roll-on roll-off

UK troops to train Mali forces

News signifies UK's deepening involvement in an effort to drive Islamist militants out of Mali

The additional up to 200-strong military force will include a roll-on, roll-off ferry to help transport heavy equipment to the French intervention force currently spearheading the fight against the Islamist militants.

http://www.independent.co.uk/news/uk/politics/uk-troops-to-train-mali-forces-8471079.html

roll-on roll-offという表現をみてみます。文中ではroll-on, roll-offという形で、コンマによって区切られていますが、roll-on roll-offで、‘describes a ship built so that vehicles can drive on at one end and off at the other’Cambridge Dictionaries Onlineという意味があります。念のためVocabulary.comでも調べてみたところ、’a method of transport (as a ferry or train or plane) that vehicles roll onto at the beginning and roll off of at the destination’というように記載されていました。なのでここは、「（＜フェリーで＞重たい装具を）積み降ろし可能な船」、つまり「輸送艦」と解釈してみました。(Shou-VR*)