During my recent August bank holiday search for new street art in the city centre I took the opportunity to visit Castlefield Viaduct, the very new and recently opened ‘garden in the sky’, a project developed by the National Trust and four local partner organisations to transform the Grade II listed disused railway viaduct into an urban green space.
The history of the Castlefield area and the viaduct dates back to 79 AD when Roman soldiers led by General Agricola chose the area as the site of a timber fort which they called Mamucium, later known as Mancunium. Protected by the Rivers Irwell and Medlock it was in a strategic position and well-located to guard important roads leading towards other larger forts. Over time the fort was repaired, enlarged, and eventually rebuilt in stone and a village was established nearby but once the Romans left around 410AD both the fort and the village declined and were eventually abandoned.
In 1086 a village called ‘Mamcester’ was recorded in the Domesday book as lying less than a mile north-east of the old fort. The village grew steadily, incorporating the site of the fort now known as Castlefield (Castle-in-the-field) and by the early 13th century it had become a town, though it wasn’t until the late 18th century that the area really became a significant part of an ever-expanding city.
The industrial heritage of Manchester began around 1758 when the Duke of Bridgewater commissioned James Brindley to construct one of Britain’s first canals, built to transport coal to the city from his mines at Worsley. The Bridgewater Canal proved to be a huge success, halving the price of coal and prompting a period of intensive canal-building across the country, and when the Rochdale Canal was completed in 1804 it joined the Bridgewater Canal at Castlefield, cutting through the site of the old Roman fort and making the area the hub of the city’s canal network.
By this time Manchester was the fastest growing city in the world thanks to the ever-increasing number of cotton mills creating jobs and bringing in trade and eventually it became clear that the canals alone couldn’t move goods fast enough. This led to the dawning of the railway age and in 1830 the Liverpool and Manchester railway opened, with the Castlefield area becoming the site of the world’s first inter-city passenger railway station, Manchester Liverpool Road, now part of today’s Science and Industry Museum.
Over the next several decades the area became recognised as the central hub for Manchester’s goods transportation network. Warehouses sprang up all over Castlefield to support the network and three railway viaducts were built over the canal basin, with the first one being opened in 1849. The second viaduct opened in 1877 and in the same year an elevated railway was constructed alongside it. In 1885 construction began on the Great Northern Warehouse, designed to be a three-way warehouse served by canal, road and rail, and in 1891 construction started on a fourth viaduct which would carry the railway line above the canal basin to both the warehouse and the adjacent Central Station.
This fourth Castlefield viaduct is a steel latticed girder construction 370yds long and 38ft wide and is an early example of using carbon steel for the girders, replacing the usual cast and wrought iron. Designed by engineer William George Scott it was manufactured and constructed by Heenan and Froude, the engineers behind the construction of the iconic Blackpool Tower, with M W Walmsley & Co. being the masonry contractors.
Supported on fifteen cast iron columns each 10ft 6ins in diameter the viaduct stands approximately 55ft above the canal basin, while the columns themselves are embedded in Portland cement, rest on solid rock some 20ft below ground, and are filled with masonry and cement. The total weight of steel and iron in the viaduct is over 7,000 tons and more than 6 million forged steel rivets were used in the construction. It was completed at a cost of £250,000 (about £20.5 million today) and in a small ceremony held on completion day a special copper rivet was fixed in the one remaining slot, though no-one these days knows exactly where it is.
For 77 years the viaduct carried heavy rail traffic in and out of the Castlefield area but along with Central Station, now a large convention centre, it closed in 1969 and has been disused ever since. It became Grade II listed on February 14th 1988 and over the years essential periodic repairs and maintenance to keep it safe have been undertaken by what is now Highways England.
Plans to convert the disused viaduct into an urban ‘sky park’ inspired by New York’s High Line were first proposed in 2012 but unfortunately fell through, however in 2021 a planning application by the National Trust received approval from Manchester City Council to transform around half the viaduct’s length into a temporary ‘garden in the sky’. Funded by private donations and support from local businesses and the People’s Postcode Lottery work began in March 2022 and the viaduct opened to the public in late July as a year-long ‘test and learn’ pilot scheme where visitors and locals can share their feedback and ideas for the structure’s long-term future.
After the very pleasant Welcome Area at the start of the viaduct a wide central path leads through an experimental planting area where hessian sand bags filled with peat-free compost are being used to encourage plant growth through the viaduct’s ballast. Following on from there is the main part of the garden with long specially designed and constructed planters separating four small partner plots set back off the path. Several of the plant species used, such as cotton grass, have connections to the local area and herbaceous perennials provide pretty splashes of colour among the densely planted ferns and grasses.
At the end of the garden is the events space, a light and airy building where visitors can leave their feedback and any ideas for the future of the viaduct. In the far wall a glass door and large windows look out onto the ‘naked viaduct’, the undeveloped section left untouched to provide a sense of how nature has reclaimed the space since the site was closed in 1969.
Visiting the viaduct is currently only by guided tour and though it’s completely free visitor numbers are limited to 100 per day with tickets having to be booked online – it was only the day after it opened that I’d tried to book but disappointingly I found it was ‘sold out’ right through August and with no dates showing in September. I’d almost put it out of my mind but during my recent search for street art in the city I decided to go to the viaduct on the chance that I might be allowed in and I was lucky – there was just one place left on the next guided tour. Not having known what to expect I was more than pleasantly surprised by what I saw and I really enjoyed my visit so (hopefully) if I can ever manage to book a ticket I’ll certainly go back another time.