Improving safety on board ships through better bridge design

The increasingly advanced automation systems controlling modern sea vessels has led to more complex user interfaces. A typical operator must interact with many different systems, often with different interface styles, during an operation. Complex and multiple interfaces can cause cognitive overload if the operator is presented with excess information. The operator can also be physically affected if the equipment is poorly placed. Depending on the ship owner, the ship yard and the suppliers of equipment, the composition of the equipment in the operator station can vary considerably and is often ergonomically sub-optimal.

Human machine interface (HMI) work has a long history in maritime settings but is often given low priority due to perceived increased development time and economic pressures. The economic aspects play an important role in a vessel’s lifecycle and issues concerning HMI and usability are, in many cases, not a part of the discussion until late in the cycle when it is too late and expensive to make vital changes to implement an optimal solution. An overall increased mental load when operating a system is tiring and leaves less mental capacity to handle safety-critical events. Poorly fitted equipment combined with low usability causes a long term problem for the operators.

The overall aim of maritime HMI and human factors (HF) research is to lower the operator’s cognitive load and make the workflow more efficient. Over the last 10 years, Rolls-Royce Marine has been engaged in a rapid process of development of both systems and devices that are vital on today’s vessels. For Rolls-Royce, the next step of developing the future systems included ensuring a good HMI environment onboard to support the complexity of offshore operations today.

In perspective

Traditional ship bridges are often cluttered with equipment, buttons and levers. The placement depends on who arrived first to install their equipment at the ship yard. With no holistic focus on where to place equipment, it is either just randomly placed somewhere in the consoles or placed according to the wish of the captain on duty that day. When asked, the crew often reply that they have concerns but that they are ‘silly details’ or ‘luxury problems’. However, it soon becomes clear that while the individual problems might be small, there are usually many of them and as they start to pile up they add unnecessarily to the operator’s mental workload.

When taking all the silly details and luxury problems into account it was possible to create a ship bridge concept that will improve operational safety and comfort on board during demanding offshore operations. The work on achieving this aim commenced late Autumn 2010.

Redesigning the ship bridge environment

The process of doing a complete redesign of the ship bridge environment, including consoles, levers and software interfaces, was done by incorporating human factors, ergonomics and usability as the basic foundation for developing a user centred design process. The user experience is a vital element and by including it, it was possible to introduce a more comfortable, clutter-free and safe working environment.

Four design principles were implemented where simplicity, performance, safety and proximity were the key elements. To fulfil these goals there was emphasis on: good ergonomics; variation of work position; proximity to touch interfaces and levers; flexibility to support operational preference; an improved view of the aft deck to support a safer operation.

The data needed to build a base of knowledge for the first concept sketches were collected and interviews with operators and visits on several different types of vessels were carried out. To actually understand the work environment and gain insight in life at sea, the gaps were filled by going on board to observe a range of real life platform supply operations in the North Sea. The knowledge gained was used to perform testing in a simulated virtual environment.

Throughout the concept development phase, realistic simulations in a virtual environment were carried out to collect data in Rolls-Royce’s Training and Technology Centre in Aalesund, Norway. The data collected using advanced eye-tracking equipment was used to identify the periods of time when the operation was at its most safety-critical. These periods were known as safety-critical focal points. With this knowledge it was possible to redesign the vessel’s bridge environment to better support the users during standard work procedures and when reaching the critical point of operation. By obtaining knowledge about the operators’ eye scanning patterns during all stages of the operation, placement of monitors, levers and console designs could be adapted to give the best possible support to the operator, with the aim of reducing the human error rate.

The results of the research were fed directly into the concept development phase of the bridge consoles. Functional analyses were carried out to investigate operator interaction with equipment and action was taken to remove ship bridge clutter. Which functions were vital, which could be removed or merged? In parallel, several different prototype iterations of bridge consoles were carried out, from cardboard and Post-Its, to polystyrene and in the end a full-scale plastic model released at the Nor-Shipping convention in Oslo in May 2011.

Ship bridge clutter and comfort

Ship bridge clutter appears when equipment from several different suppliers, with different interfaces and interaction styles, gathers in the bridge consoles. The results from the experiments introduced possible improvements from the current, more cluttered, aft bridge setup traditionally used, to the new Rolls-Royce Unified Bridge setup. The following changes were introduced:

- The armrests were moved from the operator chairs to the consoles, increasing distance/angle from torso to elbow.
- There was a supported seated and standing work position.
- The surfaces were cleared of equipment by integrating third party equipment into an auxiliary system controlled using a touch panel.
- All controllers - levers, button panels and monitors - were moved closer to the user.

These changes made it possible to reduce the amount of necessary monitors and open up the field of vision to the aft deck. This reduces visual scanning of the aft bridge and aft deck environment and means there is a smaller area over which to maintain situational awareness, which can have an impact on the operator’s workload during operation and critical phases.

Ergonomically-designed chairs were installed with a leather/alcantara combination that increased the friction and reduced dampness when seated. Situation awareness was increased by implementing a common alert philosophy where all bridge alerts could be silenced and handled from one panel, so that the operator does not have to search for the correct alert to silence. Environmental visibility and reduced reflections, both in console design/colour and graphical user interfaces, contributed to maintaining the operator’s night vision. A common dimming philosophy was also implemented so that all equipment could be dimmed from one place. With this unified interaction concept, the operators have more equipment within arm’s reach than in traditional bridge consoles.

Levers and emergency switches

The goal concerning levers and emergency switches was to simplify and prevent error. Previous experiences had shown that operators were likely to make mistakes as it was difficult to figure out which emergency switch belonged to what function. Placing them in easily recognisable positions would rule out the need for extra reminders. The vessel’s control levers were also given a makeover. Fresh designs, developed through a user-centred design process, gave levers that supported safe operation through grip, indications and easy access to functionality. The motorised levers give tactile feedback to the user and were ergonomically tested using well-known methods, such as Rapid Upper Limb Assessment, with excellent scores. Reduction of footprint in consoles was also important as in many cases two levers or more were combined into one.

A unified expression

The graphical user interfaces (GUI) on maritime applications are often the only way the operator can interact with the equipment. Careful placing of information and an easily recognisable way of navigating reduces the risk of operators becoming confused.

GUI was given a great deal of attention during the development of the Rolls-Royce Unified Bridge and a complete redesign of all Rolls-Royce applications was carried out. The Rolls-Royce Common Look and Feel (CLF) initiative was put in place to constitute a common platform for Rolls-Royce Marine software, across applications and screen sizes.

The goal has been to define guidelines for the graphical user interface, as well as principles for interaction and usability. A CLF style guide has been developed. It is a dynamic document continually edited and updated based on feedback from the various application teams and the end users. Redesigning the applications has resulted in consistent interfaces with a common way of navigating across systems, a common alarm philosophy and a common way of switching between systems, giving the user full overview and control.

From concept to product

The work of collecting user feedback based on the plastic prototype was important and the initial prototype consoles have been improved based on feedback. The front end of the consoles have been angled, so that the operator can have a better work position during operation.

The wrist is kept in a relaxed and straight position while the hand operates the lever. This is an important improvement to the operators, especially for winch/anchor handling operations which demands hours of static muscular activity, as there is no possibility of releasing the levers to run it in automatic mode. The consoles have been industrialised and are of a modular type so that the different modules can be combined to suit several different types of vessels.

The first installation of the Rolls-Royce Unified Bridge left port in August 2014 on board the platform supply vessel Stril Luna owned by Simon Møkster Shipping. The operators were equipped with user experience assessment folders, so the Rolls-Royce Unified Bridge can develop and improve in favour of the operators in the future.

By Frøy Birte Bjørneseth of Rolls-Royce Marine.

This article first appeared in issue 532 of The Ergonomist, October 2014.