I finally made a visit to the National Maritime Museum of Ireland in Dun Laoghaire last weekend, with family in tow, so it’s time for another entry in Wordfoolery’s Nautical Series – tonne.
When over-burdened with shopping (or an anchor like this lovely example outside the museum) I’d often say that it weighed a tonne. However I’ve edited the phrase out of my writing because I couldn’t get clarity on the correct spelling (tonne or ton?).
Imagine my surprise to find a detailed explanation of the phrase when researching for my coastal novels in the museum. Tonne comes from the idea of a ship’s tonnage but has little to do with the weight of the ship. Tonnage, or as it was originally know tunnage, was measured for tax purposes and related to the number of tuns of wine the ship could carry. All good ships transport nothing but wine, of course.
One tun held 252 gallons of wine (tax-men despise even numbers) which is approximately 1,150 litres or 2,2,40 pounds of weight. So when I said my bags weighed a tonne, I should have said they weighed a tun, although I’m not strong enough to lift 2,240 pounds of groceries, or wine!
If you want to get into nautical detail the gross tonnage of the ship is the volume of its cargo space while deadweight tonnage (DWT) refers not to – “Fifteen men on a dead man’s chest, yo-ho-ho and a bottle of rum” – but to the total weight of passengers, cargo, fuel, stores minus the weight of the ship herself.
As for the origin of tun as a word, that has the fingerprints of many languages – Old English tunne, Old Frisian tunne, Middle Dutch tonne, Old High German tunna, German tonne, Latin tunna, Old French tonne and possibly even Middle Irish tunna and toun (meaning hide or skin). I’ve noticed that words relating to ships often have a mixed source like this. I assume this is because the ships and their sailors moved around, pilfering words from languages when it helped them communicate with their polyglot crews and traders. Seas are fertile places for creating vocabulary.
If you’re visiting Dublin, I can heartily recommend a visit to the maritime museum in Dun Laoghaire (just hop on a DART train out from the city centre) – there are great hands-on exhibits for the kids and it’s small enough for the whole family to avoid museum fatigue. Run by volunteers (hence the reasonable entry fee), it is crammed with details on the huge and varied contributions made by the Irish to seafaring life – inventing submarines, founding several nation’s navies, shipwrecks, polar exploration, Atlantic cable-laying, the Beaufort scale, and I discovered Marconi had an Irish mother.
They were even kind enough to indulge my curious children by showing how the museum’s teddy travels between ships by breeches buoy.
Until next time, happy reading,writing, and wordfooling,
Please don’t forget to vote today for Wordfoolery in the Arts&Culture section of the Irish Blog Awards – thanks!