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Calvin72

Sheffield Tramway Manhole Covers

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Hello All! - Long time visitor, first time poster on this fascinating and addictive site :) . I am especially interested in trains and trams, especially the archaeology of the remains and structures. Ever since i first noticed them near where i used to live in Walkley, i have been interested in the 'Sheffield Tramway' covers that are dotted about the City. There are five between Barber Road and the end of South Road in pretty good condition. I have also seen them in Crookes, Broomhill, Abbeydale Road and near Northern General.

How many do we know of?

What did they access?

What is under them, if anything?

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Welcome Calvin. Wow, that's got to be a candidate for this year's most unusual topic!

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Welcome Calvin. Wow, that's got to be a candidate for this year's most unusual topic!

Thanks! Although it is only the 5th of Jan now :)

The covers i am referring to are in the pavement and there are three outside the garage opposite the Sheffield Buddhist Centre, one outside St Marys Church on South Road and one opposite Walkley library near the traffic lights. I will try to take pics when i can.

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The covers i am referring to are in the pavement

That's why I couldn't find them then. lol

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Thanks! Although it is only the 5th of Jan now :)

True, but you've set the bar pretty high for starters!

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This is one of the pavement features that i refer to outside St Marys Church, South Road, Walkley.

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After a rather chilly trip with Calvin to see these covers last week, my theory is that they were something to do with electrical supply to the tramway, or possibly to the street llights which were attached to the top of the traction poles in this part of Sheffield. Most of the covers are clustered around a fairly sharp bend, so I think tbey are access hatches to aid the feeding of heavy duty cable along an underground conduit. As the cable is very heavy and not very flexible, you would need more covers where the conduit wend around a bend to be able to gradually ease the cable around.

The cables would go from the nearest power substation to a feeder for that particular section of the overhead line, where the cable would travel up the outside of one of the traction poles and be carried across an insulating span wire to the actual trolley wire the tram runs on. These isolated sections of overhead where one section of line meets the next are easily visible in photos because the think cable can be seen going from a traction pole to the trolley wire, while the span wires from every other trolley pole are very thin or even invisible in some old pictures.

Normally a tramway would have a substation supplying a distance somewhere from half a mile to a mile of line. Lengths of line any longer would not normally work due to voltage drop at the opposite end to the sub station. In hilly locations where the trams would draw a lot of power, or where there would be a lot of trams drawing power from a section of line at the same time (such as in the city centre for example) electrical sections would be shorter, meaning more substations or more feeds from a single central power station some where nearby. However substations are always near to the electrical section they supply, again because of the problem of voltage drop, this time in the supply cable rather than the overhead itself.

The question is where in the Walkley area were the substations? These would have normally been small buildings about the size of a large garage, similar to the domestic supply substations still seen all over the place today.

Andy.

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There used to be pale green cylindical cast iron transformer boxes dotted around, though I can't now recall the location of a single one. They were about 4 feet in diameter.

Maybe some have have survived?

Not like this section box, much bigger:

edited some time later... here's what I mean:

http://www.picturesheffield.com/frontend.php?action=zoomWindow&keywords=Ref_No_increment;EQUALS;s15476&prevUrl=

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There used to be pale green cylindical cast iron transformer boxes dotted around, though I can't now recall the location of a single one. They were about 4 feet in diameter.

Maybe some have have survived?

Not like this section box, much bigger:

attachicon.gifsection box.png

edited some time later... here's what I mean:

http://www.picturesheffield.com/frontend.php?action=zoomWindow&keywords=Ref_No_increment;EQUALS;s15476&prevUrl=

There are still some electrical switch boxes around, but I'm not sure about the bigger transformer boxes. Even they wouldn't be anything like big enough to house the equipment I'm talking about. A substation would be the size of a room you could easily walk into. Supertram now has them at various places. I thnk the boex you're referring to Edmund probably transformed the 600v DC down to something lower to power the street lights that were often on top of the poles. They could also have contained switch gear and cable junctions.

I'm currently in the process of going through all the old photos I can find to work out where all the overhead section breaks were. These are the places normally where the thick feeder cables come across to the trolley wire. At this point there would be a short insulated section of trolley wire (normally a wood and metal affair spliced into the wire) and a nearby substation could feed two adjacent sections of overhead from the same place, one to each side of the insulated section.

For anyone around at the time, insulated joints in the overhead were the places where the trolley of the tram would draw a bright blue arc if it passed under the insulator while taking power. Drivers were always told to 'throw off' the controller when passing under these sections as the arc could cause a lot of damage.

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Thanks Edmund!

There is exactly one of these near the Walkley terminus round the corner from the end of South Road, although yours is in better condition!

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A variation on a theme - City Road, near the cemetery.

Sheffield Corporation Tramway

Charles Ross, Heeley.

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A variation on a theme - City Road, near the cemetery.

Sheffield Corporation Tramway

Charles Ross, Heeley.

SH link .. Charles Ross Heeley

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There used to be pale green cylindical cast iron transformer boxes dotted around, though I can't now recall the location of a single one. They were about 4 feet in diameter.

Maybe some have have survived?

Not like this section box, much bigger:

attachicon.gifsection box.png

edited some time later... here's what I mean:

http://www.picturesheffield.com/frontend.php?action=zoomWindow&keywords=Ref_No_increment;EQUALS;s15476&prevUrl=

I don't think that these circular boxes were connected with the old tramway system but were part of the early mains electrical distribution system.

They were the early examples of the rectangular cast iron boxes about 6 ft high and 2 ft wide by about 18 inches deep that used to stand on many street corners. They contained 3 phase banks of fuses with isolators down the side.

They have been mostly replaced (the rectangular ones) with section boxes let into the pavement or done away with as part of the "solidification" of the distribution network.

The circular ones have been left as museum pieces although I don't know if they are still active. There are several still about, one in Ranmoor and another at Highcliffe Road in Greystones , the Google Streetview image of the Greystones one is attached.

HD

And here for your further delectation is another at the top of Storth Lane.

Note how they have evolved a system of blending in to the background. :)

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The question is where in the Walkley area were the substations? These would have normally been small buildings about the size of a large garage, similar to the domestic supply substations still seen all over the place today.

Andy.

Old system tramways substations seem to normally have formed part of larger YEB distribution substations. They would need additional space to accomodate transformers, mercury arc rectifier sets or possibly motor generator sets to provide the DC traction supply.

There was a tramways/YEB substation at the junction of Bradfield Road / Hawkesley Avenue. As a kid I used to peer through the louves at the MAR's in operation.

This would serve the system up to the Middlewood and Malin Bridge terminii.

There is a larger than normal substation at the top of Upperthorpe just below Commonside and this could certainly provide power to South Road terminus and would be ideally situated for the heavy loading on Barber Road.

HD

Edited by hilldweller

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I don't think that these circular boxes were connected with the old tramway system but were part of the early mains electrical distribution system.

Yes, agreed, I don't think trams ever went round Highcliffe Road. They are marked on the 1950's OS maps as El P.

This thread got me to realise how little I knew about the first electric tramways and electricity supplies, so some info below. The tramway supplies were initially DC and kept totally separate from domestic supplies (though Kelham Island and Neepsend were linked in 1914 in the interests of economy).

1878 first illumination of a football match by electricity (Messrs Tasker) at Bramall Lane

1878 Sheffield United Gas Light Co. dismisses electric lighting – too bright (only arc lights available)

1881 John Tasker creates “Sheffield Telephone Exchange and Electric Light Company”

1888 Electric light used to illuminate the construction of Lodge Moor hospital

1892 S.T.E.E.L Co ordered to supply electricity to Borough of Sheffield so all supplies now to be underground – telephone interest sold to the National Telephone Co. and electricity interests became “Sheffield Electric Light and Power Co”

1894 New improved generating station in Sheaf Street opened

1896 New offices for S.E.L.P.Co opened in Commercial Street

1896 Sheffield Tramway Co lease on corporation owned tracks expires – tramways to be operated by the Corporation

1898 City Council formed an Electric Light Committee

1899 Council bought the S.E.L.P. Co.which had 688 customers and supplied 2300 kilowatts

1899 the Kelham Island generating plant for tramways was built – it was to be separate from the Corporations new electric lighting generating station. Three marine boilers (planned to expand to 7) were specified to avoid the need to build a chimney. These drive 3 British-Thomson-Houston railway type generators, each with a rated output of 225 kilowatt / 500v (tramcar voltage)

1899 First electric tramways in Sheffield opened (Nether Edge – Tinsley and Ecclesall Road, Pitsmoor, Park, Walkley)

1904 Neepsend power station opened

1907 First electric street lighting (South Street Moor and Pinstone Street)

1908 Electric street lighting extended as far as Wicker arches

1910 Electric Furnace installed at Edgar Allen, Tinsley

1917 Blackburn Meadows power station opened

1923 domestic coin meters became available

1927 1508 electric street lamps in place

1948 nationalisation moved control to British Electricity Authority

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Thanks Edmund!

..telephone interest sold to the National Telephone Co. and electricity interests became “Sheffield Electric Light and Power Co”..

I have uploaded a manhole cover from the light and power company in my 'Drainspotting' thread in 'Sheffield History Chat'. I only know of one so i have an idea of a date now. I also have a photo of a 'National Telephone Company' cover still in situ in Attercliffe which i will upload soon.

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Kenneth Gandy's book Sheffield Corporation Tramways, carries some slightly different information about the Kelham Island Generating Station.

It says the first generator was able to support 64 cars and a second 500kW generator a further 51 cars. Capacity was added as required.

The nominal generation voltage was 650 volts.

Even with the small motors on the first trams (2 X 25 HP) the volt drop would mean that Kelham Island could only support trams within a limited radius of the station. As the system expanded they would have to draw power from the Corporation system.

I worked in the early sixties at Metro-Vicks (AEI) Traction and we were still repairing tram motors at that time. They were wound for a nominal operating voltage of 600 volts allowing for 50 volts loss in the supply system.

I was amazed to observe on the modern trams that the driver's supply voltmeter shows swings between about 600 & 1000 volts depending on wether the tram is drawing current or re-genning back into the catenary.

The modern trams have 4 motors totalling 1108 kW and the supply is a nominal 750 volts DC.

HD

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Kenneth Gandy's book Sheffield Corporation Tramways, carries some slightly different information about the Kelham Island Generating Station.

It says the first generator was able to support 64 cars and a second 500kW generator a further 51 cars. Capacity was added as required.

The nominal generation voltage was 650 volts.

Even with the small motors on the first trams (2 X 25 HP) the volt drop would mean that Kelham Island could only support trams within a limited radius of the station. As the system expanded they would have to draw power from the Corporation system.

I worked in the early sixties at Metro-Vicks (AEI) Traction and we were still repairing tram motors at that time. They were wound for a nominal operating voltage of 600 volts allowing for 50 volts loss in the supply system.

I was amazed to observe on the modern trams that the driver's supply voltmeter shows swings between about 600 & 1000 volts depending on wether the tram is drawing current or re-genning back into the catenary.

The modern trams have 4 motors totalling 1108 kW and the supply is a nominal 750 volts DC.

HD

I totally agree about the limited range a power station or sub ststion could supply because of the DC voltage drop. It could probably only supply a couple of miles either side of the point it was connected to the overhead at the very most.

The last traditional British tramway (except for Blackpool) closed in 1962 (Glasgow). Could it be possible the motors you were repairing in the 60s were actually from trolleybuses, which continued until about 1970-71 ish? Trolleybus motors were very similar to tramway motors, running at 500 - 650v DC, depending on the age of the motors concerned.

The early electric trams would have run on a nominal 500v, but later models like the Roberst cars would have been designed for 550-600v. However the equipment was robust enough to take quite a bit of over powering. Blackpool & Fleetwood 'Rack 2' at Crich is one tram I know is a 500v car, but has run quite happily on 550-600v without any modification.

The number of cars out on the system and weather or not they were loaded, empty or had their internal lights on would actually make a considerable difference on the line voltage at any given time.

Supertram does indeed run at 750v and has multiple 'trolley wires' in places so there is enough contact area with the pantograph to pull the required amps. I'm not sure if thois would be too high a voltage for traditional trams to put up with, but I do know they had a traditional Berlin tram for a while in use as a works car.

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Could it be possible the motors you were repairing in the 60s were actually from trolleybuses, which continued until about 1970-71 ish? Trolleybus motors were very similar to tramway motors, running at 500 - 650v DC, depending on the age of the motors concerned.

Thinking back I have a vague memory of a load of Glasgow tram motors arriving for assessment. I think the idea was to select the most servicable ones for refurbishment. Perhaps they were for preservation trams. We had a sectioned Glasgow tram motor in our training workshop.

Strangely enough I don't ever remember a trolley bus motor, perhaps they were made by our sister company BTH at Rugby.

I do remember we made hundreds of small motors for battery vehicles such as milk floats and fork lifts.

Battery electric vehicles were very popular in the sixties and mostly ran at about 72 / 80 volts.

All good stuff, I could still undercut a commutator or use a comm-stone.

Concerning the running of an old tram on the modern Supertram system, I should think the inabilty of the old systems to deal with fault currents would be as big a problem as the higher operating voltage.

Fault energy levels on the modern system must be of the order of Megawatts and the old circuit breakers in the end cabs of the old trams would disappear in a flash of flame in the event of a short circuit.

HD

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Thinking back I have a vague memory of a load of Glasgow tram motors arriving for assessment. I think the idea was to select the most servicable ones for refurbishment. Perhaps they were for preservation trams. We had a sectioned Glasgow tram motor in our training workshop.

Strangely enough I don't ever remember a trolley bus motor, perhaps they were made by our sister company BTH at Rugby.

I do remember we made hundreds of small motors for battery vehicles such as milk floats and fork lifts.

Battery electric vehicles were very popular in the sixties and mostly ran at about 72 / 80 volts.

All good stuff, I could still undercut a commutator or use a comm-stone.

Concerning the running of an old tram on the modern Supertram system, I should think the inabilty of the old systems to deal with fault currents would be as big a problem as the higher operating voltage.

Fault energy levels on the modern system must be of the order of Megawatts and the old circuit breakers in the end cabs of the old trams would disappear in a flash of flame in the event of a short circuit.

HD

I know when Blackpool were testing a newly built one man car (either 761 or 762, i don't remember which it was) in the early hours one morning it popped the onboard breakers. The engineers reset them and a few seconds later they popped again at Gynn Square. It turned out the tram couldn't handle the 750v it was getting due to there neing no other trams out on the system at that time!

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Another different example on Newhall Road, Brightside.

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Thinking back I have a vague memory of a load of Glasgow tram motors arriving for assessment. I think the idea was to select the most servicable ones for refurbishment. Perhaps they were for preservation trams. We had a sectioned Glasgow tram motor in our training workshop.

Concerning the running of an old tram on the modern Supertram system, I should think the inabilty of the old systems to deal with fault currents would be as big a problem as the higher operating voltage.

HD

Don't forget that until the 1970's the Glasgow Underground was still using motor that were identical to the ones used on the trams, indeed when the tramway closed many parts were re-used on the underground. It wasn't until 1976 (?) that the old underground stock was retired when the system was re-built and became known as the 'Clockwork Orange'.

I don't think the Supertram Belin 4-wheeler made it out onto the main line. In the depot it set off like a rocket on first notch running on nearly 200V more than it was designed for!, I think they must have set the breakers specially.

NL

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I totally agree about the limited range a power station or sub ststion could supply because of the DC voltage drop. It could probably only supply a couple of miles either side of the point it was connected to the overhead at the very most.

The last traditional British tramway (except for Blackpool) closed in 1962 (Glasgow). Could it be possible the motors you were repairing in the 60s were actually from trolleybuses, which continued until about 1970-71 ish? Trolleybus motors were very similar to tramway motors, running at 500 - 650v DC, depending on the age of the motors concerned.

The early electric trams would have run on a nominal 500v, but later models like the Roberst cars would have been designed for 550-600v. However the equipment was robust enough to take quite a bit of over powering. Blackpool & Fleetwood 'Rack 2' at Crich is one tram I know is a 500v car, but has run quite happily on 550-600v without any modification.

The number of cars out on the system and weather or not they were loaded, empty or had their internal lights on would actually make a considerable difference on the line voltage at any given time.

Supertram does indeed run at 750v and has multiple 'trolley wires' in places so there is enough contact area with the pantograph to pull the required amps. I'm not sure if thois would be too high a voltage for traditional trams to put up with, but I do know they had a traditional Berlin tram for a while in use as a works car.

The information from Wikipedia is as follows.

The National Grid was not as developed as it is now and so the Corporation set out to generate the required current - the Corporation became the local domestic and industrial electricity supplier. A power station was built for Sheffield Corporation Tramways on Kelham Island by the river Don between Mowbray Street and Alma Street.[1] Feeder cables stretched from there to the extremities of the system, covering over 40 miles of route.

I do wonder how they got round the line resistance may be it went out as AC and the boxes, mentioned above, using mercury rectifiers then fed the DC required to the overhead system.

jiginc

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I think that many things published on Wikipedia need to be taken with a pinch of salt. I've just been comparing the article with the figures quoted in Kenneth Gandy's Sheffield Corporation Tramways book and there seem to be many differences.

I've been doing some "back of *** packet" calculations and assuming copper supply cables of 1 square inch cross section (625 mm2) and a maximum of two trams each with 2X50 HP motors, then the volt drop would be around 20 volts for each kilometer of route or around 32 volts per mile.

Assuming that the initial supply voltage was around 650 volts and the trams would operate with reduced speed and power down to at least 500 volts I suppose that energising of the entire routes was at least possible if not very efficient.

When the Kelham Island Generating Station shut down in the 1930's the supplies were then taken from the Sheffield Corporation Electricity Department and eventually YEB at different points around the system.

As far as I know the Kelham Island Generating Station had only DC generation. The green boxes (section boxes) contained large open knife switches to isolate sections of overhead and a telephone with it's own line back to the control room.

HD

Hell's teeth, it wont even let me print phag now. Who's running this show ? Mary Whitehouse ? The other day it changed stop-**** to wee wee tail.

Edited by hilldweller

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I found another of these covers opposite Tesco on Infirmary Road today, very near to the current tram stop. It is the same as the pic in #21.

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