This block found in Scotland is being called a "shipyard" block because that is where this block was found.
Besides location it also has the shape of a dock cleat.
This block is of excellent design and is unusualy graceful with surfaces suitable for all kinds of metalwork ranging from ship plate to low brass musical instruments and sculpture.
The version to the left, found in England, appeared to be modified but on further examination you will notice that the edges have been reversed with the long curve on the saddle horn side and the half rounds on the bottom.
The holes have also been relocated for the large chamfered round hole.
The second "horn" appears to have been left off or cut off so that the block could be set on end as shown.
If it is a "special" then it is an entirely different pattern made by the foundry.
From the Steve Prillwitz collection.
The Carron Company was an ironworks established in 1759 near Falkirk, in Stirlingshire, Scotland on the banks of the River Carron.
They were one of the early operations that used coke rather than charcoal to make iron.
Besides swage blocks they produced cast iron products ranging from steam engine parts for James Watt and cannons for the Royal Navy to mail boxes and ships.
It makes sense that a company such as this that made ships would also make tools for ship building.
The Carron Company was the largest ironworks in Europe by 1814.
The business faultered in the 20th Century and was bankrupt in 1982.
Small parts of the company still operate but not as the great ironworks they once were.
See: Where Iron Runs Like Water!
A new history of Carron Iron Works 1759-1982, Brian Watters, John Donald, 1998.