
We’ve already looked at the building of Sheffield’s underground tunnel system around Sheffield Station and the ingenious method of “hiding” the Porter Brook and River Sheaf. (Available to read on a separate post).
In this post, we move on from Sheffield Station (formerly Midland Station), which had doubled in size in the first few years of the twentieth century, and resulted in long stretches of the River Sheaf bidding farewell to the light of day.
After the Midland Station, the River Sheaf emerged briefly at a weir, as it does now, close to what is now the Digital Campus.
It then flowed through further culverts under the Electric Light Works (now the front of Ponds Forge International Sports Centre). The river then streamed under Commercial Street and beneath what was once the site of Sheaf Market (now the Travelodge).
Onwards it flowed under Castlefolds Markets, until being freed at Exchange Street and flowing open-air until meeting the River Don at its confluence near Blonk Street. (Remember that the River Sheaf once ran alongside Sheffield Castle).
As elaborate as the underground tunnels were underneath Sheaf Valley , the most spectacular part of the network lay underneath Exchange Street, now known as the “Megatron Chamber” – “something excellent and impressive” – a massive arched brick-lined cathedral that dwarfed any man who stood inside.
The reason for the Megatron has been provided by Heather Smith and Phil Jones from the Sheaf and Porter Rivers Trust. It seems that the giant Megatron arch was built for a very specific purpose, to carry heavy old trams across the river on Exchange Street, which rises slowly up the hill, and get them into the city.”
From the Megatron, the River Sheaf flowed out into the open-air, past the old Alexandria Theatre. This last section was culverted over in 1916 after the demolition of the theatre, another massive scheme that allowed the eventual construction of Castle Market above, the rebuilding of Blonk Street and a tunnel entrance that allowed the Sheaf to flow straight into the Don.
The underground system of tunnels is Victorian engineering at its best.
The arched roofs were built with three layers of brick, strong enough to resist the huge torrents of water that the Porter Brook and River Sheaf threw at them during times of high flood.
Alas, as good as the system is, it has failed on occasions, with stories of the old Sheaf Markets flooding at high water, and then there was the memorable Sheffield flood of 2007 when Sheffield Station found its tracks underwater for several days.
A poignant reminder from the River Sheaf that it is still around.
Mostly, the tunnels are accessible to walk through, but should never be entered without permission and expert supervision.
Underneath Sheffield Station the sound of trains can be heard rumbling overhead, and in the lower reaches, bats skim the surface of the Sheaf with fish evident.
As part of the Returning Rivers to the City Scheme, Sheffield City Council is considering reopening the last few yards of the River Sheaf from the Megatron to the River Don, in a park to be called Sheaf Field.