The type of anchors you have are the kind used for sailing vessels and early steam
powered ships and would be unlikely on anything diesel. And very unlikely on any
"large, modern -ship- such as a naval vessel. Also relatively unlikely on smaller
craft such as fishing vessels (except for sailing). Those are what I'd call "medium
duty" rather than heavy duty. The kind others pointed to with the pivoting stock are
available in sizes from about 3 pounds and on up to modern naval vessels. The
type you have - with a fixed stock - I've never seen in use or for sale ... mostly I've
seen them with sailing ships at museums. But they would have been in common
use in the 20's.
I think you may have 'missed the point'. In 1929 a lot of shipping was still done by
sail. So anchors of the type you have were still in use and still being made and
shipped even though it was an "old" design at the time of your RR.
Having said the above - I've never seen a picture of anchors of your style on/in a rail car
of any type (flat or box car). I'm not saying they weren't shipped by rail - I'm just saying I
don't remember ever seeing a picture of one/several on a rail car.
If you do decide to use them they would go to a ship chandler or naval facility near the
waterfront - probably even to one that has a dock. They would be shipped from a 'mill'
or other such business capable of casting large heavy stuff.
Anchors are heavy and need some serious weight handling equpment to move them
around. Once on the ship they are hauled up and down by use of a winch with serious
lifting power. Anchors -do- get lost (left on the sea floor) from time to time so ships
would, infrequently, need to replace them. Changing to a different style of anchor for
an existing ship would not be likely - the movable stock style normally are stowed in
the anchor chain/hawser hole and the fixed stock style are 'hung near that same
hole' ... quite different methods.