Although I feel sure there is more than one explanation for the term 'double-banked', my own experience would support the opinions offered by John Sutton (#2) and Bob Bush (# 8), when applied to two or more vessels lying alongside one another at a dockside or on a mooring. Here in Oz it is also known by members of the boating fraternity as 'rafting-up' when,on a Saturday night (or any other night come to that), several boats 'double-bank' for the purpose of having a party. One beautiful summer evening, several years ago, whilst on the Hawkesbury River (near Sydney), I witnessed 12 pleasure craft (of varying lengths up to 50 feet), all double-banked to the largest vessel which was on a mooring buoy. Certainly not best practice, it had the potential of being bl--dy dangerous, but on that particular occasion the fates were kind and the 'revellers' survived without mishap.
Many years ago when on the London -Niemegen - Cologne run with G.S.N.C. ships, I recall that the practise of 'double-banking', as I knew it then, was very common amongst the large motorised-barges on the Maas and Rhine rivers. On one memorable occasion, whilst on the 'Alouette', we arrived at Lobith on the Dutch-German border where we were required to tie-up to a barge (the outer-most of three from the river-bank). With uncommon agility (for me, that is), I went down the pilot-ladder onto the barge and then, dragging a gantline behind me (it had been made fast to a headrope) I managed to hop from one barge to another until safely on the grass-covered river bank. I then had the task of hauling the headrope over to a large stake which was embedded in the ground at the top of the bank, all of which required considerable effort. I received no word of gratitude from Captain Baker or any of my other shipmates, however, I sensed that the small group of Fresian cows that stood nearby watching my performance would have applauded had they been able to. Yes, I'm familiar with the term 'double-banked':rolleyes:
..............Roger
