The Effects of Noise in the Diving Environment

Underwater Technology

Laboratorium "°°

The Effects of Noise in the

.rch!ef

Diving Environment

&ceiwe 2, 2628 CD De!ft

S Fde t*3l*the morning session of a one-day Seminar, 28 ApriI 1987

By W. THORNILEV*

In his opening remarks the Chairman, Commander

s. A. Warner, stated that both the EEC and the 1-Icaith and Safety Executive had provided guidance on the control of noise in the workplace. Ele felt that there was no reason why offshore personnel and. in particular, underwater workers should not be subject to similar protection as their shoreside colleagues. It was. however. emphasised that the EEC directives are not legally enforceable Ofl the continental shelf outside territorial

waters.

The first speaker, Mr A. Dove of the I lealth and

Safety Executive, stated that excessive noise in the

workplace could cause hearing deficiencies in later life.

The employers in the early years of the industrial

revolution had little regard

for the health of their

workers whose life expectation was not sufficiently long for hearing deterioration to take place.

Since the 1950s the understanding of relationship between noise and hearing has increased rapidly. The risk of becoming deaf from noise in the workplace depends on noise levels averaged over the day or week and the number of years of exposure.

In the early I 970s the HSC set up a working party to propose regulations on noise control in the workplace and a draft was submitted for consultation in 1981. This initiative was overtaken by events as the EEC issued a

directive which requires member states to provide regulations by 1990.

lt is appreciated that noise limitations imposed on

workers in atmospheric pressure may not apply to

underwater workers or those subjected to pressures of more than I bar absolute. Reluctantly, the USE working party, preparing the future regulations. has decided to exclude underwater work by defining the action levels, in terms of air, at atmospheric pressure.

Mr Dove posed the question as to whether divers suffered from deafness as a result of their employment. If the answer is 'yes', he stated the employers have a responsibility under the Health and Safety at Work Act to preserve the health of their workers. He suggested

that when the problem of divers' bearing had been

further researched, perhaps the best way of protecting underwater workers was to issue a Guide or Code of

Practice.

When asked by the Secretary of the Association of Offshore Diving Contractors if the proposed legislation

would apply to divers, Mr Dove replied "As far as

reasonably practicable".

Dr John King, a consultant, was the next speaker who presented a paper entitled "Loss of Hearing in Divers". l-le stated that most men started their diving careers as

healthy young men with good hearing acuity . This can be checked annually by audiogram examination which

over the years can provide trends in hearing loss. Divers are regularly subjected to pressure either in the

water when carrying out their tasks or in an air or gas environtilent in compression chambers. It is of interest

that when in the water there

external noise signals than when the diver is in gas, as the

noise energy can be transmitted from the water directly through the skull rather than through the ear which may be protected and alniost certainly has an air hobble in it. [n the studies which Dr King has concluded and which are supported by other work on the subject, the diver is no nore likely to suffer hearing loss owing to noise in his environment than the average man. It is however possible that his hearing may be impaired by the effects of pressure and ear diseases to which some divers are prone. Also, exceptionally, some divers may suffer hearing loss from underwater explosions or from accidents such as 'blow ups'.

Dr Jim Livesey of the Admiralty Materials and

Technical Establishment/Experimental Diving Unit.

presented a paper entitled "Measurement of Noise in the

Diving Environment".

He commented that even if noise was not likely to be hazardous to the divers' health, it did cause fatigue and interfered with communications. Dr Livesey described some of the instrumentation which had been developed at EDU. l-le used a mannequin with small hydrophones set in the ears to record noises froni the diver's helmet, the water environment and also in hyperbaric chambers.

He discussed the results of video records of noise levels in the diving environment and how he believed that the instrumentation could be improved.

Dr Brian Murray of Development Engineering (Aberdeen) Ltd gave a paper entitled "Effect of

Seismographic Survey on Divers".

He stated that his paper resulted from work he carried out in 1982 for Occidental Petroleum (Caledonia) Ltd when the company asked him to clarify the safe stand-off distance

during the survey programme of the

"Following a preliminary literature survey, both the

noise levels produced by the seismic survey operations

and the blast induced pressures to which divers would be exposed were assessed. Measurements of these parameters were then made on-site. Finally, the subjective comments of a number of divers were

recorded as the seismic survey vessel steamed towards

the platform giving a progressive increase in water

noise level.

'L)ii'ing Inspectorate. Department of Lergv o,!u/ed on page 27

Gamma Classified Topics

The use of the term Gamma may be unfortunate in that it may convey the impression that the subjects listed are not important. They are important but are either addressing problems which may not be encountered for some years or current problems for which there is a solution albeit not entirely satisfactory. Much of the

work must be started soon if the results are to be

available ahead of the requirements.

I. A desk

be performed to provide

Research, including field observation and model tests, should be conducted into the suction beneath gravity

base structures during removal.

Mapping of the seabed, laboratory testing, desk studies and field data acquisition for assessing seismic risk and its effect on slope stability and liquefaction

are required.

A study of the consequences of relic features due to permafrost and iceberg scouring should be conducted.

Research should

be conducted into methods of

predicting the forces on foundations produced by soil

flow.

Foundation design procedures based directly on the results of in situ tests should be developed.

References

I. Semple, R. M., St. John, H. D. and Toolan, F. E. "Statement of Research Needs in Offshore

Foundation Design" Report to SUT, 1982.

Tjelta. T. I., Guttormsen, T. R. and Hermstad, J. "Utrge Scale Penetration Test at a Deepwater Site"

OTC 5103, 1986.

Ove Arup and Partners "Comparison of British and Norwegian research on the behaviour of piles as anchors for buoyant structures". Department of Energy Offshore Technology Report, 0TH 86 218,

HMSO. London 1986.

Clarke. J.. Rigden. W. J. and Senner, D. F. "Reinter-pretation of the West Sole Platform 'WC' pile load tests" Geotechnique Vol. 35, No.4, December1985.

Rigden, W. J. ann Semple, R. M. "Design and

Installation of the Magnus foundations: prediction of pile behaviour". In Design in offshore structures, pp. 37-51, London: Telford 1983.

Robertson, P. K., Campanella, R. G., Brown, P. T., Grof. 1. and Hughes, J. M. 0. "Design of axially and

laterally loaded piles using insitu tests;a case history"

Canadian Geotechnical Journal Vol. 22, No. 4.

November 1985.

Tomlinson, M. J. "Adhesion of piles in stiff clay" Report No. 26, CIRIA, London, 1970.

Marsiand. A. "The influence of geological process and test procedures on measured and evaluated

parameters". In Offshore Site Investigation published

by SUT, pp. 231-252, 1985.

SUT "Advances in Underwater Technology and Offshore Engineering, Volume 3, Offshore Site Investigation". 1985.

Symposium in Print "The engineering application of direct and simple shear testing". Geotechnique. Vol. 37, No. 1. March 1987.

Underwater Technology

University of

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Newcastle upon Tyne is the largest in the United Kingdom with a woddwide reputation. A number of postgraduate courses are offered to graduates both in Marine Technology and other Engineering Disciplines.

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