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Journey by Journey => London to Reading => Topic started by: stuving on January 23, 2021, 08:12:45 pm



Title: The end of an era - or at least a gas holder
Post by: stuving on January 23, 2021, 08:12:45 pm
SGN have been given approval (planning application number 201269) to take down the last of the gas holders in the centre of Reading (at Kennet Bridge). It was number 4 - for no obvious reason, even when you read the site history among the copious documentation with the application. Its two neighbours came down a while back, and the two newer ones across the Kennet were razed in 2015-6.

Trains go by close to it (especially on the Waterloo line), and the picture shows it from the old station footbridge. It's not easy to see from the new station, and new buildings and the obscured windows mean it is getting even harder to see. While some will be sad to a familar landmark go, it's hard to justify keeping it, especially to whoever owns the land. Not an easy thing to repurpose for any use of value, and once it gets so rusty it might fall down it can no longer just be left alone.


Title: Re: The end of an era - or at least a gas holder
Post by: stuving on January 24, 2021, 12:24:57 am
I said the document set was copious, and so it is - though a bit less so than it looks, since the 257-page methods document includes a lot of others as appendices. It is, however, likely to be useful to anyone who happens to have an old gas holder cluttering up their garden and wondered how to get rid if it.

On thing I can't see much about is contamination of the ground, which is a surprise. Gas works are notorious for leaking nasty liquids into the ground, and making the ground fit to build houses on usually calls for thorough washing. They say they won't break up the hard surfacing at all, just remove all the water and sludge from the pit under the gas holder and fill it up. Could it be that remediation for a future use will be the developer's responsibility? Some of the demolition documents include plans of the housing  proposed, so the future of the site is already decided (subject to planning).

And it turns out that there was an earlier planning application (190627) for the whole redevelopment including the demolition, but that part has now been taken separately (and done by SGN not the developer). There is indeed a "Geo-environmental Site Assessment" by WSP that is mainly about contamination - 715 pages of it! And even then it doesn't choose any remediation plan - it recommends a further ground investigation. To be fair, the original survey was for continued commercial use, not housing. And the Environment Agency suggest any decision should insist on such an approach.

There is also a study by SGN into how the thing might be retained if its cuteness won't allow its removal. Evidently they didn't convince themselves or RBC it was worth it. And loads of comments, mostly agin it (as usual).

One important step in the demolition plan (but with no fixed timing) is putting up a 30 m tall pole. Or rod? In this case, it's described as a "Peregrine Falcon Perch", for which WSP have provided a draft specification (with details of the perch box).



Title: Re: The end of an era - or at least a gas holder
Post by: CyclingSid on January 24, 2021, 08:56:13 am
Presumably not considered viable to do a conversion like the one on the Regents Canal.


Title: Re: The end of an era - or at least a gas holder
Post by: bobm on January 24, 2021, 09:39:46 am
As a child I lived within walking distance of the gas holders in Reading and on occasions my father would drink in a pub by the canalside while we fed the ducks or watched the trains go by.

During the brief time it was possible last year I took a trip back.

(http://www.mbob.co.uk/rforum/gas1.jpg)

(http://www.mbob.co.uk/rforum/gas2.jpg)

(http://www.mbob.co.uk/rforum/gas3.jpg)

(http://www.mbob.co.uk/rforum/gas4.jpg)


Title: Re: The end of an era - or at least a gas holder
Post by: stuving on January 24, 2021, 10:06:17 am
Presumably not considered viable to do a conversion like the one on the Regents Canal.

There is - inevitably - a document about that. Basically, its landmark status depends on its current site, and it's currently only a framework. If replaced by a solid building it would be too massive, and if left empty too expensive of land for the site revenue to recover (unlike Kings Cross). And it's not listed as of historical significance - it's Edwardian and of a standard design.

I had a look at the listing for "The Triplet", now "Gasholders" by St Pancras Dock. This describes its building at what is now Pancras Square, but with no map or pictures (or links) for its original setting. I guess it's listed as an engineering structure, not for its surroundings. It also dates its dismantling to 2001, while Google Earth shows it was long gone by then as the extension of St Pancras Station northwards (towards France?) got underway.


Title: Re: The end of an era - or at least a gas holder
Post by: Electric train on January 24, 2021, 05:39:25 pm

On thing I can't see much about is contamination of the ground, which is a surprise. Gas works are notorious for leaking nasty liquids into the ground, and making the ground fit to build houses on usually calls for thorough washing. They say they won't break up the hard surfacing at all, just remove all the water and sludge from the pit under the gas holder and fill it up. Could it be that remediation for a future use will be the developer's responsibility? Some of the demolition documents include plans of the housing  proposed, so the future of the site is already decided (subject to planning).

Gas making did generate a large amount of toxic biproducts, this was compounded in the 1960's when we moved away from Town Gas to Natural Gas, when the retort house, gas cleaners, cold tar storage etc was decommissioned all or the asbestos and other toxic waste was dumped into the decommissioned gas holder tank wells, some of the holders were used purely for cleaning and cooling and storage as such.

National Grid which now own these sites cannot just pass a contaminated site onto a new owner; and example of what is done is Southall Gas works, National Grid join with a developer, Berkley Homes in the case at Southall.   The deal is National Grid get to dispose of the land the cost of decontamination is covered by the profit from the property sales plus NG also gain some money in the process

The demo of the holder No4 is the first stage, the clearing of the ground of contamination will be dependent on planning consent


Title: Re: The end of an era - or at least a gas holder
Post by: eightonedee on January 24, 2021, 09:02:35 pm
For more on the gasworks and gas supply in Reading see

https://www.readingmuseum.org.uk/blog/goodbye-gasholders

The Peregrine Falcon platform has been provided because the old gas holder was chosen as a nest site by a pair. Sometimes I have seen them over or around the station (but not recently).

The position regarding remediation of the contamination is that the starting point is that liability lies with the polluter - here probably NG as successor to British Gas who in turn acquired the assets, undertakings and liabilities of the old town gas companies on nationalisation. Sometimes liability is passed on by agreement to the developer, but it should be the case that they will have to satisfy statutory authorities that satisfactory remediation has been completed to both render the new development safe to occupy and to safeguard against the future leakage of contaminants, sometimes involving very expensive removal, so as to discharge planning conditions and (in the case of residential development) to satisfy the building guarantee company (like the NHBC) to enable the new homes to be sold by satisfying the requirements of mortgage lenders.

Not all the "nasty bits" were buried on site. Nearly 30 years ago I was involved with a filled quarry site outside a substantial southern town which (after filling) was used by a contracting company as a depot. The company became insolvent, but its receivers discovered when preparing to sell it that the remains of the town's gasworks were buried underneath, and there was a river nearby into which who knows what might be seeping.



Title: Re: The end of an era - or at least a gas holder
Post by: stuving on January 24, 2021, 11:18:43 pm
The peregrines are reported to have been roosting, but not nesting. Quite likely there's no big enough flat surface for a nest.

I'm not sure when the distribution networks were separated off for regulation as a distinct entity, but it must have been before 1996. Coal gas production and storage was I think always local, and the national transmission network only arrived with natural gas. I found an NGN report saying they had a regulatory target to demolish 23 of their 47 remaining holders by 2020

So when the local GDN was acquired by SSE (creating SGN), it does not look like any residual liabilities were left with BG/NG/Lattice/Transco. I think the developers shoulder the contamination liability (after agreed work by SGN, and for a consideration) since they will in any case have to do so in any contract of sale. Since these are all flats, the may not be sold freehold anyway.

The Environment Agency don't seem keen to see the whole site dug up and washed. I think being next to the Kennet makes a big difference here, and leaching into the river is the biggest concern. Hence for example they ask for a condition that no surface water disposal by infiltration is to be allowed. But this isn't likely to be one of the worst sites, as this gas works wasn't built until after 1880 and in any case that was under the houses already built and up this end was just gas holders.


Title: Re: The end of an era - or at least a gas holder
Post by: CyclingSid on January 25, 2021, 07:00:45 am
When they built housing on the rest of the old Reading gas works they spent a considerable time on site preparation. I don't know how much they took away and dumped elsewhere.


Title: Re: The end of an era - or at least a gas holder
Post by: eXPassenger on January 25, 2021, 09:13:57 am
Quote
I'm not sure when the distribution networks were separated off for regulation as a distinct entity, but it must have been before 1996. Coal gas production and storage was I think always local, and the national transmission network only arrived with natural gas. I found an NGN report saying they had a regulatory target to demolish 23 of their 47 remaining holders by 2020

In the South West, and I assume elsewhere, there was an intermediate phase.  Coal based town gas works were closed and replaced by oil based plants at Avonmouth (Seabank) and Plymouth (Breakwater) with a regional gas transmission system.  Seabamk is now a CCGT power station.


Title: Re: The end of an era - or at least a gas holder
Post by: stuving on January 25, 2021, 01:59:35 pm
Quote
I'm not sure when the distribution networks were separated off for regulation as a distinct entity, but it must have been before 1996. Coal gas production and storage was I think always local, and the national transmission network only arrived with natural gas. I found an NGN report saying they had a regulatory target to demolish 23 of their 47 remaining holders by 2020

In the South West, and I assume elsewhere, there was an intermediate phase.  Coal based town gas works were closed and replaced by oil based plants at Avonmouth (Seabank) and Plymouth (Breakwater) with a regional gas transmission system.  Seabamk is now a CCGT power station.

Yes, the distribution network must have been built up over a long period, starting with supply to nearby towns and villages and moving gas works out of city centres. I expected any switch from coal to oil as feedstock to be quite late, but it turns out it was later than I thought. In fact, starting in 1964 for Seabank and 1966 for Breakwater, both ran for only ten years before being shut down in favour of natural gas.

Obviously very specific information like that must come from somewhere, and (thanks to Google and the interweb) that source is a little magazine called Historic Gas Times, from the Institution of Gas Engineers and Managers. Just one issue - the 100th - is available free (https://www.igem.org.uk/_resources/assets/attachment/full/0/37822.pdf), and by chance contains a history of the growth of the industry and infrastructure into the South Western Gas Board.


Title: Re: The end of an era - or at least a gas holder
Post by: Electric train on January 25, 2021, 02:56:29 pm
Here https://discovery.nationalarchives.gov.uk/details/r/d1078240-ba49-4b90-9298-bb7f30968196 is a history of UXBRIDGE, MAIDENHEAD, WYCOMBE & DISTRICT GAS COMPANY, the article shows how the Town Gas networks evolved from 1895 and into privatisation.

Its clear that local companies merged and concentrated gas making at a number of key sites obviously for efficiency, it does show that Towns across quite a large area were networked.


Title: Re: The end of an era - or at least a gas holder
Post by: CyclingSid on January 26, 2021, 06:52:56 am
There is a planned exhibition (subject to the various current problems) at the Riverside Museum part of Reading Museum in September of artworks related to the gas holder.


Title: Re: The end of an era - or at least a gas holder
Post by: stuving on March 08, 2021, 06:46:00 pm
Peregrines are the new newts! From the BBC (https://www.bbc.co.uk/news/uk-england-berkshire-56246744):
Quote
Peregrine falcons halt Reading gas holder demolition
The demolition of a gas holder has been halted after peregrine falcons were spotted on the landmark.

Preparation work to demolish Gas Holder No.4 in Alexander Turner Close, Reading had been due to start as part of plans to turn the site into a block of flats.

Birdwatcher Leslee Barron said it was important an independent survey now determined if the birds were nesting.

Gas distribution firm SGN said the work has been postponed until a later date following an ecological survey.

An independent ecologist last week observed peregrine falcons on the site, owner SGN said.

Spokesman Dan Brown said: "We'll continue to closely monitor the site and liaise with the ecologist on revised plans to dismantle our redundant gas holder at a later date."

SGN did not state if the birds had been found nesting or not when asked.

Peregrine falcons are protected under The Wildlife and Countryside Act.

If active nests are recorded demolition work can only proceed once all young have fledged the nest and the holder is no longer in use, Reading Borough Council said.

Ms Barron said even if the survey last week did not find a nest, the birds could still subsequently make a nest site.

"If they can prove the peregrine falcons are not nesting on the holder I'd be happy with that, because the welfare of the birds at this is point is far more important than the gas tower."

Expressing her sadness at the holder making way for 130 flats, she added: "It's part of our landscape and I think it's just a beautiful old chunk of metal."

Reading Borough Council said the local authority's biodiversity consultant has since reviewed the situation and does not think peregrine falcons are nesting at this time.

Although the local authority said it has advised the developers to cease work to allow an ecologist to fully assess the situation.

I rather liked this bit: "SGN did not state if the birds had been found nesting or not when asked." Presumably they use outside contractors for that sort of specialised work.


Title: Re: The end of an era - or at least a gas holder
Post by: Bmblbzzz on March 08, 2021, 10:45:22 pm
I remember my geography teacher, sometime in the 80s, telling us that one of his erstwhile colleagues had jacked in teaching to make his fortune welding pipes for the North Sea gas distribution network being put in. That must have been sometime previously, so I'll say, vaguely, late 70s.


Title: Re: The end of an era - or at least a gas holder
Post by: BBM on March 24, 2021, 02:33:38 pm
I've just discovered a Twitter account for the gas holder!  :)

https://twitter.com/TowerGas (https://twitter.com/TowerGas)


Title: Re: The end of an era - or at least a gas holder
Post by: stuving on April 21, 2021, 02:57:53 pm
Some more of them falcons is at it ... this time in Wales. From NR (https://www.networkrail.co.uk/news/best-laid-plans-network-rail-amends-bridge-refurbishment-work-after-protected-birds-found-nesting-in-tower/):
Quote
Best laid plans: Network Rail amends bridge refurbishment work after protected birds found nesting in tower
April 20, 2021
(https://www.networkrail.co.uk/wp-content/uploads/2021/04/5wjfe-8ej3l-pmg9n-98piy-20wsm-903x500.jpeg)

Network Rail has had to make changes to planned refurbishment works on the Grade II listed Britannia Bridge, in North Wales, after a pair of peregrine falcons were found to be calling it home.

The rare and protected birds were spotted, by a member of the public, flying back and forth to the top of the middle tower of the bridge – which links Anglesey and the mainland of Wales across the Menai Strait.

With restoration works planned on all three towers, Network Rail quickly teamed up with Ecological Consultants, Whitcher Wildlife Ltd, to get advice on how to best protect the falcons.

“After a few visits to the bridge, it soon became clear that a solitary peregrine falcon was roosting, preening and hunting from the central tower”, James Campbell, Ecological Consultant at Whitcher Wildlife Ltd said.

“It was displaying the typical field signs of an adult male, defending the nesting site and tending to feed the female peregrine falcon on the nest.

“Falcons are usually found nesting in high-up places, like cliff tops or tall buildings, but this is the first time I have been called out to monitor these magnificent and rare birds nesting in the tower of a bridge. 

“We are working closely with Network Rail to continue to monitor the birds over the next few months, with work on the central tower now paused until the young peregrines have fledged the nest, later in the year”

Following advice from the ecologist and Natural Resources Wales, the restoration work will continue on Anglesey and Caernarfon towers with scaffolding now being erected in preparation for the main work to begin next month.


Title: Re: The end of an era - or at least a gas holder
Post by: CyclingSid on June 15, 2021, 04:43:29 pm
Quote
There is a planned exhibition (subject to the various current problems) at the Riverside Museum part of Reading Museum in September of artworks related to the gas holder

I believe the dates of the exhibition are 10th-26th Sept 2021. 10:00 - 18:00 daily at The Turbine House, Riverside Museum, Reading, RG1 3EQ


Title: Re: The end of an era - or at least a gas holder
Post by: CyclingSid on September 09, 2021, 04:57:33 pm
Dates for the exhibition are confirmed
https://www.readingmuseum.org.uk/whats-on/heritage-open-days-exhibition-last-gasometer-and-reading%E2%80%99s-changing-skyline (https://www.readingmuseum.org.uk/whats-on/heritage-open-days-exhibition-last-gasometer-and-reading%E2%80%99s-changing-skyline)
Bar and restaurant (Bel & Dragon) adjacent https://belandthedragon-reading.co.uk/ (https://belandthedragon-reading.co.uk/)


Title: Re: The end of an era - or at least a gas holder
Post by: jamestheredengine on September 10, 2021, 01:11:58 pm
Dates for the exhibition are confirmed
https://www.readingmuseum.org.uk/whats-on/heritage-open-days-exhibition-last-gasometer-and-reading%E2%80%99s-changing-skyline (https://www.readingmuseum.org.uk/whats-on/heritage-open-days-exhibition-last-gasometer-and-reading%E2%80%99s-changing-skyline)
Bar and restaurant (Bel & Dragon) adjacent https://belandthedragon-reading.co.uk/ (https://belandthedragon-reading.co.uk/)
Unusual name for the bar/restaurant – named after a book of the Apocrypha.


Title: Re: The end of an era - or at least a gas holder
Post by: CyclingSid on September 15, 2021, 07:09:20 am
... and the demolition begins (or the preparation for it) https://www.bbc.co.uk/news/uk-england-berkshire-58543251 (https://www.bbc.co.uk/news/uk-england-berkshire-58543251)


Title: Re: The end of an era - or at least a gas holder
Post by: CyclingSid on September 22, 2021, 06:24:25 pm
Quote
Video report from ITV News Meridian's Mel Bloor
https://www.itv.com/news/meridian/2021-09-21/dismantling-of-readings-final-gas-holder-begins (https://www.itv.com/news/meridian/2021-09-21/dismantling-of-readings-final-gas-holder-begins)
As one of the contributors says, topographical art was common about the time the gasometer was built, but relatively rare nowadays.
Not sure how long this is available for.


Title: Re: The end of an era - or at least a gas holder
Post by: broadgage on October 03, 2021, 12:43:27 pm
Imagine the outrage if the building of similar structures was proposed today.
And the shock at discovering that they are to be filled with gas that is both toxic AND flammable. Near CHILDREN !

And the wicked fat cat persons building the evil monstrosities are then going to sell the gas at a PROFIT, charging even the poor.
Nearly as bad as the smoke breathing, spark snorting iron monsters that are roaming the countryside at will, destroying crops by fire, tumbling down the hovels of the poor, preventing hens from laying, causing horses to become extinct, and other disasters to tedious to list.
And what if a spark from such a monster were to land upon a giant gas holder ? Disaster of almost unimaginable proportions would follow.
Truly the apocalypse is upon us.


Title: Re: The end of an era - or at least a gas holder
Post by: CyclingSid on October 04, 2021, 06:59:46 am
Better not ask about the gas leak they are trying to repair on the Bath Road bridge in Reading. Did wonder if a steam locomotive going underneath would be an added hazard.


Title: Re: The end of an era - or at least a gas holder
Post by: paul7575 on October 04, 2021, 09:57:46 am
Someone posted about the apparent dangers of gas holders to modern thinking, I was wondering if records show how many were bombed intentionally or accidentally during WW2, and what the resulting damage was?

Secondly, recent news about a general lack of storage has sometimes been illustrated with images of traditional gas holders, but were they really ever providing medium term storage, or did they simply act as accumulators to deal with demand fluctuation over the normal 24 hour peaks and troughs?


Title: Re: The end of an era - or at least a gas holder
Post by: stuving on October 04, 2021, 10:34:12 am
Someone posted about the apparent dangers of gas holders to modern thinking, I was wondering if records show how many were bombed intentionally or accidentally during WW2, and what the resulting damage was?

Secondly, recent news about a general lack of storage has sometimes been illustrated with images of traditional gas holders, but were they really ever providing medium term storage, or did they simply act as accumulators to deal with demand fluctuation over the normal 24 hour peaks and troughs?

I think it's best to see them as pressure stabilisers. It would never be feasible to exactly match gas production from retorts to demand, and they are designed to keep the pressure constant. Their volume I suspect was dictated more by coping with variations in supply than demand. In the early days the one retort might only be manned during the day, and later you always needed to shut them down to clean them out, plus quite frequent unplanned outages. And later on production was moved out of town too and pumping stations had fixed capacity (when working). Later on, with north sea gas, control of pumping was good enough to exploit the capacity of the bigger long-distance pipes at higher pressure to do the same job.


Title: Re: The end of an era - or at least a gas holder
Post by: stuving on October 04, 2021, 03:12:07 pm
I think it's best to see them as pressure stabilisers. It would never be feasible to exactly match gas production from retorts to demand, and they are designed to keep the pressure constant.

That can't be quite true, of course, as each lift adds weight to the cap and increases the pressure. But all the words I've found dismiss that and say the cap is weighted. What we need is numbers!

The only numbers I can find are in "The Design of gas Holders", C S Spillsbury (1911) (https://www.ideals.illinois.edu/bitstream/handle/2142/51887/designofgasholde00pill.pdf?sequence=2). That includes as worked examples a single-lift and a four-lift design, but omits the pressure calculation from the latter - frustratingly. Elsewhere he cites pressures of 4" plus 2" per lift (water gauge), which doesn't look very constant to me!

So what stabilised the supply pressure? The governor, that's what. We'd now call that a regulator, like the one on the top of your gas meter (only bigger). So provided the holder pressure was high enough, it would be regulated down to a constant level into the supply network.

If you want a load more detailed detail about gas works' workings, I suggest you look at this combined set of four "Gas profiles" (https://www.claire.co.uk/component/phocadownload/category/27-wall-documents?download=434:gasworks-profiles). They were done by the technical director of Parsons Brinckerhoff, oddly enough, though it looks like this is a personal interest of his! Even then, he hardly mentions supply and its pressure management.

One general problem throughout this "how did it work" subject is that gas engineering advanced a lot from the early (pre-Victorian) systems to the post-1920 ones we are used to seeing awaiting demolition. And during that later period the technology keeps changing and ended up looking much like current systems.


Title: Re: The end of an era - or at least a gas holder
Post by: broadgage on October 26, 2021, 06:50:17 am
The gas in a gas holder was at a modest pressure, but this pressure varied a lot and was well in excess of the pressure supplied to consumers.
Governers or pressure regulating valves were used to maintain a constant pressure to consumers.

Gas holders were used to balance supply and demand. Large gas works worked 24/7 and the rate of production could be adjusted within certain limits, but a gas holder was still required to handle short term differences between production and demand.
Smaller gas works might only be worked for one shift per day, with demand between production shifts being met from the gas holder.
Very small gas works produced as needed, as little as once a week in summer for very small works.

The quality of the gas also varied during the production cycle, and the mixing in the gas holder gave a more consistent product to the consumer. Freshly made gas was hot and contained a lot of moisture. In the gas holder it cooled and excess water could condense out and be removed.



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