The New Zealand Railways Magazine, Volume 4, Issue 11 (June 1, 1930)
Effects of Noise on Production
Effects of Noise on Production
Reverting to the noise principle referred to in the last article it will be discovered that the worker finds the clang of hammer or the rat-tat of the riveting machine adversely affects production. Psychologically, it has been proved that the distraction due to noise lowers his output, because of the cross-currents of attention. Recently, a case was noted at Otahuhu shops. One of the workers in the undercarriage shop, where there is considerable noise due to the nature of the work, complained of feeling sick and applied for a change of shop. Investigation followed and, as a result the employee was transferred to another shop where there was, comparatively speaking, silence. Reports indicated in a definite manner that noise was a large factor in his output, while no further complaints as to his health have since been made.
On broad lines, too, noise is a fatigue factor which affects, to a serious degree, the output scheduled for the period. The schedules for jobs do not show this to any extent because of the method of computation, but a superficial examination of the employees leaving the engineering shops, as compared with those in the painting or upholstery sheds, indicates the truth of the laboratory findings. There is the strain produced by noise as well as that which is the outcome of work, irrespective of the amount of bodily exertion which the job demands. That this has a serious effect upon the nervous system cannot be denied for it reacts upon the worker who cannot make the correct motor response in a situation demanding accurate perception of the position.
Noise and Accidents.
This is demonstrated by perusing the “First Aid” book at Otahuhu. One is struck by the lack of serious accidents listed, but impressed by the number of slight accidents to hands and eyes. An investigation showed that the operators gave as reasons: “The tool slipped.” “Finger got caught on the wheel.” “Sparks rose when I didn't expect them.” “The goggles are uncomfortable;” and so on. The answers bear out what has been said in respect to the relationship between noise, fatigue and late or incorrect motor responses (or movements).
Through the courtesy of the Manager of the Otahuhu Workshops, figures which have a definite bearing on this aspect can be quoted. Selections made at random from sheets, show the relationship of accidents as follows:—
Date. | Time. | Steel Shop Accidents. | Other Shops. |
June 12th | 8–9 | 2 | 2 |
June 12th | 9–10 | 7 | Nil |
June 12th | 10–11 | 2 | Nil |
June 12th | 11–12 | 2 | 1 |
June 12th | 12.30–1 | Nil | 1 |
June 12th | 1–2 | 2 | Nil |
June 12th | 2–3 | Nil | 1 |
June 12th | 3–4 | 2 | Nill |
Oct. 22nd | 7.30–9 | 5 | Nil |
Oct. 22nd | 10–11 | 1 | 1 |
Oct. 22nd | 11–12 | 3 | Nil |
Oct. 22nd | 12.30–2 | 3 | Nil |
Oct. 22nd | 2–3 | 3 | Nil |
Oct. 22nd | 3–4 | 3 | 1 |
An analysis of the sheets indicates clearly that it is neither equipment in the shop nor carelessness on the part of the worker that throws the great incidence of cuts, foreign bodies in eyes or similar small accidents, to the account of the steel shops. But rather is it the noise, which is inseparable from the work, reacting on the nervous system, which, in turn, produces conditions suitable for mishaps.
Relation between Rhythm and Work.
Similarly has this “swing” factor been considered in riveting where the electric heaters turn out the material at the pre-determined intervals so that there is an even flow without undue haste or piling-up of ready rivets. Many numerous small points have been combined with the main machines in one shop so that there is a steady forward movement over the whole of the working unit. From the time small angle-irons are punched for rivet holes, until the complete undercarriage is strapped together, the rhythm is maintained. So complete is the organisation, that the shop has worked out a time schedule for a complete shift in the assembly shop every two hours. At the same time it must be understood that if machinery is “speeded-up” so that the rhythm at which it is intended to operate is thrown out, the effect is deleterious, even disastrous, to the machine. (Private factories, in an endeavour to increase output, occasionally fail to realise this factor.) On specialised jobs, such as boring holes in flooring sheets, thought has been given to promote movements calculated to be both natural and, at the same time, quicker. The order of boring holes has been fixed and the worker has been instructed in procedure. The saving in both time and effort will be more obvious if the reader attempts to work from left to right and proceed page break page 39 forward then to contrast with the reverse motions.
Pleasure and Displeasure Responses.
This work movement, too, is intimately bound up with the emotional life. A machine used by Titchener, and named the Automatograph, measures the effect of mental pleasure, or displeasure. It has been established elsewhere, and local experiments bear this out, that pleasure gives an involuntary forward and upward movement about 2cms. long, while displeasure shows a contrary movement, flatter and comparatively longer (up to 4cms.).
It will be apparent at once that if the work is arranged pleasurably the result will be attained with considerably less involuntary movement. One foreman, in discussing the matter, mentioned the case of a man who had had a slight accident with his machine. His output declined slightly, prompting enquiries for such falling off. This particular worker could give no reason, but desired to be put on to other work. Consideration of the position, in the light of the laboratory experiment, shows that the man, under the emotional stress of fear of a further accident really did “retire within his shell” every time he made a new movement. Given that it was 4cms. from the correct place it meant a loss of one second on each fresh movement, which at the end of the work unit, totalled a considerable loss of time and, hence, of output. On being transferred to other work the possibility of his fear being inhibited promised success. Physically the employee working under pleasure breathes quicker and weaker, with a consequent slower and stronger pulse than that observed under displeasure. This enables the repair of the cells to proceed more rapidly, so that there is less contamination of the blood stream.
Significance of Labour-aiding Devices.
In concluding the review of machinery factors, it would be incomplete if one omitted to mention the degree to which mechanical aids have been utilised. The layout of the shops indicates an appreciation of the advantages of machinery. Old, obsolete machinery passed away with the demolition of the Newmarket shops. Wherever machines can do the work these have been installed, so that production is now increasing while time schedules indicate a decreasing time-span on the job. But that is not all. Considerable thought has been given to economy of time and effort in small details. As a result, there are labour saving devices in all the shops. As an instance, the riveters use a small holder, adjustable, by means of a lever, to changing working conditions. This page 40 holder fits over the head of the rivet and maintains it securely in place until the operation is complete. The idea originated in the works and has been adopted in all the shops. The efficiency of this tool, as against the hammer of former days, cannot be denied. Then there is a simple machine used for lifting the carriage off the bogies. This “lifting” machine is a strange agglomeration of parts. The standards are part of an obsolete machine, while worms, motor-cycle chains and similar pieces make a complete whole, simple in mechanical construction, besides requiring little power for manipulation. In the painting shop an adjustable ladder is hourly in use. It is designed to fit any car, giving, at the same time, a grade suitable for men whose hands are full. It was admitted that considerable thought as to grade and stability were involved in its manufacture, but, when the time and effort saved in the aggregate were reckoned up, the return must run into millions per cent., or, conversely, “overhead,” the bugbear of many concerns, was proportionately lowered.
The Social Aspect.
The next article will discuss the other social aspects of the shops, with their bearing upon interrelationships.