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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.

Intimately bound up with the rhythm of the organism, which, in this case, is the workshop hand, is the rhythm of machinery. The average man dealing with machines learns to distinguish page 37 between “just right” and “too fast” or “too slow.” In an earlier article it was shown that “speeding-up” had an injurious mental effect. Now, machinery run at too great a speed, is, in the long run, injurious for two reasons. The output is not really increased, because fatigue sets in earlier and production is eventually slowed up, while every machine has an optimum rate for best production. The speed at which a machine will give the maximum result is that at which material can be comfortably handled, without hustle
An Interesting And Efficient Machine. (Rly. Publicity photo.) Operating the Godfrey Oxy.-gas cutting and profiling machine, Hutt Valley Workshops, Wellington.

An Interesting And Efficient Machine.
(Rly. Publicity photo.)
Operating the Godfrey Oxy.-gas cutting and profiling machine, Hutt Valley Workshops, Wellington.

or undue haste, by hands using the machinery. The relationship between rhythm and work is of paramount importance. I have seen one machine, working on a friction basis, which cuts steel rails in, approximately, nine seconds. This period is sufficient to allow two men to handle the rail with a suitable “swing.” If the time were cut down by a second, both men would be flurried, with the ever-present possibility of serious accident. Should the time be lengthened by one second, then the slowing up would induce fatigue to a greater extent for the rhythm would be broken.

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.).

A Bright And Well-Ordered Interior. (Rly. Publicity photo.) A portion of the heavy machine shop, Hutt Valley Workshops, Wellington.

A Bright And Well-Ordered Interior.
(Rly. Publicity photo.) A portion of the heavy machine shop, Hutt Valley Workshops, Wellington.

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.

While the shops are run upon strictly business lines in keeping with modern psychological findings, the social side, with its enormous reaction on shop life, has not been neglected. Mention has been made of the grounds.
(Photo, A. P. Godber.) The heater pipe system in course of erection at the Hutt Valley Workshops, Wellington.

(Photo, A. P. Godber.)
The heater pipe system in course of erection at the Hutt Valley Workshops, Wellington.

The promise of park-like surroundings is finding fulfilment. Native trees, flower beds and trim lawns are in evidence. The maintenance work is done by the employees who have also provided the material. The underlying factor that, what is provided by the hands will be appreciated by them, is recognised by the Works Manager who stimulates out-of-door activities. Nor is the fact lost sight of that such effort has a personal reflection in workshop practice. Granted that conditions under which the work is performed are pleasing, the “job” must also be superior. This is simply an emotional or aesthetic aspect which, although not always objectively measurable, is as true as the statement that poor shops invariably produce poor work. The men hastening to catch the train provided, free of cost, to take them to their city homes, use paths and avoid “short cuts.” The sward is unbroken by tracks; woe betide he who seeks to walk across the grass. “He who runs may learn” that the paths are the places on which to move. There is much civic and social training resulting from this outlook which must be reflected in pride of craftsmanship.

The next article will discuss the other social aspects of the shops, with their bearing upon interrelationships.