University of London Observatory
[Radcliffe Dome construction]
The Observatory Development Project

The Observatory is currently expanding its facilities to include three new domes to house the Joynson 6-inch Cooke refractor, the Fry 8-inch Cooke refractor and a proposed new 20-inch professional-grade reflector, as well as more office space to accommodate more staff and open-plan teaching areas.

Part of the reason for the construction project is that at the moment, first-year students rely heavily on the Joynson telescope and smaller telescopes which have to be set up and dismantled for each teaching period. They are operated out of doors where they are subject to the effects of wind and vibrations, and can deteriorate due to humidity. Telescopes housed in domes are protected from these environmental effects and can be permanently aligned with precision, leading to more effective use. The dome which currently houses the Joynson telescope is deteriorating and should be replaced.

The Observatory Development Project now underway proposes to solve these problems. A new extension will be added to a current teaching and office building, which will provide enlarged laboratory rooms for first-year students and public lectures, also including toilet facilities for disabled persons.

Building work began on May 17th 1999 and will continue until the intended completion date of September 30th, when it will be opened for the use of students entering UCL in October 1999.

Images from the Observatory Development Project

The Telescope Building


North elevation of the new telescope building

Planning permission was obtained from the London Borough of Barnet in April 1998 for the new telescope block and extension to teaching facilities. The new telescope building will be located on land previously occupied by the old Joynson dome and storage and workshop sheds which have now been demolished. Storage space will be included in the new classroom block to replace what will be lost.

The new telescope building has been carefully designed in outward appearance to reflect the architecture of the main building, which was designed in 1929 by L. Rome Guthrie. Domes will be erected by the same manufacturer who built the two already on site. The Central dome will have a diameter of 14'6" and will house the Fry telescope. The East and West domes will measure 12'6" in diameter and will contain the Joynson and the proposed new 20-inch reflector respectively.

The telescope pillars sit on 2-metre cubed blocks of concrete five metres below ground level, from which the columns emerge. The Central and West columns are 1m in diameter and the East 0.7m. The structures are isolated from the main buildings by concrete rings which support the building while the telescope columns float in clay. The diameters of these rings are 3m for the Central and west columns and 2.5m for the East. Having the telescope pillars totally isolated from the main building will ensure that precision of the instruments will not be affected by the transmission of vibrations from the building, for example, by footsteps.

Each dome will have its own control room which will be isolated from the domes by double glazing to allow heating of these occupied rooms while the telescopes can remain at a constant temperature. When necessary the three domes can be converted into a single space by the retraction of sliding doors, perhaps to allow space for a large public observing party.

Due to the Observatory Development Project, there will be improved public access to the site. At present public access is confined to alternate Fridays from October to March, and larger-scale open nights for Science, Engineering and Technology week, as well as numerous school visits. Demand for public visits outweighs what we are able to provide, but the extension should be able to accommodate the excess. In the case of special astronomical events like the appearance of Comet Hale-Bopp in March 1997, to which the Observatory opened its doors to over three-hundred people four nights running, the numbers will be much better accommodated.


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