intact on the KWVR, so I'll share them on my thread when I get a minute. There will be some duplication of yours but I trust somebody will find them useful, and as far as I am concerned, you can never have too many prototype photos. These are to be used in combination with in service photos, as we never know what you preservationist have changed to catch us out! ;)

I think from looking at this that 80002 has the same type of hanger as posted by LNERJP. I've not decided which prototype to model yet, but to be honest I'm not too concerned about the hangers and won't be getting hung up on them. Pardon the pun.

DSCF3152.JPG

Cheers,
Peter
 

Martin Shaw

Western Thunderer
Your very welcome Peter.
I can add a bit more to the spring hanger debate only gleaned yesterday. Apparently a change to the original design was proposed by BR but by that time steam had a limited life and it wasn't done. It will be obvious that the arrangement with cotters is somewhat hit and miss, and time consuming. By changing to a threaded hanger with adjusting nuts it would have been quicker and by machining a mark on the hornguide where the top of the axlebox should align, possible to adjust a spring to both the correct weight and buffer height, with relative ease. I have been told that most of the 80000s in preservation have done it and, theoretically at least, could be done with all the Std classes. Obviously some haven't.
Regards
Martin
 

P A D

Western Thunderer
Hi Martin,
Interesting.

Do you mind if I post some of you photos on my thread as and when required? I will mention they are your copywrite.

Cheers,
Peter
 

Martin Shaw

Western Thunderer
Hi Martin,
Interesting.

Do you mind if I post some of you photos on my thread as and when required? I will mention they are your copywrite.

Cheers,
Peter
Peter
Not at all, fill your boots. I'm watching your thread with some interest, not least because I am going to do one as well, but the A3 was just outstanding.
Martin
 
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Martin Shaw

Western Thunderer
A few more pics taken today.
IMG_0593.JPG
The driving wheels having been turned, the new tyre is apparent.
IMG_0594.JPG

The rear bogie

IMG_0597.JPG

One of the bogie main spring beams gently being tried

IMG_0598.JPG
Bogie wheel and axle with axlebox rotated nearly upside down

IMG_0595.JPG
Frames 1

IMG_0596.JPG
Frames 2
 

Overseer

Western Thunderer
A few more pics taken today.
View attachment 91366
The driving wheels having been turned, the new tyre is apparent.
Out of curiosity, the new tyre looks larger diameter. Presumably the other tyres are half worn or more. Do you have to turn the new tyre down to match the diameter of the worn tyres? I imagine there would be problems with excess wear in the coupling rod bearings and less steady riding with an odd sized wheel on the loco. Is this the case I reality?
 
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