Strings on orbifold lines

The orbifold lines IIA/I-8 and IIB/I-8(-1)(FL) possess BPS discrete torsion variants which carry fundamental string (NSNS) charge. We show that these variants are actually classified by an integral electric field F from the t wisted RR sector, and compute their tension and NSNS charge as a function o f F. The analysis employs equivariant K-theory and the string creation phen omenon. The K-theory results demonstrate the corrections to cohomology in t he case of torsion; it is found that 8 units of F are invisible at transver se infinity for IIA, and correspondingly 16 units for IIB.