Deep-dive experiments and events such as 1961, the world record dive by the Swiss Hannes Keller to a depth of 305 meters near the island of Santa Catalina, California, aroused the interest of various industries on the activities of man under water.


Historical Development

In 1964 Shell International offered its support for the implementation of targeted systematic research in the field of diving medicine by Professor A. A. Bühlmann, Med. University Hospital Zurich (USZ), in the context of his working as a scientist.


Prerequisite for any the research activity was the construction of an own hyperbaric chamber laboratory.


In November 1964 Shell took over the employment of Mr. B. Schenk as an operational manager of this project. Thanks to generous support from the Shell company and the goodwill of the Zurich university authorities, the first hyperbaric chamber laboratory at the USZ (University Hospital Zurich) was built in a very Spartan version in the basement of the high-rise building for nurses at Plattenstrasse 10.


Research has always focused on the well-being and performance of human beings in an atmosphere that is abnormal in terms of pressure and gas composition. This resulted in many relationships with respiratory, circulatory and altitude physiology.


In December 1964 the first examination and appraisal of the diving equipment of a fatally injured diver was carried out, by order of the Office of the Public Prosecutor.


1966 Contractual agreement with SUB SEA OIL SERVICE, MILANO (subsidiary of Shell) for cooperation in the development of deep diving techniques. The highlight of this agreement was the realization of the CAP SHELL project with dives to a depth of 220 meters in open water in the Mediterranean Sea.


In addition to the assistant doctor provided by the USZ, in 1966 the requested position of a technical assistant (Mr. M. Häusler) and a secretary (Mrs. H. Schneider, part-time) were approved by Shell. 


In 1967 the limits of what was possible for deep diving tests in the hyperbaric chamber plant at Plattenstrasse were reached. Through Shell's intervention, the British Navy temporarily provided its own hyperbaric chamber facility in Alverstoke / Portsmouth, which was to be operated on the responsibility of Shell/Bühlmann.


In 1968 and 1969 the hyperbaric chamber laboratory team of the USZ completed two deep dive experiments in the British facility with its own personnel and test persons except for the maximum permitted depth of 350 meters with three test divers each.


From 1969 on began with medical examinations and selections of “diving swimmers” (frogmen) of the Swiss Army in the hyperbaric chamber in Zurich.


1969 First hyperbaric treatment of an accidental diver with decompression sickness (DCS).


In 1969 the analysis on the performance mandate/demand resulted in the need for an in-house development of a dedicated hyperbaric chamber system for research and patient treatment purposes as there were no ready-made finished products available.


At the end of 1969 a project proposal for the new construction of a hyperbaric chamber system by Mr. B. Schenk was submitted and approved by the responsible parties for its realization.


1970 Replacement of the technical assistant Mr. M. Häusler by Mr. M. Baltensperger (financing by Shell).


1970 Publication of the decompression guidelines for mixed gas dives, developed in cooperation with the computer center of the University of Zurich, down to depths of 220 meters. 


In 1970 the first hyperbaric oxygen treatment of a patient with gas gangrene was successfully carried out in the old USZ hyperbaric chamber.


1970 The funding of the responsible manager for the operation of the hyperbaric chamber laboratory (B. Schenk) is taken over by the canton of Zurich.


In 1972 under the direction of Mr. B. Schenk, the new hyperbaric chamber system was completed and put into operation. Financing was mainly carried out by Shell and shares of the Federal Government and Canton of Zurich. As a result: appointment of B. Schenk by the US-Navy to come to the US for the purpose of assessing the hyperbaric chamber systems in operation or projected in the USA.


In 1975 medical examinations and selection of police divers in the hyperbaric chamber began.


1976 medical study under direction of PD Dr. med. O. Oelz in terms of human behavior at extreme altitudes.


1976 Publication of the decompression guidelines developed in cooperation with the computer center of the University of Zurich for air dives down to 60 meters depth, applicable up to altitudes of 3200 m above sea level (dive tables ’76). 


1979 Appointment of B. Schenk as a member of the European Diving Technology Committee.


1979 The request to Shell for support of qualified personnel in the form of two technical specialists was approved by Shell (Mr. P. Jäger from 1.12.1979 and Mr. L. De Toffel from 01.09.1979).


1981 The culmination of diving research at the Center for Hyperbaric and Hypobaric Medicine Hyperbaric Chamber Laboratory) of the USZ. Deep dive experiment with three test divers to a depth of 575 meters with diving excursions in a water tank at a diving depth of 400 meters.


As of June 30, 1981 Shell terminated its contract for the medical research agreement between Prof. A. Bühlmann, the University Hospital Zurich and Shell. 


On July 1, 1981, with the support of Shell, a contract was signed ed with NORWEGIAN UNDERWATER INSTITUTE (sponsored by Statoil) to perform technical research and development work in the field of underwater respiration technology in the framework of a project contract, with a view to safe diving to depths of 500 meters (provisional contract period until 31.12.1981).


End of 1981 Participation in the DEEP EX 11 project in Bergen, Norway (Norwegian Underwater Technology Center) as project leader of the DEEP MASK program. (Deep diving experiment at 500 meters depth with the deep-diving respiratory systems prepared in Zurich.)


As of Dec. 31, 1981 dismissal of Shell-staffed personnel at the Hyperbaric Chamber Laboratory.


In 1982 the Cantonal Government Council approved a position for Mr. M. Baltensperger in the payroll plan of the USZ. The salary runs at the expense of the police department.


1985 The Administrative Directorate issues a new operating directive for the Hyperbaric Chamber Laboratory, with references to accountability and staffing. 


1985 Development order from STATOIL for the BESK 710 deep-diving respiratory system for diving depths down to 700 meters. Contract signed in Zurich by Managing Director Mr. P. Stiefel.


1986 The successful performance and load tests in the Deep Dive Simulator of the NORWEGIAN UNDERWATER TECHNOLOGY CENTER in Bergen concluded the STATOIL development contract for BESK 710. The agreed payment amounts were transferred from STATOIL to the USZ.


1986 The medical lead of the Hyperbaric Chamber Laboratory was assigned to PD Dr. med. Med. O. Oelz. Promotion of hyperbaric oxygen treatment in the chamber (HBO) by introducing daily HBO programs.


1986 Beginning of hyperbaric oxygen treatments with patients of the Dental Surgery Polyclinic and the Oral Surgery Clinic.


1986 Application to the Administrative Directorate for the creation of a third full-time position for the Hyperbaric Chamber Laboratory (DKL).


1987 Presentation of the DKL at the exhibition "Diving 87" in Emmen and on the occasion of the "Offshore Conference and Exhibition" at the Federal Institute of Technology (ETH) in Zurich.


1987 The request to the Administrative Directorate for the creation of a third staff position cannot be met for the time being. Despite the increasing demand, the treatment operation had to be restricted. Due to insufficient staffing at the DKL, only 60% of the requested HBO treatments could be performed. Although therapeutically important, the daily second sessions had to be canceled as a result of staff shortages. Patients had to be rejected. It was tried to solve the personnel problem with part-time employees. The application possibilities were exhausted up to the responsible limit, but without being able to fulfill the required services.


1988 request to the Vincent de Paul Foundation to carry out a medical scientific study focusing on the fundamentalization of therapy depths in hyperbaric oxygen treatments (HBO) in the chamber. Counterproposal USZ: Therapeutic efficacy of hyperbaric oxygen therapy for arterial occlusive diseases in the stage of resting ischemia. As a result, the Board of Trustees ultimately decided against the study proposal of the USZ, as similar studies were already commissioned by the Foundation. The Board of Trustees expressed its interest in future cooperation.


1988 Request to the Administrative Directorate for the creation of a full-time personnel position for a third specialist in the DKL. Without a practicable solution of the personnel problem, a reduction of the current services offered was inevitably. Activation order of the USZ "Operation of the hyperbaric chamber laboratory 23.01.1985". 


1989 Adjusting safety regulations. Project in cooperation with EMPA (Swiss Federal Laboratories for Materials Science and Technology) regarding chemical, thermal reactions (auto-ignition). Risk-free use of medications, wound treatment and wound dressing materials when used in conjunction with HBO hyperbaric chamber therapies. 


1989 The possible partial relief of the DKL staff on weekends and public holidays by coordinated emergency service in cooperation with the CHUV (Lausanne University Hospital ) is not feasible according to the CHUV.


1989 - 1991 Medical study under the direction of Prof. Dr. med. U. Binswanger, Dept. of Nephrology USZ, in terms of effects on human renal function with increasing altitude. 


1991 Medical study under the direction of Prof. Dr. med. Dr. H. F. Sailer, Oral Surgery Clinic USZ, in the field of maxillofacial surgery (HBO).


1992 On request of the head of the department, Prof. Dr. F. Follath, the hyperbaric chamber laboratory will be integrated into the Dept. of DIM Pulmonology. Medical Director is Prof. Dr. med. E. Russi.


1993 First project phase with US Navy in the matter of BESK 710. Appointment of B. Schenk to the USA for the demonstration of the deep-diving respiratory system BESK 710 developed in the DKL and project agreements regarding research and development cooperation. In the following: Appreciation of the excellent development of the BESK 710, by the US Navy, but doubts about the realization due to the non-existent, but necessary implementation options (namely personnel shortage) at the University Hospital Zurich.


1993 The request for personnel to ensure the operation of the Hyperbaric Chamber Laboratory according to the assigned performance mandate could not be met until today. From the side of the Hyperbaric Chamber Laboratory it was reiterated that without a workable solution to the staffing problem, performance expectations cannot be met and that vital scientific work, such as in the field of hyperbaric medicine, can not be carried out.


1994 According to the instructions of the Administrative Directorate, the DKL (Hyperbaric / Hypobaric Medicine Center) is administratively subordinated to the Technical Service.


1995 The BSG management consultancy St. Gallen was commissioned by Mr. Stiefel as follows: Review of the whole range of questions around the Hyperbaric Chamber Laboratory (DKL) at the USZ in terms of performance, finances and personnel respecting the alternative possibilities and the health-political aspects (expertise dated 4 January 1996).


From mid-1996 initiation of the examination on the possibility of privatization of the DKL by the Administrative Directorate.


1997 medical study under direction of OA Dr. med. R. Candidas, Dept. of Cardiology DiM USZ, in terms of behavior of pacemaker patients with increasing altitude.