DMU Bogies
Springs
An important part of bogies were the springs. There were two main sets, both shown in yellow - one between the the bolster (a cross-beam, shown pale green) and the spring plank (another cross-beam, shown blue), and one between the bogie frame (purple) and the axle boxes (red).
The first set are large coil springs, mostly nested as an inner and outer pair on each side of the bolster. The second set are leaf springs, one on each axlebox, pulled down on side by layers of steel plates with rubber between which are also springs.
The bolster coil springs came in two different profiles: round or Timmis.
Spring Types
For the different bogie types and vehicle weights there were different ratings of springs for each position. This bundle of documents, which originated from Derby circa early 1960s, contains details of these variations, with drawing numbers, catalogue numbers and dimensions.
Each sheet is presented singly below, but all are available in a single pdf for those that would rather scroll through a single document.
Summary sheets
The first two sheets provided a summary of the two spring types, the leaf springs and the bolster springs.
Details of Bolster Springs and Applicability
These sheets give more details on the bolster spring. The first set are for LMR sponsored vehicles, for double nests:
Next was single nests for LMR sponsored vehicles:
Then double nests for WR sponsored vehicles:
And finally single nests for WR sponsored vehicles:
Details of Side Bearing Springs and Applicability
Similar to the above, two sheets for LMR sponsored vehicles, one for WR sponsored:
Bolster Spring Combinations
The next series of sheets seem to document the effectiveness of different combinations of bolster springs. The data was also shown in a series of graphs with some of the combinations marked as "This Combination is not Desirable".
The first sheet details the different Bolster Springs available with the "Timmis" section:
The next two sheets list the different combinations for the Timmis springs:
There are then five sheets of graphs for the above - note there are no graphs numbered 37-45 but these missing ones are not referenced on the above sheets.
This sheet lists the different round section springs:
The next three sheets list the different combinations for the round sections springs:
The final three sheets are the graphs for the above:
Drawing Lists
The final two items were two drawing lists, one for "Side Bearing Springs" and the second for "Bogie Bolster Springs". They are identified by vehicle type rather than by the spring variant.
There are two versions of each here, they are basically the same but different handwritten notes so I've included them both for completeness. One on sheet for the modified bogie Met-camm side bearing springs it notes "on our power cars these always appear to droop at ends"!
Side Bearing Springs:
Bolgie Bolster Springs:
