Pacifica Shipping chief executive Steve Chapman has cited data from the Ministry of Transport's Freight Information Gathering System (FIGS) and National Freight Demands Study (NFDS) to attack the freight performance of the Government-owned Interislander.
Mr Chapman says a comparison between the latest FIGS data and the NFDS of 2006-2007 indicate rail freight on Cook Strait has recently grown by less than one-third that of unsubsidised coastal shipping.
"It reveals that inter-island rail freight tonnage increased by six per cent in the intervening six years, compared to 21 per cent for domestic coastal cargo," he says.
"This is effectively a one per cent volume increase per annum over the period, as against over three per cent for coastal shipping."
In response, Interislander general manager Thomas Davis questioned the validity of comparing two different means of analysis, but did confirm inter-island rail volumes had declined under Toll's ownership between 2007 and 2009.
He says this situation had since reversed through KiwiRail's investment in locomotives, wagons, infrastructure and ferry capacity.
Iain MacIntyre