DMU Bogies
Swindon Bogies
The drawing (part sectioned) shows a power car bogie.
It was the plainest of the three early frames with nothing but the occasional footstep to break up the space between the leaf springs.
They also seemed less cluttered without the vacuum cylinders. Trailer cars would not have dynamos attached to the bogies, these would be underframe mounted but still belt driven from the axle.
There are some images showing some of the steps in machining new bogie parts in the Building a DMU section.
A completed bogie, another behind (marked lot 30200 No.3 T.E.), and a DMU underframe on bogies behind that. Note the horizontal frame closest dips for the fitting of cardan shaft that joins the final drive to the gearbox.
The horizontal bar at this side of the bogie (the same bogie pictured in SC51) is straight. Lot 30200 vehices were leading DMBSs, the third vehicle would be 79093. 'D.E' can be assumed to mean Driving End, the other bogie was marked 'T.E.' presumably trailing end.
A side view of the same bogie as the first two images. The right hand axlebox has a temporary cover, a distance counter would be fitted there.
B4 Bogies
These bogies were developed in time to be used on the final first generation DMU build - the Class 123 Inter-City units.
The general principle of operation remained the same, but with substantial changes to the construction, such as coil strings replacing the leaf springs for the axleboxes. All suspension damping was provided by hydraulic dampers instead of friction on rubbing plates or in hornguides. The horizontal "traction rods" which prevent the bolster rubbing on the bogie frame are seen on the side of the bogie.
The image shows one under the cab end of 52093.
When the first LMR Class 120 set was refurbished in late 1977 the centre car 59301 was given B4 bogies.
Curiously, another Class 120 vehicle was noted with B4 bogies, withdrawn power car M53674 at Vic Berrys in May 1986 (pictured, Ian Francis). It may have been a change for movement after withdrawal rather than having had them in service. Any information would be appreciated!.
Former Cravens parcel car 55997 in Research Centre use as RDB975385 would be fitted with a B4 bogie to one end in 1980 to test an experimental hydrostatic drive. Later on one would also be fitted to the other end.