Thursday, 8 March 2012

Article - The History of Thorpe Marsh Power Station (by Dave Cook)

Hope all you urban explorers enjoy - if you copy anything could you link it back to this site - cheers Dave Cook  Last Edited 14/06/12 with memorial garden renovation and 2B demolition details .

The story of the 420 acre Thorpe Marsh Power Station, just north of Doncaster, known to its staff as “The Marsh” began in 1957 when the site was purchased for the development of a 1 GW (1.5 million HP) prototype power station to be used as a test-bed for future coal fired developments. Test boring of the site was carried out to check the geology in 1958 to check its suitability. The site was chosen due to four factors: its location near the river Don giving adequate source of water for cooling, its geography was able to support the heavy weight of the concrete construction, Road and rail access to the site was good and there was a large area surrounding the site where ash could be deposited. On 16th May 1958 the Minister of Power gave the go ahead for CEGB’s North Eastern Region to build the plant at a projected cost of £40 million. Work began in 1959. Marsh Lane and Applehurst lane were “stopped up” around the edge of the site (HL 23/49/0115). It was estimated the power station would use 2.75 million tons of coal in its first year of operation.

 The CEGB’s Northern Project Group, overseen by the Resident Construction Engineer J C Goward C.Eng MIEE MIE (Aust), designed the power station and was assisted by Sir Alexander Gibb & Partners, Watson & Coates, and landscape consultant Sheila M Haywood. The main contractor during construction was Mitchell Construction Co Ltd. There is a natural coal seam below the power station and the mineral rights were requisitioned from the National Coal Board. Flood banks were added around the site and 40 feet deep caissons were sunk into the Sherwood Sandstone to protect the site from subsidence. Excavation of some land to the west provided red shale to raise the foundation level (the hole is now the lake). A total of 1 million tons of red shale and ash used to raise and level the site. Photos taken during construction of power station here

 The first test run of the first phase of the power station occurred in December 1963. This winter was one of the worst on record for the United Kingdom and this caused severe delays in testing of equipment and hampered the supply of water to the system. Severe frosting occurred inside the buildings so heaters had to be introduced to limit damage. By 1964 the Power Station was completed with two 550 Megawatt generators each with a pulverised coal fired steam raising boiler. Each boiler was fed by 5-stage FR550 pumps made by G& J Weir Ltd, capable of 4,000,000pph with a suction temperature of 485oF, which were able to pump 500,000 gallons per hour and the resultant steam from each boiler went to three cooling towers to condense the steam into the atmosphere. By 1965 the second phase started producing commercial electricity.

 Two 28 MW English Electric gas turbines were used to cover peak time electricity consumption periods. Each of these turbines were powered by two industrial versions of the Rolls-Royce Avon MK 1533-51B axial flow turbojet engine used as gas oil generators to produce 14.9MW (aircraft to use the flying version included Hawker Hunters, English Electric Canberras and Lightnings as well as Saab Lansens and Drakens). The 400oC exhaust gases then passed to a 300ft concrete chimney. This turbine order, placed in 1964 was estimated to have earned Rolls-Royce £250,000, this was the fifth order placed by the CEGB for such units.

 The six 340ft reinforced concrete cooling towers were constructed by four different companies were constructed in two phases due to their links with the turbines.  Set 1A/1B/1C are three to the east and are mirrored by 2A/2B/2C. There were also two 500 ft concrete chimneys for the boiler house.

Due to the tidal nature of the river Don three silt settling channels were created to remove any deposits before water went through the cooling water system. Approximately 15,000 gallons of water was taken from the Don every minute via four vertical spindle mixed flow water pumps.

Around one hundred tons of ash and coal dust was created every hour and 233 tons of ash and 890 tons of dust could be processed everyday. These deposits would then be crushed and sorted before the excess water was removed to be recycled back into the boiler houses. These dried remains were then transported to the ash fields to the west of the site. This ash was used for motorway and other construction projects including the M1 between Junctions 34 and 35. 60 lorry loads per day of pulverised fuel ash (PFA) were transported from June 1966 for use around the Meadowhall embankment, in total 200,000 tonnes were used on the project covering 120,000 cubic yards. Thorpe Marsh PFA was also used on the M7 and mixed with Yorkshire Gritstone. The remaining PFA on site may be used on the North Doncaster Chord development by Network Rail.

 The boiler house contained to completely different boiler units, Unit 1A/B was constructed by International Combustion Ltd with two boilers – one being used to accommodate a secondary superheater and was able to produce 550MW at 1055oF producing 3,750,000ib/hr of steam at 2,400ib/sq giving nearly twice that of the previous 300MW boilers at West Thurrock. This unit was able to process 210 tons of pulverised coal per hour. Unit 2A/B built by Babcock & Wilcox Ltd with a front walled single furnace and was the world’s most powerful single furnace natural circulation reheat boiler. They weighed in at 265 tons and over 100ft high with 54 circular burners in the front wall.

 The 550MW alternators were provided by C A Parsons Ltd and AEI Ltd. Both unit had two 2-axis cross-compounded impulse reaction type turbine driving a 275MW alternator. At first start up in 1963 the unit was only able to produce 420MW and it was many years before the full 550MW was reached. 

It was classed as two separate power stations; “Thorpe Marsh” being the coal side with sets 1A/B and 2A/B producing 1059MW and the OCGT gas turbine side being “Thorpe Marsh GT” with sets 3G and 4G producing 56 MW. The official CEGB booklet from 1967 gives the total output as 1156MW.

 In 1964 a new 400kV Trans-Pennine transmission line was given the go ahead from Thorpe Marsh to Stalybridge, this new line used the 3 mile 13 yard up-bore of the old Victorian Woodhead Tunnel which had been superseded by a new tunnel. This tunnel was cleaned of soot and a new floor was laid and several of the ventilation shafts filled in. This power line went live in 1969.

Thorpe Marsh was one of six power stations fitted with Hydrastep water level gauges in each end of the boiler drum which gave a highly accurate reading for the control room staff.

After the collapse of the cooling towers at Ferrybridge 'C' Power Station on 1st November 1965 all cooling towers were examined and structural guniting was carried out during 1966. This consisted of adding a layer of sprayed concrete to make the towers heavier and less susceptible to high winds. The towers had an exclusion zone around them at times of high winds due to the fear of another incident similar to that of Ferrybridge

Opening and Operations
Thorpe Marsh was officially opened on 2nd June1967 by Ernest G Boissier DSC CEng FIEE, the only non-royal to open a power station; he was initially a marine engineer before serving in World War 1 in the Royal Navy. He was wounded in 1917 and before and after the war worked for Aiton & Co. Pipemakers who supplied pipes to nearly every power station built in the UK. A special brochure was produced to mark the opening ceremony and a plaque was unveiled in the main reception. The Bishop of Sheffield blessed the power station. The following weekend the power station was opened to the public.

 Thorpe Marsh employed 530 staff including 14 in the canteen. There was a lawned area with flower beds with a lake and a 9 hole golf club run by the CEGB as well as facilities for cricket, billiards, bowling green and dancing as well as an annual Christmas party.

Together with Drax, Eggborough and Ferrybridge C it was able to produce 25% of the UK’s energy requirement during winter months if required.

 With any prototype problems occurred. The first major breakdown occurred in November 1967 and in 1969 several problems had arisen reducing its generating capacity due to technical faults. Questions were asked in the House of Commons on 8th July 1969 to see if it was due to “alleged constructional deficiencies” an independent inquiry was called for but not taken up. These were a mixture of problems with the boiler feed pumps, noise, temperatures in the superheater amongst many others. By the 1970’s these were eventually sorted and the power station became more reliable.

In 1970 the power station was used to test short line faults on the 275kV CEGB system in order to test circuit breaker performance and system characteristics with measured values. A fault current of up to 20kA was achieved.

During the bitter 1972-73 miners strike pickets were set up outside the power station. After an oil truck had managed to get through the lines the pickets started to make caltrops to puncture the tyres. On 31st January the pickets managed to prevent lorries of liquid hydrogen from entering the site and it had to close down – one of 12 power stations which were unable to operate during this time. At Keadby Powe Station one of the picketers; Fred Matthews “Freddie”, from Dunscroft who worked at Stainforth colliery, was killed on the picket on 4th February after a lorry tried to force its way past the picket line encouraged by the police. He was buried the following Tuesday (8th February) which was attended by thousands of miners. After the funeral a mass rally was held in London and his mother Nellie Matthews attended and spoke to the miners in favour of the strike and his four brothers, also miners, were also striking. On the same day three miners were also injured when the police went in heavy handed at Thorpe Marsh and tried to break the picket lines.

During 1972 there was a boiler house fire which severely damaged the power station (more info wanted!)

On Sunday 7th January 1973 four members of staff were killed at the power station whilst carrying out maintenance in the chamber of no.1 electrostatic precipitator. Terry Burton, Len Harris, Terry Hazeldene and Stan Lee all died of electrocution. The coroner’s inquest started on 19th February with the result being a verdict of accidental death. The actual first reports on the workers deaths stated they had been buried under a fine powder and it was initially thought they had suffocated.The CEGB however had legal proceeding put to them by HM Factory Inspectorate after alleged breaches of the Factories Act Electricity Regulations 1908. Their deaths were found to be accidental but major changes were made to the way maintenance was carried out at power stations. A memorial garden was set up in the power station grounds next to the lake. In 1990 there was also the death of a contractor at the power station.

During the 1970’s a 10 metre high horseshoe bund was created for the storage of PFA. This was again lifted to 20 metres in 1990 to give additional storage.

Thorpe Marsh Nature Reserve was officially opened on 16th May 1980. This was initially the area around the ‘dug out’ a name given to the lake which had been created when land was removed to provide a stable platform for the power station foundations. It was opened by Phil Drabble. This site was expanded after closure to include the ash deposit field and coal storage area. There is a great deal of wildlife now in this area including Great Crested Newts, palmate news, smooth newts, weasels, pipistral bats, water vowl, Reed Bunting and grass snakes. 

During 1982 the iron swing bridge over the Sheffield & South Yorkshire canal was replaced by a steel lift bridge constructed by Bagguley & Barker Ltd. This new bridge was designed to take loads of up to 180 tons.

In 1984 Friends of the Earth called upon the UK Government to meet the EEC directive for emissions of large plants over 50MW in order to reduce acid rain and provide pollution control equipment in the form of flue-gas desulphurisation equipment on 12 power stations including Thorpe Marsh. The list was drawn up using calculations from Earth Resources research Ltd’s report.

During the miners’ strike of 1984-85 the T&G members at Thorpe Marsh and eight other power stations refused to handle new coal stocks supplied from collieries. Each power station took a vote and were run down over the period due to lack of coal stocks.  Tragedy struck on the road outside the power plant during November 1984 after a car crashed off the road and ended up in the Don, the pickets were praised by police for the attempted rescue of 22 year old Susan Brigden from Askern. (Not sure if her body was found?) The four pickets including John Wright, from Thurnscoe, and Ben Foster, from Knottingley who went into the water to try and locate her and the car.   During and after the strike coal as transported to the holding area via lorry.  This high volume of heavy traffic heavily disrupted the rural roads around the power station upsetting local residents and causing lots of damage to the roads. South Yorkshire County Council suggested a new coal depot be built next to the canal but it was never built due to local objections. In order to cease the operations of huge lorries around Thorpe Marsh DMBC tried to prohibite the use of any vehicle over 7.5 tonnes except buses and access vehiclesusing Fordsteads Lane between Marsh Lane and Thorpe Bank from 1st May 1987. (was this ever enforced?).

Between 1985 and 1989 Kier Construction was contracted in to fix large cracks which had appeared in the cooling towers during the 1970's after the original steel reinforcements had corroded. These cracks were filled in and supported by 31Parafil cable stays made of type G Kevlar yarn. These resin in-filled cracks give the cooling towers their strange linear paternations. The work also included strengthening of the cooling tower bases via the addition of steel girders which were fitted to five of the six towers before the power station closed.

During the late 1980’s the CEGB retrofitted several power stations with low NO2 burners in order to reduce emissions by 30% Thorpe marsh was one of those chosen for the upgrade alongside Fiddlers Ferry, West Burton and Kingsnorth.  

During 1988 there was a large power outage at Thorpe Marsh.

At the end of the 1980's the government decided on the privatisation of the energy industry.  On 16th August 1989 Thorpe Marsh passed into the hands of National Power (later NPower) which became a private company on the stock exchange the following March. Between 1990 and 1993 around £40 million had been spent on the plant.

On 8th October 1992 Barcom Power won a three year contract for the fuel stocking contract by Npower.

 In 1991 and 1992 Thorpe Marsh set thermal efficiency records but despite this its closure was announced on 8th June 1993 with the loss of the remaining 232 jobs, just after 120 staff had been made redundant that March. 270,000 tonnes of coal delivered by Bentley Colliery in 1992 and Hatfield supplied 400,000 tonnes as well as a supply from Maltby, this was a third of both collieries sales per year (In 1977 60% of Hatfield coal was sold to Thorpe Marsh).

Thorpe Marsh was listed as one of the top 100 emitters of Nitrous Oxide in Europe in the 1990’s. NOx emissions for 1992 were 31,000 tonnes and in 1993 this had reduced to 16,635 tonnes.

The site closed on 31st March 1994 after the new 10,000MW gas fired power station at Killingholme came online. 114 signatures were signed by Labour Party MP’s (and Ken Livingstone) condemning NPowers closure of the Power station. This closure was also a great blow to the workforce of Hatfield and Bentley Collieries with a third of their market now defunct. After closure a special booklet was produced in memorial to the power station.  

The transformers were removed as quickly as the station had closed being removed in April 1994. Able UK bought the decommissioned power station in 1995 and slowly over the past two decades have removed the buildings. The boiler house and other main buildings were demolished in 1996. The three tall slim chimneys were demolished on 14th February 1999 via explosive charges.

Able wanted the site to be used to hold new cars before delivery to local dealers during 1999. The cars would have been brought in by rail and held on site until being sent out on car transporters to the relevant dealers. The application was refused by DMBC due to inadequate roads around the site for large and heavy vehicles. It was estimated that the site would create 100 jobs for the area.

In 2003 the ash tip area was considered for a 3 million cubic metre landfill site with domestic, industrial and commercial waste to be transported in by rail (Application 03/1410/P) – it was rejected after Doncaster Residents Against Inappropriate Landfill (DeRail) rallied the local population with a petition eventually getting 3,115 signatures and 175 letters of objection. In February 2003 Able produced a plan to see the site redeveloped as houses, shops and industrial units. Yet again nothing became of this plan.

The pluvial flooding of 2007 severely affected the National Grids “Sheffield Ring”  as well as blighted most of the country. On 26th June the river Don burst its banks it was clear to the substation was at risk of flooding.  Sandbags were ordered and the army were commandeered via the South Yorkshire multi-agency ‘Gold Command’ due to access issues with the flooding of local roads. Indeed all the low lying land which dominates this part of Doncaster on the Don washlands were flooded.  At 7.30 am on the 27th the water had risen enough for the staff on site to start switching out parts of the substation.  RAF Odiham sent a Chinook helicopter from 18 Squadron to drop 150 one ton sandbags in order to build barriers on the Don’s banks at Bentley, Almhouse Lane and the power station which were positioned by the Royal Engineers. Nottinghamshire Fire Brigade provided a team called Swift Water Rescue from Retford Fire Station to supplement South Yorkshire Fire Service, Environment Agency and National Grid efforts to deploy high volume pumping equipment to prevent flooding around the transformers. These 24 inch pumps weighed in at 5-tonnes and were able to pump 1,000 litres of water per second.  38 Engineer Regiment based in Ripon and captained by John Kirkman ferried sandbags via four assault boats over the treacherous waters in order to stop the banks from overflowing as well as ensuring the substations emergency generators were able to run by ferrying 45-gallon drums of diesel. The substation was partially switched back into National Grid at 3pm and fully back on at 1.50am on 28th June. 

The memorial garden had become overgrown since the closure of the power station and during the spring of 2012 several National Grid staff began cleaning the trees and moss that had enveloped the area.  Peter Randall, Phil Catterall, Steve Harvey, Malcolm Jacobs, Derek Gilleeney and Paul Chadwick gave their time and are currently after photo's of the garden in its prime to restore it to its former glory.

Early in the morning on April 1st 2012 Cooling tower 2C was demolished leaving a roughly 30ft high section of the base remaining. It was decided to remove this tower first as the strengthening work to the base supports and kevlar wrapping had not been started on this tower before the power station closed in 1994 making it structually unsound during times of high wind.  2B was pulled down at 7am on 10th June 2012 using the same principle.  The remaining four 340ft cooling towers are all that remain of the physical infrastructure of the power station apart from the 275 kV sub-station and 750 MVA 275/400kV transformer and two transformers which step the voltage down to 66kV to the south. All four are due to be pulled down through the summer of 2012 using the same technique.

The power station has been on TV as part of the Amongst Giants (1998) and episodes 4 and 5 of The Last Train (1999) TV series (at this point all the power station was still standing), Red Riding (2009) and the music video by To Kill a King called “Cold Skin” as well being used to record a live song “The Tower” by Seth Cooke on the compilation album Missing Nothing.   The power station was used as part of the background for the cover on The Verve single “Slide Away”. The photo was taken on the field just south west of the power station.

The Future
The Department of Energy approved plans on 31st October 2011 for Acorn Power Developments to build a 1,400 MW Combined Cycle Gas Turbine and 100MW open cycle gas turbine power station expected to give around 60% efficiency. The plans were submitted for approval on 25th February 2010 prior to this the plan had been to build two 480MW CCG Turbines. The initial cost of the 2009 power station was estimated at £600million.  The Friends of Barnby Dun had opposed the new power station stating the new structure would increase noise levels and lower house prices.   It has been suggested the new power station will create 100 jobs and 6-800 jobs during its construction. General Electric, 50% owner of Acorn through its subsidiary Power Partners, will be the main provider of equipment in the form of turbines and power equipment.The new power station will be built in two phases at a projected cost of £984 million. This means the present site will need to be completely cleared to facilitate the new structures.  On 19th January 2012 SES Demolition blew up the two ash slurry silos Video here: The first phase will include two combined cycle and one open cycle turbines whilst phase two will be a further combined cycle gas turbine. It has been suggested by Private Eye that

"Thorpe Marsh Power Ltd" is a temporary front for Scottish & Southern Energy (SSE) and that the replacement power station may never be built! See There is also the potential for wind turbines to the south of the site which would help to overcome the loss of the beautiful cooling towers once they are pulled down.

There will also be major work done to the National Grid infrastructure around Thorpe Marsh which is due to be completed on 31st July 2013 with a new 400kV 4 bay double busbar AIS substation on site and eventually will eventually add 2 skeleton generator bays, 4 circuit feeder bays as well as 4 new transformers.The power station is expected to connect to the National Grid on 31st October 2016.

Rail Network

The defunct Hull & Barnsley and Great Central Joint railway line to Bullcroft Junction was reopened and extended in December 1961 for coal trains to access the power station. Initially trains were pulled by BR owned ex-War Department 2-8-0 locomotives with 20t wagons using to supply the vast quantities of coal needed to power the furnaces. The original layout comprised of four lane exchange sidings being used to hold the wagons. CEGB provided their own industrial shunter in the shape of WG Bagnall Industrial shunter no.2679/43 “Ferrybridge 2”. This system was eventually replaced by a MGR unloading facility in the early 1960’s and class 47’s became the norm when  MGR operations commenced in South Yorkshire during 1964. During 1970 the rail link was altered from running to Bullcroft Junction to new junction at Applehurst Junction (WR015) at 163m45c and new signalling was installed around the power station sidings.  

The old route was finally closed on 7th September of that year – two of the sidings associated with this line survived until 1994 as emergency storage sidings when they were finally lifted. One of the last trains to use the HB&GC line was a 2 car DMU railtour organised by the RCTS.

The coal plant was designed to handle 2 trains at a time with a maximum unloading capacity of 1200 tons per hour to the vast underground bunker. This coal was unloaded into a 800 ton hopper before being processed through a overband magnetic pulley to remove any metal objects before going through wire mesh screens and crushed in a mud hog crusher which could process 300 tons per hour. The coal store could hold 820,000 tons of coal – enough for 12 weeks supply. 

On 29th June 1980 Applehurst Signal Box closed with the control passing to Doncaster Power Box.

On January 21st 1982 withdrawn Class 45 “Peak” locomotive 45029 was reinstated and moved from Swindon and moved to the power station in March as a static generator after a generator exciter failure, during May it received attention at Doncaster locomotive depot before returning. The loco stayed until August, a lucky move for the loco as it re-entered service and later became 97410, eventually getting scrapped by MC Metals in October 1991.

The coal supplied from Hatfield Colliery was eventually transferred from canal to rail in 36-wagon MGR trains each taking around 1,100 tonnes with three trains being loaded daily. A special blend of coal called 50mm P/C smalls were sent containing a precisely measured 15.4% ash content, 13.3% moisture content and a calorific value of 24,000. During May 1988 61,291 tonnes were supplied, in December 37,702 tonnes and February 1989 65,541 tonnes. Notice was given in 1976 by British Rail that trains to this power station had to have a minimum base load of 30 wagons and if a cripple was taken off the good wagons had to be reattached to the train to keep a maximum figure spare wagons were kept at the power station in order to make up numbers.

56077 was named ‘Thorpe Marsh Power Station’ in September 1990 commemorating 37 million tonnes of coal brought to the plant by rail.  It denamed 31st Marsh 2000 and is now dumped at Crewe Diesel Depot in Loadhaul livery awaiting disposal.

Two KPA bogie wagons were added to a rake of HAA MGR hoppers in September 1992 and used on loading/unloading trials between Harworth Colliery and Thorpe Marsh – it was found no advantage for unloading these bigger hoppers could be obtained so services were not continued.

The last coal delivery was made from Silverwood colliery on 11th June 1993 hauled by 56068. The last crippled wagons were removed the following Saturday morning. The signals were decommissioned on 25th November 1994 and coal recovery was made between 2nd February 1994 and March 1995 and loaded onto MGR wagons via shovel loaders, the coal was transferred to Eggborough Power Station. 200,000 tonnes of coal was recovered from the storage area. The last train to leave was on 2nd March 1995 headed by 56087. The points were removed in 2007 during relaying of the freight line.

The sidings are currently the property of HJ Banks & Company Limited (they are currently negotioating with Network Rail over the acquisition of these sidings see It looks like the remains of the cooling towers will be crushed and become part of the banking for the North Doncaster Chord ECML avoiding line. Part of the LNER pattern 3 ground frame was saved from the cripple sidings and is now used at Embsay station courtesy of Able. Preliminary work for the North Chord line should start around July 2012 improving access to the site and signal cable alterations. The chord itself is due to commence in December 2012 and last until April 2014.

Pre Power Station

Thorpe Marsh was enclosed by act on 16th September 1768. The land was drained in 1835 under the Dun Drainage Act. A barrier bank was built around 1933. There was a proposed gas works for the site in 1944 owned by the Doncaster Corporation Gas Department but this looks like it wasn’t constructed. In the late 1940’s a section of the flood banking around the Don collapsed due to being constructed over a layer of peat making it unstable. This was fixed by insertion of vertical sand drains at 3 metre intervals along the toe of the bank. This peat layer also explains why the cooling towers have not been blown up as the liqufication of this layer could lead to mass flooding.

An amazing collection of photographs of the power station is available at


  1. An informative read, thanks.

    If interested, some of the earlier 'quiet' demolitions featured in the first episode of Scrapheap Challenge season 3:

    Not entirely sure that the intro is Thorpe Marsh? The second story section with Cathy Rogers definitely is though (the workforce are all wearing Able UK branded safety jackets):

    However on that one, it appears that the editor may have cut together clips of Thorpe Marsh with another site as the number of chimneys doesn't seem to tie up.

  2. This comment has been removed by a blog administrator.