It's a Plimsoll mark. You know, the sign you can see low on the hull of cargo wessels for showing the waterline depending of how much cargo it got. So more likely something to do with ships or that kind of transportation.
The Plimsoll mark seems show the amount of cargo you can load in to get a ship to it's maximum draft. Actually it is the opposite way around, and it shows the minimum freeboard (hull out of the water) the ship is allowed. It was based on an English Act of Parliament, to stop the so-called coffin ships. The lines on the right pointing right are the various freeboards you can have in tropical, summer, winter and Winter North Atlantic. Winter N.A. is the lowest, as you are expecting the worst weather there. This is only for vessels less than 100m. The lines pointing left correspond to the top 2 lines pointing right, but allowing for freshwater. Freshwater being less dense than salt water means the ship will sit deeper in the water at a river berth than in the sea. All sounds a bit confusing... Here is a brain teaser, would you see these marks on the port or starboard side of a ship?
@MarkC I thought these days cargo vessels were required to have it on both port and starboard. Cheers Tony
They are on both sides, but the plimsoll mark is always in front of the loadline marks. They ask these sort of silly questions when you go for your Ship Officer oral examinations. The marks that match the tie-pin would be on the port side
@MarkC Thanks for the information. There are a pair of cuff links that match the tie pin, all port side marked. I’ve no idea of the history of the objects, now wonder why and for who they were made...
I have seen a pewter beer tankard engraved with similar markings, and with the captains name. Believed to be a gift to a newly qualified captain. And as regards the Plimsoll line on an actual ship, it is said that if a ship is moored in the lower reaches of the Thames, that it will float slightly slower or higher in the water according to the state of the tide. Salt water at high tide and fresh water at low tide. Ships masters are warned of the risks of accidentally overloading a vessel in such conditions. There is otherwise a risk that a vessel might be loaded to the "freshwater" mark on the assumption that it is in river water when in fact it is already in salt water and thus overloaded for a sea voyage.
