Abstract: The Full Mission Bridge Simulator (FMBS) can be used as a tool for scientific research where real-life experiments are impossible or too costly.

 This paper describes 3 different research-programs in which the Full Mission Bridge Simulator of the Royal Netherlands Navy was used.

 The first program shows how the simulator was used during a PhD project of ms L.Aarts on "Keeping overview on the ship's bridge" and gives the results of this study in terms of predictability, consistency and reliability.

 The second program describes a short study by lieutenant W.Talma on the relationships of Mental Rotation, Situational Awareness, Capacity of Memory and Cognitive Lock-up of watch-officers, where the Full Mission Bridge Simulator was used in connection with PC-based laboratory research and shows that apart of the relationship of Mental Rotation and Situational Awareness no evidence was found for such correlations.

 The third program describes the status of preparations of a "Naval Operator Working Group" in the use of a Full Mission Bridge Simulator for research on and training in "operational decision making" and "risk-management considerations" by operators of ships when encountering marginal sea-states (like hurricanes).

 Special attention is paid to the specific requirements for marine simulators in terms of "feeling the bad weather", wave-model and mathematical model.

 The paper describes further the relationship of the "Naval Operators Working Group" and the "Naval Stability Standards Work Group", when determining the limits of man and machine during such conditions, as a basis for revaluating stability standards for navy vessels.

　

PREAMBLE.

 The Royal Netherlands Naval College is, next to training and education, using the bridge-simulator system for scientific research on items that are to the interest of the Royal Netherlands Navy (RNLN)

 Cadets of our academy, supervised by our professors do the research, but when it is of interest to the RNLN, scientist of universities or other centrums of applied sciences are invited.

 As human factors play an important role in the operation of the RNLN, more and more research is carried out on those matters. At this moment human behaviour on ships bridges is seen as an important matter. Of accidents with ships, 80% is said to have a human background, but scientific research is nevertheless hardly available.

 The RNLNC has reserved time and manpower on the FMBS for scientific research on this kind of human behaviour. Programs carried out lately with the FMBS as a tool were:

 From other studies and from experience of ship's teams, it is well known that a for this kind of research a FMBS must satisfy certain demands.

 For the studies described the FMBS of the RNLNC was used with the following particulars:

- Manufacturer: Marin (MSCN)

- Look alike real ship's mock-up bridges

- Screen distance: 10 m.

- 9 DLP-projectors, each sector 1024 x 768 pix's

- Horizontal field of view: 270 dgs

- Validated Mathematical Models

　

　

　

 As presenting the programs with all their psychological and behavioural findings and conclusions, would be out of reach of this paper, I will describe the simulator-part of three studies and their conclusions.

 Detailed information about the whole studies can be derived from the NNLNC

　

 In working environments that require more or less simultaneous monitoring of a number of different information sources, like the ship's bridge, it is very important to keep the overview. When the overview gets lost, serious accidents can be the result when not discovered and recovered in time. The overview can get lost in a number of ways, and may therefore appear in diverse forms. Preoccupation with only one source of information, meanwhile neglecting other sources is one way in which the overview may get lost. This is known as 'cognitive lockup' (Moray & Rotenberg, 1989), or 'cognitive tunnel vision' (Moray, 1981). In the case of cognitive lockup, the operator may be literally 'locked up' in the performance of only a part of his total amount of tasks. When something happens in an information source that is neglected and this is not discovered in time, it may go seriously wrong. Although in most of the literature cognitive lockup is reported as due to high mental workload, this seems not necessarily to be the case.

 Human beings have their particular capacities in processing information, but it is obvious that they are certainly far from perfect, as are computer systems in their way. While safe interaction and co-operation between man and machine has to be guaranteed as much as possible, it is important to know which factors enhance or undermine this interaction. These factors can be divided into a) human factors, and b) task factors.

 This report is a summary of three experiments that have been performed in order to get more knowledge about human factors in relation to the ability to keep the overview. The general question of these experiments has been if the individual has the ability to keep the overview, and more in particular if he has the ability to be resistant against cognitive lockup and is consistent over situations and independent of context and task paradigms. Evidence for high individual consistency in the ability to keep the overview would offer prospects to select future operators for (dynamic) multiple task jobs that require the ability to keep the overview in order to operate safely.

　

 Summary of this experiment:

 In this first experiment, 32 experienced watch officers of the Royal Netherlands Navy were tested on two tests: a) a simulated process control task, called Space Station, and developed at the Dutch TNO Human Factors institute and b) a test on the bridge simulator of the Royal Netherlands Naval College. The last mentioned test has been especially developed for this experiment, and will be called BRISIM I. It was investigated whether the loss of overview in a simple computer simulation of a process control task would correspond with the loss of overview in a more realistic setting such as a (simulated) ships bridge.

　

　

Description:

 In a space station 2 tasks have to be performed by an astronaut.

Task 1 : because of increasing temperatures of the top tank, the fuel-tanks (4) have to be rotated every 1,5 minutes

Task 2 : problems in the production process have to be solved.

　

 The candidate has to toggle between task 1 and task 2, as they are not visible at the same time.

　

 In BRISIM I, the participant had to sail a winding channel, simulated in a bridge simulator. The participant was on his own (no team) and had to steer by hand in the non follow-up mode. The weather was fine, light winds, a good visibility and an inward current of 1 knot. The simulated ship was the 18.000-ton naval-provision vessel Hr. Ms. Amsterdam The sailing area was the Humber, destination the port of Hull and the ship's track through 7the Hawk- and the Sunk Channel.

 A speed of 15 knots was required in order to arrive at the Birmingham oil station where a pilot would board the ship, in time. All equipment of the bridge was available with the restriction that the use of the VHF (communication-task) could not be combined with the steering-task, because the VHF-apparatus was too far (3m) from the steering stand

 The simulated starting time was 3.00 PM.

　

　

 The participant was on the bridge alone, but there was no heavy traffic or other disturbances as the following prepared incidents:

1) When closing in at Spurn Head, the "Amsterdam" has on her portside an anchored ferry. The ferry calls the "Amsterdam" to tell that she will lift her anchor and proceed to the pilot-station at Immingham oil Terminal and she will stay close behind the "Amsterdam", because the ETA at the pilot-station is the same as for the Amsterdam. The watch-officer has to be aware of her presence this during the test in case he would reduce his speed.

2) Just before Spurn Head the pilot calls and gives a long list of details concerning his boarding (e.g. the rigging of the pilot ladder, arrival time etc.). The pilot asks for a confirmation of the details

3) During the passage of an extending spit of land (Spurn Head) the captain asks for a situation report. If the participant gives too little information, the captain will ask for more details.

4) A fishing vessel is on port side on a collision course. The fishing vessel may not, according the rules, impede the "Amsterdam" but she is closing in. No real collision danger is arising. In case the participant tries to contact the fishing vessel, it will not answer.

5) After the fishing vessel incident at app. 2 miles an outward-bound ferry is calling for a passage arrangement, because of a dredger working on the starboard side of the channel.

6) For the second time, the captain calls for a situation report. Immediately after the report a strange loud sound is heard. If the participant calls for technical support, the message will be that there is a little problem with the temperature of the exhaust gasses. This will have no consequences for the speed.

7) Passage of a huge container vessel. It is important to keep enough distance because of the suction between both vessels. Behind the container vessel, two little vessels sail just outside the channel. They are of no problem but may distract the attention.

8) The outward-bound naval vessel (Hr.Ms "Rotterdam") is coming to meet the "Amsterdam." When she is making a call for a passage-arrangement, the strange loud sound is heard again. It keeps going on for a long time and it is impossible to finish the call. The technical support will call after the alarm stops ringing, and will give orders to reduce the speed. After the arrangement with the "Rotterdam" is

made, the run is at end.

 The actions taken by the participants were judged according to the level of severity. If a failure was made, this was weighted according to the seriousness of the outcome in small, medium and severe. Fig.4 shows the distribution of failures expressed in small, medium and severe (cognitive lock-up) at each of the incidents and fig.5 shows the correlation of cognitive lock up in the space station and in BRISIM1.