WARTIME POWER STATION OPERATION PROBLEMS
Talk by Mr. L.A.E. Fosbrooke (member)
At the Durrington Community Centre, 12th February, 1992.
The speaker first gave a short historical summary of the electricity supply industry in the United Kingdom. Before the 1920’s there were many small and unreliable stations and systems operating at several different voltages and frequencies. The 1924 Electricity Act set up the Central Electricity Board to effect a change to a single three phase 50 HZ nationally interconnected network operation at 132 kV. The Board was to carry out the work and to control the output from each of some 450 Power stations, purchasing electricity surplus to local requirements and selling it to undertakings having no power plant.
By 1939 there were 15 power stations of 100 MW or greater capacity, nine of which were in the London area. The war brought the bombing and partial evacuation of the metropolis and the building of munition factories in the South West and South Wales. To cater for the change in requirements, heavy duty grid lines and towers were obtained from the U.S.A., through the Lease Lend Agreement, to supplement the grid network and enable the resulting idle plant in London to supply these factories.
Mr. Fosbrooke was a young engineer employed in various capacities in Littlebrook, Fulham, Battersea, and Deptford power stations. This would be interesting and challenging in normal times but in wartime conditions it became also exciting, dangerous and very varied,. The talk, given in a relaxed conversational manner, described some out of the ordinary situations and events, including the following:-
The gas washing plants at both Fulham and Battersea were shut down because of the chimney steam emissions being clearly visible from the air, particularly in moonlight. This caused excessive grit discharges in their neighbourhoods and at Battersea a massive overload weight of grits to build up in the rooftop slurry hoppers which nearly collapsed along the whole length of the boiler house.
As a result of four 500 kg. bombs through the turbine house roof at Fulham completely wrecking three fully loaded 60 MW turbo alternators, all machines, where possible throughout the country, were hurriedly protected by reinforced concrete covers and anti-blast walls.
At Littlebrook, built on marshland, heavy vibration took place on running turbo alternators when bombing occurred within 100 m. whilst a ‘close miss’ caused 650 lbs./in2 steam mains, the length of the station, to swing violently on their hangers hitting one another, knocking off the lagging and exposing cherry red glowing pipes.
A 30 m. high coal unloading crane stood erect on ‘stubs’ after the bottom 2m. of its four legs were blasted away when a bomb blew a 4m. diameter hole immediately underneath it in the concrete jetty.
During another raid a L.P. turbine wheel, 4.2m overall diameter and 380 m.m. thick at the boss, split radially on full 6O MW load at 1500 r/min. On shutting down the machine the resulting excessive vibration progressively increased down to 750 r/min. causing the discs of induction type protection relays to rotate and trip out various auxiliaries. The split in the wheel was found to be 1 inch wide.
All the sheds of the 132 KV porcelain insulators of the outdoor busbars and transmission lines were destroyed by falling shrapnel during the first two weeks of the Battle of Britain. In spite of adverse atmospheric conditions the remaining ‘cores’ though arcing badly, never flashed over throughout the winter!
When the 132 kV switchgear was bombed losing the station output, the fires of all the P.F. boilers were simultaneously blown out by blast from two bombers diving low on to the station when they were hit by machine gun fire from a passing ship! A 30 MW set had consequently to run for a week just to keep the station lighting on.
At Battersea a bomb in the office corridor blew over the 60 m long control room panel. Three days later full output was restored when an emergency control centre was commissioned.
A 500 kg. bomb landed in the roof top gas washer chamber and was later found broken in half, whilst a dud A.A. shell fell through the roof, landing on the turbine house floor.
Whilst he was here Mr Fosbrooke was required to instruct some 500 Royal Engineers on how to wreck a power station in two minutes using only sten guns and sticky bombs, so they could do this to enemy power stations.
Deptford East and West Stations were very vulnerable being in the centre of dockland. Forty two employees were killed on site and treble that number when off duty. Forty seven flying bombs landed within a quarter of a mile of the site and eight were observed to fly between Wests two chimneys, skimming the boiler house roof. No fewer than six small bombs were removed in eighteen months from coal travelling on conveyor belts to the bunkers, having been unloaded from Swedish boats. These had been thrown into the holds during loading by German agents posing as Swedish seamen.
In lighter vein Mr Fosbrooke told of a difficulty when a woman boiler cleaner could not exit through the man hole in a boiler drum and had to divest her clothing and apply grease liberally to ease herself through the opening.
Concluding, the speaker compared the 450 relatively small stations of wartime with the present day 80 or 90 of which half the total capacity is in the Midlands or Yorkshire, close to the coalfields. The modern stations are equipped with four 660 MW units, each set having one shaft only, and the unit boiler operating at 2500 lbs/sq.in. 1750° F. Some 18% of generation is now from nuclear stations. Throughout the war the maximum plant outage due to enemy action was only 5% of total capacity .
To-day with each generating unit of greater capacity than of both Battersea A and B, combined, it would be a different story.
H. B. Calverley.