Third IMO Greenhouse Gas Study 2014

Annex 7 263
Ship productivity projection
Figure 40: Productivity of container and liquefied gas ships
measured in thousand tonne-miles per dwt, 1999–2013
For all ship types, the 2012 productivity of the ship types is lower than the long-term historical average. We
assume that this is caused by the business cycle, rather than by structural changes in the shipping market in
the last year. Productivity cycles have appeared before. In liquid and dry bulk, they appear to have a length of
25–30 years. In container shipping, we do not have data for a sufficiently long period to determine the length
of the cycle.
Based on this analysis, we assume future productivity development that converges towards the ship type’s
average productivity. We therefore assume that productivity reverts back to the 25-year 1 mean value within
10 years (i.e. by 2022).
The ship productivity indices used in the emissions projection model, which can be specified per five-year
period, are given in Table 34.
Table 34 – Ship type productivity indices used in emissions projection model
2012 2017 2022–2050
Liquid bulk ships 100 113 125
Dry bulk ships 100 102 104
Container ships 100 109 118
Liquefied gas carriers 100 106 113
Productivity of liquid bulk ships is therefore taken to be the same as for oil tankers, and that of dry bulk ships
to be the same as for bulk carriers carrying the five main dry bulk goods.
For general cargo ships, since the data did not allow plausible historical productivity to be determined, we
assume that the productivity of general cargo ships evolves according to the productivity of container ships
in the model.
1
For container ships and liquefied gas ships, due to a lack of historical data, we take the average of the 1999–2013 period (i.e. a
14-year period).