Summary
Scientific research hut of 1949, extended in 1953 and altered in 1955 for Robert Hanbury Brown. Built using pre-cast concrete frame and concrete block walling with a mineral felt roof, and retaining features specifically introduced for the first experiments in optical intensity interferometry.
Reasons for Designation
The Link Hut, a scientific research hut of 1949 originally known as the Cosmic Noise Hut, extended in 1953 and altered in 1955 for Robert Hanbury Brown, is listed at Grade II for the following principal reasons:
* Scientific importance: for its role in important developments in astronomy, and in particular as the site of the first experiments in optical intensity interferometry, which led to the discovery of the Hanbury Brown and Twiss effect and the creation of the field of quantum optics;
* Degree of survival: being relatively little-altered and having been enhanced with features specifically relating to the major optical intensity interferometry experiments, notably the concrete floor pads for equipment, which are retained;
* Group value: as a representative example of the first phase of permanent building early in the history of the site, together with the Park Royal Building (List entry 1443093) and the Electrical Workshop (List entry 1444238).
History
The observatory at Jodrell Bank is one of the earliest planned sites for radio telescopes in the world. As such it had a pivotal role in the development of the new science of radio astronomy which was one of the first steps towards modern astrophysics, revolutionising our understanding of the universe. The site was first used for academic purposes in 1939 when the University of Manchester's Botany Department purchased three fields in the Cheshire countryside covering around 11 acres. The earliest use of the site for radio astronomy occurred in December 1945 when Bernard Lovell, who worked for the university’s Physics Department, moved here to escape the radio interference that occurred in Manchester city centre. His first observations used ex-army radar equipment located at the south end of the site, close to two pre-existing botany huts. Subsequently his team expanded northwards with the continuing construction of more permanent buildings, and purpose-built aerials and telescopes to support their research. Jodrell Bank’s status as a world-class centre of ongoing scientific research continues to this day with the construction of the global headquarters for the Square Kilometre Array project linking hundreds of telescopes and aerials in South Africa and Western Australia.
The buildings around The Green were the hub of both research and teaching onsite. The construction of these new buildings marked a serious commitment by the University to the development of a permanent radio observatory at the Jodrell Bank site, and they are the earliest surviving purpose-built structures for that use. The Link Hut (originally called the Noise Hut or Cosmic Noise Hut) was built in 1949 as a control and receiving room for the adjacent 30ft telescope (a paraboloid mesh radio-telescope that was sited to the west of the hut). This telescope was designed to investigate ‘cosmic noise’, i.e the background extra-terrestrial radio signals that had been first discovered by Karl Jansky in 1932. This was the first paraboloid telescope at Jodrell Bank purpose-built for radio astronomy, and marked a development from using the modified fixed ‘Transit’ telescope which was originally built to study cosmic rays and meteors. The first work based in the Noise hut related to the scintillation of radio sources, analogous to the twinkling of stars observed in visible light, and by working with others, Jodrell Bank showed that the ionosphere produced this effect. In late 1953, the 30ft telescope was modified to observe emission at low frequency from inter-stellar hydrogen, without success. However, higher frequency hydrogen emissions were successfully observed, and assisted in work on measuring the distances to radio stars, which proved important when the Lovell Telescope (Grade I, List entry 1221685) became operational.
Externally the appearance of the original building is little altered except for the painted finish and plastic rainwater goods. However, also in late 1953, the Noise Hut was extended with a darkroom to house a spectrohelioscope given to the observatory. It was attached to the east of the original hut, but originally it extended slightly further to the north; it has since been reduced in depth so that its rear wall is now aligned with that of the original hut. Concrete pads in the floor relate to the change of use of this room in 1955, for the experiments that led to the discovery of the Hanbury Brown and Twiss effect. The window in the front wall of the extension is also an insertion, as is the internal cross-partition which also overlies one of the concrete floor-pads. The left-hand front doorway of the original hut has also been blocked. In the 1970s the Development Lab was attached to the east wall of the extension. The original roofing material has been replaced with similar material.
Robert Hanbury Brown (1916-2002) was one of the original ‘boffins’, working from 1936 to 1942 under Sir Robert Watson-Watt on the development of radar. Arriving at Jodrell Bank in 1949, in 1950 he was one of the astronomers responsible for confirming sources of radio emissions beyond our own galaxy. In 1955, together with Richard Q Twiss, he conducted in the Noise Hut the first experiments in optical intensity interferometry. This relies on the effect of interference between simultaneous signals from the same source, on simultaneous measurements of the intensity of that source. When applied to the interaction of sub-atomic particles the Hanbury Brown and Twiss effect also explains observed results and has been important in advancing our understanding of quantum physics.
Details
Research hut using a standard construction system, 1949 with 1953 extension, altered 1955 for Robert Hanbury Brown and with later modifications.
MATERIALS: pre-cast concrete frame, concrete block walls, metal windows, felt roof.
PLAN: single-storey, L-plan building with the front facing south.
EXTERIOR: standing at the north-west corner of the part of the site known as ‘The Green’, and attached by the Development Lab (not included) to the 21ft Telescope Control Room (also not included) to its east.
The windows are metal-framed, multi-paned casements with concrete surrounds, except in the extension where they have only sills. The walls are of large block-work, now painted. The front wall has a doorway at the left (now blocked*). To the right of this are two windows, a further doorway with paired replacement part-glazed timber doors* with vertical timber panels and an overlight*, and a further window. The central window has a mullion. A grey plastic gutter* runs the length of the eaves, with a down-pipe* at either end. The extension is set back at the right, with a large central window* and a lower flat roof.
The west wall returning at the left has two windows close to the centre, and the roof falls very slightly to either side of a central ridge. Returning at the left again, the rear (north) wall has a half-glazed timber door at the right with a window to its left, and a further two windows at the left of the original building. Metal ducting* carries cabling out of the building. Further to the left, the extension has a lower roof, and a window at either end. The east wall of the extension is obscured by the attached Development Lab. The northern half of the east wall of the original hut is obscured by the extension, but the southern half with its window is visible.
INTERIOR: the concrete frame is visible in the original hut, comprising posts with projecting heads that support the roof beams; the extension has load-bearing walls, of concrete block at the front and sides, and brick at the rear. The walls are unlined, but painted*. The floor is of herringbone parquet throughout, with linear edgings indicating the original location of partitions. Modern electrical and heating services* have been fitted throughout. The ceilings are of fibreboard panels fitted into a metal grid. Within the extension, two concrete pads within the parquet floor relate to the first experiments in optical intensity interferometry, which took place here.
*Pursuant to s1 (5A) of the Planning (Listed Buildings and Conservation Areas) Act 1990 (‘the Act’) it is declared that the aforementioned items are not of special architectural or historic interest.
