HL Deb 16 November 1965 vol 270 cc445-8

2.50 p.m.


My Lords, I beg leave to ask the Question which stands in my name on the Order Paper.

[The Question was as follows:

To ask Her Majesty's Government whether they will make a statement regarding the concrete cooling towers which were blown over at the Ferrybridge C Power Station near Knotting-ley, Yorkshire, during the recent gales; whether models of the towers were properly tested in wind tunnels and what steps are being taken to prevent similar occurrences in the future.]


My Lords, on Monday, 1st November, during a gale reaching 80 m.p.h. three out of eight concrete cooling towers on the site collapsed. The first tower collapsed about 10.30 a.m., the second about ten minutes later and the third at 11.20 a.m. The towers, each 375 feet in height, were under construction by contractors working for the Central Electricity Generating Board. Three workmen sustained slight injuries. There were no prior wind tunnel tests of this particular size of tower, but tests to develop design have been carried out for nearly ten years. The towers are constructed in two rows of four, and it was three of the towers in the row on the leeward side from the wind which collapsed. This has led to the speculation that the collapse may have been due to the funnelling effect of the wind passing through the front line of towers, but final judgment must await the findings of the Committee of Inquiry which the Board has set up. Towers approaching the size of those at Ferry-bridge have been tested and have been in operation for a number of years without mishap. The steps necessary to prevent a repetition must await the findings of the Committee of Inquiry under the Chairmanship of Dr. L. Rotherham, F.R.S., the Board Member for research.


My Lords, I am most grateful to the noble Lord for making that Statement. There are one or two supplementaries that I should like to ask him. Is it not true that the towers were tested only to resist winds of up to 63 m.p.h. when, as he said, there were some gusts of up to 80 m.p.h., and even up to nearly 100 m.p.h., and that these tests were at 40 feet, whereas these towers are 375 feet high? Secondly, may I ask whether he thinks these towers are the right shape? Has not the Research Laboratory of the C.E.G.B. thought for some time that this was not the ideal shape, which had reached the brink so far as wind resistance was concerned, and that they have been thinking lately of a new type of cooling tower—the flat igloo type.

Thirdly, may I ask whether the noble Lord thinks that these towers were sited in the right place? Fourthly, can he tell me what is likely now to be the delay in the commissioning of these cooling towers? Is the result of this going to be further cuts in electricity this winter, or some restrictions? I understand that the Chairman of the board of inquiry is coming from the C.E.G.B. Does the noble Lord think that this is the best way of conducting the investigation?


My Lords, perhaps I may answer the noble Earl's questions in reverse order. With regard to the point about the Chairman of the Committee of Inquiry coming from the Board, he is a very eminent man. The noble Earl will be aware that, since these towers cost £290,000 each, the C.E.G.B. has a major interest in learning the answers to all the questions he has asked. The Committee includes such independent people as Professor A. L. L. Baker, Professor of Concrete Structures and Technology, Imperial College of Science and Technology; Professor P. R. Owen, Zaharoff Professor of Aviation, Imperial College of Science and Technology; and Professor A. H. Chilver, Chadwick Professor of Civil Engineering, University College, London. Therefore, I think that we can be satisfied that the Committee of Inquiry is of sufficient stature. With regard to siting the towers, the National Physical Laboratory have been asked to carry out tests on the velocities at the site and to ascertain the effect of wind directions and velocities on the towers in the position in which they were placed on the site.

With regard to the Board getting tired, as it were, of this shape of tower, I would mention that towers approaching the size of those at Ferrybridge and of similar construction have been in operation for years at Castle Donington, Skelton Grange, Willington, High Marnham, Rugeley, Thorpe Marsh, Drakelow, Richborough, Chadderton, Hams Hall and Huncoat, which adds up to a fairly notable record of experience. In addition to that, there are towers of the same construction on other sites. May I remind the noble Earl that the concrete of these towers, at the foot, is 12 inches thick; at the throat, 5 inches, and that it comes out at the top at 14 inches. All this seems to indicate that a great deal of thought has been given to this problem.

With regard to testing up to a wind velocity of only 63 m.p.h., tests to develop design have been successfully accomplished with regard to these other towers, and at least in one case the tests were on a tower as high as 350 feet. I understand that a great deal of thought has gone into this matter also.

As to the noble Earl's fifth question, of whether this unfortunate happening is likely to cause power cuts this year, I understand that it is not likely to affect the programme of commissioning of the first 500 megawatts by December, which is the only part of the programme likely to affect supply this winter. As to whether it will affect future potential, or whether there will be any pulling down of these towers, we must await the results of the Committee of Inquiry.


My Lords, did the noble Lord say that the vital statistics were 4-8-12 or 14-8-12?


My Lords, I think I said that they were 12-inch towers at the hips, 5 inches at the throat and 14 inches at the top. One other vital statistic I might mention is that the consent to this construction was given in August, 1961, and the contract was placed in August, 1962. Therefore, it is fair to suggest that, although these were Tory towers, it might have been a Labour wind that blew them down.


My Lords, may I ask who bears the financial responsibility for this damage?


My Lords, the financial responsibility is borne by the C.E.G.B.


My Lords, in view of the somewhat elliptical reply which the noble Lord gave to my noble friend on the loss of electricity, I wonder if he would comment more precisely on the estimate that has been made, that Ferrybridge Station C could be out of use for two years; that the money already spent would be lying idle, so that the consequent full expense might be something like £10 million, plus the reconstruction cost, which can scarcely be less than £1 million.


My Lords, I am sorry if the noble Lord thought that my reply was somewhat elliptical, but I would repeat part of it in more detail. We do not think that the collapse of some towers will delay the commissioning of the first 500 megawatts next December. I do not think that there is anything elliptical about that. With regard to any further delay in the programme of commissioning, that must depend on the results of the Inquiry. As regards the extent of any potential loss, that is really guesswork. I gave the cost per tower, but we do not know whether any more will have to be taken down, and they have not all been completed. It is pure guesswork and one would have thought that the noble Lord's estimate of £10 million is rather high.


My Lords, despite the noble Lord's answer to one of my noble friend's questions, living as I do within sight of this now depleted system of towers, I would ask him whether he can confirm, so far as construction is concerned, that the three towers blown down were Socialist towers and the five towers remaining are Tory towers?


My Lords, unfortunately they are all Tory towers. I only hope that there was nothing malignant in the noble Lord's eyes when he looked out on them. He might have been under the mistaken impression that they were Labour towers.