Adrian wrote: snipped: > It is appropriate to have a charge related to size only where, er, > size matters. To have one where size does not matter would be like > charging people with red hair more for cinema tickets than those with other colours.
As I expected you use an argument that attempts to justify your preferences. > However, for navigation, it is not appropriate to charge by craft > size, because there is no shortage of water surface area on the > waterways in general, and because a vessel (of a size within the gauge > of the waterway) passing along the waterway effectively "consumes" the > same amount of space irrespective of its beam. Up to a point Sir Humphrey, but a wide beam craft will always require dredging to a wider(better) standard than could be 'got away with' for narrow beam craft. I'm not encouraging poor dredging standards, only pointing out that more significant dredging will be required for your type of craft at a time when waterway maintenance budgets are in free-fall. > > One could argue that a larger vessel takes more room in a lock, and in > the extreme one such vessel requires a lock(ing) all to itself while > two smaller ones could share. However, BW has calculated that the > marginal cost of of any vessel navigating a waterway is so small that > it is not worth charging for, so the difference between "so small" and > "half so small" is not significant enough to reflect in the charges. So, in the case of a broad beam craft wishing to navigate Braunston tunnel, for example, the cost of providing two waterways employees to close the tunnel to other craft and usher the broad beam through the tunnel early in the morning, isn't classed as a significant cost in your eyes? Perhaps, in that case, a prohibitively high passage-charge would be a more appropriate solution than an area-based licence to discourage the use of the tunnel by such craft? Roger
