Well, if you insist on cutting with a angle grinder or circular saw, and your not really worried about your safety, at least keep every one else out of the way. Not trying to be the safety police here, but after 37 years of working for the railroad, I have seen plenty of stupid stuff. Lots of limbs cutoff, dead and crippled. Can you cut the rail with a angle grinder and abrasive blade, sure you can, but without a proper guard and just a little bit of binding, you can cut your hand off just as easy. Play it safe, beg borrow or steal a oxy/act setup. If the torch you borrow doesnt have a big enoung tip to cut thru the rail, just cut thru the ball, (top of the rail) and wack it good with a sledge and it will probably break the rest of the way thru. What ever you do, dont try to free hand cut rail with an angle grinder. The abrasive grinder the railroads use for cutting rail has a clamp on guide to keep the gas powerd or hydraulic powerd saw straight and steady. They can cut thru a 132lb rail in about over a minute. Your angle grinder wont have a guide, nor the power to cut thru the rail with any serious speed. You get tired, wobble the grinder a little bit, and its a trip to the hospital. Have i said this yet, Dont use a angle grinder to cut rail!!