Collision accident reconstruction in NMS-90 simulator - Baltic Master

VERTIGO & ZIEMIA LODZKA COLLISION 

accident reconstruction in NMS-90 simulator 

Wiesław Juszkiewicz 

Maritimie University of Szczecin 

Wały Chrobrego ½ 70-500 Szczecin 

e-mail: w.juszkiewicz@am.szczecin.pl

INTRODUCTION 

Basic tasks set for navigational-radar simulators can be used both in the 

navigators training process and in research works. 

Technological progress enables more and more excellent modeling 

phenomena presented in the process of the simulation. The interactivity of 

actions taken in simulators and the huge data sets recording possibility are very 

important. But very important are also possibilities of multiply repeating 

created scenarios and getting results in relatively short time. 

Possibilities of using real collision situations for officers training can 

seriously improve knowledge about deck officers behavior in dangerous 

situations. 

Simulators are useful but very important is to know their advantages and 

disadvantages. 

2009-10-20 

VERTIGO & ZIEMIA LODZKA collision - 

accident recontruction in NMS-90

INTRODUCTION 

The attempt of reconstruction of ZIEMIA LODZKA and VERTIGO 

collision was taken in the experiment carried out in the NMS-90 simulator. 

This accident was chosen on the basis of analysis of material gathered in the 

process of salvage proceedings because it was precisely described in official 

documents and the mathematical model of bulk carrier is available in simulator 

database. 

Analysis of the possibility of using the NMS-90 simulator for ship’s 

collision reconstruction was the aim of experiment. 

2009-10-20 



GENERAL SIMULATOR CHARACTERISTIC 

The NMS-90 simulator was designed to 

meet the needs of training both Maritime 

University students and deck officers in the 

scope of the operation of radar and ARPA 

devices. 

Scenarios carried out in simulator are 

very similar to real situations. The place of 

exercises can be chosen in restricted or an 

open sea area. They can be also improved 

by hydro meteorological conditions (winds, 

currents, rain etc.) and different emergency 

states can be also additionally simulated. 

The instructor can use one of the set of 

recorded coastlines or build by himself. 

Typical NMS-90 configuration. 

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GENERAL SIMULATOR CHARACTERISTIC 

Up to 60 targets can be controlled by 

the instructor from his console and 3 own 

ships motion simulated separately at the 

same time. 

Many different navigational conditions 

can be simulated, for example: 

• own ships’ and targets’ positions, true 

courses and speeds 

• ships’ characteristics influencing echo 

size (ship’s length, width, height, radar 

cross section, depth), 

• simplified dynamic target 

characteristics 

• programmed target tracks (up to 600 

waypoints). 

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SIMULATION POSSIBILITIES 

An example of coastline echo simulation result. 

The NMS-90 simulator enables to set 

the main radar parameters: gain, range, 

Sea-Clutter, Rain-Clutter, radar shadow 

sectors, radar impulse time characteristic or 

antenna height. There are also possibilities 

to simulate many types of marine radars 

and weather conditions influencing radar 

work. 

The basic characteristics of radar 

echoes from different objects depend on 

their size, the height and their property of 

reflecting radar waves. Programmed radar 

parameters and its working conditions have 

a serious influence on the characteristics of 

radar clutters. 

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SIMULATION POSSIBILITIES 

Every coastline has the alterable depth 

chart where it is possible to place up to 

3000 sounding values, as well as the chart 

of currents, with the maximum number of 

300 programmable vectors. 

Placing up to 500 navigational marks 

defined by their position, size, and, if 

necessary, racon signal is also possible. 

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NAVIGATIONAL BRIDGES’ CHARACTERISTIC 

The NMS-90 simulator consists of the 

instructor console and three separate ship’s 

bridges. Every bridge is equipped with 

steering console, steering gear, the main 

equipment board and radar/ARPA devices. 

The main navigational equipment is 

ARPA. It is used for obtaining both 

navigational and anti-collision information. 

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NAVIGATIONAL BRIDGES’ CHARACTERISTIC 

The simulator is equipped with 

following ARPA devices: 

• bridge no 1: FAR-2815 Furuno 

• bridge no 2: Krupp-Atlas 9800 Series 

• bridge no 3: DB-10 Norcontrol and 

Rascar 3400M Sperry. 

2009-10-20 



SCENARIO SIMULATION PROCESS 

The most important stages of navigational scenario programming process are: 

1. The choice/creation of the appropriate coastline. 

2. Ship’s parameters programming (selection of an appropriate mathematical model and 

- if required - alteration its parameters). 

3. The choice of the way of ship’s steering (from the instructor console, on the basis of 

the programmed route or from the navigational bridge). 

In the first mode (used during simulation) all manoeuvres are carried out 

systematically on the basis of their execution time. In this case factors which have 

the influence on the accuracy of reconstruction are: the different technique of 

steering or the synchronization of carrying individual manoeuvres out. The 

automatic mode requires from the instructor implementing turn points and values of 

ship’s courses, speeds, turn rates, speed rates etc. It is possible to choose the mode of 

waypoints coordinates calculating. 

4. Programming of extrinsic factors (hydro meteorological conditions, currents and tides 

characteristics, wind, blasts of wind, rainfall, etc.). 

5. Programming of radar parameters. 

2009-10-20 



SCENARIO SIMULATION PROCESS 

One of the most important moment in programming process is the property 

ship mathematical model choice. Individual models of different vessel types are 

in the database of the simulator. 

In the case of the discussed reconstruction a model of the bulk carrier was 

chosen for the simulation. 

Ship type 

Ship data 

Lenght: 147 m 

Draft: 12 m 

Bulk Carrier 

DWT: 54600 T 

RPM (Full Ahead): 125 

Speed (Full Ahead): 14,8 w 

2009-10-20 



ACCIDENT DESCRIPTION 

Collision 

The collision took place in the area 

close to the Agersoe Flak. 

It is narrow area where two 

navigational routs (T and H) join 

together. 

South going vessels have to change 

their course about 50 degree to 

starboard to follow Route T (Deep 

Water route direction). So very 

important is to proceed in the proper 

side of appropriate center line. 

During the accident there was calm 

weather with good visibility (3-4 NM). 

It was 1.5 knots north going current. 

VTS Great Belt area - position of collision 

2009-10-20 




Name of the ship 

ZIEMIA LODZKA 

Home Port 

Monrovia, Liberia 

Call sign 

A8DQ4 

IMO number 8418746 

Type of ship 

Bulk carrier 

Construction year 1992 

Gross Tonnage 26 264,00 

Net Tonnage 17 458 

Lenght Overall [m] 179,97 

Breadth [m] 28,00 

Engine Power [kW] 5 415,00 

ZIEMIA LODZKA was manned in 

accordance with the Minimum Safe 

Manning Certificate and their officers 

held the required statutory certificates. 

All crewmembers were all Polish 

citizens. 

The engines and the steering 

equipment were fully functioning. 

ZIEMIA LODZKA was equipped with 

two radars, with ARPA, and AIS, which 

were fully operational. 

There is no indication that any 

technical failure or any failure of the 

bridge equipment has influenced the 

circumstances leading to the collision 

2009-10-20 




Name of the ship 

VERTIGO 

Home Port 

Montego Bay, Jamajka 

Call sign 

6YRD5 

IMO number 8417601 

Type of ship 

Bulk carrier 

Construction year 1986 

Gross Tonnage 26 666,00 

Net Tonnage 15 502 

Lenght Overall [m] 164,24 

Breadth [m] 26,00 

Engine Power [kW] 5 034,00 

VERTIGO was manned in 

accordance with the Minimum Safe 

Manning Certificate and their officers 

held the required statutory certificates. 

VERTIGO had a mixed crew of 

Rumanian and Philippine citizens. 

VERTIGO engines and the steering 

equipment were fully functioning. 

Vessel was equipped with two radars, 

one of which with ARPA, and AIS. The 

equipment was fully operational. 

There is no indication that any 

technical failure or any failure of the 

bridge equipment has influenced the 

circumstances leading to the collision. 

VTS Great Belt area - the collision position. 

2009-10-20 




Extracts from the report of the Danish Maritime Authority 

VTS radar at 00:22 

ZIEMIA LODZKA 

VERTIGO 

On the 7 December 2005, shortly after midnight, the fully loaded bulk 

carrier ZIEMIA LODZKA was proceeding south in Route T in the Great Belt, 

and the fully loaded bulk carrier VERTIGO was proceeding north in Route H. 

2009-10-20 





AIS plot 

00:30 

Both vessels were proceeding at normal sea speed, ZIEMIA LODZKA at 

about 12 knots and VERTIGO at about 13 knots. Both vessels reported 

positions to VTS Great Belt when passing VTS reporting line. 

2009-10-20 





AIS plot 

00:33 

When the vessels approached the narrow area off Agersoe Flak ZIEMIA 

LODZKA was positioned at the centre line of Route T and VERTIGO was 

slightly offset to the west of the centre line of Route H. 

2009-10-20 





ZIEMIA LODZKA’s master intention was to 

continue southwest in Route H. When passing 

buoy # 33 he therefore executed a change of 

course to starboard, when the distance to 

VERTIGO was 0.5-0.8 miles. 

AIS plot 

VERTIGO’s master became in 

doubt of the intention of ZIEMIA 

LODZKA, and when ZIEMIA 

LODZKA was right ahead on a 

crossing course he executed a full 

turn to port. 

This was approximately 15 

seconds after the start of the turn 

of ZIEMIA LODZKA. 

00:33 

The vessels were on crossing courses with VERTIGO bearing 

approximately 20° on the starboard bow of ZIEMIA LODZKA. 

2009-10-20 





AIS plot 

00:35:30 

At 0036 hours the vessels collided in position 55°12.29 N - 011°05.46 E. 

The port bow of ZIEMIA LODZKA struck the starboard side of VERTIGO. 

2009-10-20 





VERTIGO suffered heavy structural damage in the starboard side and 

foundered at position 55°13’ N - 011°05’ E at 11 meters depth of water. 

2009-10-20 





VERTIGO’s superstructure was above water level. The crew abandoned the 

vessel in lifeboat and was taken on board STENA CARRIER. There were no 

injuries. 

ZIEMIA LODZKA suffered structural damages on port side of the bow and 

was anchored approximately 3 miles north of the collision position. 

There was no pollution caused by the collision. 

2009-10-20 



SIMULATION ACCURACY ANALISYS 

Basing on this material three variants of simulation were carried out. Each of 

them used a different option of programming offered by the NMS–90 simulator. 

The programmed variants were: 

1. POSITION BASED option v.1 (PBV1): scenario time and ship’s courses 

are calculated on the basis of its given positions and speeds 

2. POSITION BASED option v.2 (PBV2): ship’s courses and speeds are 

calculated on the basis of its given positions and scenario time 

3. TIME BASED option (TBV): the way points positions are calculated on 

the basis of given ship’s courses, speeds and simulation time. 

2009-10-20 




AIS information 

ZIEMIA LODZKA 

Time Position C/COG/SOG 

[°/°/kn] 

Bearing/Distan 

ce 

[°/NM] 

Pozycja 

VERTIGO 

C/COG/SOG 

[°/°/kn] 

00:30 55°13,33' 

011°05,92' 

00:31 55°13,12' 

011°05,95' 

00:32 55°12,95' 

011°05,95' 

00:33 55°12,70' 

011°05,94' 

175/174/12,4 201/2,3 55°11,21' 

011°04,50' 

180/177/12,5 202/1,9 55°11,40' 

011°04,72; 

181/182/12,5 203/1,5 55°11,58' 

011°04,95'' 

181/180/12,5 205/1,0 55°11,77' 

011°05,17' 

027/034/13,4 

028/036/13,4 

026/034/13,6 

026/033/13,7 

00:33:40 ZIEMIA LODZKA begins to alter course to starboard – distance to VERTIGO is app. 0,8 NM. 

00:33:55 VERTIGO bedins to alter course to port – distance to ZM is app. 0,5 NM. 

00:35 55°12,32' 

011°05,81' 

236/220/10,9 212/0,15 55°12,16' 

011°05,57' 

333/007/12,0 

00:35:30 55°12,27' 

011°05,68' 

265/-/9,2 Kolizja 55°12,23' 

011°05,56' 

300/-/10 

2009-10-20 




Results of the simulations differed from one another. Data coming 

Investigation Report of the Danish Division for Investigation of Maritime 

Accidents was the base of the simulation accuracy assessment. 

Data sets of ships’ positions, courses, speeds, turn and speed rates were 

recorded and ships’ positions plotted (plot interval was 5 second) during 

simulations. These data sets and plots allowed to compare simulations with AIS 

data sets recorded by Great Belt VTS. 

2009-10-20 




Scenario 1 (Position Based Variant no 1) 

There was collision recorded during the 

simulation. 

Main differences between Investigation 

Report (IR) and simulation were: 

• period of 19 second difference in arrival time to 

the last waypoint occurred during the 

simulation of ZIEMIA LODZKA track and 4 

second in the simulation of VERTIGO track 

• differences between simulated and recorded in 

IR vessels’ courses are: up to 29 0 (more to 

starboard) in the ZIEMIA LODZKA case and 

up to 20.3 0 (more to port) in the VERTIGO 

case. 

• because of the manoeuvre execution delay 

(mathematical models characteristic), vessels’ 

tracks were moved about 18 m for ZIEMIA 

LODZKA and 15 meters for VERTIGO. 

• the impact point was moved more toward 

VERTIGO stern part (about 60 m difference) 

and collision angle value was calculated 5-15 0 

less than reported by witnesses. 

2009-10-20 




Scenario 2 (Position Based Variant no 2) 



• differences between simulated and recorded 

in IR speeds and courses occurred both for 

VERTIGO and ZIEMIA LODZKA (up to 

1,54 kn) 

• simulated vessels’ track are very similar to 

presented in IR. 

• the impact point was moved about 20-30 m 

(the impact point is located close to 

VERTIGO superstructure) and collision angle 

value was calculated 10-20 0 less than 

reported by witnesses. 

There was collision recorded during the 

simulation. 

2009-10-20 




Scenario 3 (Time Based Variant) 



• the first three waypoints’ positions for both 

vessels are calculated properly 

• two last waypoints’ positions for both vessels 

are calculated imprecisely. 

• there are slight differences between recorded 

in IR and simulated tracks (up to 10 m) 

• ZIEMIA LODZKA passed astern of 

VERTIGO in the distance of 5 m. 

There wasn’t collision recorded during 

the simulation. 

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FINAL SIMULATION RESULTS 

Scenario 1 (PBV1) 

Scenario 2 (PBV2) 

Scenario 3 (TBV) 

2009-10-20 



CONCLUSIONS 

• According to data obtained from Investigation Report, three variants of ZIEMIA 

LODZKA - VERTIGO accident were programmed in NMS-90 simulator. 

Accuracy reconstruction analysis leads to the conclusion that the most accurate 

simulation was scenario based on waypoints’ positions and simulation time 

(PBV2). 

• Some differences raised between the simulation and reported data (speeds and 

courses are not exactly the same as really recorded by VTS) but the impact point 

and value of collision angle are very similar to those reported by witnesses. 

• In the course of the simulations main factors influencing the reconstruction 

process are determined. One of the main simulator restrictions is a limited set of 

mathematical vessel models. Because of this the used mathematical bulk carrier 

model demonstrated some own characteristics which were different from those of 

real vessels and, therefore, some differences between simulated and obtained from 

Investigation Report tracks were visible. There were some delays in ships’ 

manoeuvres execution registered. 

2009-10-20 



CONCLUSIONS 

• Increasing simulation accuracy is possible by a new mathematical model creation, 

specifically for every simulated vessel. 

• Research results lead to the main conclusion that it is possible to use navigational 

simulators for maritime collision reconstructions, but two basic conditions must 

be fulfilled. First of all data accuracy. Witnesses statements cannot be the base of 

calculation because of their ambiguity and low precision. Sometimes they are 

contrary to one another. 

• Research shows that enough accuracy data can be obtained from AIS but 

sometimes they are burdened with a bigger error. In the future VDR data could be 

more useful. 

• Reconstructed accidents can be a good exercise for navigators both for training 

and recognizing navigators’ behaviour in difficult situations. 

2009-10-20 



VERTIGO & ZIEMIA LODZKA COLLISION 

accident reconstruction in NMS-90 simulator 

Wiesław Juszkiewicz 

Maritimie University of Szczecin 

Wały Chrobrego ½ 70-500 Szczecin 

e-mail: w.juszkiewicz@am.szczecin.pl 

Thank You for attention…

Collision accident reconstruction in NMS-90 simulator - Baltic Master

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