46329 what? I was assuming that that meant 46329 tons, i.e., the same volume as that weight of water, based on both the name and on the fact that you were saying that one number was less than the other (which is only a meaningful statement if they’re in the same units).
Register tons (I think I should have written Gross Register Tonnage above). Wikipedia says they were defined as 100 cubic feet.
Wait, what? That’s pretty whack, even by “customary system” standards. I mean, I can buy using units with the same name for weight and volume, so long as they’re based on something sensible like the density of water. But naming a unit “ton” that’s equal to the volume of 3.1ish tons of water? Bwuh?
Tonnage is meant to be what the vessel will carry. So of value to the commercial proposition. Not the construction.
For a passenger vessel it isn’t a useful metric.
For a cargo vessel it is usefully derived from the dimensions of the vessel, not its mass.
Container ships tend to use TEU, twenty foot equivalent units, as the metric of carrying capacity. Which is a volume, but of defined dimensions.
Well, that one makes sense, because that’s a direct measure of the kind of cargo that they carry. However it came to be a standard, the cargo container is a de facto standard. But cargo containers aren’t trying to pretend to be some other unit.
It was evidently useful enough for people to quote the tonnage for any passenger liner that was built. I have a book about passenger liners written in about 1911 that gives every ship’s tonnage and also the total tonnages for the various shipping lines. I would guess that it gives an indication of the number of passengers a ship could carry.
Regarding cargo ships, I think that when people say something like “x million tons of allied shipping was lost to U-boats on the North Atlantic Convoys” they generally mean register tons, ie tonnage, ie volume. However it is often unclear because writers do not understand the 2 different meanings of “ton”.
They still also use tonnage in relation to such ships, though nowadays gross tonnage is defined differently from the gross register tonnage that was used before 1982.
True. I do get the feeling that was more simply because they could, rather than it being meaningful. OTOH, in some ways it provides a reverse mechanism to indicate the size of a vessel, no matter what its purpose or construction. Allowing people a shorthand way of indicating size of ships, even of different purposes, in a way that was more generally indicative of size than just length. Liners competed on speed, and that brings with it a whole new dimension of design metrics.
I always though this was the case, but never really gave it much thought. Once the vessel is lost, that cargo capacity is lost. So it is wider than just the cargo lost on that voyage, or the ship lost. It is the cargo transport capacity permanently lost from the war effort.
And all these years, I have been bitching about the role-playing game Traveler for using “ton” for volume. Learn something new every day.
sorry for stating the obvious:
Elon could have built 88 Titanics (mk2 to mk89) for the price of twitter???
That’s unthinkable!
A speech therapist can help you with that lisp…
