Plan E 39.7972 — Comparison of two suspension damper solutions (1963)

In this document

The approval note (p. 3)

Page 3 bears a handwritten note dated "25-12-63" and an approval in red ink "Vu Moyer" (reading of the name is uncertain), as well as a pencil reminder: "Front and rear suspension assembly", "Plan E 39.7972", "25.12.63". A technical diagram appears in transparency through the sheet, but its details remain illegible and are therefore not exploited here.

The technical drawing (p. 4)

Page 4 presents, on tracing paper, two damper solutions compared for the same front and rear suspension assembly:

• the "DS type damper solution", with indications "Brazed", "NOT bonded" and a "Crimping", as well as diameters Ø=39 and Ø=30 (Section B);
• the ""Double retention damper" solution" (Section A), including an axis noted "identical to "b": K4-P", a "Case-hardened zone", and the specification "415 in normal position, without rubber compression".

An operating datum also appears: "Inflation pressure: 40 Kg/cm²".

The official title block identifies the document: drawn by Agostini, dated 25.12.63, referenced Plan E39.7972, plate "33-98", designation "FRONT and REAR SUSPENSION ASSEMBLY", issued by the Société Anonyme André Citroën, with the mention "Reproduction prohibited".

Context

This plan dates from the end of December 1963, in the middle of the development and evolution period of the DS, whose hydropneumatic suspension — designed in particular by Paul Magès — had been the flagship innovation since 1955.

The comparison between a "DS type" solution and a "double retention" variant is likely part of the continuous work of improving the range's dampers, a permanent project at Citroën during the 1960s to refine comfort and road holding.

Archivist's perspective

This document clearly illustrates the design office's working method: comparing an existing and proven solution ("DS type") with an experimental variant ("double retention") on the same plan, probably to evaluate their respective merits p. 4.

The "Vu Moyer" approval p. 3 attests to a hierarchical control of the document, a sign that it is an officially validated piece in the study circuit, and not a simple draft.

The precision regarding the inflation pressure (40 Kg/cm²) and the behavior of the rubber "in normal position" p. 4 testifies to the concern for fine specifications typical of the Magès archives. This plan can usefully be compared with the Suspension project plan — drawing VITIER, ref. E 201-294, dated December 27, 1963, i.e., two days later, which seems to be part of the same development effort.