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1 INTRODUCTION

The research described in the paper is the initial part

of the research into the impact of Port of Split marine

traffic on the environment and the city. The research

is similar to other researches [4, 6] trying to determine

best and most effective means to reduce overall

pollution. “The Port of Split is one of busiest marine

traffic regions in the Adriatic Sea and third largest

port in the Mediterranean“ [2, 9]. The Port of Split

consists of several geographically separated units or

basins situated at different locations around the city

[8] (Figure 1).

Four of the basins are designated for the

international marine traffic:

− Gradska luka basin, or City harbour basin is part

of the Port of Split situated near the centre of the

city. There are 27 berths for various ship size with

maximal draught of 10.5 meters [8].

− Vranjic-Solin basin, is situated at the, 4 kilometres

north from centre of the city. It is called also

“Sjeverna luka” (Northern harbour). There are 8

berths with maximal draught of 10.3 meters [8].

− Kaštela B basin is situated at the northern part of

the Kaštela Bay, at the place called Kaštel Sućurac.

There are 5 berths for ships with draught of 6.8 to

8.5 meters [8].

− Kaštela C basin is situated at the north eastern part

of the Kaštela Bay, at the place called Sv Kajo.

There are 8 berths for ships with draught of 4.0 to

10.5 meters [8].

As the article is considering the international

marine traffic air pollutant emission distribution,

only above listed four basins will be analysed in the

article. Kaštela basins A and D are not included in

this analysis due to their predestined purpose for

national traffic.

Distribution of the International Marine Traffic Air

Pollutant Emissions in the Port of Split

L. Mihanović

, B. Lalić

, K. Bratić

& L. Stazić

Croatian Military Academy "Dr Franjo Tuđman", Zagreb, Croatia

University of Split, Split, Croatia

ABSTRACT: The paper describes the initial part of the research into the impact of the Port of Split marine traffic

on the environment and the city. The Port of Split is situated in the middle of the Adriatic Sea and it is one of

busiest marine traffic regions in the Mediterranean. The Port consists of six geographically separated basins,

two of them for smaller vessels, other four for the international marine traffic. The paper presents type and size

of vessels in basins, engine size, stay in Port and finally quantity of the international marine traffic air pollutant

emission per each basin. The distribution

of the international marine traffic and its air pollutant emission

pinpoint exactly main sources of the emissions in the area around the city and its dependency on various factors

linked to the vessels, showing that the city is encircled by with multiple pollution sources.

http://www.transnav.eu

the International Journal

on Marine Navigation

and Safety of Sea Transportation

Volume 15

Number 3

September 2021

DOI: 10.12716/1001.15.03.15

612

Figure 1. Port of Split basins

There is also limit of the size of vessels in this

analysis. To exclude numerous smaller vessels like

fishing boats and yachts, all vessels smaller than

500 GT are removed from this inventory.

2 THE METHODOLOGY

The Port of Split international marine traffic air

pollutant emission is the sum of emissions per basins,

given in the Equation 1:

Total Gradska luka Vranjic Solin Kastela B Kastela C

EE E E E

−

= + ++

(1)

where:

E - Emission

Air pollutant emission calculation used in this

paper is using the ship engines’ power [11] and is

recommended by the EMEP/EEA (2009) air pollutant

emission inventory guidebook [3]. That method is

called a full bottom-up model because “emission

evaluation is bottom up, and the geographical

characterization of emissions is bottom-up’’ [5, 12]. To

enable this model, extensive data about ship and ship

movement in the port has been collected, obtaining

the information from the Split port authority [6] and

Port of Split [10].

Air pollutant emission is calculated separately for

each basin, for manoeuvring and for whole period on

berth (so called hotelling). Manoeuvring to and from

the berth is calculated separately in order to quantify

the air pollutant emission according to the activity of

the vessel. Manoeuvring air pollutant emission is

calculated according to equation [11]:

( ) ( )

)

maneuvering ME AE

E ME LF EF AE LF EF



=⋅ ⋅ ⋅+⋅ ⋅



(2)

where:

D – Distance travelled (NM),

v – Average ship speed (knots),

ME – Main engine power (kW),

ME – Main engine load factor (%),

AE – Auxiliary engine power (kW),

AE – Auxiliary engines load factor (%),

EF – Emission factor, vary on the type of fuel and the

engine speed (g/kWh).

Main engine and auxiliary engines load factors are

taken from the methodology recommendations [3,

11], as well as emission factors. Both papers [3, 11] are

recommending same factors which vary upon engine

size, type of fuel, type of engine, engine

manufacturing year,…. Manoeuvring distances for

the Port of Split are calculated as a distance between

pilot boarding station (cca 0.5 Nm in front of Gradska

luka) and basins. Manoeuvring distances for the Port

of Split are given in the Table 1:

Table 1. Manoeuvring in Port of Split [based on [9]]

_______________________________________________

Berthing point Manoeuvring distance

_______________________________________________

Gradska luka basin 0.5 Nm

Vranjic-Solin basin 6.93 Nm

Kaštela B basin 5.67 Nm

Kaštela C basin 6.52 Nm

_______________________________________________

Following the recommendation of the

International Regulations for Preventing Collisions at

Sea [1], the manoeuvring speed in the Port of Split

and approach is reduced to 6-8 knots [7]. During stay

in the port ships are emitting the following air

pollutant emission:

[ ]

hotelling AE

E T AE LF EF=⋅⋅ ⋅

(3)

where:

T – Average time at berth (h).

3 STATISTICS OF ARRIVALS PER BASINS

Gradska luka is passenger port and only passenger

ships are visiting Gradska luka basin. Table 2 shows

total number of arrivals of cruise ships in 2017 and

2018; value in brackets is giving the percentage of

overall arrivals in the Port of Split in that year.

Table 2. International cruise vessels in the Port of Split

_______________________________________________

Gradska luka basin

_______________________________________________

2017 2018

_______________________________________________

Cruise ships 232 247

Percentage of all arrivals (%) 29.97 32.58%

Average time in port [h] 15.91 15.52

Average engine size [kW] 14980

19970

_______________________________________________

Table 3 is presenting data of cargo ships in the

international marine traffic, sorted according to

basins. All tables have fields with average time in

port and average engine size which will be used later

in discussion.

Table 3. International cargo marine traffic in the Port of

Split

_______________________________________________

Basin: Vranjic-Solin Kaštela C Kaštela B

Ship type 2017 2018 2017 2018 2017 2018

Bulk Carrier 97 80 12 10 221 172

Tanker nil nil 115 122 nil 1

Container 39 40 nil nil 1 nil

General/other 20 52 23 6 14 28

Total 156 172 150 138 236 201

_______________________________________________

Percentage of all 20.16% 22.69% 19.38% 18.21% 30.49% 26.52%

arrivals

Average time in

54.66 47.10 29.21 25.46 36.89 44.03

port [h]

Average engine

3486 3663 1816 1729 1243 1141

size [kW]

_______________________________________________

613

4 AIR POLLUTANT EMISSION IN 2017 AND 2018

The calculation of manoeuvring air pollutant

emissions is performed according to Equations 2 and

3, using average manoeuvring speed of 8 knots, while

the manoeuvring distance (d) is changed according to

data given in Table 1.

Table 4. Air pollutants in Port of Split in 2017 [9]

_______________________________________________

Tons Manoeuvring In port

SOx PM NOx SOx PM NOx

_______________________________________________

Gradska luka 0.65 0.63 18.07 10.09 9.84 283.45

Kaštela B 0.04 0.04 1.21 0.32 0.31 9.74

Kaštela C 0.03 0.03 0.95 0.36 0.35 9.83

Vranjic-Solin 0.06 0.06 1.82 0.44 0.43 13.60

_______________________________________________

Total 0.78 0.76 22.05 11.21 10.93 316.62

_______________________________________________

When all emissions are added together, total air

pollutant emission of the international marine traffic

in 2017 in the Port of Split was:

− SOx – 11.99 ton,

− PM – 11.69 ton,

− NOx – 338.67 ton.

Table 5. Air pollutants in Port of Split in 2018

_______________________________________________

Tons Maneuvering In port

SOx PM NOx SOx PM NOx

_______________________________________________

Gradska luka 0.91 0.89 25.04 13.36 13.03 365.73

Kaštela B 0.03 0.03 0.99 0.29 0.29 8.86

Kaštela C 0.03 0.03 0.81 0.30 0.29 8.17

Vranjic-Solin 0.05 0.05 1.65 0.47 0.46 13.78

_______________________________________________

Total 1.02 1.00 28.49 14.42 14.07 396.54

_______________________________________________

Total air pollutant emission of the international

marine traffic in 2018 in the Port of Split was:

− SOx – 15.44 ton,

− PM – 15.07 ton,

− NOx – 425.03 ton.

5 AIR POLLUTANT EMISSION DISTRIBUTION

Distribution of the NOx air pollution emission is

presented in Figures 2 and 3, respectively for each

year separately. Other pollutants share for each basin

is very similar to the presented NOx air pollution

distribution.

Figure 2. Distribution of NOx emissions in 2017

Figure 3. Distribution of NOx emissions in 2018

From Figures 2 and 3 it is visible that overall air

pollutant emission distribution changed from 2017 to

2018. Gradska luka basin, as a berthing port for cruise

vessels increased its share of the pollution to from

89% to 92%. All other basins decreased their share of

the air pollutant emission despite the fact that there

was a slight increase of the overall air pollutant

emission in the Vranjic-Solin basin.

6 DISCUSSION

Results presented in Tables 4 and 5 show significant

increase of over 25% of the overall air pollutant

emissions in the period of one year. Tables 2 and 3

give the reason of this increase. Although overall

international marine traffic in 2018 in the Port of Split

slightly decreased, from 774 to 758 arrivals (the

decrease of 2%), there was an increase of the arrivals

of cruise vessels, as it is visible on the Figure 4. Cruise

traffic share of arrivals raised 2.5% to close to one

third of all international marine arrivals in 2018.

Figure 4. Arrivals in Port of Split

Average time in port is compared on the Figure 5

and shows that values changed, but the overall

change is not significant.

614

Figure 5. Average time in port [h]

The last analysed parameter give the real reason

for the increase of the overall air pollutant emission

of the international marine traffic in the 2018. As it is

visible on the Figure 6, the average size of cruise

vessels engines increased significantly from around

15000 kW to close to 20000 kW.

Figure 6. Average engine size [kW] in 2017 and 2018

This reason, together with the increased number of

cruise vessels arriving to the Port of Split caused

mentioned increase of the air pollutant emission.

7 CONCLUSION

Total air pollutant emission of international marine

traffic in Port of Split increased from 2017 to 2018 by

more than 25%. At the same time, overall number of

arrivals in the international marine traffic decreased

by 2% while stay in port changed only slightly, not

causing mentioned increase of the air pollutant

emission.

That increase is explained in the increase of the

number of overall cruise vessels arrivals in 2018,

combined with the increase of the ship and engine

size (cruise ship engine size increased by 33% in

2018).

Distribution of the air pollutant sources is in line

with above presented facts. Due to the much larger

engine size (5-10 times larger, depends of the basin)

and much larger fuel consumption, majority of the air

pollutant emission sources is concentrated in the

Gradska luka basin, where 89% of all international

marine traffic air pollutant emission was released in

2017. In 2018 that percentage increased tom 92%,

followed with the increase off the size of vessels and

respectively engines.

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