When Were The High Voltage Cables Laid Under London's Towpaths

[alan_fincher]

An odd request this!

 

Whilst engaged by some of the members of the London branch of the NBTA (National Bargee Travellers Assosciation), they were making a lot of claims about the loss of much of London's towpaths as a result of the high voltage cables now laid underneath them.

 

They were adamant much of this work has only been carried out within the last 10 years.

 

As far as I know, this is complete nonsense, and I believe the laying of most, (possibly all) of these cables was done around the late 1970s, or possibly early 1980s.

 

A page on the CRT website says this....

Canals are wonderfully versatile, and in 1979 the British Waterways Board allowed underground electricity cables to be laid in a trough below the towpath between St John’s Wood and City Road. Pumped canal water is used to cool these high voltage cables, which now form part of the National Grid.

 

This sounds about right to me, but is anybody able to confirm for certain that this date is correct, and, if so, by what date the work was completed.

 

Have there been significant further schemes of this type since, and if so when and where, please?

 

Or are the NBTA just making statements that have no basis in actual facts?

[Tiggs]

Why would they close the towpath even if it did have high voltage cables under it?

[alan_fincher]

Why would they close the towpath even if it did have high voltage cables under it?

 

Loss of the tow-paths for moorings, (because there is nothing to tie up to, and no safe way of putting in stakes), not actual "closure of the towpaths".

 

(And yes, I know some suggest use of a Hilti gun to add your own fixtures, but I'm happy to believe not many people actually do this).

 

NBTA are claiming much tow-path mooring has been lost because of this in the last decade.

 

I don't think that's right, but maybe some has - hence my question.

[David Mack]

I moved to London in late 1980 and I remember the cables were in, but they were still finishing off the building work at the pumping station opposite the Pirate Castle. So your date of late 70s/early 80s sounds about right to me.

 

The installation of the cables, with their concrete covers did rather limit the ability to bang mooring spikes into the towpath. As a result the London Branch of IWA lobbied BW to get bollards fitted at each of the locks, which I think CEGB paid for.

[zenataomm]

I was in London, moored at Lisson Grove around 1980, and they were closing off the odd bit of towpath for snagging.

[AMModels]

I would suggest the NBTA are making assertions to back their agenda rather than grounded in facts.

 

 

edited because it took an hour to post and my first query had been answered.

Edited June 22, 2016 by AMModels

[Derek R.]

I worked at London Zoo in the sixties flanking the cut, and the towpath was a closed area to all and sundry unless on maintenance. There were locked gates beneath several bridges that crossed the canal primarily to prevent people from bunking in to the Zoo free. Back then, the section of canal from Cumberland Basin to beyond the Zoo boundary was heavily overgrown, trees almost meeting each other across the cut. Then the Zoo Waterbus service was begun, and a lot of work began cutting back and piling (or repairing piles). The bit about water cooled cables sounds highly improbable. I'd left by the time cables were installed, but would guess in the seventies, though fibre optics may have been laid more recently.

[OldGoat]

Derek R., on 23 Jun 2016 - 08:53 AM, said:

I worked at London Zoo in the sixties flanking the cut, and the towpath was a closed area to all and sundry unless on maintenance. There were locked gates beneath several bridges that crossed the canal primarily to prevent people from bunking in to the Zoo free. Back then, the section of canal from Cumberland Basin to beyond the Zoo boundary was heavily overgrown, trees almost meeting each other across the cut. Then the Zoo Waterbus service was begun, and a lot of work began cutting back and piling (or repairing piles). The bit about water cooled cables sounds highly improbable. I'd left by the time cables were installed, but would guess in the seventies, though fibre optics may have been laid more recently.

 

Methinks the water cooling is a bit of an urban myth. Eon is laying HV cable underground near me and they are certainly not water cooled.

It's the fibre optic and other communication cables under parts of the GU that may be what NTBA (mistakenly) are going on about as in some places there was no room to lay the cables away from the towpath.

[GUMPY]

Even the fibre optic cables were laid the best part of 20years ago

[tree monkey]

Methinks the water cooling is a bit of an urban myth. Eon is laying HV cable underground near me and they are certainly not water cooled.

It's the fibre optic and other communication cables under parts of the GU that may be what NTBA (mistakenly) are going on about as in some places there was no room to lay the cables away from the towpath.

National grid underground services tend to be oil cooled, voltages from 275 to 400, the local distribution networks don't routinely cool their underground network, voltages from 11 to 132KV

[magnetman]

I was thinking they may be confused about the fibre optic stuff as Oldgoat and Loddon have already mentioned but this was mid nineties I believe.

 

Sounds like bs to me.

 

The other suggestion I heard was to use Pitons. When coming through Regents park recently I noticed this could actually be done but I wonder if CRT would allow it?

 

Pitons are those little metal wedges used by climbers which they hammer into cracks in rocks. I think judicious use of these may be successful. It was Chris Pink who suggested this in a thread I started about using a nail gun

Edited June 23, 2016 by magnetman

[Pluto]

National grid underground services tend to be oil cooled, voltages from 275 to 400, the local distribution networks don't routinely cool their underground network, voltages from 11 to 132KV

However, if the canal leaks they could be water cooled, he said shockingly.

[rjasmith]

Ok I can add to this as an ex CEGB (Transmission Division) and then National Grid engineer! Although I should also say that I was not personally involved in this actual project. If Ryeland (another ex CEGB member of CWDF) is reading this he might also remember these dates.

 

During 1976 I lived in Noel Road, Islington very near the bit of Regents Canal where the 275kV cable circuit was laid in the towpath between St Johns Wood substation (off Lodge Road) and City Road substation next to the canal basin.

 

The work was certainly underway in 1976 and I remember trying to walk carefully along by the top edge of the new, but still empty, cable troughs.

 

I had not long met my then to be wife and we were on a hot summers day walk to visit Victoria Park and buy ice creams! When we got there we found we only had enough money for one between us!

 

I can't remember precisely but I expect the job was finally commissioned by 1979. Because of the complexities of this sort of project it would have taken this length of time.

 

For those who doubt the use of water cooling for these cables I can certainly confirm that they had this. Supergrid (275 and 400kV) underground cables are invariably water cooled. The system uses separate water cooling pipes run alongside the cables with associated pumping and cooling stations along the route. CEGB had to build one of these opposite the "Pirates Castle" in a matching style to meet planning approval. I can remember pictures of the two buildings being much trumpeted in our house rag "Power News" at the time!

 

More recently there has been further supergrid reinforcement of St Johns Wood and City Road to bring in 400kV circuits to a new City Road North s/stn but I don't know whether this has involved more towpath cable work as it has happened since I retired.

 

Equally canal towpaths may have been used elsewhere in London for lower voltage (non supergrid) cables but if they have these installations will be much smaller in scale and won't have the complication of water cooling so will probably not be so invasive of the towpath space.

 

Richard

 

 

Edited June 23, 2016 by rjasmith

[rjasmith]

Here's a link to an NG publicity document about more recent new supergrid cable projects. All of these are in dedicated deep tunnels with air blown cooling and therefore don't involve canal towpaths!

 

Richard

[Lady Muck]

Alan, I think they got mixed up, it was mentioned (possibly by yours truly) that some of the towpath, which used to have a grass verge, which you could put pins in, was paved, it was a stretch from Islington to Hackney and it happened around five or six years ago. The NBTA then confabulated this into the whole lot being done recently.

Yes it annoyed me, I think it's important to have the facts, not make things up. No one could predict how busy it was going to get, so to claim it was done deliberately. No.

But I note, around the same time, the whole stretch along Victoria Park, where it wasn't possible to moor, when they drained and rebuilt the bankside, they put rings in.

I think we've a lot more moorable space than we had, Theres good reason that some bits dont have rings. I personally feel the stretch along Regents Park is quite narrow. The trip boats are deep draughted. If you allowed mooring down there (especially widebeams), if they didn't dredge, you'd have problems.

Edited June 23, 2016 by Lady Muck

[tree monkey]

Ok I can add to this as an ex CEGB (Transmission Division) and then National Grid engineer! Although I should also say that I was not personally involved in this actual project. If Ryeland (another ex CEGB member of CWDF) is reading this he might also remember these dates.

 

During 1976 I lived in Noel Road, Islington very near the bit of Regents Canal where the 275kV cable circuit was laid in the towpath between St Johns Wood substation (off Lodge Road) and City Road substation next to the canal basin.

 

The work was certainly underway in 1976 and I remember trying to walk carefully along by the top edge of the new, but still empty, cable troughs.

 

I had not long met my then to be wife and we were on a hot summers day walk to visit Victoria Park and buy ice creams! When we got there we found we only had enough money for one between us!

 

I can't remember precisely but I expect the job was finally commissioned by 1979. Because of the complexities of this sort of project it would have taken this length of time.

 

For those who doubt the use of water cooling for these cables I can certainly confirm that they had this. Supergrid (275 and 400kV) underground cables are invariably water cooled. The system uses separate water cooling pipes run alongside the cables with associated pumping and cooling stations along the route. CEGB had to build one of these opposite the "Pirates Castle" in a matching style to meet planning approval. I can remember pictures of the two buildings being much trumpeted in our house rag "Power News" at the time!

 

More recently there has been further supergrid reinforcement of St Johns Wood and City Road to bring in 400kV circuits to a new City Road North s/stn but I don't know whether this has involved more towpath cable work as it has happened since I retired.

 

Equally canal towpaths may have been used elsewhere in London for lower voltage (non supergrid) cables but if they have these installations will be much smaller in scale and won't have the complication of water cooling so will probably not be so invasive of the towpath space.

 

Richard

 

 

Thats intresting thank you, I was under the false impression oil was used not water.

Live and learn

[Tam & Di]

We had several craft on hire to Balfour Kilpatrick for this work, and bought a joey they owned from them at the end of the job. My records note it had BCN no.2267 and we bought it May 1984, so the London end of the job must have been pretty well complete then.

 

The towpath bearing these cables at Park Royal started to collapse in about 1986, and we had 3 canal size lighters (Cam, Ben Cruachan and Ben McDhuie on hire there for several years while the insurance liability was worked out. They were sunk alongside the bank to prevent further collapse and had become quite a water feature by the end of the job - it's a wonder some nature conservation group did not put a protection order on them

 

Tam

[David Mack]

Thats intresting thank you, I was under the false impression oil was used not water.

Live and learn

 

Richard might like to confirm, but I think that high voltage cables of that era are oil filled (to provide the necessary electrical insulation), but water cooled. The oil in the cables is maintained with external header tanks. Hence there is a need for both oil and water plumbing systems associated with the cables.

 

With advances in materials technology new high voltage cables don't need to be oil filled, but may still need cooling.

[matty40s]

 

Richard might like to confirm, but I think that high voltage cables of that era are oil filled (to provide the necessary electrical insulation), but water cooled. The oil in the cables is maintained with external header tanks. Hence there is a need for both oil and water plumbing systems associated with the cables.

 

With advances in materials technology new high voltage cables don't need to be oil filled, but may still need cooli

I think this is correct.

There was a closure/stoppage a couple of years ago where one of the cables became ruptured and oil contaminated the canal on the Paddington Arm

[Tim Lewis]

National grid underground services tend to be oil cooled, voltages from 275 to 400, the local distribution networks don't routinely cool their underground network, voltages from 11 to 132KV

 

The cables under the Regents Canal towpath are definately water cooled, there area number of locations where you can see the outfalls. Also it is not unusual to see water fountains along the towapth where the pipes leak.

 

Have often heard said that the installation of the cables killed off barge traffic on teh Regents as the towpath tractors could not operate whilst the cable works were in progress.

 

There have been a number of towpath closures over recent years whist teh towpath has had to be reinforced to protect the cables.

 

Tim

[Martin Megson]

The following extract from the London Canals site seems to confirm the 1970's with additional work in 1985.

 

During the 1970's a huge scheme to install electricity cables underneath the towpath between Acton power station and Islington got underway. Despite not actually being part of the towpath improvement schemes, it did contribute greatly towards a better environment for walking. By the mid 1970's people were easily able to walk westwards from Little Venice as far as the Grand Junction Arms in Harlesden on a hard surface towpath. Unfortunately this scheme introduced that awful contraption which still stands to this day above the eastern portal of Maida Hill tunnel. This 'contraption' carries the electricity cables down to the towpath after travelling under the pavements between Blomfield Road and Aberdeen Place.

In 1985 the towpath was further improved and widened by the electricity generating board. Much of the canal towpath between Harlseden and East London is its responsibility as well as Canal & River Trust's.

[J R ALSOP]

As others have said, I have worked with Wood Hall & Heward providing work boats to Balfour Beaty who 5 years ago renewed the water pumps and switching gear for the cooling of the oil filled cables.As a aside someone told me the GEC (at the time) took over the control of the towpaths where the cables run Acton to end of Hertford Union.

[tree monkey]

Ace thread, ive learnt loads

[jonesthenuke]

I worked for CEGB starting in early 1980s and the work was complete then. I remember seeing it on TV (probably Tomorrow's World) and would guess it was mid to late 1970s.

 

The cables may be water cooled but they will be oil insulated (paper insulation filled with pressurised oil within a metal outer jacket). The oil is essentially static within the cable thus does not actively cool the cable by flowing.

[alan_fincher]

Ace thread, ive learnt loads

 

Yes, I agree!

 

I thought I might be lucky if I found someone who knew something about it, but CWDF has come up trumps with lots of knowledge on the subject.

 

Next time NBTA try quoting their version of things at me, I will be even more forthright in my replies.

 

Actually I think LM is probably correct - I suspect mooring is easier in more places in London now than it was 10 years ago, so not what they are claiming at all.