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Nocturnal ship simulator
for 120 contraventions of them. The Health and Safety at Work Act 1974 provided the additional new legal sanctions of improvement and prohibition notices and since it came into force at the beginning of last year 8181 notices have been issued, 84 of them in connection with the use of asbestos. These notices were not a substitute for prosecution. In 1975 there were 1433 cases heard as well". The strength of the Factory Inspectorate, too, was being built up, Mr Walker added. Since 1970 it has increased in size by about 30%. As well as employing more sophisticated monitoring aids, the Inspectorate now had Field Specialist Groups backed up by mobile laboratories. Training for Inspectors had become more rigorous, involving a six month University course and continuing refresher courses.
Nocturnal ship simulator The nocturnal ship simulator, which simulates ship handling and manoeuvring for training bridge staff was developed for the Ship and Marine Technology Requirements Board of the Department of Industry by Decca Radar Ltd, at a cost to the Government of £330 000. It consists of a wheelhouse with a bridge control console including wheel and autopilot, radar, communications and chart table; noise and vibration effects are also generated. It is housed in two low cost Portakabins, where from the bridge window can be seen a night time view of the ship's bow, lights of navigation marks and lights of other ships. All the lights move and are properly co-related with the echoes on the radar display. The simulator provides anti-collision, navigation, pilotage and handling exercises to simulate vessels ranging in size from a coastal craft to a 500 000 tonnes oil tanker. Tides and currents can be fitted into the system and shallow water conditions can also be reproduced. The computer mathematical model governing the manoeuvring behaviour of the vessel was developed jointly by the National Physical Laboratory and Decca. The project dates from 1973 when the Ship and Marine Technology Requirements Board commissisoned a survey on the availability of this type of equipment in other countries, This led to the Department of Industry placing a contract for a low cost nocturnal simulator with Decca, the costs of which will partly be recovered by a levy on sales and sale of the prototype to the Southampton School of Navigation. The marine application of this equipment will be the training of bridge staff, individually or as
members of a team, in practical and realistic exercises under routine conditions or with emergency situations. It will also be valuable for research into instrument development, bridge layout (which the SMTRB is supporting at present) and collision avoidance exercises. Training courses at Southampton are in preparation in association with the Merchant Navy Industry's Training Board, the General Council of British Shipping and the Marine Division of the Department of Trade.
Work chair developed in Denmark A Danish Surgeon, A.C.Mandai, has developed a chair based on his and fellow surgeon's experiences of working for long periods in the sitting position. The result is a work chair designed to reduce the postural stress on the neck, thighs and lumbar regions of the body. This chair is now being marketed in the UK by Siemens Ltd, Great West House, Great West Road, Brentford, Middlesex. It is intended for use in offices, factories engaged in light assembly work, schools, or any situation where people sit down to work for long periods. Superficially the Mandal chair resembles a typist's chair in that it has a back-rest, is adjustable for sitting height and is light enough to be easily moved around. However, the conventional typist's chair has a seat that slopes backwards about 5°; an ideal angle for typing and resting, but not at all suitable for working at a desk or table. The Mandal work chair's seat adjusts itself to the optimum position: sloping backwards for resting and sloping forwards for working. Siemens state that the criterion for the optimum working position is the distance from the eye to the workpiece or page, ie, the viewing distance. In adopting the optimum viewing distance whilst sitting in a conventional chair whether it be for reading, writing, filing or assembly work - the upper part of the body assumes a 'bent over' position. A chair with a flat or backward sloping seat makes bending over tiring - the slumped position of many school children working at flat-topped desks is an example of what can happen after a prolonged period. The reason for this is because the spine assumes the shape of a taut bow, causing tension in the neck and lumbar regions and inflecting the hips beyond 90 ° . This working position soon becomes uncomfortable and consequently most people move towards the front edge of the seat, whereupon its sharp edge digs into the softer parts of the thighs, often causing pressure on the sciatic nerve. In this position the hips are not flexed more than 90 ° , but the neck and lumbar regions are still under stress. Siemens
claim that evidence that this position is the one most frequently adopted can be seen by looking at the seats of wellused office chairs; the seat covers are more worn along the front edges. Sitting on the edge of the seat is an uncomfortable and stressful position and is eased by tilting the seat up to a maximum of 15 ° forwards. On the Mandal work chair this rotary movement takes place without conscious effort because it originates below the body's centre of gravity. According to Siemens, the work chair literally pushes the upper part of the body forward into a more relaxed working posture. In this position the pelvis tilts forward of its own accord and the lumbar region adopts a more natural attitude. Furthermore, the spinal cord is said to rest in its natural swaying state and therefore does not require much muscular effort to maintain its position; resulting in less strain on the related ligaments. All children understand the advantage of tilting forward on the chair when working at a table. In a balanced forward-tilting position a back support is unnecessary and is only of use in the resting position. Moreover, in the forward-tilting position the thighs and the nerves associated with the hips are supported over the whole area of the seat and not just by the forward edge, as is often the case with conventional seats. Even
;i i!!~i; !i
Mandal work chair available from Siemens
Applied Ergonomics September 1976
185
Nocturnal ship simulator The nocturnal ship simulator, which simulates ship handling and manoeuvring for training bridge staff was developed for the Ship and Marine Technology Requirements Board of the Department of Industry by Decca Radar Ltd, at a cost to the Government of £330 000. It consists of a wheelhouse with a bridge control console including wheel and autopilot, radar, communications and chart table; noise and vibration effects are also generated. It is housed in two low cost Portakabins, where from the bridge window can be seen a night time view of the ship's bow, lights of navigation marks and lights of other ships. All the lights move and are properly co-related with the echoes on the radar display. The simulator provides anti-collision, navigation, pilotage and handling exercises to simulate vessels ranging in size from a coastal craft to a 500 000 tonnes oil tanker. Tides and currents can be fitted into the system and shallow water conditions can also be reproduced. The computer mathematical model governing the manoeuvring behaviour of the vessel was developed jointly by the National Physical Laboratory and Decca. The project dates from 1973 when the Ship and Marine Technology Requirements Board commissisoned a survey on the availability of this type of equipment in other countries, This led to the Department of Industry placing a contract for a low cost nocturnal simulator with Decca, the costs of which will partly be recovered by a levy on sales and sale of the prototype to the Southampton School of Navigation. The marine application of this equipment will be the training of bridge staff, individually or as
members of a team, in practical and realistic exercises under routine conditions or with emergency situations. It will also be valuable for research into instrument development, bridge layout (which the SMTRB is supporting at present) and collision avoidance exercises. Training courses at Southampton are in preparation in association with the Merchant Navy Industry's Training Board, the General Council of British Shipping and the Marine Division of the Department of Trade.
Work chair developed in Denmark A Danish Surgeon, A.C.Mandai, has developed a chair based on his and fellow surgeon's experiences of working for long periods in the sitting position. The result is a work chair designed to reduce the postural stress on the neck, thighs and lumbar regions of the body. This chair is now being marketed in the UK by Siemens Ltd, Great West House, Great West Road, Brentford, Middlesex. It is intended for use in offices, factories engaged in light assembly work, schools, or any situation where people sit down to work for long periods. Superficially the Mandal chair resembles a typist's chair in that it has a back-rest, is adjustable for sitting height and is light enough to be easily moved around. However, the conventional typist's chair has a seat that slopes backwards about 5°; an ideal angle for typing and resting, but not at all suitable for working at a desk or table. The Mandal work chair's seat adjusts itself to the optimum position: sloping backwards for resting and sloping forwards for working. Siemens state that the criterion for the optimum working position is the distance from the eye to the workpiece or page, ie, the viewing distance. In adopting the optimum viewing distance whilst sitting in a conventional chair whether it be for reading, writing, filing or assembly work - the upper part of the body assumes a 'bent over' position. A chair with a flat or backward sloping seat makes bending over tiring - the slumped position of many school children working at flat-topped desks is an example of what can happen after a prolonged period. The reason for this is because the spine assumes the shape of a taut bow, causing tension in the neck and lumbar regions and inflecting the hips beyond 90 ° . This working position soon becomes uncomfortable and consequently most people move towards the front edge of the seat, whereupon its sharp edge digs into the softer parts of the thighs, often causing pressure on the sciatic nerve. In this position the hips are not flexed more than 90 ° , but the neck and lumbar regions are still under stress. Siemens
claim that evidence that this position is the one most frequently adopted can be seen by looking at the seats of wellused office chairs; the seat covers are more worn along the front edges. Sitting on the edge of the seat is an uncomfortable and stressful position and is eased by tilting the seat up to a maximum of 15 ° forwards. On the Mandal work chair this rotary movement takes place without conscious effort because it originates below the body's centre of gravity. According to Siemens, the work chair literally pushes the upper part of the body forward into a more relaxed working posture. In this position the pelvis tilts forward of its own accord and the lumbar region adopts a more natural attitude. Furthermore, the spinal cord is said to rest in its natural swaying state and therefore does not require much muscular effort to maintain its position; resulting in less strain on the related ligaments. All children understand the advantage of tilting forward on the chair when working at a table. In a balanced forward-tilting position a back support is unnecessary and is only of use in the resting position. Moreover, in the forward-tilting position the thighs and the nerves associated with the hips are supported over the whole area of the seat and not just by the forward edge, as is often the case with conventional seats. Even
;i i!!~i; !i
Mandal work chair available from Siemens
Applied Ergonomics September 1976
185