University of Cambridge warns East West Rail route will impact internationally important research at Mullard Radio Astronomy Observatory

The University of Cambridge has warned there is a “clear and obvious risk” that East West Rail will interfere with research of international importance undertaken at its Mullard Radio Astronomy Observatory (MRAO).

It says East West Railway Company failed to consider the “environmental effects on research” at the site when it chose its preferred route for the new £6billion railway line from Oxford to Cambridge, which is due to head south from a new station at Cambourne to reach the under-construction Cambridge South station.

In a letter to David Hughes, EWR Co’s chief executive, the university says: “We are unable to support the current route proposals for the area around Lord’s Bridge.”

It stresses that the Mullard site has been home to “some of the largest and most advanced radio astronomy instruments in the world since it opened in 1957”, and adds: “Notably, these instruments have supported research leading to two Nobel Prizes and countless discoveries which have placed Cambridge and the UK at the forefront of astronomy research.”

The observatory, at Lord’s Bridge on the A603 south of Cambridge, “contains unique radio and optical telescopes which are of international importance and must be safeguarded”, the university explains.

It continues: “The facilities measure signals that are very weak, and hence highly susceptible to many forms of interference, specifically electric-magnetic interference (EMI), light pollution and mechanical vibration from domestic, industrial plant and other sources such as vehicles and aircraft.”

Currently on site are state-of-the-art aperture synthesis radio telescopes, such as the Large and Small Arcminute Microkelvin Imager arrays and a 32-metre dish that is part of the e-Merlin national facility.

The site is also used to help develop and test international instruments that are deployed elsewhere – often in large numbers – under collaborations worth millions to the university.

The most important of these is work led by Cambridge on the Square Kilometre Array (SKA), which is under construction in South Africa and Australia, and which brings around £3million per year to the university in research funds.

The letter tells Mr Hughes: “The SKA is a €1.2bn construction project in its first phase. Cambridge leads the design of several elements of the telescope including the software and, importantly, the low-frequency telescope which will be deployed to Western Australia. There are two test arrays at Lord’s Bridge and a third currently in construction.”

The observatory is also due to play a central role in phase II.

Smaller wide field instruments used by the radio cosmology group for schemes such as the £2.4million REACH project could also be heavily impacted, the university says, along with the large vibrationally and temperature-stable optics laboratory that is used to test and validate optical instruments for several large international ground-based telescope projects.

Councils have long recognised the importance of the site in their Local Plans, protecting it from “inappropriate development”, but the letter says EWR Co appears “to assume that the actual emissions from the operation of the railway will correspond to the maximum levels permitted” under electromagnetic regulations.

The university warns: “This is a major concern, as constant emissions at maximum levels would have a significantly detrimental impact on the work of the MRAO.”

Actual predicted emissions “need to be understood” to assess the risk to the site, the university says.

Its letter goes on: “The university urges East West Rail to carry out an assessment of the likely environmental effects arising from the construction and operations of the route and specifically concerning EMI and vibration in the vicinity of Lord’s Bridge, so that a conclusion can be reached on the amount of interference likely to be caused, and to identify what measures could be put in place to mitigate harmful effects.”

And it warns: ”Despite the absence of any detailed information from the proposed East West Rail, university experts in radio astronomy research and optical instrument development anticipate that the effects from EMI and vibration during the construction and/or operational phases, arising from the unmitigated proposals as set out in the consultation documents, will be significant. There is a clear and obvious risk of interference to research.”

Warning that the stretch of line between Comberton and Shelford is likely to breach current planning policies protecting the site, the university sets out the tests that it would expect EWR Co to carry out, and proposes a series of ways it could reduce the risk.

It points out that it could route the railway further away and at least outside the ‘Lord’s Bridge Restricted Area’ or by putting the railway in a tunnel as it passes the observatory.

“Neither of these options are proposed nor appear to have been explored. Instead, the railway is proposed to run through the heart of the Lord’s Bridge Restricted Area and within 1km of the SKA testing site and the COAST optical laboratory,” the university says.

It could also prevent harm to the observatory “by designing the railway at grade, with appropriate vibration suppression, and screened behind an earth bund, neither of which are proposed”. But, the letter notes: “Instead, the railway is proposed to operate on an 11m high embankment, without any form of screening, as it passes Lord’s Bridge.”

The letter, from director of estates Graham Matthews, concludes: “We are concerned that East West Rail has assumed reliance on a mitigation strategy that depends solely on measures that would compromise research through the release of radio frequencies up to the maximum levels… and with no regard to vibration disturbance suppression.

“The university does not support the approach to environmental assessment and mitigation being proposed and requests that East West Rail urgently consider ways to avoid and prevent adverse impact on the university’s nationally and internationally important radio astronomy research.”

It also seeks “certainty” that “land within the core of the Mullard Radio Observatory” that EWR Co plans to take for habitat creation or mitigation would be returned to the university, as it is needed “to secure future research undertaken at the observatory”.

The letter does, however, offer support for the “strategic objectives of East West Rail”.

“Development of the railway will enable mass transit movements by sustainable modes, and have a significant beneficial impact in extending the travel to work area for Cambridge including, importantly, the Cambridge Biomedical Campus.

“The railway will support the continued growth of the Greater Cambridge area, significantly enlarging its travel to work area and providing connection to innovation economies along the route.”

The university notes that about 20 per cent of its staff currently commute into Cambridge along the A428/Madingley Road corridor and welcomes plans for a Cambourne station.

It urges EWR Co to ensure the new station “supports first mile/last mile journeys from/to Cambourne, for the benefit of residents, workers and visitors” and integrates with the proposed Cambourne to Cambridge busway, which will connect Cambourne to the university’s Cambridge West development.

It says this is “a strategically important employment location for which outline planning permission was granted in June 2023 for development of 370,000 sq m of academic and commercial research space, with up to 170,000 sq m commercial research”.

The university also supports the proposal to create a turnback at Cherry Hinton, noting: “This would create the opportunity to create a new station at Cambridge East, supporting the development of thousands of homes and jobs, and enabling cross-city mass-transit movement.”

A spokesperson for EWR Co told the Cambridge Independent: “East West Rail will better connect communities in Cambridgeshire, offering greater access to homes and jobs. We are grateful for all responses to our non-statutory consultation and following the end of this process we are now reviewing this feedback which will help inform the final design of our railway.

“We continue to have constructive engagement with the University of Cambridge to develop appropriate mitigation measures with regards to the Mullard Observatory.”