The IRAM Executive Council held an extraordinary meeting in Grenoble on January 27 , 2000 in order to discuss the situation after the two terrible accidents which happened in the course of 1999 when transporting people to and from the Plateau de Bure Observatory: the cable car accident on July 1 , 1999, which took the lives of all twenty passengers, and the helicopter accident on December 15 , 1999, in which five people died.
The Council started with a moment of silence in memory of the victims. Having heard what is currently known about the circumstances and possible causes of the accidents, the Council then faced the question if in the light of these events the observatory's activities must be stopped completely, or if they can be resumed at some point in the future, under conditions to be defined. All three IRAM partners as well as members from the IRAM staff came to the conclusion that the Plateau de Bure Observatory must have a future as one of the leading installations of its kind because of the contributions it can make to answering the most important questions of present day astronomy. This view was also shared by a CNRS scientific advisory committee which had addressed this question in an earlier meeting. In addition, it was felt that the facilities on the Plateau de Bure will have an important role to play in preparing one of the biggest astronomy projects of the future, the Atacama Large Millimetre Array (ALMA). The scientific use of the instrument should therefore be made possible again, under the best of conditions.
The most important of these conditions concerns the safe access to the Observatory. This question will be addressed in two steps, and the community will be informed as progress is made.
The first step consists of a number of studies which include:
The results from the official inquiries into the causes of the accidents will, of course, play a key role in deciding on any new solution.
The CNRS who is responsible for providing access to the Plateau de Bure announced that at the end of this phase, which will last several months as a minimum, a decision on the means of access will be taken after listening to the advice and the wishes of the IRAM partner organisations, the IRAM staff, the Committees for Hygiene and Safety of IRAM, INSU and the CNRS, the local authorities, as well as from the wider community.
Should it be decided to reconstruct a cable car and/or to construct a road, execution will start as soon as possible. Taking into account the administrative steps for obtaining the necessary authorisations and performing the necessary controls and tests, one can hope that by the end of the summer of 2001 a new, regular means of access to the Plateau de Bure will exist. The General Direction of the CNRS, with the support from its Executive Council and the Ministry of Education and Research, has already created a budget line for these activities.
Concerning the near-term future, the IRAM Direction presented to the Executive Council the rules and guidelines which have been established in consultation with the IRAM Committee for Hygiene and Safety, for the present activities on the Plateau de Bure. The main elements of this scheme are:
An analogous set of strict rules is enforced for people who wish, for personal reasons, to come to the Plateau by ground route under the responsibility of a mountain guide.
The IRAM Executive Council supported these measures taken by the IRAM Direction.
Concerning the medium-term future, the CNRS/INSU informed the other two IRAM partners about the plan to repair the existing cable car installations, to construct a ``blondin'' to ensure the de-icing of the cables to avoid further damages, and to bring up material to the Plateau de Bure with this load carrying device, to reduce the number of helicopter flights. The feasibility of this plan is presently being studied by the chosen project manager (E.R.I.C.), and a final decision will be taken soon. The IRAM Executive Council strongly endorsed this concept.
As described above, at present no observations are carried out with the Plateau de Bure Interferometer. It was decided, however, that the CNRS/INSU and IRAM should start discussions with the various groups concerned about the conditions under which observations could be restarted, at least in some limited way. These discussions will involve the staff, the Committee for Hygiene and Safety of IRAM, the local authorities, as well as the wider community. In parallel, a risk analysis will be made by independent experts, considering the transport problem and the risks associated with the various tasks that must be executed if observations were to restart, and the full system would have to be maintained.
It is important to stress that the present compact configuration of the antennas allows important scientific projects to be carried out even if it remains unchanged until summer has arrived.
Another decision of the IRAM Executive Council concerns the completion of Antenna 6. A ``green light'' was given to restart this work later in the spring and to aim for its completion by the end of the summer 2000. With this additional antenna, the efficiency of the interferometer will greatly be enhanced. The Council considered the proposals made by the IRAM Direction in consultation with the IRAM staff both for the operation of the array and for the construction work as justified and feasible.
Looking at longer-term aspects, the Council has expressed its confidence in the teams and in the Institute. The receiver development program, the active participation in the preparation of the ALMA project, and the co-ordination of the work of the three IRAM partners in this project will allow IRAM to play a key role in mm-astronomy for many years to come.
Finally, the IRAM Executive Council took note of the negotiations concerning the implementation of the new French labour legislation which enforces an average regular working time of no more than 35 hours per week, to be compared with 39 hours in the past. This change will have a profound impact on the organisation of the work at the IRAM sites. The idea is to compensate some of the loss in manpower by new hirings. This will, however, only be possible in a concerted effort between the IRAM staff, the Direction, and the IRAM partners.