Ergonomic aspects of ship design in particular with regard to ship's bridges and wheelhouses

1 2 JUN 1974

/6

ARCHIEF

Thema : (POCVNIWATUI

y2ii.

ERGONOMIC ASPECTS OF SHIP DESIGN,

IN PARTICULAR WITH REGARD TO

SHIP'S BRIDGES AND WHEELHOUSES

Human Engineering Problems in the Design of Ship's Bridges from point of view of Practical Experience

by J. N. F. Lameijer

(Royal Netherlands Shipowners' Association)

Lab. v. Scheepsbouwkunde

Technische Hogeschool

Delft

HUMAN ENGINEERING PROB= IN THE DESIGN OF SHIP',S BRIDGES

FROM A POINT OF VIEW OF PT2ACTICAL EXPERIENCE. INTRODUCTION

Since the 1960's a good number of serious studies have been made on

the design, lay-out and instrumentation of the bridge/wheelhouse,

A great number of very good publications on these subjects have been

produced. Unfortunately, however, this work does not seem to bear fruit

An the way it should have done. Although. there are examples of .modern. ship's'bridges where one can clearly notice the influence of these'

studies and publications, there are Still too'tany ships being built

today with an astonishing lack of proper design, lay-out and

instrumentation of the bridge/wheelhouse. There are two main reasons

for this phenomenon.

The first reason is conservatism, borne by tradition.

For centuries the ship's bridge contained only one instrument: the compass,

and one control: the whipstaff, and later the steering-wheel.

Very gradually more equipment was introduced on the ship's bridge.

The introduction of steam propulsion made two-way communication from

bridge to engine-room necessary. Hence the engine-room telegraph made

appearance on the ship's bridge.

Advances in technology gradually made more navigation- and control

equipment available, such as the gyro-compass, the radio-direction

finder, the echo-sounder, the rudder angle indicator and the

R.P.M.-indicator. After the second world-war there was a sudden increase in

the number of equipments and instruments, which could be used in the

interest of navigation, for instance the Radar, Loran and Decca Navigator, All these instruments found theirway to ship's bridges, and were

installed most of the time at random, because they ware regarded as more or less useful aids but not really essential for sailing the ship,

Deep at heart the mariner has still the feeling that he can manage with. only steering and engine control, the compass and the sextants

-The second of the reasons is lack of appreciation by many shipowners

and shipbuilders of the real importance of thelaidge/wheelhouse, its

equipment and instrumentation for a ship.

Time and again one can observe that the bridge/wheelhouse

require-ments are regarded secondary to other requirerequire-ments. The result is often

insufficient space in the wheelhouse and bad viewing conditions.

A third reason might be the lack of co-ordination between the parties

concerned in the design, lay-out and instrumentation of ship's bridges.

An impressive amount of studies and work by various interested experts

has been done. To my knowledge however, a co-ordinated effort combining

the know-how of all parties which play a distinct role in this field, has not yet been carried out.

To optimalize the result and to obtain agreement on the whole by

everybody concerned it is necessary to make a co-ordinated study

combining the specialized knowledge of :

the marine navigation expert

the naval architect

c. the human engineer

d0 the perception

engineer-the electronic-nautical instrumentmaker

the remote-control expert

Many very good and detailed descriptions of modern ship's bridges

have already been published. Having 15 years of experience in the

field of design, lay-out and instrumentation of ship's bridges, I could

make another detailed contribution in this field. I do not think, however, that with the material already available I would be able to

cover new ground. In many respects it would no doubt be a mere repetition

of what has been published already before.

An inventory of the various aspects which play a role in the

.design degiderata of the bridge/wheelhouse, would in my opinion be more

of all relevant issues at stake and to ihdibate the existing problems. In this way it may serve as a guideline fdr the necessary. Coordinated. 'studies, which must be undertaken.

The need to adapt the tridge/wheelhouse _{arrangement,_} its equipment and instrumentation

The control of the safe conduct of the vessel _{in its environment}

has undoubtedly become more complex since the _{time that the whipstaff}

And the compass were the only control-features on the ship's bridge. There are a number of factors which contribute to this increased

complexity,

1. _{The ever increasing density of traffic in sea areas Of cot*erging} traffic.

Since

1947

_{the number of vessels sailing the high seas have-more}

than doubled. It is'predicted that in the next 25 years the'voiuie of cargo to be shipped

_by

_{Marine transport will-be three tithe} amount carried

today.

_{This will not result}

_in

_{three times the}

_amount

of vessels at sea, but it is estimated that it may amount to

_about

double the number of vessels, which _{are today sailing the 'high seas.} If one takes into account the decrease _{on turnround-tiie}

_of

_ships, because of higher speeds, rationalization and automatization in cargo handling, one can

easily

_{see that traffic density may more} than double itself in the sea areas of converging traffic),

More and more V.L.C.C, s with very deep-draughts will become part of the population at sea,

Because of the, depth in certain tea _{areap precision navigation is} required and because of the ship' _{restricted manoeuvring they cause} problems to other shipping,

3.

The speed of vesselshas increased.

This in itself creates problems, because more information has

to be processed, more decisions and more actions have to be taken

in the same period of time. It also causes an increase in

differentation between speeds of vessels present in one and the

. same sea area, which increases the risk of collision.

40 The number of people available on board of ships to take part in

the .navigation and control of the vessel has decreased

because of rationalization and automatization of various

.- shipboard activities;

tecauSe of the structural shortage of, well,-trained navigators and sailors.

Many,Vessels used to sail with a number of junior deck officers

'and/or cadets on board, So that on each watch one such junior

officer was available. Many of the less responsible and less

.important-routine -jobs were carried

out

by these young offiCers.

.

Today

on board and one is in a privileged position if there is one on

board at all,

Ships carrying very dangerous and poisonous liquids and gases have

become part of maritime traffic.

Accidents with these ships can result in serious disasters involving

not only the life of people on board of ships and the property

concerned but which could also inflict serious damage to the

environ-ment. This problemconcerns not only the dangerous cargo. carriers but also all other vessels at sea.

The community becomes more and more aware of this and demands

protection of the environment. Shipping has to respond to this claim. ships have to sail without a junior officer

60 _{The investment in sophisticated navigation and control equipment}

improves the expedition of ships.

Naturally this is reflected in the schedules of voyages of vessels. The ship is more or less expected to proceed under all weather conditions.

7. _{Exploration of the sea-bottom is an ever expanding industry.}

More and more production rigs are being built in navigable waters. In some sea areas, like in parts of the Gulf of Mexico, ships have to follow certain tracks in order to keep _{out of the way of oil rigs.}

This causes undoubtedly concentration of traffic _{on these tracks.} Before long we may be faced with a similar situation in the North Sea and other sea areas of the world.

Accident statistics show us that _{we are already loziying f-r}

increased complexity in the control of _{the'.safe Conduct of the. veesel..} 'Useful figures were published by Beer in

_1969.

_{'Thee show that annual}

ships' losses from all causes increased from 0.25 percentof tonnage risk in the late nimteen fifties to 0.48 per cent in 1966. These

absolute magnitudes are still not large, _{but the trend is disquieting,}

We must take account of this increase, especially when it is clear that a large part of the accidents at _{sea are due to human errors. It is}

worthwhile to consider in this respect some figures for ships' casualties from widely differing sources.

Of 276 ships reported as abandoned in Lloyd's List in the secOnd half of

_1963,

_{not less than 121 were involved in groundings or} collisions due to ,"errors in navigation";

The U.S. Coast Guard Committee's

₁₉₆₃

_{report on tanker hazardS} surveyed collision records for

_1957-159.

_{There were}

₃₉₈

_vessels involved in 199 _{collisions. There was "mechanical failure" in}

These figures and the current reports of casualties which have

taken place in the North Sea and Dover Strait imply that the human

operator is a weak link in the organisation. of the safe conduct of

vessels at sea.

It-is therefue necessary to investigate the reasons why these

errors occur. Human errors can be divided into those of apprehension

those of-decision. The first happen at the interface between the

instrument or machine and the human being.

The situation at this interface is not satisfactory.

Each instrument or control mechanism in itself may be technically. perfect, but the display of information to be sunplied, or the controls

which have to be handled, are not always efficiently made available to

the human operator. Moreover, the grouping and the assemblage of the. displays and control mechanisms, as installed on many ship's bridges, are often unsatisfactory and do not preclude wrong interpretation or

faulty handling. In fact the arrangement of displays and control mechani

can be confusing or even misleading.

Finally, the whole environment of the enclosure in which control

operations for the safe conduct of the vessel take place, could in the majority of cases be considerably improved.

It is evident that human errors are generated by bad or even wrong

ergonomic designing.

In the interest of improving the safe conduct of the vessel in its

environment, it

is

essential that we tackle the problem of suitable adalitation-to the' human operators of:

-a.-the environment of the bridge enclosure, and

b. the necessary instrumentation and control mechanists, together. with-ail other necessary equipment.

Improvements in education and training of seamen are even more

--important to reduce human errors,. caused-by wrong decisions.

and

However this aspect is outside the Scope of this paper. It would'

lead much too far to discuss it here; it is, however, a subject which

.deserves our utmost attention...

Operations on ship's bridges

Before we. can s art to investigate the problems of ergonomics

ship's bridgesbridges it is essential to analyse the operations that take place On ship's bridges. For each type of vessel, these operations are depending On the different phases in which a port-to-port ship's yOyage.can be

broken down and also on the conditions that can prevail during, the

voyage.

These phases are:

At-ship's destination:

Berthing, tn-berthing, anchoring.

Underway:

in pilotage waters

in open sea, but in confined-areas with dense traffic

in open sea with little or no traffic in the vicinity

Each phase has to be considered under different.conditions, that _is good visibility

adverse weather conditions

C. bad visibility

Job studies are necessary for the analysis of the operations _{on ship's.} bridges. A number of job studies have been made. Literature of job studies carried out in the U.S.A. is available. From these studies we learn that the phases (1) and (2) in conditions of bad visibility require most manpower on the bridge. This is of course completely in line with the

experience on board ships. There is generally no difference

in

_requirement of manpower for phases (1) and (2).

The most dangerous phase is 'beyond any doubt phase

(2)0

Severity per cent Of all collisions occur when vessels are

underway in

pilotage watersi

_

In the design of ship's bridges, one

should concentrate therefore on

the operations for phase (2) taking into due-account the

other phases..

It should be possible to match the requirements Of the less dangerous

phases to those of phase (2).

Based on the present day knOWledge -and experience

of. the operations;

that take place on 'board, several attempts have been

made to rationalize

bridge designs, layout and instrumentation.

It is, however, disturbing to see that all

these attempts show

fundamental differences in the resulting plan of the

bridge/wheelhouse.

The reason for this might be that - as pointed

out earlier - it was

never the result of a really co-ordinated effort. Another reason is that

one can doubt whether it is

possible to optimalize in ship's bridge

design, instrumentation and lay-out, without doing

comparative studies.

These stu-dies can not be carried out on existing vessels, because one

can. not change the existing condi-lions

with regard to lay-out,

instrument-ation

equipment. Simulation techniques have to be

used9 Trained

mariners like pilots

captains and mates could volunteer in studies

ashore, using models and simulators. Amodel.and

. -

simulator like the one on

display at this exhibition can be used, Ithen

suitably further developedas auseful

-tool for such studies. Ultimately, for final optimalization, a

ship-manoeuvring. simulator, in which all phases of a ship's voyage can be

simulated, should become available to make realistic

experiments on

all aspects, of bridge-ergonometrics.

Identified problems of today's ship's bridges

-

-today, one discovers a great variety 'in designs, lay-outs and

instrumentation. It is of course not admissible that all of these

varieties are giving the right ergonometric solution.

I shall try to indicate the most important problems in this

respect.

(i) Wheelhouse or bridge-enclosure

The function of the wheelhouse is to create the right

environment for the persons engaged in operations in this

place. This includes:

The right environmental lighting

Good visibility

Adequate working space

Limitation of light reflections

Adequate heating and air conditioning

Limitation of noise level

E. The right working.pbsitiptr;

a. The right environmental lighting.

.

One should be able to work with the same ease under all

light--conditions. Even on-a Pitch dark night, one should- be .able to MOVE

freely accross the bridge and also be able to observe all.

instruments, without impairing the vision for a good look-but.

Red light is known to be the right type of be used at high intensity without losing night vision.

_-Important is also the area in the vicinity of the bridge-and

wheelhouse outside as well as inside of the deckhouse-. One should

match the lighting of the areas adjacent to the bridge, so that

it does not harm light-conditions on the bridge. For instance,

when opening the wheelhouse door to the accomodation, a gulf of .

white light penetrates very often into the wheelhouse, which is'

a disturbing factor. Curtains are generally used to diminish this

effect, but unfortunately such-an arrangement is not very

10

-(1) b. Good visibility.

Deficiency in look-out appears to be a major cause of

collisions and of poor "Rule of the Road" discipline. Naturally,

this is in the first place a problem of human alertness, but it

is also important to create on the bridge the best possible

conditions to exercise a good look-out.

The wheelhouse configuration and its window-arrangement on

many vessels leaves much to be desired.

Excellent Visibility in the forward direction, preferably to

22,5 degrees abaft the beam, should be a general requirement for

ship's bridges. Bridge-window frames should be as small as

possible, giving a maximum visibility from conning positions

inside the wheelhouse. One should also strive for a maximum

visibility into the aft direction. Fortunately, vessels such as

tankers, bulk carriers, container, vessels, lash-vessels etc.,

which have no obstruction in the form of big masts, cranes or

derricks

in

front of the wheelhouse, are becoming predominant. In these vessels it should be possible to realize optimal viewing

conditions from-inside the wheelhouse.

Window-wipers and de-icing devices are part of the system to

create good viewing conditions and should be incorporated in the design of the wheelhouse.

.(i) c. Adequate working space.

Many times one observes,.bedause of insufficient distance between

the front and the aft bulkhead

of

the wheelhouse and also because of 4 scattered arrangement of equipment-and consoles, that the

operating space is cramped and the passage from port to starboard

accross the bridge is too narrow.

For an efficient operation it is essential to have an adequate

- 11'

pass each other freely..

It

is

also essential to ensure that the different operational units, suoh as steering-stand, chart-table, radar-indicators, engine-room,

telegraph or remote control mechanisms are easily accessible.

d. Limitation of light reflections.

Light reflections can be very disturbing, they can distract the

attention of the men on the bridge and even give rise to unnecessary

action. Sloping windows can do much to minimize reflections.

There are two schools of thought on this problem.

The first advocates inwardly sloping windows by which any light,.

reflections appear above the horizon.

The second is in favour of outwardly sloping windows, which have the

advantage that one Can have a better view of the decks below ihe

bridge, while the installation Of-a forward instrument conso]eis also

easier. Reflections of instrument lighting of these consoles can be better avoided in this way.

The sloping angle of the windows varies also widely on different vessels,

i.e. from 7 degrees to about 45 degrees. It would be of advantage to establish the optimum solution of both the direction of slope and the

angle. Reflective surfaces in the wheelhouse should be avoided to minimize

reflections. It should be investigated what kind of finish and what

colour should be used for vertical surfaces, such as bulkheads, as well

as for the deck-head or ceiling of the wheelhouse.

e. Adequate heating and air conditioning.

Temperature control in the wheelhouse is important to create the right

operational atmosphere. The temperature should not be too hot; this is

important to avoid drowsiness of the watchkeeper, but neither should one

(i)

) ao

12

-f. Limitation of noise level,

The noise level in the wheelhouse should be limited to a reasonable

level and distracting sounds should be restricted as much as

possible. On the bridge of many vessels there is too much noise.

Specifications regarding the sound pressure level on the bridge

of vessels are necessary. One should avoid, if possible, the

H

installation of equipment which generate noise, such as electrical

converters, radar transceivers etc..

A special instrument room adjacent to the wheelhouse, Where

equipment which does not require constant watching can be

installed, should be considered: It does not only have the merit

of decreasing the noise level, but also the merit of enabling

better servicing of the equipment. In a separate instrument room

one can always, also at night with normal white light available,

,

carry out the possibly necessary servicing without disturbing

,

'

the operations on the bridge.

The right working position "sit or stand".

Traditionally every man engaged in watch duty on the bridge of

a ship had to do his work in standing position.

The conning situation was inthe past almost always such that the

navigator had to move accross the bridge to obtain a full view of

the horizon. There were to many obstructions in the form of sails

and later masts derrick poles, cranes etc. to be able to obtain

a good view over the horizon from one position.

So the navigator had to do his work while standing up-right,

why should then any subordinate 'on the bridge not do the same ?

Such was the feeling and this traditional feeling is still generally

accepted. Science and in particular the human engineer has,

howeyer, found

out

that in many cases where it is equally possible to work in a sitting position the rdbult of the'work is better,

13

-especially when the job to .be,d6ne is of some lengthy duration.

As a,result for instande-reet_cat drivers today do not stand up

any more but sit when they are doing their work. Why should not

the same criterion apply to the man who is steering the ship, the

7

helmsman and also why should it not apply to the radar-operator

and in many cases to the look-out and even the navigator.

_ _

As I indicated before it is fortunate that vessels, which have

no obstructions in front of the wheelhouse, are becoming

predominant. It is possible to create on these vessels excellent

viewing conditions from conning positions inside the wheelhouse,

which would make it possible to let the men on duty on the bridge

sit rather than stand up while doing their work.

In my opinion this would be a logical step, but in any case it

is an aspect which should be studied.

(ii) Location and arrangement of operating posts in the wheelhouse

Operations

on

the bridge and in the wheelhouse are concentrated on a number of operating posts.

These are:

Steering stand, engaging the helmstan

- .

Visual navigation conning position, engaging captain, pilot

.

and officer on duty

-Radar navigation position, engaging captain, pilot and officer on duty

Ship's propulsion remote control unit, or engine room

telegraph, engaging officer on duty

Chart-table - ship's position fixing centre, engaging captain and officer on duty '

Bridge wing berthing control post.

On many modern bridges one has tried to group and-arrange equipment

14

-a w-ay- -as to -achieve, logic-al concentrations of equipMent and instruments' for these operating posts. One has also tried to arrange these groups

of instruments for the different operating posts An an orderly fashion

and, in the most logical way in'the wheelhouse, bearing in mind their

relationship to each other. It is, however, striking to see how many

variations there are in the arrangement of the different operational

posts in the wheelhouse of modern vessels.

The Steering-stand should contain the steering controls for

main-and auxiliary steeringeystems together. with the displays, which

_

are used to.control the steering. These are: Compass indicator

Rudder angle indicator

-Rate of turn. indicator

The position of the steering-stand is mostly in the Centre-line of

the vessel it should be situated in.such a way that the helmsman

can see a reference point on the forward part of the Vessel, to aid

. .

the:steering. in confined waters.

- There

is

a_controversy about the position of the steering-stand-v. some experts advocate the location of the steering-stand in front

of the wheelhouse and some in a more set-back position.

In my opihion, the position of the steering-stand is related to

the visual navigation conning position of the officer on duty,

because he has to verify the actions of the helmsman, and should be

able to correct them instantaneously if necessary. I would therefore

favour a location of the steering-stand in front of the wheelhouse.

Off centre-line positioning of the steering-stand should be considered

as a.realistic solution, especially,on vessels which haVe visibility

obstructions in front of the wheelhouses (ii)( ) The Steering-stand.'

15

-(ii)(b) Visual navigation Conning pcsltion..

One sees more variation in the grouping and assemblage of

instruments for this position than for the steering-stand. A

console or combined instrument panels for the displays or

indicators which are used to control the safe conduct of the

vessel is often used and contains for instance a compass

indicator, a rudder angle indicator, a speed or log indicator,

an R.P.M.-indicator, a clock, together with equipment for

internal and external communications, such as telephone,

loud-hailer, V.H.F. radio-telephone, intercom-systems, whistle

controls, light signalling morse key etc.. The optimal location

of display panels for speed, R.P.M. and rUdder angle

- above or below the windows - should be studied.

The position of this operational post is of course very

important. Again its situation varies on different ship's bridges.

One finds centre-line location, as well as location to port of the

. centre-line and to Starboard of the centre-line.

The existence of visibility obstructions influences the-location

of this post. On vessels which have no visibility obstructionS in

the forward direction, I would be inclined to locate- this visual

navigation conning post in the centre-line or just to the port of

the

centre line, because of the nearby port-to-port passings of vessels which occur in confined waters.

(ii)(c) Radar navigation position.

The radar navigation position seems to be travelling all over

modern bridges. One sees the radar indicator or indicators

installed in front of the wheelhouse on the port 'side as well

as on the starboard side and they are often installed next to

the chart-table. They are installed standing freely in the

wheelhouse, or in a specially created enclosure. There does not

-

16-ships! wheelhouses.

-A.study and investigation of this problem is most desirable.

It. is surprising th t so many radars are still located in such'

a way that a viewing hood is required for observation of the

indicator in daylight conditions. In my opinion a viewing hood

is a monstrosity. It creates constantly eye-adaptation problems

and it is very tiring. Radar indicators should be situated

in such a way that more than one person can watch the screen.

As. long as the problem of daYq-ight viewing of the radar-screen is not really solved, it seems to me that one could

create a special environment in the wheelhouse for the radar

indicator, which then

has

to be set lack from the front of the

I

wheelhouse. Duplication

of

the necessary controls and

displays for complete control

of

safe conduct of the vessel from the radar navigation post should be considered.,

When two radar indicators are installed they should be

located side by side, so that one can observe both indicators

from the same position. In this way one has the benefit of

being able to observe simultaneously differing range scales

an ,different modes of operation, such as relative motion and

, !

true .motion.

However, this is a personal opinion, the optimal solution

_should be developed by the investigation and the study of

the problem. One

should

also take into account that, apart -from the use in anti-collision navigation, radar is also used

as a general tool of navigation and therefore the location

of the radar navigation position is closely related to that

of the visual navigation conning positions.

(ii)(d) Ship's propulsion .remote control unit or engine-room telegraph pbsitibn

17

-or set back, on the p-ort side

W,

n the starboard side is found on ship's bridges. This post could, in.my.ornioni very well be

integrated with the post for the visual navigation .conning position.

One finds enormous differences in the equipMent and instrumentation

of ship's propulsion remote control units. They var'Y from .a rather simple installation, with only few controls, indicators and alarms,

to very elaborate panels with illuminations with a Christmas-tree

effect.

It is desirable to lay down realistic specifications for these

control units. In my view only those controls, indicators and

alarms, which are absolutely necessary for control of the safe

conduct of the vessel, should be installed in the wheelhouse.

All technical refinements which are essentially dealing with

engine safety and reliability belong in the engine control.-room,

A standardization in controls, indicators and alarms- of

propulsion remote control units is very desirable and should be

incorporated in the studies for bridge-design.

ii)(e) Chart-table - ship s_position fixing centre.

The open wheelhouse - chartroom arrangeifent seems to have become a

more or less common lay-out; which is a sound development, because

this post is an integral part of the entire wheelhouse arrangement.

There is less variety-in the location of the chart-table in the

wheelhouse of various vessels. It is mostly set-babk in the wheelhouse

there is a difference in location on the port- or starboard side of

the centre. There seems to be merit in choosing a starboard side

location, because of being the burdened vessel for vessel

approaching from the starboard side.

One should be able to have a reasonably good view ahead and into

the starboard direction from behind the chart-table. Location of

18

-chart-table and preferably in such a. way that one does not have to

turn one's back to the front of the wheelhousei when operating these

:

instruments.

_ .

Special attention Should be given uo the illumination of the

chart-table. Chart-working requires a rather high intensity of light.

Unfortunately, red light is not very suitable for this kind of work

because of the different colours used on the chart. Orange-coloured

light seemsto be a possible solution. It would be of importance to

study this problem tlproughly. Hydrographers should be asked to

participate in the study of this problem to see whether improvements

in the Printing of the chart could improve roadability in artificial

light conditions. The screening of the lighting on the chart-table

and- the.Trevention of light-reflections, to eliminate any disturbing

light-effects at other operating positions is equally important.

Thib problem is still not satisfactorily solved and should therefore

also be studied.

(ii)(f) Bridge-wing berthing control post.

--:,Thb.type of instruments and equipment for this post -is depending on the type and size of the vessel and the employment of same.

The.equipment and instruments in use should be arranged in the best

possible way. Intercom between bridge-wings and wheelhouse should

be considered' if the distance is long.

IN CONCLUSION of the problems of the location of operating posts in the

wheelhouse, I,would say that it is necessary to establish the principles of the

arrangement And the positioning of these posts,-talcing into account the

19

-,

(iii) Efficient grouping and assemblage of dis la s and indicators into consoles

The efficient grouping and assemblage of the various displays or

indicators into consoles or combined instruments is hampered

because of differences in:

the housing of the displays

the method of mouffUng of the displays the illumination of the displays

the electrical system for illumination of the displays

) the different display dials in use.

It is known that the best way to indicate the information for the

bridge is to use black dial-plates, white lettering and pointers,

and red dimmable lighting. Yet there are still many displays for

ship's bridges on the market, which have different dial--plates,

for instance a white dial-plate and black lettering and which

moreover, have green or white lighting instead of red. There .is also

a great variety in the method of indication. The digital indication

system is in use together with analogic indicators for the same

type of equipment. Not to mention the different dimensions of. the. same instruments that are of different

manufacture.-Standardization of bridge instruments and especially of displays,

which have to be assembled in combined instrument panels or bonsoles,

is highly recommended. Furthermore research should be done to find

out the best way of presenting the necessary information given by

instruments and displays.

(iv) Ship's internal and external communication systems

Efficient communication systems are essential, for the safe conduct'

of the vessel in its environment.

- 20

An automatic telephone system

Sound-powered telephone systems between bridge,

main engine-room, steering engine-room, radio station etc.

A crew-call intercom system .

An interCom system between bridge-wings and wheelhouse

A talk-1346k loudspeaker system between bridge, forecastle

and poop

A V.H.F. radio telephone system

A direct or hotline telephone or voicepipe from bridge to

engine-control-room

and

captain's cabin.

Usually a number of these systems are employed on Ship's bridges.

Here we are faced with the problem of arranging the dialing units of

the selected communication-systems effic.iently in the consoles or combined instrument panels of one or more operating posts.

The configurations and dimensions of these dialing units are

generally not suitable for a really efficient assemblage together with

other equipment and instruments in a console or combined'instrument

panel.

Selection of the right type of communication equipment and the

integration of dialing units for different communication-systems

should be studied to improve the handling efficiency and the

assemblage with other equipment and instruments in logically placed

units for operating posts.

(v) Radar displays and plotting systems

Every radar manufacturer has his own ideas about the lay-Out of a radar-display. Every mark of radar is different from the others.

Ergonometrics should be a principal factor in the design of the lay-out

of-radar-displays.

The available plotting systems show an even greater variety than the

radar-displays. They differ widely.in concept as well as in plotting

21

-4

Some plotting systems present the plotting information on

the actual radar-display, other plotting systems supply their

information on a special display. The method of displaying the

plotting information differs fundamentally in different systems.

Sometimes it is displayed in a digital form on a television-display

and sometimes graphically on a P?P.I.. The capacity of plotting

systems varies from a few targets to about fifty targets. The

work to be done by the radar-observer to obtain a plot

varies from a rather intricate operation to almost nothing in a

computerized automatic system.

There are too many systems with fundamental differences On

the market. A certain degree of standardization in radar-displays

and radar plotting-systems, both from the point of view of

ergonometrics and from the point of view of efficient

anti-collision navigation is highly desirable.

It is important to lay down the principles on which

developments.in this field should be based, in order to avoid an

undesirable diversity in radar plotting systems, which only would

be confusing to the mariner.

Feasibility of Standardization

To realize a certain degree of optimalization in ergonomics

for the bridge/Wheelhouse, it is of vital importance to realize

a certain degree of standardization of bridge/wheelhouse

instruments and equipment. Such a standardization would also help

to decrease the risk of error as officers and pilots transfer

between ships.

It is often said that this kind of standardization would not

really be feasible, because of the diversity in types of vessels

and the way in which they are employed.

22

-All

ships

are using basically the same kind of sensors, the

information simply has to be displayed in the most efficient way.

Surely, standardization of these basic 'instruments would be possible'.

The air-industry has successfully tackled this problem. They have

found a way'thrOugh a co-operative effort of the air-companies, the air-craft manufacturers and the instrument manufactures.

There is no reason why the marine-industry should not be able to

follow the same pattern: I an convinced that in the long run

standardization would be .a benefit to.all parties concerned, that is

-the navigator, -the shipowner, -the shipbuilder and not in -the least -the

'7

instrument

manufacturer.-CONCLUSION

There are still many problems in the design, lay-out and

instrumentation of ship's bridges.

-Only by a co-ordinated multi-disoiplinary approach in the study and

research of this problem, one can hope to achieve the ultimate aim,

that is to secure the optimum transfer of information from sensors to

brain and to ensure, once the information has been processed by the

.

brain, optimum operating conditions so as to obtain the safest and

7

most efficient control of the vessel.

One could hope that bridge lay-out and designs would ultimately b

governed by such a co-ordinated

and

methodical approach, rather than by the preferences of individual experts.

The introduction of computers for navigation and other highly

sophisticated navigation equipment, such as integrated position-fixing

4

systems certainly amplifies the necessity of such co-ordinated

multi-'

disciplinary approach. It has been suggested that one should concentrat

23

-control on board. I do.nbt think:that-this solution will be a'

realistic one for the fabme.

A computer can only act on infolmation, which has been fed into

its memory. Is it conceivable to feed all the information into the memory of the computer, so that it can cope with all the

imponderables of the sea ?

It is not likely to become a realistic proposition.

Even in the navigation of supersonic aircraft, the crew is

indispensable and exercises an overriding control over the

automation; at sea the environmental and operational factors are

less predictable. Let us therefore concentrate on the human operator

and create the right environment for him to exercise his

responsibilities. Maritime Institutes combine within their

organisations experts of different disciplines, who could take part

in the required co-ordinated multi-disciplinary study.

International co-operation in this field would be of great

advantage. The European Maritime Institutes should join their

efforts by setting up an international forum of experts through

which an international co-operation could be born.

I do hope that these thoughts will serve as a contribution to

start a co-operative effort, to improve conditions on the ship's