Differences between BR B4 and B5 bogies.

[TravisM]

I’m modelling Mk1 RBR 1730 as part of the Scottish Railway Preservation Society’s excursion set that I saw here at Peterborough in 2019, and according to Platform 5 publications, 1730 is riding on a set of B5 bogies.

 

I know that the B5 is a heavy duty version of the B4 and used on Mk1 based EMU’s, but is there any visual difference between the two as I’m struggling to find any.

 

Any help would be most grateful.

 

Edited February 26, 2021 by jools1959
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[zarniwhoop]

According to some notes I made years ago, based on what was in Model Rail #151 (Christmas 2010) p58 on the B5 the traction bar (I think that is the upper piece at centre left) should be square section, not round as on a B4 - my notes suggest padding it with microstrip. And the spring plank (I think that is the heavy central part at the bottom) does not have a lip at its edge on a B5, but does on a B4.

 

Whether any of that would be visible at normal (non-camera) viewing distance is another matter entirely.

 

ĸen

[45125]

Replica do a B5 if you model 4mm, there a lot of other differences on a B5 the two obvious ones been the bolster control rod (square section) the spring plank much heavy section almost square in section. The axle boxes are also slightly beefier as the bearing are larger, lots of subtle differences such as springs etc. The Southern B4 and B5s are a totally different in many respects.

 

 

[keefer]

Standard B4 bogie:

 

B5 bogie:

 

Both photos (c) Brian Daniels on Flickr

 

If doing them in fairly new/clean condition, I think the primary springs are red on the B4 and blue on the B5.

Edited February 26, 2021 by keefer
Info

[Stevebr]

If I recall the B4 had an axle diameter of 4.5 inches and the B5 4 7/8”. Also in BRB speak they were the BT42 and BT45. Disk brake versions were BT21.

[keefer]

A couple of variations:

B4 disc-braked bogie. Originally for the Mk2 coaches on the cl.27 push-pull trains. The other side of the bogie does not have the pipework.

 

B5(S) bogie, trailer bogie for SR EMUs. Note, this one has had the friction-type primary dampers replaced with hydraulic ones (either side of the primary springing). Also note the mounting points for a shoe-beam (below the primary springs):

Photos (c) Brian Daniels on Flickr

Edited February 26, 2021 by keefer

[Stevebr]

Axle journal diameter not axle diameter 

[Wickham Green too]

I'm surprised the bogie under 9708 hasn't got guard irons .......... these seem to be surplus to requirements !

 

 

Edited January 24 by Wickham Green too
photo reinstated

[Bomag]

22 minutes ago, Wickham Green too said:

I'm surprised the bogie under 9708 hasn't got guard irons .......... these seem to be surplus to requirements !

 

 

 

The bogie on 9708 is on the inner end, not the driving end.

[Wickham Green too]

AH ! ............ I was fooled by the yellow paint ! : used to signify a driving end yer know !

[HGR]

On 26/02/2021 at 11:50, keefer said:

Standard B4 bogie:

 

B5 bogie:

 

Both photos (c) Brian Daniels on Flickr

 

If doing them in fairly new/clean condition, I think the primary springs are red on the B4 and blue on the B5.

The colours of the springs denote their 'rate' or loading capacity. Other colours are available such as white, yellow, green, etc., but red and blue are the common ones. Note that the bogies at each end of a coach could have different (coloured) springs if the coach was heavier at one end - for example some of the catering cars. One B4 and one B5 under the same coach being the extreme case.

 

There were different 'marks' of B4 and B5 with detail differences and different weight ranges (heavy / medium / light).

 

The B5 under the TPO coach shows the 24 V alternator used on these, mounted on the inner end of the bogie and driven by six 'V' belts, instead of the older dynamo that was suspended under the underframe running off a flat belt.

 

[Peter749]

On 26/02/2021 at 15:28, Wickham Green too said:

I'm surprised the bogie under 9708 hasn't got guard irons .......... these seem to be surplus to requirements !

 

Why do you think this is Coach 9708?

And why does it have Guard Irons?

 

Peter

[Wickham Green too]

Driving Brake Standard No.9708 was clearly identifiable in Keefer's picture on Friday ............. MY picture is of the R.P.S.I.'s Brake First No.463 ( formerly B.R. 14091 ) which has acquired a guard-iron fitted bogie from an 80 class 'Thumper' or, more likely, from N.I.R. 'Enterprise' Driving Brake Standard No.916.

 

 

Edited January 22 by Wickham Green too
photo reinstated

[dasatcopthorne]

Here is a pic of a 4Rep.

 

They had the same bogies but without the shoebeam, of course.

 

Dave.

Edited January 22 by dasatcopthorne

[rodent279]

On 26/02/2021 at 12:30, keefer said:

B4 disc-braked bogie. Originally for the Mk2 coaches on the cl.27 push-pull trains. The other side of the bogie does not have the pipework.

The first disc braked B4 bogies (and I think the first mainline stock built from new with disc brakes) were the late lamented 1965/6 build class 310 EMUs, BRs best EMU.*

 

*other opinions exist 🙃

[45125]

On 24/01/2024 at 07:53, rodent279 said:

The first disc braked B4 bogies (and I think the first mainline stock built from new with disc brakes) were the late lamented 1965/6 build class 310 EMUs, BRs best EMU.*

 

*other opinions exist 🙃

After the 310s the next B4s with disc brakes went under a handful of mk2as for the eastern, we'll before E-G push pull.