Eastham and Rhodes published results of loss measurements on transposed superconducting NbTi cables and concluded basing on an extrapolation to very large numbers of wires that transposed superconductors could be used favourably in cables for power transmission. There are some reasons to question the correctness of their extrapolation. We calculated losses for transposed superconductors in self field and got results different from those of Eastham and Rhodes. Loss measurements were performed the results of which give evidence for the correctness of our calculations. Our results lead to the conclusion that the use of transposed cables of irreversible type 2 superconductors for power transmission is not advantageous.