AIR-RAID PRECAUTIONS (SIRENS, PURCHASE). (Hansard, 16 November 1938)

§ Mr. Silverman
On 3rd November I asked a question of the Home Secretary about a memorandum circulated by the Home Office to local authorities, in effect recommending the local authorities to purchase sirens for air-raid warnings from a particular firm. It seemed to me, from the information which I had, that the procedure adopted had been unfair, and had had the unfortunate, and I am quite sure undesigned, effect of giving a monopoly, or a virtual monopoly, of the manufacture and sale of those articles to a firm in Leicester, which, after all, is not a place suffering unduly from unemployment and the other things which create a Special Area, and taking it away from the town of Nelson, which has an unemployment percentage of 45 and 1012 which is in many other respects suffering severely in these days. I am quite certain that that was not the intention, but I am equally certain that it was the effect. I gave notice then that I intended to raise the matter on the Adjournment, and I consulted with the Under-Secretary on Monday of this week to see whether that evening would be convenient. It was not convenient, and to our mutual satisfaction we arranged that I should raise it to-night. I would like at the outset to offer my congratulations and thanks to the Under-Secretary for having so availed himself of the reprieve, if I may use that word, as to meet or virtually to meet the complaint I had to make. I want to say that at once, because his action makes it the less necessary that I should dwell at length upon this matter. But it is worth while, since the matter has been raised, to point to the process that was adopted in this case so that it may be avoided in other cases.
The facts appear to be that in July of 1937 the Home Office wrote to Messrs. Carters, a firm in Nelson, and invited them to submit their 20 horse power siren to a test which was to take place at the end of that month. There is a reference to some previous correspondence which I have not seen. I know there is a dispute 1013 between the Home Office and the firm I have mentioned as to whether it was the Home Office that selected and invited the firm to submit a 20 horse power siren or whether the firm volunteered to submit the 20 horse power siren. As to that, I can only say that the firm told me most emphatically and repeatedly that they submitted the 20 horse power siren only because they were invited by the Home Office to submit such a siren. The siren was tested against a number of other sirens, and in particular against an eight horse power siren submitted by a firm called Gents, of Leicester.
That was the last that my constituents heard of the matter until August of this year, 12 months later. They then became aware of a memorandum circulated by the Home Office to all local authorities telling them that there was a suitable siren manufactured by Gents, of Leicester, that the Metropolitan Police were using it, and that it was the only one recommended by the Home Office. When they saw that it was a four horse power siren they began to wonder what had happened, because a four horse power siren, as far as they knew, had never been tested in competition with any other siren at all, and certainly not with the 20 horse power siren or with the eight horse power siren which Gents had in fact submitted to that test. They wrote to the Home Office and complained, and for four weeks got no answer of any kind. Since then there has been correspondence between Members of this House and the Home Office into which I no longer need enter because I hope the matter has now been satisfactorily resolved, but it seems rather an unusual method of making a test and making a recommendation that they should be invited to submit one type and then virtually to be excluded from the market altogether because the type which they had been invited to submit was not the type the Home Office required.
The firm in Nelson manufacture a five-horse-power siren at least equal in power to, so I am informed, and no dearer in price than, the one recommended. In order to reinforce their argument that they were able to supply an article that completely filled the bill as well as if not better than the Leicester firm's siren, they tell me, and I have no reason to doubt what they say, that the Chief Constable of Liverpool, not knowing which siren came from which firm, 1014 not knowing anything about the dispute, not knowing that there was a dispute, but testing the sirens against each other on their merits, had no hesitation whatever in choosing the Nelson siren.
The firm complain—and I think the House will see the force of their complaint—that a Memorandum of that kind, circulated to local authorities at the end of August of this year, has operated to deprive Nelson of a great many orders. It seems to me almost impossible not to infer that local authorities would be afraid not to go to Leicester for their sirens, because they would fear that the Home Office would not make their grant to any local authority that chose something which they did not recommend. Therefore, local authorities had to place their orders in Leicester. I have no doubt—although I have no evidence of this, but it is a reasonable inference from the facts to suggest—that the Leicester firm probably has far more orders than it can possibly execute in the time required, while this firm in Lancashire has none at all.
If there has been any misunderstanding which is now over, let me say nothing to cause any further misunderstanding. I understand that the Home Office have now invited Messrs. Carter to submit a siren of comparable size, and that if, after further tests, it fulfils requirements, the Home Office will issue another Memorandum to the local authorities, pointing out that a suitable siren can be obtained in Nelson. I hope the test will be carried out quickly, and that if it is satisfactory the Memorandum will be circulated quickly, too. It is not right that anything should be done by Government action to make the industries of Lancashire less effective than they are at present. It may be that they can do little to help, but I am sure they do not desire to do anything to hinder.

§ Mr. Burke
I am also interested in this case, because a firm in Burnley manufactures parts for the firm in Nelson. The Under-Secretary will know that I have been corresponding with him about the matter. What surprises me is this, that any one firm should be singled out and advertised to the local authorities throughout the country in any circumstances at all, but if that should happen, it ought not to happen unless there was a very fair 1015 test. From the information supplied to me, which I have sent to the Home Secretary, it did not seem that the test was in any way fair, because the firm in Lancashire were, as they say, invited to supply a 20-horse power siren, whereas the actual contract was for a siren of a very much less horse power. It lends itself to a good deal of suspicion if one firm's name is mentioned. I do not know whether it is the practice of Government Departments to single out one firm, but if that is to be done in the interests of efficiency it ought not to be done unless there is a very adequate and very fair test. The firms about which I have been in correspondence with the Home Office claim that they did not have a fair test.

§ Mr. Lloyd
Of course I entirely agree with the proposition of hon. Members that it would be wrong for a Government Department to discriminate unfairly between one firm and another or between one industrial area and another. I should like to put to the House some considerations which I think show this matter in a rather different light. When the Home Office turned its attention to instruments suitable for giving public air-raid warnings, it found that there was very little knowledge available in a readily accessible form with regard to the effectiveness of sound-producing instruments or the range over which sound could be transmitted. There were no data and the manufacturers themselves did not seem to have any clear idea as to how far sirens would carry, which from the Home Office point of view was a vital matter.
The Home Office therefore called together an informal committee to advise it. This committee included, besides representatives of various Government Departments, three expert scientific members in the persons of the Engineer-in-Chief of Trinity House, a member of the Physics Department of the National Physical Laboratory and a member of the research staff of the Royal Engineers and Signals Board who was especially concerned with the problems of sound ranging and sound location under the War Office. This committee decided at the outset that the problem of transmitting air-raid warnings was one on which the solution could not be given by existing 1016 data and it accordingly instituted special trials. These trials were of a comprehensive and comparatively elaborate nature. They lasted from March, 1937, until April, 1938.
The form of the trials adopted was to sound instruments from an elevated platform and to have the strength of the signals recorded by observers posted in circles round the site at varying intervals. These observers were carefully instructed beforehand how to record their impressions of the individual sounds in accordance with one of four classifications of audibility ranging from an arresting sound to a sound that was just perceptible, and points were awarded to each instrument according to the report made by each individual observer. The result was that the trials were primarily judged from the manner in which the instruments impressed themselves upon human observers, since the purpose of the trials was to find instruments which would convey the air-raid warning signals to individual members of the public. At the same time, the opportunity was taken of measuring the noise produced by each instrument by means of an objective noise meter supplied by the National Physical Laboratory.
In these trials the committee was aiming at finding instruments which had a range of not less than one mile, and the committee selected from among the instruments whose existence was known to the Department all those which gave promise of achieving this range. The manufacturers of each instrument were then invited by the Department to lend the instrument for inclusion in the trial, and in the great majority of cases they did so. It must be said that to a very great extent the results of the trials were disappointing. What I mean is that it was found to be surprisingly difficult to transmit a clearly audible sound over any long range in a built-up area.
The committee reported in August, and the Home Secretary felt that it was his immediate duty to notify to local authorities the instruments which had been found by the committee to be capable of this standard of performance. This was accordingly done by a circular on the 29th August. I have mentioned that in the course of the trials measurements of the instruments were taken by the National Physical Laboratory with an 1017 objective noise meter. By means of a correlation between these measurements and the observers reports it has been possible to frame a rough formula that an instrument which will give measurements of a certain standard on the objective noise meter at a certain distance and under certain conditions is likely to give an effective range of audibility comparable with those of the recommended instruments. This therefore gives a means of applying a test by which further instruments can be measured and it is the Home Secretary's intention that an opportunity should be given for instruments which were not brought to the notice of the committee during the trials to be tested at the National Physical Laboratory by these means. If, on test, they reach the required standard the Home Secretary will be prepared to add them to the list of recommended instruments.
I will now refer specifically to the instruments manufactured by Carter and Company of Nelson. They are electrical sirens, and I will preface my remarks by explaining that two types of electrical sirens were included in the Home Office trials, one a vertical type and the other a horizontal type. The horizontal type was in fact represented by the instruments of one firm only. There were numerous examples of the vertical type, both British and foreign. When the results of the trials came to be analysed it was found that the horizontal sirens of the one firm were the only electrical sirens which reached the standard the committee required and they, or rather one of the two instruments, was the only electrical siren which the Home Secretary was in a position to recommend. The House will however, of course, appreciate that until the conclusion of the trials neither the committee nor the Department knew that the horizontal siren would prove superior to the vertical siren.
To come to the position of Carter and Company. This firm was asked by the Department in March, 1937, to furnish particulars of the sirens they manufactured, and in their reply they stated that they had recently designed a new 20 h.p. siren which was about to go to test and asked that they might be allowed to postpone supplying the information until those tests had been completed. The following month particulars were furnished 1018 of a range of sirens all of the vertical type from ½ h.p. to 20 h.p., the last being their new instrument for which a considerable range of audibility was claimed.
The firm was therefore asked to submit this instrument for trial and did so. It was included in a trial held on the 22nd July, 1937. There was subsequently further correspondence with the firm on the subject of prices of their various instruments but the type of instrument, namely vertical sirens, remained unchanged so far as correspondence with the Department disclosed. The committee finally reported as I have described and its report disclosed that the 20-horse power vertical siren made by Carter & Company was not as efficient as the 4-horse power horizontal siren made by Gent & Company, Limited, the latter being the only type of electrical siren which the committee recommended. The Home Secretary's recommendation to local authorities therefore included no electrical siren except the Gent 4-horse power horizontal siren.
It was not until after the Committee had reported and the Home Secretary had issued his recommendation, namely, not until September of this year, that Carter & Company informed the Department that they made a 5-horse power horizontal siren which was in design and performance similar to the Gent 4-horse power horizontal siren which had been recommended.
The Committee's trials, as I have explained, had shown conclusively that the efficiency of sirens could be judged solely by their performance and not by their size or power. The Home Secretary was therefore unable to accept without confirmation the claim of Carter & Company that their 5-horse power horizontal siren was as good as the 4-horse power siren made by Gent & Company, Limited. I have however referred to the possibility of a noise measurement test at the National Physical Laboratory and an invitation has now been sent to Carter & Company to send one of their horizontal sirens to the National Physical Laboratory for test.
I want to emphasise two things: first that the instrument of Carter's which was included in the Home Office trials was the instrument which they put forward to the Department as being the one of all 1019 their instruments which had the longest range; and secondly that the existence of a Carter siren of the horizontal type was not brought to the notice of the Department until September of this year. The Home Secretary has no wish to withhold his recommendation from any British instrument which is of the required standard of efficiency but his duty to local authorities and to the taxpayer who provides the money for air-raid precautions grant compels him to be satisfied beyond doubt as to the efficiency of any instrument which he recommends for use as an air-raid warning signal.
I would conclude by saying that I hope I have removed the misunderstandings 1020 by which, I think was very easy for this matter to become clouded, and to express the hope that owing to the fact that we now know of the existence of this siren, the test will now take place. I would also express the hope that this siren may indeed fulfil the qualifications and that it may be possible for my right hon. Friend to issue a recommendation to the local authorities for this siren as well.