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Ship bridge layout and design

bridge layout and design ships


Command and the navigation of a ship have been linked operations for millennia and this is still true today even if modern electronics technology can allow a ship to be navigated from any place on board or even – as has been demonstrated on several occasions in the last few years – remotely from a shore centre.

Remote operation of ships is something that is much discussed but which, apart from a few demonstrations of the possibility, is not something that most observers expect to become commonplace in the immediate future. For the time being, the bridge will remain the place from which the ship is commanded and navigated under the control of the Officer of the Watch (OOW).

A navigational watch can involve any number of personnel from a single individual to many under normal circumstances; it would be normal procedure for a single crewmember to call for assistance in times of need. When there are more personnel on the bridge some form of organisational management is needed to ensure that tasks are not duplicated or overlooked.

Bridge Team Management – or rather lack of it – is often cited as being at the root of many marine casualties and the concept is being strengthened through training courses and changes to the STCW Code which sets out minimum standards for seafarers of all ranks.

Today, most of the regulations concerned with navigation on board vessels are found almost entirely within the texts of STCW and SOLAS but there are both flag and port state elements that will also need to be investigated.

There are very few chapters of SOLAS that do not mention the bridge in one way or another even if it is just to require that an alarm or status indicator for a piece of equipment is to be provided. For the majority of systems and equipment, as well as for standards for bridge layout, it is Chapters IV and V that are the main source of regulation. Chapter IV of SOLAS covers radio communications and equipment and it is here that the requirements for GMDSS equipment are to be found.

Navigation as a subject is not covered by SOLAS until Chapter V and then most of the regulations are concerned with matters such as weather information, ice patrols, bridge layout, navigation warnings, hydrographic services, life-saving signals and ancillary equipment.

In the past, most regulation of bridge equipment was prescriptive – laying down performance standards – but recently goal-based standards have become more common. The exact requirements for individual ships will vary depending upon ship type, size and age. In the case of the communications equipment that must be carried under GMDSS, the area in which the ship operates is also a deciding factor.

The advent of GMDSS has meant some changes to bridge procedures, notably the disappearance of the dedicated radio officer and the translocation of communications equipment from the radio room to the main area of the bridge. In addition to the international requirements, flag states are always at liberty to impose additional requirements for vessels on their registries. Such rules should be communicated to ships by the appropriate government department, usually by way of Merchant Shipping Notices. Ships joining a flag will normally be subjected to some form of inspection and any deficiencies should be picked up by the surveyor and advised to the operator for immediate rectification.

The Merchant Shipping Notices of most flag states are relatively easy to locate but while some countries issue very few, others seem to legislate and advise on a vast number of topics. In the latter case, rule changes and notices are superseded regularly and keeping up to date requires careful attention to detail. SOLAS changes are more easily followed but care needs to be taken to ensure that alternatives allowed in SOLAS are also accepted by flag states.

Carriage requirements for the key navigation systems such as radar, compasses and tracking systems do not appear until Regulation 19 where they are laid out in a way that deals firstly with all ships and then lists the additional requirements that come with increased ship size, as measured by gross tonnage.

The divisions of ship type and size according to Chapter V Regulation 19 paragraph 2 are:

  • 2.1 All ships, irrespective of size;
  • 2.2 All ships of 150 gross tonnage and upwards and passenger ships irrespective of size;
  • 2.3 All ships of 300 gross tonnage and upwards and passenger ships irrespective of size;
  • 2.4 All ships of 300 gross tonnage and upwards engaged on international voyages and cargo ships of 500 gross tonnage and upwards not engaged on international voyages and passenger ships irrespective of size. This section only covers AIS;
  • 2.5 All ships of 500 gross tonnage and upwards (2.6 details some duplication requirements) 2.7 All ships of 3,000 gross tonnage and upwards;
  • 2.8 All ships of 10,000 gross tonnage and upwards;
  • 2.9 All ships of 50,000 gross tonnage and upwards.

In some instances alternative ‘other means’ are permitted for certain requirements. When ‘other means’ are permitted under this regulation, they must be approved by the flag state in accordance with Regulation 18. The navigational equipment and systems referred to in Regulation 19 shall be so installed, tested and maintained as to minimise malfunction. Regulation 19 2.10 covers the ECDIS carriage requirements.

Under the SOLAS regulations, navigational equipment and systems offering alternative modes of operation shall indicate the actual mode of use. Integrated bridge systems shall be so arranged that failure of one subsystem is brought to the immediate attention of the officer in charge of the navigational watch by audible and visual alarms and does not cause failure to any other sub-system. In case of failure in one part of an integrated navigational system, it shall be possible to operate each other individual item of equipment or part of the system separately.

Performance standards for the various systems are laid out in numerous IMO documents and are subject to changes from time to time. When the performance standards do change, it is not normally necessary to replace equipment fitted prior to the change of date but in some cases, ECDIS is a good example, a change in the performance standards may necessitate an adaption to the equipment fitted.

When a new system or piece of equipment is added to the mandatory carriage requirements because of new IMO regulations, there is often a rollout programme which will see different ship types and sizes affected over a period of time.

E-navigation is a new concept that has been permitted by modern technology. Although details are still being worked, it could be said that it may result in something akin to an air traffic control network. In the IMO’s own words its work is “to develop a strategic vision for e-navigation, to integrate existing and new navigational tools, in particular electronic tools, in an all-embracing system that will contribute to enhanced navigational safety (with all the positive repercussions this will have on maritime safety overall and environmental protection) while simultaneously reducing the burden on the navigator.”

The IMO says that, as the basic technology for such an innovative step is already available, the challenge lies in ensuring the availability of all the other components of the system, including electronic navigational charts (which is now in progress with the mandatory carriage of ECDIS) and in using it effectively in order to simplify, to the benefit of the mariner, the display of the occasional local navigational environment.

E-navigation would thus incorporate new technologies in a structured way and ensure that their use is compliant with the various navigational communication technologies and services that are already available, providing an overarching, accurate, secure and cost-effective system with the potential to provide global coverage for ships of all sizes. What the IMO and other proponents of e-navigation appear to have overlooked is that the ECDIS regulations apply only to passenger ships over 500gt and cargo vessels above 3,000gt.

Bridge Ergonomics

Bridge Ergonomics

View from the bridge

Most modern ships feature some form of integrated bridge system with multiple screens allowing navigators to swap between views from different navigation equipment. Older vessels will have equipment installed over time and sometimes fitted in less-than-optimal positions.

Regardless of vessel age and the position of equipment on the bridge, being able to observe other ships and the immediate environment from the bridge is essential.

Today there are several regulations affecting bridge design and layout. First among these is SOLAS V Regulation 22 that governs navigation bridge visibility requirements, and which applies to all vessels over 55m in length built after 1 July 1998. The requirements are quite comprehensive and extend to the layout, material and angle of bridge windows.

They do not however cover the overall design of the bridge in relation to the ship as a whole, other than with regards to line-of-sight requirements. Most modern ship designs have the bridge placed aft with most of the cargo holds extending forward. On ships with deck cargoes, this means that the line of sight does not allow vision of the area immediately in front of the ship. It is for this reason that the bridge position in very large container ships has been shifted forward from its traditional position to a point somewhere amidships.

Some ships do have a design which places the bridge at the most forward part of the vessel. This is particularly true of offshore ships and car carriers as well as some smaller ship types. Placing the bridge and other superstructure forward does have a negative effect on the aerodynamic properties of the vessel and some designs have sought to overcome this by removing hard edges.

This has been taken to extremes on a small number of ships including the car carrier City of Rotterdam which has an almost spherical section of the forward part of the ship. Initially this was hailed as an innovation, but it was also cited as the cause of a collision between the ship and another vessel in the river Humber in the UK in 2015.

An official investigation by the UK’s Marine Accident Investigation Branch (MAIB) identified that the unconventional design caused the pilot to become disorientated and put the vessel on a collision course with the other ship. Apparently, the pilot’s disorientation was due to ‘relative motion illusion’, which caused him to think that the vessel was travelling in the direction in which he was looking when in fact it was not.

The MAIB investigation identified that the City of Rotterdam had been set into the path of the other vessel, but this had not been corrected because the pilot on board had become disoriented after looking through an off-axis window on the semicircular shaped bridge.

Following the accident and an early MAIB recommendation, action has been taken by the City of Rotterdam’s managers to reduce the likelihood of relative motion illusion and to improve the bridge resource management of its deck officers.

Man machine interface

Ergonomics and improved man-machine interfaces have been in vogue for many years and across a whole range of industries including shipping. While there is much to be said in favour of harmonising symbology and controls to some degree, it is an acknowledged fact that humans are individuals and a one-size-fits-all approach must inevitably result in some compromises in design.

In December 2000, the IMO distributed MSC/Circ.982 which included the Guidelines on Ergonomic Criteria for Bridge Equipment and Layout. The guidelines had been developed by the Maritime Safety Committee to “assist designers in realising a sufficient ergonomic design of the bridge, with the objective of improving the reliability and efficiency of navigation” and were in support of amendments to Regulation V/15 of the SOLAS Convention – Principles relating to bridge design, design and arrangement of navigational systems and equipment and bridge procedures, which were to enter into force on 1 July 2002.

The 31-page document is extensive in its reach and detail even to the point of laying down minimum and maximum dimensions for specific areas of the bridge and positioning of controls and introducing requirements for placing pencils and tools around the bridge. There is also an element of transition that can be seen in the guidelines particularly around ECDIS which is now at the end of a mandatory roll-out programme.

Most versions of ECDIS now warrant a display at the centre of the integrated bridge system but in December 2000 they were usually standalone systems and might have been found either at the navigation and manoeuvring workstation at the front of the bridge or at the planning and documentation workstation at the rear of the bridge.

For obvious reasons, the guidelines only apply to new vessels and identify no less than seven separate workstations, which are described in the regulation section together with a list of equipment, systems and controls that should be found there. The workstations and their associated equipment are supposed to allow for the most ergonomic bridge permitted by modern equipment, but it is difficult to equate them with the bridge layouts seen on some of the latest vessels, which appear minimalistic by comparison with bridges from just a few years ago. Some of that conception has been brought about by integrating the various controls digitally into just a few display screens that allow overlaying of information systems according to user requirements.

The principles of ergonomics also seem to be constantly evolving, as does the technology that allows new forms of man-machine interfacing, such as touchscreens and wide-screen displays and even the promise of using nothing more than gestures, as with some modern computer gaming consoles, to operate controls or switch between displays. Bringing information together in fewer places also makes life easier on those ships that have minimum personnel on the bridge. 

Overcoming size differences

The rules and guidelines on ergonomics say little about differences in individual physical characteristics of navigators or those using the equipment. In fact SOLAS in many instances is quiet on this very obvious point although the fact that differences do exist is at least recognised in regard to life jackets and other safety equipment.

In SOLAS Chapter V, Regulation 22 covering navigation bridge visibility, there is one reference to the difference in crew heights and that is point 1.8 which reads: “The upper edge of the navigation bridge front windows shall allow a forward view of the horizon, for a person with a height of eye of 1,800mm above the bridge deck at the conning position, when the ship is pitching in heavy seas. The Administration, if satisfied that a 1,800mm height of eye is unreasonable and impractical, may allow reduction of the height of eye but not to less than 1,600mm.”

It is difficult to say what percentage of seafarers fall outside the range of those two height-of-eye measurements, but there are undoubtedly quite a few and with initiatives to encourage more women into shipping, the number is likely to increase. Obviously, adjustable seating or a platform will allow for shorter seafarers to reach the minimum measurements if necessary.

US-based Marine Technologies has presented at some exhibitions an adjustable version of its Bridge Mate IBS. Although many systems are claimed to be ergonomic, the fact that the human frame comes in many shapes and sizes means that they must be optimised to one particular standard. The Marine Technologies bridge goes some way to addressing the problem faced by navigators that do not meet the norm by incorporating a mechanism that allows the console and displays to be raised or lowered to suit.

All of the leading bridge manufacturers and several of the smaller players now offer integrated bridge and navigation systems. In recognition of this, the leading classification societies – which, through IACS, played a part in devising the IMO rules and guidelines – have also introduced class notations for ships that are fitted with the new systems. Offshore vessels – probably because excellent all-round vision is vital in the roles they undertake – seem to have been at the centre of many recent bridge design projects.

For example, Vard’s SeaQ bridge features several innovations, including a transparent floor which allows navigators to view the deck and helipad of the ship without any blind spots caused by the consoles and displays and haptic controls. While any individual bridge can be customised, one display version featured two seated command workstations each of which was served by two touch panel displays within easy reach and a trio of multifunction displays for the likes of ECDIS, radar and conning and helm controls. In addition, a comprehensive overhead display allows for an optimal workspace.

Integrated bridge and integrated navigation systems

Integrated bridge and integrated navigation systems

Modern ships are obliged to carry an extensive array of navigation and control systems and equipment on the bridge most of which have evolved at different periods in time over the past 60-70 years. The most recent system to have been mandated under SOLAS is ECDIS but there will also be a significant number of ‘smaller’ ships below 3,000gt that are not required to install it.

As a consequence of the continual addition of new equipment, many ships have a bridge comprised of disparate stand-alone systems. On newer vessels it is possible to integrate systems so that two or more can share data or sensor input with most of the very latest vessels having integrated navigation systems (INS) or integrated bridge systems (IBS).

There is a deal of confusion over the difference between the two terms and many consider them interchangeable. The IMO however does have different definitions: an INS is defined in MSC.86(70) and an IBS is defined in Resolution MSC.64(67). Comparing the definitions shows that an INS is a combination of navigational data and systems interconnected to enhance safe and efficient movement of the ship, whereas IBS inter-connects various other systems to increase the efficiency in overall management of the ship.

More specifically, the IMO definition of an IBS applies to a system performing two or more operations from:

  • Passage execution;
  • Communication;
  • Machinery control; and
  • Loading, discharging and cargo control and safety and security.

By contrast the IMO defines three versions of an INS with each ascending category also having to meet the requirements of lower categories:

  • INS(A), that as a minimum provide the information of position, speed, heading and time, each clearly marked with an indication of integrity;
  • INS(B), that automatically, continually and graphically indicates the ship’s position, speed and heading and, where available, depth in relation to the planned route as well as to known and detected hazards; and
  • INS(C), that provides means to automatically control heading, track or speed and monitor the performance and status of these controls.

The two definitions do not have a common requirement as to the navigation element so it cannot be said that an IBS is an extended INS although many consider this to be the case. The difference between the two is likely to disappear gradually as most shipowners are specifying high degrees of integration for new vessels in many cases going beyond that defined as an IBS. Both systems along with ECDIS are seen as being essential for e-navigation to be given a framework and direction.

Integrated systems and VDR have a common element in that both bring together data from disparate systems. In fact VDRs, as opposed to simplified versions (S-VDRs), were made more possible by integrated systems than perhaps any other development in navigation technology or regulation.

There is no doubt that there are significant advantages for navigators from integrated systems since it is possible to monitor and use all systems and instruments from a single workstation. In addition, an integrated system with several workstations and screens confers a high degree of redundancy and system availability. The inclusion of ECDIS also permits passage planning and chart work to be done on the main bridge as opposed to in the chart room.

Every major navigation system provider offers an integrated system of some description as well as offering stand-alone systems. 

Bridge alarm systems

Bridge alarm systems

Modern ships operate with fewer crew members than in the past and it is not unusual for ships to have just a single man on watch in the bridge or engine room at any given times. As a ship’s command and control centre, it is vital that the bridge has a means of alerting officers to problems and also to ensure that when only one person is on the bridge, that person is alert and active.

Bridge navigation watch alarm systems (BNWAS) are intended as a means of preventing incidents such as collisions and groundings when there is a single officer of the watch (OOW) on the navigation bridge. The idea is that regular alarms and monitoring will alert a distracted OOW or be able to summon assistance if the officer is incapacitated.

Denmark was the first country to require Bridge Watch Alarms some time before they were made mandatory for all flags by the IMO under SOLAS. This highlights that it is often the action by one flag or port state that sets in motion the wheels at the IMO and the development of a global regulation.

By 2008, the IMO had formulated performance standards for BNWAS which are laid down in MSC.128(75). Ships with alarms fitted prior to the standard being agreed may still comply as the IMO standards were based upon existing requirements of certain states. The standards say that the system must monitor the awareness of the OOW and automatically alert the master or another qualified OOW if for any reason the OOW becomes incapable of performing his duties. This is done by way of an initial visual alarm and subsequent audible alarms which the OOW must acknowledge within a specified time period. IMO rules state that the BNWAS should be operational whenever the ship’s heading or track control system is engaged, unless inhibited by the master.

On several occasions, the standards refer to the alarm being reset but do not prescribe how the acknowledgement or reset should be made. Following several approaches from industry bodies and governments, the IMO has decided that although a BNWAS with only a reset button will be allowed, they should be avoided. IMO considers it advisable to install systems making use of a combination of sensors to reduce the number of alarms and avoid unnecessary stress and inconvenience to the OOW.

As a result, many of the systems being marketed are fitted with motion sensors of one type or another. Passive infrared sensors are popular choices and can be fitted at various places around the bridge. For an operator selecting a BNWAS, it is important to note that the exact interpretation of the performance standards is a matter for the flag state and while most will accept motion sensors this should not be taken for granted.

In some cases where flag states do accept motion sensors there are additional rules that govern their siting and performance. Flag state surveyors and approved recognised organisations should be aware of the requirements for vessels of that flag and efforts should be made to ensure that an otherwise type-approved BNWAS will not be rejected when the Safety Equipment Survey is carried out. Some manufacturers add in extra degrees of sophistication and modes of their own. This has resulted in the incorporation of features such as password protection, automatic activation when the ship’s speed (determined from GPS input) exceeds a fixed rate and the ability to switch between auditory or visual alarms.

Most systems are stand-alone units, but some manufacturers have incorporated their system into a wider alarm device such as a Bridge Alert Management System (BAMS) or even into an integrated bridge system. In units of this kind, there are connections to any number of other systems, bringing all of the alarms likely to sound on the bridge into a single device. It should be noted that the BNWAS performance standards say that the alarms should not be capable of being confused with fire or general alarms used on the vessel.

Interpretation of regulations connected with BNWAS has been variable to say the least. In May 2014 at MSC 93 some changes to the performance standards were proposed with particular regard to the automatic function of some systems which it was decided should no longer be used. Flag states were invited to use the guidance as an interim measure until such time as the performance standards can be reviewed and revised. The guidance is contained in MSC.1/Circ.1474. The roll-out for mandatory BNWAS on vessels above 150gt has now been completed, ending in 2018.

BAMS – Managing alerts

This is a subject that should not be confused with BNWAS as they deal with very different situations. Unlike BNWAS, which are in place to monitor navigators, the navigators themselves must constantly monitor the proper functioning of the vessel and its equipment.

SOLAS requires many of the systems found on a ship to indicate failures and problems by way of an audible or visual alert on the bridge. Some of these can be found on the equipment itself – especially in stand-alone navigation equipment – while those for watertight doors, fire alarms, steering and the like are generally incorporated into an alarm display located somewhere on the bridge. These displays are not always in a location that is convenient to monitor while engaged in navigating the ship. It is not uncommon to find that even where the

alarms are banked together, the display may be on the back wall of the bridge meaning that monitoring them means the navigator must turn away from what is happening outside the bridge windows.

Another issue with alarms is that the alarm in each individual piece of equipment will have been determined by the equipment maker and can sometimes be difficult to discern under normal conditions. Operationally, when each piece of equipment has a unique alarm that is not integrated into any form of control panel, prioritising alarms is almost impossible.

Integrated bridge and navigation systems that were made possible by advances in electronics and which began to appear over the last two decades or so were seen as being an ideal way of centralising the alarms.

In 2006 when performance standards for integrated systems were being drawn up, alarm management was discussed at NAV 52 and a report by a working group on the subject presented draft standards. Part C of the INS performance standards represents a first draft regarding an alarm management module. The report discussed at the meeting says that: “an alarm management system should harmonise the operation, handling, distribution and presentation of alarms.

To avoid further uncontrolled increase of alarms, a set of priorities based on the urgency of the required response is needed to improve the operator’s situation awareness and his ability to take effective action.” Therefore, in the performance standards a new philosophy is followed for the prioritisation and categorisation of alarms. An ‘alert’ is defined as an umbrella term for the indication of abnormal situations with three different categories of priority of alerts:

  1. Alarms
  2. Warnings
  3. Cautions

The alert management module is developed with a structure and concept extendable to all alerts on the bridge. In the future, the alert management system could be a separate performance standard and could be extended in a second step to include all alerts on the bridge. So the alert management module in Part C is drafted with the layout of independent performance standards. Four years later, the IMO adopted guideline performance requirements that are detailed in the annex to IMO Resolution MSC.302(87).

The IMO has recommended the use of bridge alert management systems to governments for ships flying their flags but has not yet taken the step of agreeing that they should be mandatory. Operators should check with flag states to confirm the requirements for their vessels.

Other documents that should be consulted when investigating BAMS include MSC.252(83); A.694(17) and MSC.1021(26) from the IMO and IEC 61924 ed.2. Since the performance standards are now in force, a BAMS or the BAM Module human machine interface must be type-approved but is not required for mandatory carriage according to SOLAS V/18. If BAM and INS are both installed, alert information must be integrated into a Central Alert Management (CAM)/Human Machine Interface (HMI) in the INS.

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