Magès note of 25 November 1973: plea for the hydrostatic variator of the “L” vehicle

In this document

The problem posed

The note opens with the observation that an “automatic gearbox” is requested for the “L” vehicle, a study entrusted to Automotive Product p. 53. Magès sees this as an “easy solution” where Citroën would be content to have it studied by a third party and validated by its Test Laboratory, without committing itself p. 53. He pleads for taking the step towards the Hydrostatic variator, recalling that the team has been working on this problem “for 17 years”, and calls for the “sceptics” to speak out rather than acting “behind the scenes” p. 53.

Eight to nine arguments in favour of the variator

Magès then develops a list of reasons, numbered from 1° to 9° (the handwritten numbering skips 3°):

Influence on engine technology

A separate “C” section explains that the variator, by allowing “very long” ratios, eliminates the need to seek a compromise between low-end torque and high-end power; Magès notes that “this advantage should be well appreciated by the Wankel” p. 56.

Context

The “L” vehicle refers, in the internal Citroën vocabulary of the time, to a project in development (context external to the document). Automotive Product and BorgWarner were equipment manufacturers specialising in automatic transmissions; their mention illustrates the alternative paths then being studied by the manufacturer. The Wankel (rotary) engine, mentioned at the end of the note, was the subject of joint research between Citroën and NSU (Comotor) at that time — a contextual element not developed in the document itself.

This note is part of Magès' long career at the Citroën design office, having joined the company in August 1925 and remaining there until his retirement in September 1974 (photographs of Paul Magès' retirement): written less than a year before his departure, it testifies to his commitment until the end of his 49 years with the manufacturer.

Archivist's perspective

This note, dated 25 November 1973 and numbered “1” in the margin, appears to be an internal advocacy document, almost a manifesto, intended to weigh in on the arbitration regarding the transmission of the “L” vehicle. The personal and committed tone (“for us, it is a mistake”, the call to the “sceptics”) distinguishes this piece from the more technical notes in the collection.

It is part of a coherent set around the same project, notably the Citroën Plan E 3091 — Hydrostatic transmission of the L vehicle, dated 1974, which seems to concretise shortly after the orientations defended here. It can also be compared to P. Magès' presentation on the hydrostatic transmission, presented to the B.E.A. in the same weeks, which probably develops similar arguments before a wider audience.