Randomiser wrote
Yes it's quite surprising, but if you look at Captain Igloo's post of 6 Mar
LAMA Says
1)Holy Langhorne is built to accept barges 130x35 ft
2)later 'pre-gunpowder' canals are limited to no more than 110x10ft
MTaT says
3)Mainland really long haul barges are limited to about 125 ft
4)New Northland locks = Delthak locks can cope with 140x45 ft
So it looks like New Northland > Holy Langhorne > pre-gunpowder canals and the Delthaks can't operate on the Holy Langhorne. Except that 3) seems to contradict 2), so we may have a continuity error about the relative sizes of the canals between the books.
Is the problem the width of the canal or the width of the locks?
My observation while in Holland a few years ago was that in order to allow two-way traffic locks were half the width of the shipping lane.