Lead or Rumour info - - Sheffield 'Gigatron' | Leads, Rumours and News... | 28DaysLater.co.uk

Lead or Rumour info - Sheffield 'Gigatron'


Hasnt Ex'd many Urbs!!
28DL Full Member
Im not a drainist at all but Im sure this will interest many. Advance appologies for vague info, but this is from my fuzzy distant memories!!

Was discussing all things underground/abandonned recently with a good friend of mine, and we both remembered some massive underground civil construction in the centre of Sheffield in early 1990s which went on for quite some time.

I can not remember where precisely where, exept that it was either somewhere along the Wicker, Park Squre or Pond Street area. I recall looking down it many times from the top deck of the bus (93 or 52!)

It was to construct a massive tunnel underground. It had a massive vertical circular shaft (fnar fnar) big enough to fit a dumper truck down. So deep you couldnt even see the bottom from the top of the bus. I recall rumours of it being 30 - 50 metres deep, and allegedly big enough to drive a small bus through. Have no ideas where it went from or to.

'Gigatron' .... coz its bigger than the Megatron!


28DL Full Member
The tram started running in '94, could have been something do do with that, especially if it was around Park Square, I'm thinking something to do with supporting the bridge on Park Square roundabout maybe, if that was the place?

Don't suppose you have any more info, or a more specific location? Pond Street, Park Square and the Wicker aren't that close together really.

Maybe part of Megatron was opened up for some sort of construction work? It covers the right sort of area.


Hasnt Ex'd many Urbs!!
28DL Full Member
Tablets - no. Not "t'ole in t'road"! Look how little traffic there is in your pic!

Kaplan - No, definately nothing to do with the tram system. I recall it was definately a water related civil engineering project. What ever it was, it was completed very early 90's.... possibly before I started at the Poly in '91 me thinks. Appologies, I know Im not being much help here (Its called Leads & Rumours..... call this a strong rumour! I know it happened, just cant remember where.). Im racking my aged brains to try and pin down where it was. :sad

I know those locations arnt exactly close together, but I do recall it was in the centre of town somewhere in that triangle, and that it was not possible to see the bottom from the top deck of the bus! The chatter at the time was that it was DEEEEEP! +Dont forget the shape of the Park Square island changed massively too when the tram was put through.

(unrelated) I know they did a lot of work (probably Megatron) after the city centre flooded in 2000. Seem to remember a massive fuss being kicked up after it was found the waterway was blocked with years of uncleared shite, including a number of large trees and other generic debris!


28DL Full Member
28DL Full Member
There was THIS in Millhouses Park, but that is after the period you're talking about and not in the right area.

I did have a Bing map compiled by YW that listed all the Sheffield water installations, but can't find a link now. Know I shared it with a few of the Sheffield lot - anyone still got it?


Staff member
It's unlikely that they will be specifically monitoring a sewer via cctv, more like council related cctv for crime prevention, someone local needs to go and climb down and bring some instagrams or flashtastics back :p:


Northern Monkey
28DL Full Member
There is another quote on the Sheff Forum thread that would kinda make sense with the location
They probably mean the Interceptor Sewer - which runs underneath the River Don. I was taken down it when they were constructing it in the 80's - it's massive. It's designed to stop all the drains emptying directly into the Don, especially when there's heavy rain.

It ends at the circular white building at Blackburn Meadows where they pump everything back up to the surface.


28DL Full Member
28DL Full Member
>> "Subscriber only content"
Strange, I'm definitely not a subscriber...

Going down a storm

10 February, 2005 | By Bernadette Redfern
A rethink of the construction methods being used to build a stormwater storage tank in Sheffield was needed when groundwater flooded the site, discovers Bernadette Redfern.

Yorkshire Water knew that providing 13,175m 3 of stormwater storage in Sheffield City Centre was not going to be easy. Access to the cramped site was difficult, and joint venture contractor EarthTechMorrison found unexpectedly high ground water flooding the site.

Despite the setbacks the £7.5M project is still on time and £300,000 under budget.

Extra stormwater storage is being installed at four different locations within the city and will cut combined sewer overflow discharges into the River Sheaf.

'We usually put projects greater than £2M out to tender but for this project we decided to stick with our framework contractor, ' says Yorkshire Water solutions manager, Peter Ward.

'It was a leap of faith but it has paid off.' The Council felt comfortable enough with the relationship to allow Yorkshire Water to dig up 2,100m 2 of the city's finest green area, Millhouses Park. The hole will contain a 10,000m 3 concrete storage tank and subcontractor Barhale is midway through the installation. Another 3,175m 3 of storage is being spread between three circular offline storage shafts downstream of the tank.

The decision to construct a tank rather than another shaft was taken after boreholes revealed 'massive blocks of hard sandstone underlying mudstone, and high artesian water pressures 7m-8m down', says EarthTech Morrison project manager John Eaton. 'If we had gone for a shaft it would have had to be 30m deep, and were told that we would need specialist breaking work to get past it. It was too risky.' 'The alternative was to dig a shallower horizontal box. Usually in an urban location like this you wouldn't have the space, ' says Ward. Luckily the council offered up the park.

EarthTech Morrison was by no means home and dry, though. As the excavation neared its deepest point, water began to flood the box. 'The lads on site told us that they had never seen anything like it in 25 years, ' Eaton says. The aim was to dig the box, pour a concrete base, and then start on the main box walls and the 'dwarf walls', which act as separators within the tank. Ground anchors were installed into the walls, keeping the tank floor clear and smooth.

But things did not go quite as planned.

'We were using 6m long Macalloy bars to anchor the tank in place. Once these were placed, the 80mm [diameter bored] holes were filled in with grout, but ground water was washing the grout away, ' says site supervisor Alice Chaplin.

'The concrete contractor was following the ground anchor people, so delays installing the anchors were throwing the concreting programme out. We had to re-programme and move the anchors so the concrete team could carry on working, ' she says.

Simply moving the anchors was not enough to address the runaway grout problem, though.

The steel bars were slipped into socks which both held the grout fast and expanded hard against the boreholes as the grout was pumped in. 'It was an 80mm hole but they were 100mm socks, so they really locked in to the jagged edges of the mudstone, ' Chaplin explains.

Where sleeved anchors failed under test loading 4m long stainless steel rock bolts were installed and grouted into place.


Hasnt Ex'd many Urbs!!
28DL Full Member
tablets - I dont recall 'the shaft' being in the Sheaf Street/Station area. The CCTV camera will probably be this one...
..... A council operated traffic camera.

mstarmatt - Sounds about right. Evedently it didnt do its job too well in 2000!

Muttley - that Bing map sounds most 'useful'... any ideas where you obtained it?! At best I could use it to bump off any idiotic speed bumps the council have put in! (Regulations state they're not to be within a set distance of pipe work... as shockwaves from passing traffic eventually causes damage/failure to pipework)


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28DL Member
28DL Member
Well there is a huge network of culverts for both the River Sheaf and the Porter Brook in that area, the Sheaf in culverted under the Midland Station and Sheaf St, runs uncovered for about 50 yds then in culverted all the way to where it flows into the Don at Blonk St, I suppose it could be something to do with this, as it flows more or less in a line from Pond St, under where Commercial St and Exchance Place come off the Park Sq and flows into the Don under the Blonk St bridge, which isn't very far from the Wicker. I should imagine that the buses were a good few yards away from a hole the size you mention too, and there would be a lot of raised reinforcement around the top of the hole, so it would appear a lot deeper than it actually was, if you go and take a look at the open streach of the Sheaf between Sheaf St and Pond Hill at the back of Ponds Forge, I'd say its about 20 foot deep there, and looking at this pic on wikipedia http://upload.wikimedia.org/wikipedia/commons/4/42/RiverSheafJoinsDonAtSheffield038.jpg it looks as though this has had the culvert wall rendered at some point in the last 20 - 30 years.