In reply to Rampikino:
I've just had four made by my nearest metal fabrication firm. They are about three feet long, quarter inch thick 2.5 inch angle iron, or thereabouts, with a point cut on one end. They cost me a fiver each which is cheaper than a Rock 1 on wire. They should last years, even if though they will rust eventually. You could delay the rusting a bit by getting them galvanised I guess.