Thaon-Cadiou memorandum (18 March 1955): transmission of documentation on "Hydra-Springs"

In this document

This consists of four almost identical copies of the same internal Citroën memorandum, issued by the Purchasing department, dated 18 March 1955 (mention "DACT MR 18/3/55", p. 8-11).

The author, Mr. Thaon, addresses it to Mr. Cadiou, with a copy to Mr. Magès p. 8-11. Referenced "ACHATS N° I N K684" p. 8-10 or "ACHATS K684" p. 11, it bears the title "- RESSORTS "HYDRA-SPRINGS" -" ["HYDRA-SPRINGS" SPRINGS].

Thaon indicates that he is transmitting, "following your request", documentation received from the Wales Strippit Corporation company, based in North Tonawanda, New York State (U.S.A.) p. 8-11. He specifies that "the principle of these springs is based on the compressibility of a special fluid" and asks Cadiou to indicate to him "if it is appropriate to request samples" p. 8-11.

Page 8 is accompanied by an advertising photograph in blue tones showing three metallic cylindrical actuators inscribed "Hydra Spring" and "WALES", accompanied by a mention of patents pending ("Patents pending and applied for on Wales Hydra Springs, seals, comproils, methods of manufacture, presses...") for the United States and "most foreign countries" p. 8.

Each copy bears handwritten traces of archiving or circulation: the number "55" in red ink p. 8-9, initials or signatures in the "VISA" box p. 8-10, including a possible uncertain "AS" p. 10.

Context

Wales Strippit Corporation was an American manufacturer of hydraulic springs, known as "Hydra Springs", operating on the principle of the compression of a special fluid (the "Comproil"). This principle is close to that used elsewhere by Citroën for its own hydropneumatic suspension, then in development for the future DS, presented in October 1955.

It was common at that time for the technical and purchasing departments of major car manufacturers to carry out international monitoring of competing or complementary innovations, particularly American ones, in the field of fluid springs.

Archivist's perspective

This note, although purely administrative in form, attests that the Citroën Purchasing department played an active role in technological monitoring by copying Paul Magès on foreign documentation relating to his field of expertise: compressed liquid springs p. 8-11.

It seems that this transmission initiated, within the Magès file, an entire section of archives devoted to Wales Hydra Springs — the Hydra News technical bulletins that followed in the years 1953-1954 are probably the direct extension of this, as is the Wales "Hydra Springs" Bulletin of 1952. One can also compare this approach with Magès' later reflections comparing gas springs and liquid springs, as in his note of March 1961.

The multiplication of copies (four almost identical versions) suggests a wide distribution within the departments concerned, a sign of the interest aroused by this competing technology.