I have used a lump hammer and a sharp cold chisel on a steel block. Make sure you bind tape around the wire where you want to cut so that the strands don't spring apart when cut. Make one hefty thump with the hammer instead of lots of taps. You should get a very clean cut. Best of luck.
A Dremel goes through it quickly and cleanly with the right attachment, even a battery one, which is handy on a boat with no mains power. An angle grinder will too, but needs mains. Tape the cut location as others have said to stop wires splaying.
14mm diameter! Sorry the huge size didn't register - in that case it will have to be a hacksaw job. If you have a steel V block that will make it easier to hold the wire as you saw it, even a wood block with a V cut in it will make life easier.
I have mains - didn't think of an angle grinder, guess I just assumed it would get trapped in the fibres and disintegrate the blade.
The cable is for some running rigging and moorings. Our mooring posts were ripped out in the gales last week. /forums/images/graemlins/frown.gif
As the rigging is due for replacement, I thought I just cost buying a whole coil and cut to size on site. Cosalt sell a range of wire ropes and wire grips.
I had some rigging made at an industrial cable suppliers years ago. I went along to watch them make it. They cut the cable with a sort of captive pivoting angle grinder. Went through the cable like a hot knife through butter. They taped the cut point first. I've used a normal mains angle grinder since, and it's no effort at all, gives a very clean cut. Dangerous beasties though, angle grinders. Gloves, goggles, etc.
A little Dremel is slower, but still gets there with little effort, but a bit of persistence.
If you want to use an angle grinder to cut stainless wire rope, or even galv I strongly suggerst you use a 115mm mini grinder and a slice disc. These are only 1 to 1.5mm thick and make a fine cut in stainless without burning. Be carefull not to twist the machine as the blades are not as strong as conventional cut-off wheels. I used them all the time, even cut RSJ's with them before. Cut stainless like a knife through butter with hardly any burr.