LMS LWB Black Fives

[John Isherwood]

It is my understanding that the later Black Fives had a wheelbase of 27'-6'', as opposed to the 27'-2'' of the earlier locos.

 

However, the prototype notes which accompanied a Brassmasters Black Five kit indicates that the LWB locos also had an extended smokebox.

 

Can anyone tell me how these ESB smokeboxes differed visually / externally from the standard smokeboxes? Was the overall length of the smokebox / boiler / firebox the same in both cases or, if not, what was the difference in length attributable to the extended smokebox?

 

Can anyone point me at a drawing of a LWB / ESB Black 5, please?

 

Many thanks in anticipation.

 

Regards,

John Isherwood.

[Wickham Green]

I'd guess there's something in LMS Loco Profiles No. 6 Mixed Traffic Class 5s Nos. 5225-5499 & 4658-4999 - David Hunt et al    [Publisher:  Wild Swan  2004]  

[LMS2968]

The extended wheelbase came with the introduction of roller bearings. These are larger than plain bearings and the intermediate ones would have fouled the front of the firebox. So the boiler / firebox assembly was moved rearwards by four inches to accommodate this, the trailing axle moving rearwards by the same amount, thus extending the wheelbase. The smokebox was also extended by this amount to maintain its front end in the same plane, so the extra four inches were between the chimney and front ring of the barrel.

 

Although needed only for the roller bearing locos, the extended wheelbase was applied to all new Black Fives following its introduction, including those with plain bearings.

[John Isherwood]

13 minutes ago, LMS2968 said:

The extended wheelbase came with the introduction of roller bearings. These are larger than plain bearings and the intermediate ones would have fouled the front of the firebox. So the boiler / firebox assembly was moved rearwards by four inches to accommodate this, the trailing axle moving rearwards by the same amount, thus extending the wheelbase. The smokebox was also extended by this amount to maintain its front end in the same plane, so the extra four inches were between the chimney and front ring of the barrel.

 

Although needed only for the roller bearing locos, the extended wheelbase was applied to all new Black Fives following its introduction, including those with plain bearings.

 

Thanks for that - much appreciated.

 

So - I have a spare body from Hornby 44781 (SSB / SWB) and a Comet LWB chassis kit; I'd like to model 44766 (ESB / LWB / double chimney).

 

If I am to be strictly accurate I should cut off the smokebox / boiler / firebox from the footplate / cab and remove 1.3mm. from the back of the firebox, before reattaching it to the footplate / cab. A 1.3mm. thick circle of plastic card should be attached to the front of the smokebox before refitting the door. If I wish to go further, (!), I should remove the backhead, increase its length by 1.3mm., and reattach it.

 

Hmmm !!

 

Regards,

John Isherwood.

[John Isherwood]

1 minute ago, cctransuk said:

 

Thanks for that - much appreciated.

 

So - I have a spare body from Hornby 44781 (SSB / SWB) and a Comet LWB chassis kit; I'd like to model 44766 (ESB / LWB / double chimney).

 

If I am to be strictly accurate, having removed the chimney, I should cut off the smokebox / boiler / firebox from the footplate / cab and remove 1.3mm. from the back of the firebox, before reattaching it to the footplate / cab. A 1.3mm. thick circle of plastic card should be attached to the front of the smokebox before refitting the door. If I wish to go further, (!), I should remove the backhead, increase its length by 1.3mm., and reattach it.

 

Hmmm !!

 

Regards,

John Isherwood.

 

Nope - that's wrong.

 

The smokebox should remain attached to the footplate, and the circle of plastic should be added to the back of the smokebox.

 

Even more hmm !

Edited February 7, 2020 by cctransuk

[LMS2968]

The change didn't alter just the wheelbase but the entire loco, which was four inches longer on all dimensions. The boiler / firebox was in the same position relative to the trailing axle and hind buffer beam. So you need to add your 1.3mm not only to the rear of the smokebox but also to the running plate, but that would be aft of the mechanical lubricators and sandbox fillers.

[John Isherwood]

6 minutes ago, LMS2968 said:

The change didn't alter just the wheelbase but the entire loco, which was four inches longer on all dimensions. The boiler / firebox was in the same position relative to the trailing axle and hind buffer beam. So you need to add your 1.3mm not only to the rear of the smokebox but also to the running plate, but that would be aft of the mechanical lubricators and sandbox fillers.

 

Actually, that makes it easier in some ways.

 

The cut would be in front of the rear rivets on the smokebox; below the sandbox fillers, and through the footplate behind the motion hanging bracket. The lubricators can be moved forward by 1.3mm.

 

That's do-able !

 

Regards,

John Isherwood.

Edited February 7, 2020 by cctransuk

[Gibbo675]

On 07/02/2020 at 12:46, LMS2968 said:

The extended wheelbase came with the introduction of roller bearings. These are larger than plain bearings and the intermediate ones would have fouled the front of the firebox. So the boiler / firebox assembly was moved rearwards by four inches to accommodate this, the trailing axle moving rearwards by the same amount, thus extending the wheelbase. The smokebox was also extended by this amount to maintain its front end in the same plane, so the extra four inches were between the chimney and front ring of the barrel.

 

Although needed only for the roller bearing locos, the extended wheelbase was applied to all new Black Fives following its introduction, including those with plain bearings.

Hi LMS,

 

At the same time as the frame alteration to the wheelbase of the driving and rear axles the piston and con rod lengths were also altered to allow for piston ring examinations without the need for removing the piston rod from the cross head or removal of the gland plate. The piston rod was lengthened and the con rod shortened  each by 4" also, this was as a result of an attempt to save material for the con rods of WD 8f's, the maintenance feature was a useful happenstance as a result. The motion bracket is unaltered but the slide bars are also longer in the later types.

 

Having worked upon 45407 and 44871 at Riley's some years back I can tell you that they are a class apart not just in construction but also in performance terms. 

 

Black five details are a total confusion and will drive you absolutely crackers !

 

Gibbo.

[LMS2968]

Yes, and the change in the piston rod / union link / connecting rod lengths on the Fives and 8Fs was a very worthwhile modification, as you say, but I didn't think it was contemporary to extending the wheelbase. I referred to John Powell* on this: the piston rod change was from 5472 (Derby 4/43) and 8126 (Crewe1/41). The extended wheelbase was from 4758 (Crewe 9/47), but Black Five numbering is complicated as batches were numbered chronologically in blocks, but the blocks themselves, when full, would be followed by lower numbered blocks so a later engine wmight have a lower number. They certainly are fun engines to research!

 

The performance of the different batches is also controversial. I fired them only in preservation so am in no position to judge, but I think it was the same  John Powell who reckoned that the early 21 element superheater engines were the best steamers. That makes some sense, but the high superheat of later engines would more than make up for this. But it is significant that at least two of the early type (5025 and 5110) made it right to the end in August 1968.

 

*Stanier Locomotive Classes, A.J. Powell (1962, reprinted 1991) Ian Allan, Shepperton ISBN 0 7110 1962 2 An excellent reference work and highly recommended.

[John Isherwood]

1 hour ago, Gibbo675 said:

Black five details are a total confusion and will drive you absolutely crackers !

 

The Brassmasters Black 5 kit came with a very comprehensive technical history of the prototype in book form, with tables listing the many and varied detail differences of the different batches.

 

I found it relatively easy to determine which details applied to which batch, and there were also details of in-service modifications.

 

No doubt there are bound to be the odd anomalies, but such detailed information makes life a great deal easier for the modeller.

 

Regards,

John Isherwood.

['CHARD]

I would dearly love to see a photograph of the 'normal' and 'extra-length' locomotives together, to see how apparent the difference actually was.

[John Isherwood]

11 minutes ago, 'CHARD said:

I would dearly love to see a photograph of the 'normal' and 'extra-length' locomotives together, to see how apparent the difference actually was.

 

I am slowly coming to the conclusion that, if I can ignore a discrepancy in rail gauge of 1.8 mm., I can also ignore a discrepancy of 1.3 mm. in boiler / footplate length.

 

However, I have Comet LWB chassis for the two LWB locos that I am planning to build, so I will have to watch out for firebox / rear driving wheel interference.

 

Regards,

John Isherwood.

[LMS2968]

51 minutes ago, 'CHARD said:

I would dearly love to see a photograph of the 'normal' and 'extra-length' locomotives together, to see how apparent the difference actually was.

It wasn't easy to see. With the 5XPs and the vertical and sloping throatplates, sometimes referred to as short and long fireboxes, you can see the difference with reference to the intermediate splashers, but there aren't any on Black Fives (Caprrottis excepted) to show a comparison.

[Wickham Green]

On 09/02/2020 at 10:46, LMS2968 said:

...................... it is significant that at least two of the early type (5025 and 5110) made it right to the end in August 1968.

Have they still got early-type superheating though ?

[LMS2968]

All the Fives' boilers, which were Class 3B, which had vertical throatplates but not retrospectively fitted with domes went to 21 element superheaters, up from 14 elements. The vertical throatplate boilers which were fitted with domes had 24 elements; sloping throatplate boilers had either 21, 24 or 28 elements depending on the build date. 5025 and 5110 (and 5000) are domeless, so 21 elements.

 

Information from Raising Steam on the LMS A.F. Cook (1999) RCTS, Huntington ISBN 0 901115 85 1.

 

As I said, fun engines to research!

[Wickham Green]

45 minutes ago, LMS2968 said:

All the Fives' boilers, which were Class 3B, which had vertical throatplates but not retrospectively fitted with domes went to 21 element superheaters, up from 14 elements. The vertical throatplate boilers which were fitted with domes had 24 elements; sloping throatplate boilers had either 21, 24 or 28 elements depending on the build date. 5025 and 5110 (and 5000) are domeless, so 21 elements.

 

Information from Raising Steam on the LMS A.F. Cook (1999) RCTS, Huntington ISBN 0 901115 85 1.

 

As I said, fun engines to research!

Indeed - but I bet no amount of research would track-down this little incident at Lostock Hall - near the end in '68 .............. sorry, nothing whatsoever to do with Long Wheelbase Fives - but it's a nice photo an' it is a Five.