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Sunday, November 30, 2008

Kincardine and Longannet Power Stations

Below is a copy of the cover of the memorial booklet issued to commemorate the opening of the Kincardine on Forth power station (generating station as they were called in those days) by Queen Elizabeth II and Prince Philip on 12th October 1960 - 49 days before I was born. (I was going through some boxes today and chanced across a load of old stuff)

My father-in-law was the Deputy Manager there in the late 60's before becoming the first Station Manager at Longannet when it opened in '72. Both plants were very unique when they came on line and were only 3 miles apart on the north bank of the River Forth in Clackmannanshire, Scotland. I worked at Longannet between '85 and '88 and also did some short term work at Kincardine. Kincardine has been long shutdown and the site was cleared during the late '90's. Longannet still pumps the juice out.


The Queen and Prince Philip in all their glory.


Kincardine had three 120MWe sets which at the time where the largest electrical machines around and then the station was expanded by the addition of two further units rated at 200MWe that came on line in 1963. Longannet, some photos below, was an incredible place and used to be the biggest coal fired power plant in Europe. It was very unusual as it had four 600MWe but it has cross-compound turbines, i.e. instead of each 600 MWe unit having one turbine/alternator unit, which is the norm, Longannet has two turbine/alternator lines per unit. One line was a high pressure (HP) line with the other an intermediate pressure (IP)line. Both lines having a 300MWe alternator attached with one boiler providing the steam to each cross-compound set. The result of this was the turbine hall was over 1/4 mile long and at certain time so of the year it would snow inside.

I understand that two explanations for the cross compound nature of the station have been told, neither have I confirmed at this time and maybe both may have applied at the time of design.

The first is that boiler technology had gotten to the point where one boiler could provide enough steam to generate 600MWe (which needs about 1800MWth of heat) but that alternator technology was the limiting factor, i.e. 300MWe maximum due to cooling limitations. The second reason was that basically English Electric had some 'spare' 300 MWe alternators from a canceled order they needed to move so a deal was struck with the SSEB. (I think the former basis is probably the more accurate)


This is a picture of Longannet taken 17 September 1970 looking southerly. The turbine house is in the forefront, the boiler house behind with the stack and the lights in the background across the River Forth being Grangemouth a very large and infamous oil refinery.



Longannet from Grangemouth - the River Forth at this point is a mile across hence you can scale the size of the plant knowing the distance from where the photo was taken. You will note the lack of cooling towers that is traditionally the norm for such large plants. Because of the magnitude of the river at this point and the associated volume of water Longannet could take its cooling water in, complete the cooling requirements and discharge the water back into the river further downstream and maintain the temperature within the gradient required to ensure no impact on the rivers wildlife negating the need for the cooling towers.



This picture does not give the turbine hall justice but if you look closely you can see stairways which give some sense of scale.

The picture is taken from the west end of the turbine hall with Unit 1 being the nearest to the camera. The first and nearest line being the HP line and it's partner, the IP line, both with matching covers over their respective 300MW alternators. This picture, also taken in 1970 shows Units 3 and 4 in the distance still under construction.

The picture below is taken from the east end of the Turbine Hall where you can see Units 3 and 4 undergoing build. Unit 4 IP line is actually shown at the very bottom of the picture with only approximately 30% of the line visible. The first complete line nearest the camera visible is Unit 4 HP. The Unit 4 turbine rotors have yet to be installed because you can see the bottom low pressure (LP) casings. If you look very closely on the next line, U3 IP line you can actually see to the right of the photo a HP and an IP rotor awaiting installation.

Note that the large green colored vertical cylinders in the preceding photo and those that are red in the photo below are the High Pressure (HP) feed heaters. These are used to put heat back into the water (a closed loop system) as the water is returned from doing its work in the turbines back to the boiler to be heated once again and turned back into superheated steam.




The photograph below shows a Low Pressure (LP) rotor being prepared for installation. The workers adjusting the rigging give some sense of scale for the turbines. Note that each unit had four of these LP rotors making a total of sixteen LP rotors.



The following photograph is of the control room at Longannet taken from the rear of the room. You can see the entrance doors in the center with the control desks for Unit 1 to the right of the doors and Unit 4 to the left. Again, taken during construction, you can see that the Unit 4 desk and control panels are void of the instrumentation that can be seen installed on the Unit 1 completed desk and panels.

When you consider that this control room was designed in the late 60's you can see that it was quite futuristic with is 'circular' design and elevated illuminated ceiling.



The sketch below shows the side elevation of one of the four boilers at Longannet to give some further impression of how large these plants are. If you look closely near the center at the bottom you will see the outline of a man with a further one near the top of the sketch toward the upper left hand corner and another on the right of the picture mid height.

These boilers, when at 'full' load, produce over 1800 tons of steam each and every hour 'eating' 240 tons of coal per hour to do such! You can start to imagine the magnitude and complexity of the other ancillary equipment necessary to allow this to happen - this then enables one to get a sense of why electricity costs what it does and why it is such an undervalued commodity especially when you switch that switch and it's there come rain or shine, day or night.

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