 More Type MP1 tenders, from which the Type MR would later be rebuilt, entered service from 1913 to 1920 as tenders to the Classes 12A, 12B, 14A, 14B, 15, 15A, 16, 16A, 16B and 16C.These locomotives and tenders were built by Baldwin Locomotive Works, Beyer, Peacock and Company, Henschel and Son, J.A.Maffei and North British Locomotive Company.